accounted/extensions/general/enable-banking/index.ts

import type { Extension, ExtensionContext } from '@/lib/extensions/types'
import { NextResponse } from 'next/server'
import {
  startAuthorization,
  getASPSPs,
  getPreferredAuthMethodDetails,
  deleteSession,
  isSandboxMode,
  SessionExpiredError,
  AspspUnavailableError,
  REAUTH_REQUIRED_MESSAGE,
  SYNC_FAILED_MESSAGE,
  BANK_UNAVAILABLE_MESSAGE,
  type ASPSP,
} from './lib/api-client'
import { syncAccountTransactions } from './lib/sync'
import { triggerConnectionSync } from './lib/trigger-sync'
import { findReusableSessions, countLiveSiblings } from './lib/session-sharing'
import {
  runUnattendedReconciliationSweep,
  toSweepSummary,
} from '@/lib/reconciliation/unattended-sweep'
import {
  runReconciliation,
  DEFAULT_UNATTENDED_CONFIDENCE_THRESHOLD,
} from '@/lib/reconciliation/bank-reconciliation'
import { resolveCashAccountScope } from '@/lib/reconciliation/cash-account-scope'
import { checkRateLimit } from '@/lib/auth/rate-limit-http'
import { requireCapability } from '@/lib/entitlements/has-capability'
import { CAPABILITY } from '@/lib/entitlements/keys'
import type { StoredAccount } from './types'
import type { Transaction } from '@/types'

// Per-user limits keep one tenant from spamming any single bank handler.
// Sliding 60s windows: generous enough for legitimate retry, tight enough
// to prevent UUID probing or status-machine abuse.
const RATE_LIMIT_ACCOUNTS = { maxRequests: 20, windowMs: 60_000 }
const RATE_LIMIT_SYNC = { maxRequests: 10, windowMs: 60_000 }
const RATE_LIMIT_DISCONNECT = { maxRequests: 10, windowMs: 60_000 }
const RATE_LIMIT_ATTACH = { maxRequests: 10, windowMs: 60_000 }

const MAX_ENABLED_UIDS = 50

/**
 * Enable Banking (PSD2) extension
 *
 * Provides automatic bank transaction sync via PSD2 open banking.
 * This is an opt-in extension: uncomment the import in loader.ts to activate.
 *
 * Required environment variables:
 * - ENABLE_BANKING_APP_ID
 * - ENABLE_BANKING_PRIVATE_KEY (base64-encoded PEM)
 *
 * Optional:
 * - ENABLE_BANKING_API_URL (default https://api.enablebanking.com; api.tilisy.com = sandbox)
 * - ENABLE_BANKING_PSU_TYPE (default business)
 */
export const enableBankingExtension: Extension = {
  id: 'enable-banking',
  name: 'Enable Banking (PSD2)',
  version: '1.0.0',

  settingsPanel: {
    label: 'Bankintegration (PSD2)',
    path: '/settings/banking',
  },

  // Registry-resolved services for core callers (core cannot import
  // @/extensions). Contract: lib/bank-sync/trigger-sync-contract.ts.
  services: {
    // Agent-triggered sync behind POST /api/v1/.../bank-connections/{id}/sync.
    triggerConnectionSync,
  },

  apiRoutes: [
    {
      method: 'GET',
      path: '/banks',
      handler: async (_request: Request, ctx?: ExtensionContext) => {
        const log = ctx?.log ?? console
        try {
          // Detect PSU type from company entity_type
          let psuType: 'personal' | 'business' = 'business'
          if (ctx?.companyId && ctx?.supabase) {
            const { data: company } = await ctx.supabase
              .from('companies')
              .select('entity_type')
              .eq('id', ctx.companyId)
              .single()
            if (company?.entity_type === 'enskild_firma') {
              psuType = 'personal'
            }
          }

          const aspsps = await getASPSPs('SE', psuType)
          const banks = aspsps.map((aspsp: ASPSP) => ({
            name: aspsp.name,
            country: aspsp.country,
            logo: aspsp.logo,
            bic: aspsp.bic,
          }))
          return NextResponse.json({ banks, psu_type: psuType, sandbox: isSandboxMode() })
        } catch (error) {
          log.error('Error fetching banks:', error)
          return NextResponse.json({
            banks: [
              { name: 'Nordea', country: 'SE', bic: 'NDEASESS' },
              { name: 'SEB', country: 'SE', bic: 'ESSESESS' },
              { name: 'Swedbank', country: 'SE', bic: 'SWEDSESS' },
              { name: 'Handelsbanken', country: 'SE', bic: 'HANDSESS' },
            ],
            sandbox: isSandboxMode(),
          })
        }
      },
    },
    {
      // Live PSD2 sessions the user already holds in their OTHER companies that
      // still have unclaimed accounts. Drives the "reuse this connection" offer:
      // several ASPSPs allow one active AIS session per PSU, so authorizing the
      // same bank again for a second company kills the first company's feed.
      // An empty list is the normal case and renders no offer at all.
      method: 'GET',
      path: '/reusable-sessions',
      handler: async (_request: Request, ctx?: ExtensionContext) => {
        const log = ctx?.log ?? console
        const supabase = ctx?.supabase ?? await (await import('@/lib/supabase/server')).createClient()
        const { data: { user } } = await supabase.auth.getUser()

        if (!user) {
          return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
        }
        if (!ctx?.companyId) {
          return NextResponse.json({ error: 'Company context required' }, { status: 400 })
        }

        try {
          const sessions = await findReusableSessions(supabase, user.id, ctx.companyId)
          // Never ship session_id to the browser: it is the bearer of the PSD2
          // consent. The client only needs to name the offer and post back the
          // source connection id, which is re-validated server-side on attach.
          return NextResponse.json({
            sessions: sessions.map(s => ({
              connection_id: s.connectionId,
              company_id: s.companyId,
              company_name: s.companyName,
              bank_name: s.bankName,
              consent_expires: s.consentExpires,
              available_account_count: s.availableAccounts.length,
            })),
          })
        } catch (error) {
          log.error('[enable-banking] Failed to list reusable sessions', error)
          return NextResponse.json({ sessions: [] })
        }
      },
    },
    {
      // Attach the ACTIVE company to a session authorized for another of the
      // user's companies. No BankID, no new /auth call, nothing revoked: the
      // new row shares session_id + consent_expires and carries only the
      // accounts no company has claimed. Lands in 'pending_selection' so the
      // existing AccountPickerDialog does the ledger mapping, IBAN-aware.
      method: 'POST',
      path: '/attach',
      handler: async (request: Request, ctx?: ExtensionContext) => {
        const log = ctx?.log ?? console
        const supabase = ctx?.supabase ?? await (await import('@/lib/supabase/server')).createClient()
        const { data: { user } } = await supabase.auth.getUser()

        if (!user) {
          return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
        }
        if (!ctx?.companyId) {
          return NextResponse.json({ error: 'Company context required' }, { status: 400 })
        }
        const companyId = ctx.companyId

        const blocked = await requireCapability(supabase, companyId, CAPABILITY.bank_sync)
        if (blocked) return blocked

        const rl = await checkRateLimit({
          prefix: 'enable-banking:attach',
          identifier: user.id,
          ...RATE_LIMIT_ATTACH,
        })
        if (!rl.ok) return rl.response!

        const { connection_id } = await request.json()
        if (!connection_id) {
          return NextResponse.json({ error: 'connection_id is required' }, { status: 400 })
        }

        try {
          // Re-derive the offer server-side rather than trusting the posted id.
          // findReusableSessions re-checks ownership (same user), that the
          // source is a DIFFERENT company, that its session is active with a
          // live consent, and which accounts are genuinely unclaimed.
          const sessions = await findReusableSessions(supabase, user.id, companyId)
          const source = sessions.find(s => s.connectionId === connection_id)
          if (!source) {
            return NextResponse.json(
              { error: 'No reusable session available for this connection' },
              { status: 404 }
            )
          }

          // A company already syncing this bank must go through reconnect, not
          // attach: a second live row for the same provider would sync the same
          // accounts twice into one set of books.
          const { data: existingForCompany } = await supabase
            .from('bank_connections')
            .select('id')
            .eq('company_id', companyId)
            .eq('provider', source.provider)
            .in('status', ['active', 'pending_selection'])
            .limit(1)
            .maybeSingle()

          if (existingForCompany) {
            return NextResponse.json(
              { error: 'This company is already connected to that bank' },
              { status: 409 }
            )
          }

          const { data: created, error: insertError } = await supabase
            .from('bank_connections')
            .insert({
              user_id: user.id,
              company_id: companyId,
              provider: source.provider,
              bank_name: source.bankName,
              session_id: source.sessionId,
              psu_type: source.psuType,
              consent_expires: source.consentExpires,
              accounts_data: source.availableAccounts,
              status: 'pending_selection',
            })
            .select('id')
            .single()

          if (insertError || !created) {
            log.error('[enable-banking] Failed to attach shared session', {
              message: insertError?.message,
              sourceConnectionId: source.connectionId,
              companyId,
            })
            return NextResponse.json({ error: 'Failed to reuse connection' }, { status: 500 })
          }

          log.info('[enable-banking] Attached company to an existing PSD2 session', {
            connectionId: created.id,
            sourceConnectionId: source.connectionId,
            companyId,
            bankName: source.bankName,
            accountCount: source.availableAccounts.length,
          })

          // This company gains access to bank data, so it is a consent grant
          // from an audit standpoint even though no new consent was signed
          // (ASVS V16 / GDPR Art.30), same event the callback emits.
          try {
            const emit = ctx?.emit ?? (await import('@/lib/events/bus')).eventBus.emit.bind((await import('@/lib/events/bus')).eventBus)
            await emit({
              type: 'bank_connection.consent_granted',
              payload: {
                connectionId: created.id,
                bankName: source.bankName ?? null,
                accountCount: source.availableAccounts.length,
                consentExpiresAt: source.consentExpires ?? null,
                userId: user.id,
                companyId,
              },
            })
          } catch (emitError) {
            log.error('[enable-banking] Failed to emit consent_granted on attach', emitError)
          }

          return NextResponse.json({
            connection_id: created.id,
            account_count: source.availableAccounts.length,
          })
        } catch (error) {
          log.error('[enable-banking] Attach failed', error)
          return NextResponse.json({ error: 'Failed to reuse connection' }, { status: 500 })
        }
      },
    },
    {
      method: 'POST',
      path: '/connect',
      handler: async (request: Request, ctx?: ExtensionContext) => {
        const log = ctx?.log ?? console
        const supabase = ctx?.supabase ?? await (await import('@/lib/supabase/server')).createClient()
        const { data: { user } } = await supabase.auth.getUser()

        if (!user) {
          return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
        }

        if (!ctx?.companyId) {
          return NextResponse.json({ error: 'Company context required' }, { status: 400 })
        }
        const companyId = ctx.companyId

        const blocked = await requireCapability(supabase, companyId, CAPABILITY.bank_sync)
        if (blocked) return blocked

        const { aspsp_name, aspsp_country, psu_type: explicitPsuType, connection_id: reconnectId, force_new: forceNew } = await request.json()

        // Reconnect mode: re-authorize an EXISTING connection in place (no
        // disconnect required). The aspsp identity falls back to the stored row
        // when the client omits it, so a closed/expired session can be renewed
        // with one click. A fresh connect still needs the bank name + country.
        const isReconnect = !!reconnectId
        if (!isReconnect && (!aspsp_name || !aspsp_country)) {
          return NextResponse.json(
            { error: 'aspsp_name and aspsp_country are required' },
            { status: 400 }
          )
        }

        try {
          // For reconnect, load the existing connection up front (company-scoped)
          // so we can revoke its dead session and reuse its bank identity.
          let existing:
            | { id: string; bank_name: string; provider: string; session_id: string | null; psu_type: string | null }
            | null = null
          if (isReconnect) {
            const { data, error: findErr } = await supabase
              .from('bank_connections')
              .select('id, bank_name, provider, session_id, psu_type')
              .eq('id', reconnectId)
              .eq('company_id', companyId)
              .single()
            if (findErr || !data) {
              return NextResponse.json({ error: 'Connection not found' }, { status: 404 })
            }
            existing = data
          }

          // Resolve the aspsp identity. For a reconnect the bank is already
          // known, so derive it authoritatively from the stored row and IGNORE
          // any client-supplied aspsp_name/aspsp_country: the client
          // (BankSyncNowButton) derives the country by string-splitting the
          // provider slug, and trusting that back is needless attack surface
          // (compliance: ASVS V8.2.1/V4.5). A fresh connect has no stored row,
          // so it uses the client values (already required+validated above).
          // The provider slug ends with the country code, e.g. "nordea-se".
          const resolvedAspspName = isReconnect ? existing?.bank_name : aspsp_name
          const resolvedAspspCountry = isReconnect
            ? existing?.provider?.split('-').pop()?.toUpperCase() || 'SE'
            : aspsp_country
          if (!resolvedAspspName) {
            return NextResponse.json(
              { error: 'aspsp_name and aspsp_country are required' },
              { status: 400 }
            )
          }

          // Detect PSU type: explicit override > stored type (reconnect) >
          // company entity_type > default 'business'. Reusing the stored type on
          // reconnect is the key fix: re-deriving from entity_type would flip a
          // working 'personal' connection (e.g. an AB owner who signs with a
          // personal Mobile BankID) back to 'business' on every consent renewal,
          // failing at the bank's signing step. The client can still pass an
          // explicit psu_type to switch account type in place.
          let psuType: 'personal' | 'business' = 'business'
          if (explicitPsuType === 'personal' || explicitPsuType === 'business') {
            psuType = explicitPsuType
          } else if (isReconnect && (existing?.psu_type === 'personal' || existing?.psu_type === 'business')) {
            psuType = existing.psu_type
          } else {
            const { data: company } = await supabase
              .from('companies')
              .select('entity_type')
              .eq('id', companyId)
              .single()
            if (company?.entity_type === 'enskild_firma') {
              psuType = 'personal'
            }
          }

          // Resolve the bank's preferred auth method. Handelsbanken (and some
          // other Swedish banks) expose Mobile BankID only as a hidden DECOUPLED
          // method; without pinning it, Enable Banking defaults to the REDIRECT
          // method, which for Handelsbanken *corporate* PSUs cannot complete
          // with Mobile BankID: the user approves in the app and then hits an
          // error. Only hidden methods applicable to this psu_type are pinned;
          // banks whose decoupled method is visible (e.g. Lunar) get undefined
          // so their own working default flow runs untouched.
          const preferredMethod = await getPreferredAuthMethodDetails(
            resolvedAspspName,
            resolvedAspspCountry,
            psuType
          )
          const authMethod = preferredMethod?.name

          log.info('[enable-banking] Starting bank connection', {
            user_id: user.id,
            bank: resolvedAspspName,
            country: resolvedAspspCountry,
            psu_type: psuType,
            auth_method: authMethod ?? '(aspsp default)',
            // Chosen method's metadata, so prod logs can verify per-bank pinning
            // behavior after deploy (hidden-only + psu_types selection). A
            // pinned method with no psu_types (the documented Handelsbanken
            // shape) applies to all PSU types and logs '(all)': the
            // '(aspsp default)' sentinel is reserved for the unpinned case,
            // where it would otherwise contradict auth_method on the same line.
            auth_method_approach: preferredMethod?.approach ?? '(aspsp default)',
            auth_method_hidden: preferredMethod?.hidden_method ?? '(aspsp default)',
            auth_method_psu_types: preferredMethod
              ? (preferredMethod.psu_types ?? '(all)')
              : '(aspsp default)',
            reconnect: isReconnect,
          })

          // Reject if there's already a recent pending connection for this user+bank
          // to prevent double-click race conditions that confuse the bank's consent
          // flow. Skipped for reconnect: that deliberately re-authorizes a known row.
          if (!isReconnect) {
            const { data: recentPending } = await supabase
              .from('bank_connections')
              .select('id, created_at')
              .eq('company_id', companyId)
              .eq('bank_name', resolvedAspspName)
              .eq('status', 'pending')
              .order('created_at', { ascending: false })
              .limit(1)
              .maybeSingle()

            if (recentPending) {
              const pendingAge = Date.now() - new Date(recentPending.created_at).getTime()
              const STALE_THRESHOLD_MS = 30 * 1000 // 30 seconds: long enough to cover the redirect handoff, short enough that an abandoned attempt doesn't block the user

              if (pendingAge < STALE_THRESHOLD_MS) {
                log.info('[enable-banking] Rejecting duplicate connect: recent pending exists', {
                  existing_id: recentPending.id,
                  age_ms: pendingAge,
                })
                return NextResponse.json(
                  { error: 'En anslutning pågår redan. Vänta och försök igen.' },
                  { status: 409 }
                )
              }
            }

            // Sweep failed attempts that never became a live connection:
            // stale 'pending' rows (abandoned redirects past the threshold)
            // and 'error' rows left by earlier denied/failed connects.
            // DELETE instead of marking 'error': a parked 'error' row renders
            // forever as an "Åtgärd krävs" card, so a failed attempt followed
            // by a successful retry showed up as two connections to the same
            // bank. The session_id/accounts_data guards protect established
            // connections (anything that ever completed the callback has
            // accounts_data); never-activated rows have no dependents, and
            // the transactions/cash_accounts FKs are ON DELETE SET NULL.
            const { data: sweptRows } = await supabase
              .from('bank_connections')
              .delete()
              .eq('company_id', companyId)
              .eq('bank_name', resolvedAspspName)
              .in('status', ['pending', 'error'])
              .is('session_id', null)
              .is('accounts_data', null)
              .select('id')

            if (sweptRows?.length) {
              log.info('[enable-banking] Swept never-activated connection attempts', {
                count: sweptRows.length,
                bank: resolvedAspspName,
              })
            }

            // A fresh connect while a DEAD-BUT-ESTABLISHED connection to the
            // same bank exists (expired/error/pending_selection) is almost
            // always a renewal that should go through the reconnect path: a
            // second row duplicates the connection and used to strand the old
            // one in "Åtgärd krävs" forever. 409 with the existing id lets
            // the client offer "förnya i stället". An ACTIVE row never
            // triggers the guard: two legitimate logins at the same bank
            // (disjoint account sets, e.g. privat + företag) must remain
            // creatable through the UI, and the callback's supersede leaves
            // non-overlapping account sets alone. force_new stays as the
            // deliberate escape hatch. Runs AFTER the sweep so a
            // never-activated zombie cannot block a legitimate fresh connect.
            if (forceNew !== true) {
              const { data: establishedRow } = await supabase
                .from('bank_connections')
                .select('id, status')
                .eq('company_id', companyId)
                .eq('bank_name', resolvedAspspName)
                .in('status', ['expired', 'error', 'pending_selection'])
                .order('created_at', { ascending: false })
                .limit(1)
                .maybeSingle()

              if (establishedRow) {
                log.info('[enable-banking] Rejecting fresh connect: dead connection needs renewal', {
                  existing_id: establishedRow.id,
                  existing_status: establishedRow.status,
                  bank: resolvedAspspName,
                })
                return NextResponse.json(
                  {
                    error: `Du har redan en koppling till ${resolvedAspspName} som behöver förnyas. Använd Förnya samtycke på kopplingen i stället.`,
                    code: 'EXISTING_CONNECTION',
                    existing_connection_id: establishedRow.id,
                  },
                  { status: 409 }
                )
              }
            }
          }

          const redirectUrl = `${process.env.NEXT_PUBLIC_APP_URL}/api/extensions/enable-banking/callback`

          // Generate cryptographic state token for CSRF protection
          const oauthState = crypto.randomUUID()

          if (isReconnect && existing) {
            // Persist the CSRF state to the existing row BEFORE asking the bank
            // to start an authorization. The OAuth callback locates this row only
            // by oauth_state, so writing it first guarantees that once the bank
            // holds a session bound to this state a matching row already exists.
            // If startAuthorization ran first and this UPDATE then failed, the
            // bank session would be orphaned with no row to complete it.
            //
            // Reuse the SAME row: the callback drives it back to
            // pending_selection → active, so existing transactions and the
            // cash_accounts mirror stay linked. Deliberately keep status
            // 'expired' (NOT 'pending') during the round-trip: this row's
            // created_at is old and the cron deletes stale 'pending' rows after
            // 1h: a reconnect must not be eligible for that. Staying 'expired'
            // also keeps it visible in "Åtgärd krävs" so an abandoned reconnect
            // is recoverable. The callback's oauth_state lookup accepts 'expired'.
            const { error: stateError } = await supabase
              .from('bank_connections')
              .update({
                oauth_state: oauthState,
                status: 'expired',
                // session_id is deliberately KEPT here. The callback needs the
                // session being replaced to carry the renewed consent across to
                // sibling companies sharing it (lib/session-sharing.ts); nulling
                // it made the renewal invisible and left the siblings pointing
                // at a session the bank had just superseded. 'expired' already
                // marks the row dead, and the probe pass skips expired rows.
                error_message: null,
                psu_type: psuType,
              })
              .eq('id', existing.id)
              .eq('company_id', companyId)

            if (stateError) {
              log.error('[enable-banking] Database error staging reconnect state', {
                errorMessage: stateError.message,
                errorCode: stateError.code,
                connection_id: existing.id,
                user_id: user.id,
              })
              throw new Error(`Failed to update connection: ${stateError.message}`)
            }

            // Best-effort revoke the dead consent at Enable Banking. A
            // closed/expired session is often already gone, so a failure here is
            // expected and non-fatal: the new authorization supersedes it.
            // Logged at WARN so a systematic revoke failure is visible to
            // monitoring (compliance: ASVS V16 / ISO 27001 A.8.15).
            // Never revoke a session other companies still hold. On a shared
            // consent this revoke would kill their feeds instantly, before the
            // replacement session exists, and permanently if the user abandons
            // the bank flow. The callback moves the siblings onto the new
            // session once it lands; the superseded one lapses on its own.
            let oldSessionShared = false
            if (existing.session_id) {
              const { createServiceClient } = await import('@/lib/supabase/server')
              const serviceSupabase = await createServiceClient()
              oldSessionShared =
                (await countLiveSiblings(serviceSupabase, existing.session_id, existing.id)) > 0
              if (oldSessionShared) {
                log.info('[enable-banking] Old session shared with other companies: not revoking', {
                  connection_id: existing.id,
                })
              }
            }

            if (existing.session_id && !oldSessionShared) {
              try {
                await deleteSession(existing.session_id)
              } catch (revokeError) {
                log.warn('[enable-banking] Old session revoke skipped (likely already expired)', {
                  message: revokeError instanceof Error ? revokeError.message : String(revokeError),
                  connection_id: existing.id,
                })
              }
            }

            const { url, authorization_id } = await startAuthorization(
              resolvedAspspName,
              resolvedAspspCountry,
              redirectUrl,
              oauthState,
              psuType,
              authMethod,
              companyId
            )

            // Record the bank's authorization_id for audit/traceability. The
            // callback matches on oauth_state alone (already persisted above), so
            // a failure here cannot orphan the flow: log and continue.
            const { error: authIdError } = await supabase
              .from('bank_connections')
              .update({ authorization_id })
              .eq('id', existing.id)
              .eq('company_id', companyId)

            if (authIdError) {
              log.warn('[enable-banking] Could not persist authorization_id on reconnect (non-fatal)', {
                errorMessage: authIdError.message,
                connection_id: existing.id,
              })
            }

            return NextResponse.json({
              connection_id: existing.id,
              authorization_url: url,
            })
          }

          // Fresh connect: create the bank authorization, then persist the new
          // row carrying its oauth_state so the callback can find it.
          const { url, authorization_id } = await startAuthorization(
            resolvedAspspName,
            resolvedAspspCountry,
            redirectUrl,
            oauthState,
            psuType,
            authMethod,
            companyId
          )

          const { data: connection, error } = await supabase
            .from('bank_connections')
            .insert({
              company_id: companyId,
              user_id: user.id,
              provider: `${resolvedAspspName.toLowerCase().replace(/\s+/g, '-')}-${resolvedAspspCountry.toLowerCase()}`,
              bank_name: resolvedAspspName,
              authorization_id,
              oauth_state: oauthState,
              status: 'pending',
              psu_type: psuType,
            })
            .select()
            .single()

          if (error) {
            log.error('[enable-banking] Database error storing connection', {
              errorMessage: error.message,
              errorCode: error.code,
              errorDetails: error.details,
              user_id: user.id,
              bank: resolvedAspspName,
            })
            throw new Error(`Failed to store connection: ${error.message}`)
          }

          return NextResponse.json({
            connection_id: connection.id,
            authorization_url: url,
          })
        } catch (error) {
          log.error('[enable-banking] Connect handler error', {
            message: error instanceof Error ? error.message : String(error),
            stack: error instanceof Error ? error.stack : undefined,
            name: error instanceof Error ? error.name : undefined,
            user_id: user.id,
            aspsp_name,
            aspsp_country,
          })
          return NextResponse.json(
            { error: error instanceof Error ? error.message : 'Connection failed' },
            { status: 500 }
          )
        }
      },
    },
    {
      method: 'POST',
      path: '/sync',
      handler: async (request: Request, ctx?: ExtensionContext) => {
        const log = ctx?.log ?? console
        const supabase = ctx?.supabase ?? await (await import('@/lib/supabase/server')).createClient()
        const { data: { user } } = await supabase.auth.getUser()

        if (!user) {
          return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
        }

        if (!ctx?.companyId) {
          return NextResponse.json({ error: 'Company context required' }, { status: 400 })
        }
        const companyId = ctx.companyId

        const blocked = await requireCapability(supabase, companyId, CAPABILITY.bank_sync)
        if (blocked) return blocked

        const rl = await checkRateLimit({
          prefix: 'enable-banking:sync',
          identifier: user.id,
          ...RATE_LIMIT_SYNC,
        })
        if (!rl.ok) return rl.response!

        // Default 120 days: most callers (Sync Now button, post-activation gap fill)
        // want a deep refresh, not a 30-day blip. Cron uses 7-day incrementals separately.
        // Bank may still cap at ~90 days per PSD2 without fresh SCA: asking for more
        // is harmless and surfaces whatever the ASPSP is willing to return.
        const { connection_id, days_back: rawDaysBack = 120 } = await request.json()
        const days_back = Math.min(Math.max(1, rawDaysBack), 365)

        const { data: connection, error: connectionError } = await supabase
          .from('bank_connections')
          .select('*')
          .eq('id', connection_id)
          .eq('company_id', companyId)
          .single()

        if (connectionError || !connection) {
          return NextResponse.json({ error: 'Connection not found' }, { status: 404 })
        }

        // 'error' is retryable: a transient upstream failure (e.g. ASPSP_ERROR)
        // parks the connection in 'error' while the PSD2 session is still
        // alive, so the UI's "Försök igen" must be allowed through; a
        // successful sync below restores 'active'. 'expired' stays rejected:
        // a dead consent needs re-authorization via /connect, not a retry.
        if (connection.status !== 'active' && connection.status !== 'error') {
          return NextResponse.json({ error: 'Connection is not active' }, { status: 400 })
        }

        try {
          // Keep the full list for write-back; sync only the enabled subset.
          // undefined enabled === true for back-compat with rows that predate
          // the per-account toggle.
          const allAccounts = (connection.accounts_data as StoredAccount[] || []).map(a => ({ ...a }))
          const accounts = allAccounts.filter(a => a.enabled !== false)

          if (accounts.length === 0) {
            return NextResponse.json(
              { error: 'Inga konton är valda för synkning. Öppna "Hantera konton" för att aktivera minst ett.' },
              { status: 400 }
            )
          }

          const toDate = new Date().toISOString().split('T')[0]
          const fromDate = new Date(Date.now() - days_back * 24 * 60 * 60 * 1000)
            .toISOString()
            .split('T')[0]
          const syncStartedAt = new Date().toISOString()

          // Use ctx.services.ingestTransactions when available
          const ingestFn = ctx?.services.ingestTransactions

          // Detect SIE overlap: skip auto-categorization if the sync range
          // overlaps with a completed SIE import to prevent double-booking.
          // Reconciliation still links bank transactions to existing GL lines.
          const { data: sieOverlap } = await supabase
            .from('sie_imports')
            .select('id')
            .eq('company_id', companyId)
            .eq('status', 'completed')
            .gte('fiscal_year_end', fromDate)
            .limit(1)
            .maybeSingle()

          // Check if user is a viewer: viewers get rawInsertOnly (no categorization)
          const { data: membership } = await supabase
            .from('company_members')
            .select('role')
            .eq('company_id', companyId)
            .eq('user_id', user.id)
            .maybeSingle()
          const isViewer = membership?.role === 'viewer'

          // Use strategy=longest when the caller asks for >= 30 days of history
          // (initial sync, manual backfill). Short windows get the implicit
          // default since there's no older data to surface.
          const syncOptions = {
            ...(sieOverlap ? { skipAutoCategorization: true } : {}),
            ...(isViewer ? { rawInsertOnly: true } : {}),
            ...(days_back >= 30 ? { strategy: 'longest' as const } : {}),
          }

          if (sieOverlap) {
            log.info('SIE import overlap detected: suppressing auto-categorization', {
              sieImportId: sieOverlap.id,
              fromDate,
              toDate,
            })
          }
          const results = await Promise.all(
            accounts.map(account => syncAccountTransactions(
              supabase,
              companyId,
              user.id,
              connection.id,
              account,
              fromDate,
              toDate,
              ingestFn,
              syncOptions
            ))
          )

          const totalImported = results.reduce((sum, r) => sum + r.imported, 0)
          const totalDuplicates = results.reduce((sum, r) => sum + r.duplicates, 0)

          // When SIE overlap is detected, run a batch reconciliation sweep.
          // The greedy algorithm considers all candidates globally (highest-
          // confidence first) and catches matches the inline per-transaction
          // pass may have missed due to processing order. One scoped run per
          // enabled cash account (issue #1298): the pooled run could persist a
          // cross-account journal_entry_id.
          // Skip for viewers: reconciliation updates transactions which viewers cannot do.
          if (sieOverlap && totalImported > 0 && !isViewer) {
            try {
              const reconResult = await runUnattendedReconciliationSweep(
                supabase,
                companyId,
                user.id,
                { dateFrom: fromDate, dateTo: toDate },
              )
              // Stamp the outcome so the UI can render "Vi matchade X av Y" and
              // the review surface knows there is something to granska.
              await supabase
                .from('bank_connections')
                .update({
                  last_sie_sweep: toSweepSummary(reconResult, {
                    dateFrom: fromDate,
                    dateTo: toDate,
                  }),
                })
                .eq('id', connection.id)
              if (reconResult.applied > 0 || reconResult.skippedBelowThreshold > 0) {
                log.info('Post-sync batch reconciliation matched additional transactions', {
                  applied: reconResult.applied,
                  skippedBelowThreshold: reconResult.skippedBelowThreshold,
                  accounts: reconResult.accounts.map((a) => ({
                    accountNumber: a.accountNumber,
                    applied: a.applied,
                    skippedBelowThreshold: a.skippedBelowThreshold,
                  })),
                })
              }
            } catch {
              // Non-critical: transactions remain uncategorized for manual review
            }
          }

          const syncedAt = new Date().toISOString()
          // Mirror refreshed balances into cash_accounts: the Bank-page source
          // picker and the reconciliation status read that table, and without
          // this the balance there froze at connect time.
          {
            const { updateBalancesFromSync } = await import('@/lib/cash-accounts/service')
            await updateBalancesFromSync(
              supabase,
              companyId,
              connection.id,
              allAccounts.map((a) => ({
                external_uid: a.uid,
                balance: a.balance,
                available_balance: a.available_balance,
                balance_updated_at: a.balance_updated_at,
              })),
            )
          }
          await supabase
            .from('bank_connections')
            .update({
              accounts_data: allAccounts,
              last_synced_at: syncedAt,
              // A successful sync proves the session works again: recover an
              // 'error' connection to 'active' (so the cron picks it up again)
              // and clear any stale failure message from the settings panel.
              ...(connection.status === 'error' ? { status: 'active' } : {}),
              ...(connection.status === 'error' || connection.error_message
                ? { error_message: null }
                : {}),
            })
            .eq('id', connection.id)

          if (totalImported > 0) {
            const { data: syncedTransactions } = await supabase
              .from('transactions')
              .select('*')
              .eq('company_id', companyId)
              .eq('bank_connection_id', connection.id)
              .gte('created_at', syncStartedAt)
              .order('created_at', { ascending: false })
              .limit(totalImported)

            if (syncedTransactions && syncedTransactions.length > 0) {
              const emit = ctx?.emit ?? (await import('@/lib/events/bus')).eventBus.emit.bind((await import('@/lib/events/bus')).eventBus)
              await emit({
                type: 'transaction.synced',
                payload: { transactions: syncedTransactions as Transaction[], userId: user.id, companyId },
              })
            }
          }

          // A bank that refused the requested window answered a narrower one;
          // say so instead of reporting a truncated sync as complete (#2202).
          // history_from is the LATEST effective date across the accounts:
          // the date from which every account is complete.
          const narrowedFrom = results
            .filter((r) => r.historyNarrowed && r.effectiveFromDate)
            .map((r) => r.effectiveFromDate as string)
          const historyFrom = narrowedFrom.length > 0
            ? narrowedFrom.reduce((a, b) => (a > b ? a : b))
            : null

          return NextResponse.json({
            imported: totalImported,
            duplicates: totalDuplicates,
            last_synced_at: syncedAt,
            requested_from: fromDate,
            history_narrowed: historyFrom !== null,
            history_from: historyFrom,
          })
        } catch (error) {
          // The bank refused a window it has answered before, or every
          // narrower one: not a dead session and not a broken connection, so
          // the row is left alone (no 'error', no renewal advice) and the
          // client is told to try again later (#2202).
          if (error instanceof AspspUnavailableError) {
            log.warn('[enable-banking] Sync: bank unavailable, narrowing cannot help', {
              reason: error.reason,
              dateFrom: error.dateFrom,
              status: error.status,
              body: error.body,
              user_id: user.id,
              connection_id,
              bankName: connection.bank_name,
            })
            return NextResponse.json(
              {
                error: BANK_UNAVAILABLE_MESSAGE,
                code: 'BANK_UNAVAILABLE',
                retryable: true,
                connection_id: connection.id,
              },
              { status: 503 }
            )
          }

          log.error('[enable-banking] Sync handler error', {
            message: error instanceof Error ? error.message : String(error),
            stack: error instanceof Error ? error.stack : undefined,
            name: error instanceof Error ? error.name : undefined,
            user_id: user.id,
            connection_id,
            connectionStatus: connection.status,
            bankName: connection.bank_name,
          })

          // A dead PSD2 session (closed/expired/invalid consent) can't be fixed
          // by retrying: the user must re-authorize. Flip the connection to
          // 'expired' so the UI surfaces the reconnect affordance, and tell the
          // client re-auth is required (reauth_required) so it can offer a
          // one-click "Förnya anslutning" instead of a dead-end error. No
          // disconnect needed: /connect reconnects this same connection in place.
          if (error instanceof SessionExpiredError) {
            await supabase
              .from('bank_connections')
              .update({ status: 'expired', error_message: REAUTH_REQUIRED_MESSAGE })
              .eq('id', connection.id)
              .eq('company_id', companyId)
            return NextResponse.json(
              {
                error: REAUTH_REQUIRED_MESSAGE,
                code: 'SESSION_EXPIRED',
                reauth_required: true,
                connection_id: connection.id,
              },
              { status: 409 }
            )
          }

          // Non-session failure: the settings panel toasts this error verbatim
          // and renders error_message on the connection card, so both must be
          // the short Swedish message: the raw Enable Banking body (an English
          // JSON envelope) is already in the server log above. Refresh the
          // stored error_message on rows already in 'error' so a failed retry
          // replaces any stale raw body persisted by older code.
          if (connection.status === 'error') {
            await supabase
              .from('bank_connections')
              .update({ error_message: SYNC_FAILED_MESSAGE })
              .eq('id', connection.id)
              .eq('company_id', companyId)
          }

          return NextResponse.json({ error: SYNC_FAILED_MESSAGE }, { status: 500 })
        }
      },
    },
    {
      method: 'PATCH',
      path: '/accounts',
      handler: async (request: Request, ctx?: ExtensionContext) => {
        const log = ctx?.log ?? console
        const supabase = ctx?.supabase ?? await (await import('@/lib/supabase/server')).createClient()
        const { data: { user } } = await supabase.auth.getUser()

        if (!user) {
          return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
        }

        // company_id must come from the verified extension context, never fall
        // back to user.id (which is a different identifier dimension and would
        // silently mis-scope queries in multi-tenant deployments).
        if (!ctx?.companyId) {
          return NextResponse.json({ error: 'Company context required' }, { status: 400 })
        }
        const companyId = ctx.companyId

        const rl = await checkRateLimit({
          prefix: 'enable-banking:accounts',
          identifier: user.id,
          ...RATE_LIMIT_ACCOUNTS,
        })
        if (!rl.ok) return rl.response!

        const body = await request.json().catch(() => null)
        const connection_id = body?.connection_id
        const enabled_uids = body?.enabled_uids
        const rawLookback = body?.initial_lookback_days
        const rawLookbackFromDate = body?.initial_lookback_from_date
        const account_mappings = body?.account_mappings

        if (typeof connection_id !== 'string' || !connection_id) {
          return NextResponse.json({ error: 'connection_id krävs' }, { status: 400 })
        }
        if (!Array.isArray(enabled_uids) || !enabled_uids.every(u => typeof u === 'string')) {
          return NextResponse.json({ error: 'enabled_uids måste vara en lista av strängar' }, { status: 400 })
        }
        if (enabled_uids.length === 0) {
          return NextResponse.json(
            { error: 'Välj minst ett konto, eller koppla bort banken om inga konton ska synkas.' },
            { status: 400 }
          )
        }
        if (enabled_uids.length > MAX_ENABLED_UIDS) {
          return NextResponse.json(
            { error: `Max ${MAX_ENABLED_UIDS} konton per anslutning.` },
            { status: 400 }
          )
        }

        // account_mappings is optional. When present, it's an array of
        // { uid, ledger_account } pairs that route per-account ingest to a
        // specific BAS account (e.g. EUR account → 1932 instead of the default 1930).
        // Restrict to BAS class 19 (kassa/bank). Accepting e.g. 3001 (revenue)
        // or 2640 (input VAT) here would silently misroute every bank-side
        // journal-entry leg into a revenue/VAT account, corrupting both the
        // ledger and momsdeklaration. The chart-of-accounts existence check
        // below is necessary but not sufficient: those accounts likely do
        // exist in the chart, but they're the wrong class.
        const BAS_ACCOUNT_PATTERN = /^19[0-9]{2}$/
        type AccountMapping = { uid: string; ledger_account?: string | null }
        let mappings: AccountMapping[] = []
        if (account_mappings !== undefined) {
          if (!Array.isArray(account_mappings)) {
            return NextResponse.json(
              { error: 'account_mappings måste vara en lista' },
              { status: 400 }
            )
          }
          for (const m of account_mappings) {
            if (!m || typeof m !== 'object' || typeof m.uid !== 'string') {
              return NextResponse.json(
                { error: 'account_mappings: varje post kräver uid (sträng)' },
                { status: 400 }
              )
            }
            if (m.ledger_account != null && (typeof m.ledger_account !== 'string' || !BAS_ACCOUNT_PATTERN.test(m.ledger_account))) {
              return NextResponse.json(
                { error: 'account_mappings: ledger_account måste vara ett BAS-konto i klass 19 (1900-1999)' },
                { status: 400 }
              )
            }
          }
          mappings = account_mappings as AccountMapping[]
        }

        // initial_lookback_days only applies on the pending_selection→active transition.
        // Default 120; clamp to [30, 365]. Ignored for selection edits.
        // PSD2 obliges ASPSPs to ~90 days without fresh SCA, but many Swedish banks
        // return more if asked: request 120 and accept whatever the bank gives back.
        //
        // If the client sent initial_lookback_from_date (preferred for fiscal-year-anchored
        // backfills), derive days from that and reject future dates outright. Otherwise
        // fall back to initial_lookback_days (or the 120-day default).
        if (typeof rawLookbackFromDate === 'string' && /^\d{4}-\d{2}-\d{2}$/.test(rawLookbackFromDate)) {
          const from = new Date(rawLookbackFromDate + 'T00:00:00Z')
          if (!Number.isFinite(from.getTime())) {
            return NextResponse.json(
              { error: 'initial_lookback_from_date är inte ett giltigt datum.' },
              { status: 400 }
            )
          }
          const diffMs = Date.now() - from.getTime()
          const daysFromDate = Math.ceil(diffMs / (24 * 60 * 60 * 1000))
          if (daysFromDate <= 0) {
            return NextResponse.json(
              { error: 'initial_lookback_from_date måste ligga i det förflutna.' },
              { status: 400 }
            )
          }
        }
        const initialLookbackDays = (() => {
          if (typeof rawLookbackFromDate === 'string' && /^\d{4}-\d{2}-\d{2}$/.test(rawLookbackFromDate)) {
            const from = new Date(rawLookbackFromDate + 'T00:00:00Z')
            // Future/invalid dates already rejected above; days > 0 is guaranteed.
            const diffMs = Date.now() - from.getTime()
            const days = Math.ceil(diffMs / (24 * 60 * 60 * 1000))
            return Math.min(365, Math.max(1, days))
          }
          const n = typeof rawLookback === 'number' && Number.isFinite(rawLookback) ? rawLookback : 120
          return Math.min(365, Math.max(30, Math.round(n)))
        })()

        const { data: connection, error: connectionError } = await supabase
          .from('bank_connections')
          .select('id, status, accounts_data, bank_name')
          .eq('id', connection_id)
          .eq('company_id', companyId)
          .single()

        if (connectionError || !connection) {
          return NextResponse.json({ error: 'Connection not found' }, { status: 404 })
        }

        if (connection.status !== 'pending_selection' && connection.status !== 'active') {
          return NextResponse.json(
            { error: 'Anslutningen kan inte konfigureras i nuvarande status.' },
            { status: 400 }
          )
        }

        const existing = (connection.accounts_data as StoredAccount[] || []).map(a => ({ ...a }))
        const knownUids = new Set(existing.map(a => a.uid))
        const unknownUids = enabled_uids.filter(uid => !knownUids.has(uid))
        if (unknownUids.length > 0) {
          return NextResponse.json(
            { error: 'Ett eller flera konton kunde inte hittas.', unknown_uids: unknownUids },
            { status: 400 }
          )
        }

        // Mirror the enabled_uids guard for account_mappings: without this,
        // a typo'd UID in the mapping list is silently dropped (the entry
        // never lands in the resulting accounts_data) while the response is
        // still 200, leaving the client to believe the mapping was applied.
        const unknownMappingUids = mappings.map(m => m.uid).filter(uid => !knownUids.has(uid))
        if (unknownMappingUids.length > 0) {
          return NextResponse.json(
            { error: 'account_mappings innehåller okända konto-uid.', unknown_uids: unknownMappingUids },
            { status: 400 }
          )
        }

        // Verify any provided ledger_account values actually exist in the
        // company's chart of accounts. Prevents users from typing arbitrary
        // numbers via the API and breaking journal entry creation later.
        const requestedLedgerAccounts = mappings
          .map(m => m.ledger_account)
          .filter((a): a is string => typeof a === 'string')
        if (requestedLedgerAccounts.length > 0) {
          const { data: chartRows } = await supabase
            .from('chart_of_accounts')
            .select('account_number')
            .eq('company_id', companyId)
            .in('account_number', requestedLedgerAccounts)
          const validAccountNumbers = new Set((chartRows || []).map(r => r.account_number as string))
          const invalid = requestedLedgerAccounts.filter(a => !validAccountNumbers.has(a))
          if (invalid.length > 0) {
            return NextResponse.json(
              {
                error: 'Ett eller flera bokföringskonton finns inte i kontoplanen.',
                invalid_accounts: invalid,
              },
              { status: 400 }
            )
          }
        }

        const enabledSet = new Set(enabled_uids)
        const mappingsByUid = new Map(mappings.map(m => [m.uid, m]))
        const updatedAccounts: StoredAccount[] = existing.map(a => {
          const mapping = mappingsByUid.get(a.uid)
          const next: StoredAccount = {
            ...a,
            enabled: enabledSet.has(a.uid),
            // Apply ledger_account from mapping when present. Explicit null clears it.
            // Absent mapping leaves the existing ledger_account untouched (back-compat
            // with selection-edit calls that don't include account_mappings).
            ...(mapping
              ? { ledger_account: mapping.ledger_account ?? undefined }
              : {}),
          }
          // Enabling an account is the deliberate takeover the callback's
          // guard flags exist to force: once made, the flags are stale (the
          // account syncs HERE now) and would keep rendering a false
          // "synkas i annat bolag" note in every later picker.
          if (next.enabled) {
            delete next.claimed_by_company_id
            delete next.claimed_by_company_name
            delete next.deselected_elsewhere
          }
          return next
        })

        // Accounts the callback guard left disabled AND unmirrored (no ledger
        // anywhere) stay that way through a save that does not enable them:
        // allocating a 19xx slot and upserting a cash_accounts row for a
        // still-disabled claimed account would recreate exactly the state the
        // guard exists to prevent (another company's IBAN and name in this
        // company's chart and routing table), one screen after the callback
        // avoided it. Disabled accounts that already have a ledger or a
        // mirrored row keep the existing behavior: their row's enabled flag
        // must still flip off.
        const neverMirroredDisabledUids = new Set<string>()

        // Resolve the effective mirror ledger for every account up front and
        // reject collisions with a 400 — the mirror pass below writes into
        // cash_accounts, whose UNIQUE (company_id, ledger_account) constraint
        // would otherwise fail per-account and get swallowed, leaving accounts
        // silently unmirrored.
        const { resolvePsd2LedgerAccount, upsertFromPsd2, getRevokedConnectionIds, normalizeIban } =
          await import('@/lib/cash-accounts/service')

        const { data: companyCashRows } = await supabase
          .from('cash_accounts')
          .select('id, external_uid, bank_connection_id, ledger_account, iban')
          .eq('company_id', companyId)
        const cashRows = (companyCashRows ?? []) as Array<{
          id: string
          external_uid: string | null
          bank_connection_id: string | null
          ledger_account: string
          iban: string | null
        }>

        // Rows that already represent one of THIS connection's accounts, matched
        // on IBAN rather than on the provider uid. After a re-authorization (new
        // uids) or a fresh connect to an already-connected bank (new connection
        // row), these are the user's own mappings wearing a stale owner: they
        // must not be treated as another bank's territory, and the mirror pass
        // below promotes them in place instead of inserting a second row.
        const rowByIban = new Map<string, { id: string; ledger_account: string }>()
        for (const r of cashRows) {
          const normalized = normalizeIban(r.iban)
          if (normalized && !rowByIban.has(normalized)) {
            rowByIban.set(normalized, { id: r.id, ledger_account: r.ledger_account })
          }
        }
        const reuseRowByUid = new Map<string, { id: string; ledger_account: string }>()
        for (const a of updatedAccounts) {
          const normalized = normalizeIban(a.iban)
          const row = normalized ? rowByIban.get(normalized) : undefined
          if (row) reuseRowByUid.set(a.uid, row)
        }
        const ownIbanRowIds = new Set([...reuseRowByUid.values()].map(r => r.id))
        const existingLedgerByUid = new Map(
          cashRows
            .filter(r => r.bank_connection_id === connection.id && r.external_uid)
            .map(r => [r.external_uid as string, r.ledger_account])
        )
        // Slots held by OTHER connections' PSD2 accounts — an explicit mapping
        // onto one of those would violate the unique constraint. Manual rows
        // are not foreign: upsertFromPsd2 promotes them in place. Rows held by
        // a REVOKED connection are not foreign either: those are orphaned
        // leftovers (disconnect predating the claim release, or a lost demote)
        // and upsertFromPsd2 promotes them in place too. Excluding them here
        // is the self-heal path for companies whose bank was disconnected
        // before disconnect started releasing ledger claims.
        const foreignConnectionIds = [
          ...new Set(
            cashRows
              .filter(r => r.bank_connection_id !== null && r.bank_connection_id !== connection.id)
              .map(r => r.bank_connection_id as string)
          ),
        ]
        const revokedConnectionIds = await getRevokedConnectionIds(
          supabase,
          companyId,
          foreignConnectionIds
        )
        const foreignConnectedLedgers = new Set(
          cashRows
            .filter(
              r =>
                r.bank_connection_id !== null &&
                r.bank_connection_id !== connection.id &&
                !revokedConnectionIds.has(r.bank_connection_id) &&
                // Same IBAN as one of this connection's accounts: the same
                // physical account under a stale owner, not a foreign claim.
                !ownIbanRowIds.has(r.id)
            )
            .map(r => r.ledger_account)
        )

        const effectiveLedgerByUid = new Map<string, string>()
        const usedLedgers = new Set<string>()
        const duplicateLedgers = new Set<string>()
        const conflictingLedgers = new Set<string>()

        // First pass: accounts with an explicit or previously mirrored ledger.
        for (const a of updatedAccounts) {
          const ledger = a.ledger_account ?? existingLedgerByUid.get(a.uid)
          if (!ledger) continue
          if (usedLedgers.has(ledger)) duplicateLedgers.add(ledger)
          if (foreignConnectedLedgers.has(ledger) && existingLedgerByUid.get(a.uid) !== ledger) {
            conflictingLedgers.add(ledger)
          }
          usedLedgers.add(ledger)
          effectiveLedgerByUid.set(a.uid, ledger)
        }

        if (duplicateLedgers.size > 0) {
          return NextResponse.json(
            {
              error: 'Flera bankkonton kan inte bokföras på samma konto. Välj olika bokföringskonton.',
              duplicate_accounts: [...duplicateLedgers],
            },
            { status: 400 }
          )
        }
        if (conflictingLedgers.size > 0) {
          return NextResponse.json(
            {
              error: 'Bokföringskontot används redan av ett bankkonto från en annan bankanslutning.',
              conflicting_accounts: [...conflictingLedgers],
            },
            { status: 400 }
          )
        }

        // Second pass: allocate a free slot for accounts with no ledger at all
        // (legacy connections mirrored before allocation existed, or mappings
        // explicitly cleared). Allocation failure must never block selection
        // save — fall back to the pre-allocator behavior (1930) and let the
        // mirror pass surface any collision per-account, as before.
        for (const a of updatedAccounts) {
          if (effectiveLedgerByUid.has(a.uid)) continue
          // See neverMirroredDisabledUids above: a disabled account that has
          // never held a ledger or a mirrored row gets neither allocated nor
          // mirrored by this save.
          if (!enabledSet.has(a.uid) && !reuseRowByUid.has(a.uid)) {
            neverMirroredDisabledUids.add(a.uid)
            continue
          }
          let allocated: string | null = null
          try {
            const resolved = await resolvePsd2LedgerAccount(supabase, companyId, user.id, {
              iban: a.iban,
              currency: a.currency,
              accountName: a.name,
              exclude: usedLedgers,
            })
            allocated = resolved?.ledgerAccount ?? null
          } catch (allocErr) {
            log.warn('[enable-banking] ledger allocation failed on selection save', {
              connectionId: connection.id,
              uid: a.uid,
              error: allocErr instanceof Error ? allocErr.message : String(allocErr),
            })
          }
          const ledger = allocated ?? '1930'
          usedLedgers.add(ledger)
          effectiveLedgerByUid.set(a.uid, ledger)
        }

        // accounts_data mirrors the resolved assignment so the picker
        // pre-fills reality on the next open. Skipped disabled accounts keep
        // no assignment: their slot is only claimed if they are ever enabled.
        for (const a of updatedAccounts) {
          if (neverMirroredDisabledUids.has(a.uid)) continue
          a.ledger_account = effectiveLedgerByUid.get(a.uid)
        }

        // State machine: only transition pending_selection → active. Once
        // active, the status field is omitted from the update so the same
        // endpoint can be reused to change account selection without
        // re-asserting a transition that has already happened.
        const updatePayload: { accounts_data: StoredAccount[]; status?: 'active' } = {
          accounts_data: updatedAccounts,
        }
        if (connection.status === 'pending_selection') {
          updatePayload.status = 'active'
        }

        const { error: updateError } = await supabase
          .from('bank_connections')
          .update(updatePayload)
          .eq('id', connection.id)

        if (updateError) {
          log.error('[enable-banking] Failed to update account selection', {
            errorMessage: updateError.message,
            connectionId: connection.id,
            userId: user.id,
            companyId,
          })
          return NextResponse.json({ error: 'Kunde inte spara kontoval' }, { status: 500 })
        }

        // Mirror the user's selection into cash_accounts so routing decisions
        // and reconciliation pick up the new enabled state + ledger mapping
        // without reading the JSONB column.
        {
          for (const a of updatedAccounts) {
            // Never-mirrored disabled accounts (callback-guard leftovers the
            // user did not enable) get no cash_accounts row: see above.
            if (neverMirroredDisabledUids.has(a.uid)) continue
            const ledgerAccount = a.ledger_account ?? '1930'
            // Only reuse the IBAN-matched row when it already sits on the
            // ledger we are about to write. If the user deliberately remapped
            // the account to a different BAS number, promoting the old row
            // would move a row out from under the ledger it still holds.
            const reuseRow = reuseRowByUid.get(a.uid)
            const reuseCashAccountId =
              reuseRow && reuseRow.ledger_account === ledgerAccount ? reuseRow.id : null
            try {
              await upsertFromPsd2(supabase, companyId, {
                bank_connection_id: connection.id,
                external_uid: a.uid,
                currency: a.currency,
                ledger_account: ledgerAccount,
                iban: a.iban ?? null,
                bban: a.bban ?? null,
                name: a.name ?? null,
                balance: a.balance ?? null,
                available_balance: a.available_balance ?? null,
                balance_updated_at: a.balance_updated_at ?? null,
                enabled: a.enabled ?? true,
                reuse_cash_account_id: reuseCashAccountId,
              })
            } catch (cashErr) {
              log.error('[enable-banking] Failed to mirror cash_account on selection save', {
                connectionId: connection.id,
                uid: a.uid,
                error: cashErr instanceof Error ? cashErr.message : String(cashErr),
              })
            }
          }
        }

        const newStatus = updatePayload.status ?? connection.status
        log.info('[enable-banking] Account selection saved', {
          connectionId: connection.id,
          enabledCount: enabled_uids.length,
          totalCount: existing.length,
          previousStatus: connection.status,
          newStatus,
          userId: user.id,
          companyId,
        })

        try {
          const emit = ctx?.emit ?? (await import('@/lib/events/bus')).eventBus.emit.bind((await import('@/lib/events/bus')).eventBus)
          await emit({
            type: 'bank_connection.account_selection_changed',
            payload: {
              connectionId: connection.id,
              bankName: (connection as { bank_name?: string | null }).bank_name ?? null,
              previousStatus: connection.status,
              newStatus,
              enabledCount: enabled_uids.length,
              totalCount: existing.length,
              userId: user.id,
              companyId,
            },
          })
        } catch (emitError) {
          log.error('[enable-banking] Failed to emit account selection event', {
            errorMessage: emitError instanceof Error ? emitError.message : String(emitError),
            connectionId: connection.id,
            userId: user.id,
            companyId,
          })
        }

        // Initial backfill on activation. Run inline so the user has data the
        // moment they finish account selection: no 24h cron wait. Failures
        // here don't fail the PATCH; the cron will retry on its next run
        // (gated on initial_sync_completed_at IS NULL).
        let initialSyncSummary: {
          imported: number
          duplicates: number
          auto_matched: number
          requested_from: string
          returned_min_date: string | null
          returned_max_date: string | null
        } | null = null
        let initialSyncError: string | null = null

        if (connection.status === 'pending_selection') {
          const accountsToSync = updatedAccounts.filter(a => a.enabled !== false)
          const toDate = new Date().toISOString().split('T')[0]
          const fromDate = new Date(Date.now() - initialLookbackDays * 24 * 60 * 60 * 1000)
            .toISOString()
            .split('T')[0]

          // Same guard the manual /sync route and the cron apply. This path also
          // runs on RENEWAL (reconnect resets status to pending_selection), and a
          // fresh consent often makes the bank release history the first connect
          // never delivered, straight over an already-bookkept period. Without
          // the guard those rows would be auto-categorized into brand-new
          // verifikat (double-booking) instead of being linked to the ones that
          // already describe them.
          const { data: sieOverlap } = await supabase
            .from('sie_imports')
            .select('id')
            .eq('company_id', companyId)
            .eq('status', 'completed')
            .gte('fiscal_year_end', fromDate)
            .limit(1)
            .maybeSingle()

          const { data: membership } = await supabase
            .from('company_members')
            .select('role')
            .eq('company_id', companyId)
            .eq('user_id', user.id)
            .maybeSingle()
          const isViewer = membership?.role === 'viewer'

          log.info('[enable-banking] Starting inline initial backfill', {
            connectionId: connection.id,
            accountCount: accountsToSync.length,
            lookbackDays: initialLookbackDays,
            fromDate,
            toDate,
            sieOverlap: Boolean(sieOverlap),
          })

          let timeoutHandle: ReturnType<typeof setTimeout> | undefined
          try {
            const ingestFn = ctx?.services.ingestTransactions
            const syncPromise = Promise.all(
              accountsToSync.map(account => syncAccountTransactions(
                supabase,
                companyId,
                user.id,
                connection.id,
                account,
                fromDate,
                toDate,
                ingestFn,
                {
                  strategy: 'longest',
                  ...(sieOverlap ? { skipAutoCategorization: true } : {}),
                  ...(isViewer ? { rawInsertOnly: true } : {}),
                }
              ))
            )
            // If the timeout wins the race, the underlying Promise.all keeps
            // running. Without a registered handler, a late rejection from the
            // bank API would surface as an unhandledRejection: Node 22 (the
            // self-hosted Docker runtime) terminates the process by default on
            // those, taking the whole server down. The cron retries the
            // backfill via initial_sync_completed_at IS NULL, so a no-op
            // catch is the right policy here.
            syncPromise.catch(() => {})

            const TIMEOUT_MS = 60_000
            const timeoutPromise = new Promise<never>((_, reject) => {
              timeoutHandle = setTimeout(() => reject(new Error('initial_sync_timeout')), TIMEOUT_MS)
            })
            const results = await Promise.race([syncPromise, timeoutPromise])

            const totalImported = results.reduce((sum, r) => sum + r.imported, 0)
            const totalDuplicates = results.reduce((sum, r) => sum + r.duplicates, 0)

            // Min/max booking date across all synced accounts
            const minDates = results.map(r => r.returnedMinBookingDate).filter((d): d is string => !!d)
            const maxDates = results.map(r => r.returnedMaxBookingDate).filter((d): d is string => !!d)
            const returnedMin = minDates.length > 0 ? minDates.reduce((a, b) => (a < b ? a : b)) : null
            const returnedMax = maxDates.length > 0 ? maxDates.reduce((a, b) => (a > b ? a : b)) : null

            // Post-backfill reconciliation sweep, mirroring the manual /sync
            // route: link just-imported rows to the verifikat that already
            // describe them so a re-released period does not resurface as
            // hundreds of "ohanterade" transactions. Unlike the /sync and cron
            // sweeps this runs once per enabled ledger account with a resolved
            // cash-account scope: the pooled unscoped form can cross-link
            // accounts (#1290/#1298). Both a thrown scope resolution AND an
            // unresolved cash-account row (found: false) skip that account's
            // sweep instead of widening to the pooled form.
            //
            // The window opens at the OLDEST booking date the bank actually
            // returned when that is older than the requested fromDate: some
            // ASPSPs over-return history, and rows outside the requested window
            // would otherwise be ingested but never swept.
            const sweepDateFrom = returnedMin && returnedMin < fromDate ? returnedMin : fromDate
            // The sweep writes bank-feed metadata only (transactions.journal_entry_id,
            // reconciliation_method, is_business): journal tables are never touched,
            // so BFL immutability and period locks (which guard journal entries) are
            // not in play. Links to opening-balance verifikat are blocked by the
            // check_transaction_link_not_opening_balance trigger, and every link is
            // reversible via unlinkReconciliation without any ledger write.
            let totalAutoMatched = 0
            if (sieOverlap && totalImported > 0 && !isViewer) {
              // Filter, not `?? undefined`: an undefined accountNumber makes
              // resolveCashAccountScope fall back to the primary account with
              // includeUnassigned=true, which is the pooled form this block must
              // never widen to. The allocator gives every enabled account a
              // concrete ledger_account, so nothing is skipped in practice.
              const ledgerAccounts = Array.from(
                new Set(
                  accountsToSync
                    .map(a => a.ledger_account)
                    .filter((l): l is string => typeof l === 'string' && l.length > 0)
                )
              )
              for (const ledgerAccount of ledgerAccounts) {
                try {
                  const scope = await resolveCashAccountScope(supabase, companyId, ledgerAccount)
                  if (!scope.found) {
                    log.warn('[enable-banking] No cash_accounts row for ledger account; skipping its reconciliation sweep', {
                      connectionId: connection.id,
                      ledgerAccount,
                    })
                    continue
                  }
                  const reconResult = await runReconciliation(supabase, companyId, user.id, {
                    dateFrom: sweepDateFrom,
                    dateTo: toDate,
                    accountNumber: scope.accountNumber,
                    currency: scope.currency,
                    cashAccountId: scope.cashAccountId,
                    includeUnassigned: scope.includeUnassigned,
                    // Unattended run: nobody reviews a dry-run first, so never
                    // commit low-confidence (fuzzy / date-range) matches.
                    confidenceThreshold: DEFAULT_UNATTENDED_CONFIDENCE_THRESHOLD,
                    // ...but don't DROP them either: the 0.75-0.89 band feeds
                    // the "Granska förslag" review surface.
                    persistSuggestions: true,
                  })
                  totalAutoMatched += reconResult.applied
                  if (reconResult.applied > 0 || reconResult.skippedBelowThreshold > 0) {
                    log.info('[enable-banking] Post-backfill reconciliation linked imported rows to existing verifikat', {
                      connectionId: connection.id,
                      accountNumber: scope.accountNumber,
                      applied: reconResult.applied,
                      skippedBelowThreshold: reconResult.skippedBelowThreshold,
                      total: reconResult.matches.length,
                    })
                  }
                } catch {
                  // Non-critical: rows stay unmatched for manual review.
                }
              }
            }

            // Mirror the balances the backfill just fetched into cash_accounts.
            // accounts_data is deliberately NOT re-written here (see below), so
            // without this the balances fetched during the initial sync would
            // reach neither store until the next scheduled sync.
            try {
              const { updateBalancesFromSync } = await import('@/lib/cash-accounts/service')
              await updateBalancesFromSync(
                supabase,
                companyId,
                connection.id,
                updatedAccounts.map((a) => ({
                  external_uid: a.uid,
                  balance: a.balance,
                  available_balance: a.available_balance,
                  balance_updated_at: a.balance_updated_at,
                })),
              )
            } catch (mirrorErr) {
              log.error('[enable-banking] Balance mirror after initial backfill failed', {
                connectionId: connection.id,
                error: mirrorErr instanceof Error ? mirrorErr.message : String(mirrorErr),
              })
            }

            const completedAt = new Date().toISOString()
            // Don't re-write accounts_data here: the first update already wrote it.
            // Including it again races with any concurrent writer (e.g. cron firing in
            // the sub-60s window) and would silently overwrite their changes.
            const { error: metaUpdateError } = await supabase
              .from('bank_connections')
              .update({
                last_synced_at: completedAt,
                initial_sync_completed_at: completedAt,
                initial_sync_requested_from: fromDate,
                initial_sync_returned_min_date: returnedMin,
                initial_sync_returned_max_date: returnedMax,
                initial_sync_lookback_days: initialLookbackDays,
              })
              .eq('id', connection.id)

            if (metaUpdateError) {
              // The sync itself succeeded (transactions are ingested) but we
              // couldn't persist that. Falsely reporting success would tell the
              // client "imported N transactions" while the DB still has
              // initial_sync_completed_at = NULL, causing the cron to re-run a
              // 90-day backfill next morning. Surface this as initial_sync_error
              // so the UI shows a "background sync needs retry" warning, and the
              // cron's gate (initial_sync_completed_at IS NULL) will self-heal.
              initialSyncError = `metadata_update_failed: ${metaUpdateError.message}`
              log.error('[enable-banking] Failed to persist initial_sync metadata after backfill', {
                connectionId: connection.id,
                error: metaUpdateError.message,
                userId: user.id,
                companyId,
              })
            } else {
              initialSyncSummary = {
                imported: totalImported,
                duplicates: totalDuplicates,
                auto_matched: totalAutoMatched,
                requested_from: fromDate,
                returned_min_date: returnedMin,
                returned_max_date: returnedMax,
              }

              log.info('[enable-banking] Inline initial backfill complete', {
                connectionId: connection.id,
                ...initialSyncSummary,
              })
            }
          } catch (syncError) {
            initialSyncError = syncError instanceof Error ? syncError.message : String(syncError)
            log.error('[enable-banking] Inline initial backfill failed: cron will retry', {
              connectionId: connection.id,
              error: initialSyncError,
              userId: user.id,
              companyId,
            })
          } finally {
            if (timeoutHandle) clearTimeout(timeoutHandle)
          }
        }

        return NextResponse.json({
          success: true,
          enabled_count: enabled_uids.length,
          total_count: existing.length,
          ...(initialSyncSummary ? { initial_sync: initialSyncSummary } : {}),
          ...(initialSyncError ? { initial_sync_error: initialSyncError } : {}),
        })
      },
    },
    {
      method: 'DELETE',
      path: '/disconnect',
      handler: async (request: Request, ctx?: ExtensionContext) => {
        const log = ctx?.log ?? console
        const supabase = ctx?.supabase ?? await (await import('@/lib/supabase/server')).createClient()
        const { data: { user } } = await supabase.auth.getUser()

        if (!user) {
          return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
        }

        if (!ctx?.companyId) {
          return NextResponse.json({ error: 'Company context required' }, { status: 400 })
        }
        const companyId = ctx.companyId

        const rl = await checkRateLimit({
          prefix: 'enable-banking:disconnect',
          identifier: user.id,
          ...RATE_LIMIT_DISCONNECT,
        })
        if (!rl.ok) return rl.response!

        const { connection_id } = await request.json()

        if (!connection_id) {
          return NextResponse.json({ error: 'connection_id is required' }, { status: 400 })
        }

        const { data: connection, error: findError } = await supabase
          .from('bank_connections')
          .select('id, session_id, status, bank_name')
          .eq('id', connection_id)
          .eq('company_id', companyId)
          .single()

        if (findError || !connection) {
          return NextResponse.json({ error: 'Connection not found' }, { status: 404 })
        }

        // Revoke the PSD2 consent only when no other company still depends on
        // it. Sessions are shared across a user's companies (see
        // lib/session-sharing.ts), so a blind revoke here would silently take
        // down a sibling company's bank feed: exactly the failure this feature
        // exists to remove. countLiveSiblings needs the service client because
        // RLS hides a sibling living in a company the user has since left, and
        // an unseen sibling would read as "safe to revoke".
        let sharedWithSiblings = false
        if (connection.session_id) {
          const { createServiceClient } = await import('@/lib/supabase/server')
          const serviceSupabase = await createServiceClient()
          const siblingCount = await countLiveSiblings(
            serviceSupabase,
            connection.session_id,
            connection.id,
          )
          sharedWithSiblings = siblingCount > 0
          if (sharedWithSiblings) {
            log.info('[enable-banking] Session still in use by other companies: skipping revoke', {
              connectionId: connection.id,
              siblingCount,
              userId: user.id,
              companyId,
            })
          }
        }

        if (connection.session_id && !sharedWithSiblings) {
          try {
            await deleteSession(connection.session_id)
          } catch (error) {
            // The revoke is best-effort: an expired or already-closed session
            // is the normal case here, and the disconnect continues either
            // way, so this is a warning and not an error.
            log.warn('[enable-banking] Failed to revoke PSD2 session (may be expired)', {
              message: error instanceof Error ? error.message : String(error),
              sessionId: connection.session_id,
              connectionId: connection_id,
              connectionStatus: connection.status,
              userId: user.id,
              companyId,
            })
          }
        }

        const { error: updateError } = await supabase
          .from('bank_connections')
          .update({ status: 'revoked', session_id: null })
          .eq('id', connection.id)

        if (updateError) {
          log.error('[enable-banking] Failed to mark connection revoked', {
            errorMessage: updateError.message,
            connectionId: connection.id,
            userId: user.id,
            companyId,
          })
          return NextResponse.json({ error: 'Failed to disconnect' }, { status: 500 })
        }

        // Release the connection's ledger claims by demoting its cash_accounts
        // rows to manual (bank_connection_id = null). The rows themselves stay:
        // transactions.cash_account_id and the ledger history reference them,
        // and upsertFromPsd2 promotes a manual holder in place on reconnect so
        // the same bank lands back on its original BAS account (e.g. 1930)
        // instead of overflowing to the next free slot.
        const { error: releaseError } = await supabase
          .from('cash_accounts')
          .update({ bank_connection_id: null })
          .eq('company_id', companyId)
          .eq('bank_connection_id', connection.id)

        if (releaseError) {
          // Don't fail the disconnect: the connection is already revoked, and
          // the allocator / collision guard also skip revoked connections, so
          // the orphaned rows self-heal on the next picker save.
          log.error('[enable-banking] Failed to release cash_accounts ledger claims on disconnect', {
            errorMessage: releaseError.message,
            connectionId: connection.id,
            userId: user.id,
            companyId,
          })
        }

        try {
          const emit = ctx?.emit ?? (await import('@/lib/events/bus')).eventBus.emit.bind((await import('@/lib/events/bus')).eventBus)
          await emit({
            type: 'bank_connection.revoked',
            payload: {
              connectionId: connection.id,
              bankName: (connection as { bank_name?: string | null }).bank_name ?? null,
              userId: user.id,
              companyId,
            },
          })
        } catch (emitError) {
          log.error('[enable-banking] Failed to emit revoke event', {
            errorMessage: emitError instanceof Error ? emitError.message : String(emitError),
            connectionId: connection.id,
            userId: user.id,
            companyId,
          })
        }

        return NextResponse.json({ success: true })
      },
    },
  ],

  eventHandlers: [],
}