/**
 * Parties, phase 0: shadow evaluation of the key pre-classifier against the
 * founder-labelled golden set.
 *
 * WHAT: every counterparty key from the books must be routed before entity
 * resolution: a real party, a category text, payroll, an adjustment, an
 * authority, a bank product, or an intermediary. This script scores two
 * candidate routers against the founder's labels on the same held-out rows:
 *   1. a deterministic rule set (prefixes, lexicon, dominant account), and
 *   2. the model behind getAiService().generateStructured, zero-shot and with
 *      twenty founder examples in the prompt.
 * Agreement is reported as strict label match plus, for the routing decision
 * that matters (party vs not), true-positive and true-negative rates, because
 * failures are rare and raw agreement flatters.
 *
 * SAFETY: read-only. Reads a gitignored JSONL, calls the AI service for the
 * model variants, writes a JSON report next to the input. It never opens a
 * database connection. The golden rows contain customer voucher text; keep
 * the report in dev_docs as well.
 *
 * Usage:
 *   npx tsx scripts/parties/eval-preclassifier.ts \
 *     --golden dev_docs/parties/golden/golden-2026-09-02.jsonl \
 *     --env .env.local [--out <report.json>] [--no-llm] [--batch 25]
 */
import { createHash } from 'node:crypto'
import { readFileSync, writeFileSync } from 'node:fs'
import { resolve } from 'node:path'
import { config as dotenv } from 'dotenv'
import { z } from 'zod'

const LABELS = ['party', 'category', 'payroll', 'adjustment', 'authority', 'bank', 'intermediary', 'unsure'] as const
type Label = (typeof LABELS)[number]

interface GoldenRow {
  id: number
  stratum: string
  k: string
  example: string
  n: number
  cos: number
  acct: string | null
  sek: number
  label: Label
}

function arg(name: string): string | undefined {
  const i = process.argv.indexOf(`--${name}`)
  return i >= 0 ? process.argv[i + 1] : undefined
}
const flag = (name: string) => process.argv.includes(`--${name}`)

const goldenPath = resolve(arg('golden') ?? 'dev_docs/parties/golden/golden-2026-09-02.jsonl')
const envPath = resolve(arg('env') ?? '.env.local')
const outPath = resolve(arg('out') ?? goldenPath.replace(/\.jsonl$/, '') + '.eval.json')
const batchSize = Number(arg('batch') ?? 25)
const runLlm = !flag('no-llm')

dotenv({ path: envPath })

// ── Golden set ──────────────────────────────────────────────────────────────

const rows: GoldenRow[] = readFileSync(goldenPath, 'utf8')
  .split('\n')
  .filter(Boolean)
  .map((line) => JSON.parse(line) as GoldenRow)
  .filter((r) => LABELS.includes(r.label))

// Deterministic split: the 20 rows with the lowest md5(key) are few-shot
// examples; every classifier is scored on the remaining rows only.
const md5 = (s: string) => createHash('md5').update(s).digest('hex')
const ordered = [...rows].sort((a, b) => md5(a.k).localeCompare(md5(b.k)))
const examples = ordered.slice(0, 20)
const exampleIds = new Set(examples.map((r) => r.id))
const evalRows = rows.filter((r) => !exampleIds.has(r.id))

// ── Deterministic router ────────────────────────────────────────────────────
// The rules live in lib/parties/classify.ts so the product and this
// evaluation share one implementation. --vocab is kept for the report's
// history: 'names' is what the library does; 'full' is no longer supported.
import { classifyKey } from '@/lib/parties/classify'
import { BAS_REFERENCE } from '@/lib/bookkeeping/bas-reference'

export function ruleLabel(row: { k: string; acct: string | null }): Label {
  return classifyKey({ key: row.k, acct: row.acct })
}

// ── Model router ────────────────────────────────────────────────────────────

const SYSTEM = `Du sorterar nycklar från svensk bokföring innan de går vidare till motpartsmatchning.
Varje nyckel är en normaliserad verifikationstext från importerade verifikat, med exempeltext, dominerande BAS-konto, antal verifikat och antal bolag.
Sätt exakt en etikett per nyckel:
- party: en riktig motpart som bolaget betalar eller fakturerar (leverantör, butik, tjänst, kommun som fakturerar). Prefix som "levfakt", "leverantörsfaktura från", "levbet" betyder alltid party.
- category: bara en kostnadstext utan motpart i sig ("inköp av varor", "banktjänster", "fika", "diesel", "hyra momspliktig").
- payroll: lön, förmån, utlägg eller ersättning till en person.
- adjustment: periodisering, kostnadsföring, omföring, lagerförändring, nedskrivning, rättelse, valutaomräkning.
- authority: myndighet som mottagare av en avgift eller skatt (Skatteverket, Transportstyrelsen).
- bank: bankavgifter och bankprodukter.
- intermediary: betalväg eller marknadsplats som inte är den egentliga motparten.
- unsure: går inte att avgöra från texten.
En nyckel som nämner en leverantör men bokförts på ett kategorikonto är ändå party: identiteten avgörs här, kontot kommer från bokföringen.
Svara med exakt de id som frågan innehåller, inga andra.`

const ResponseSchema = z.object({
  labels: z.array(z.object({ id: z.number().int(), label: z.enum(LABELS) })),
})

const jsonSchema = {
  type: 'object',
  properties: {
    labels: {
      type: 'array',
      items: {
        type: 'object',
        properties: { id: { type: 'integer' }, label: { type: 'string', enum: [...LABELS] } },
        required: ['id', 'label'],
        additionalProperties: false,
      },
    },
  },
  required: ['labels'],
  additionalProperties: false,
}

function basName(acct: string | null): string {
  if (!acct) return ''
  const hit = BAS_REFERENCE.find((a) => a.account_number === acct)
  return hit ? hit.account_name : ''
}

function describe(r: GoldenRow): string {
  return `id ${r.id}: nyckel "${r.k}" | exempel "${r.example}" | konto ${r.acct ?? '?'} ${basName(r.acct)} | ${r.n} verifikat | ${r.cos} bolag`
}

async function modelLabels(
  batch: GoldenRow[],
  fewShot: GoldenRow[] | null,
): Promise<{ labels: Map<number, Label>; usage: unknown; model: string }> {
  const { getAiService } = await import('@/lib/ai')
  const service = getAiService()
  const shots = fewShot
    ? `Så här har grundaren märkt tjugo andra nycklar; följ samma bedömning:\n${fewShot
        .map((r) => `${describe(r)} => ${r.label}`)
        .join('\n')}\n\n`
    : ''
  const prompt = `${shots}Märk följande ${batch.length} nycklar:\n${batch.map(describe).join('\n')}`
  let lastError: unknown
  for (let attempt = 0; attempt < 2; attempt++) {
    try {
      const result = await service.generateStructured({
        tier: 'assistant',
        system: SYSTEM,
        prompt,
        maxTokens: 4096,
        schema: { name: 'key_labels', description: 'One label per key id', jsonSchema },
      })
      const parsed = ResponseSchema.parse(result.value)
      const valid = new Set(batch.map((r) => r.id))
      const labels = new Map<number, Label>()
      for (const l of parsed.labels) if (valid.has(l.id) && !labels.has(l.id)) labels.set(l.id, l.label)
      return { labels, usage: result.usage, model: result.model }
    } catch (err) {
      lastError = err
    }
  }
  throw lastError
}

// ── Scoring ─────────────────────────────────────────────────────────────────

interface Score {
  n: number
  strict_agreement: number
  agreement_excluding_founder_unsure: number
  party_tpr: number
  party_tnr: number
  per_label: Record<string, { precision: number | null; recall: number | null; support: number }>
  confusions: { id: number; k: string; founder: Label; predicted: Label | null }[]
}

function score(pred: Map<number, Label | null>, subset: GoldenRow[]): Score {
  let strict = 0
  const decided = subset.filter((r) => r.label !== 'unsure')
  let strictDecided = 0
  let tp = 0, fn = 0, tn = 0, fp = 0
  const per: Record<string, { tp: number; fp: number; fn: number }> = {}
  for (const l of LABELS) per[l] = { tp: 0, fp: 0, fn: 0 }
  const confusions: Score['confusions'] = []
  for (const r of subset) {
    const p = pred.get(r.id) ?? null
    if (p === r.label) strict++
    else confusions.push({ id: r.id, k: r.k, founder: r.label, predicted: p })
    if (p) {
      if (p === r.label) per[p].tp++
      else {
        per[p].fp++
        per[r.label].fn++
      }
    } else per[r.label].fn++
  }
  for (const r of decided) {
    const p = pred.get(r.id) ?? null
    if (p === r.label) strictDecided++
    const isParty = r.label === 'party'
    const predParty = p === 'party'
    if (isParty && predParty) tp++
    else if (isParty && !predParty) fn++
    else if (!isParty && !predParty) tn++
    else fp++
  }
  const r4 = (x: number) => Math.round(x * 10000) / 10000
  const perLabel: Score['per_label'] = {}
  for (const l of LABELS) {
    const { tp: a, fp: b, fn: c } = per[l]
    perLabel[l] = {
      precision: a + b > 0 ? r4(a / (a + b)) : null,
      recall: a + c > 0 ? r4(a / (a + c)) : null,
      support: subset.filter((r) => r.label === l).length,
    }
  }
  return {
    n: subset.length,
    strict_agreement: r4(strict / subset.length),
    agreement_excluding_founder_unsure: r4(strictDecided / decided.length),
    party_tpr: r4(tp / Math.max(1, tp + fn)),
    party_tnr: r4(tn / Math.max(1, tn + fp)),
    per_label: perLabel,
    confusions,
  }
}

// ── Main ────────────────────────────────────────────────────────────────────

async function main() {
  console.log(`golden rows ${rows.length}, few-shot examples ${examples.length}, scored rows ${evalRows.length}`)

  const rulePred = new Map<number, Label | null>(evalRows.map((r) => [r.id, ruleLabel(r)]))
  const report: Record<string, unknown> = {
    golden: goldenPath,
    scored_rows: evalRows.length,
    example_ids: [...exampleIds],
    rules_v0: score(rulePred, evalRows),
  }

  if (runLlm) {
    for (const variant of ['zero_shot', 'few_shot'] as const) {
      const pred = new Map<number, Label | null>()
      const usages: unknown[] = []
      let model = ''
      for (let i = 0; i < evalRows.length; i += batchSize) {
        const batch = evalRows.slice(i, i + batchSize)
        const res = await modelLabels(batch, variant === 'few_shot' ? examples : null)
        for (const r of batch) pred.set(r.id, res.labels.get(r.id) ?? null)
        usages.push(res.usage)
        model = res.model
        console.log(`${variant}: batch ${i / batchSize + 1} done (${res.labels.size}/${batch.length} labelled)`)
      }
      report[`model_${variant}`] = { model, usages, ...score(pred, evalRows) }
    }
  }

  writeFileSync(outPath, JSON.stringify(report, null, 2))
  const line = (name: string, s: Score) =>
    `${name.padEnd(16)} strict ${s.strict_agreement}  excl-unsure ${s.agreement_excluding_founder_unsure}  party TPR ${s.party_tpr}  TNR ${s.party_tnr}  (n=${s.n})`
  console.log(line('rules_v0', report.rules_v0 as Score))
  if (runLlm) {
    console.log(line('model_zero_shot', report.model_zero_shot as Score))
    console.log(line('model_few_shot', report.model_few_shot as Score))
  }
  console.log(`report: ${outPath}`)
}

main().catch((err) => {
  console.error(err)
  process.exit(1)
})