import { describe, it, expect, vi, beforeEach } from 'vitest'
import { validateBalance, getSwedishLocalDate, createDraftEntry, reverseEntry } from '../engine'
import { BookkeepingDatabaseError, AccountsNotInChartError, CannotReverseStornoError } from '../errors'
import type { CreateJournalEntryLineInput, JournalEntryStatus } from '@/types'

// Mock Supabase client for createDraftEntry/reverseEntry tests
function createMockChain(overrides: Record<string, unknown> = {}) {
  const chain: Record<string, unknown> = {
    select: vi.fn().mockReturnThis(),
    single: vi.fn().mockResolvedValue({ data: overrides.singleData ?? null, error: overrides.singleError ?? null }),
    eq: vi.fn().mockReturnThis(),
    insert: vi.fn().mockReturnThis(),
    update: vi.fn().mockReturnThis(),
    delete: vi.fn().mockReturnThis(),
    in: vi.fn().mockReturnThis(),
    lte: vi.fn().mockReturnThis(),
    gte: vi.fn().mockReturnThis(),
    order: vi.fn().mockReturnThis(),
    limit: vi.fn().mockReturnThis(),
  }
  return chain
}

// Mock event bus
vi.mock('@/lib/events', () => ({
  eventBus: { emit: vi.fn().mockResolvedValue([]) },
}))

// Mock the on-demand BAS backfill, default: nothing seedable. Individual
// tests override per scenario.
const mockBackfill = vi.fn().mockResolvedValue([])
vi.mock('@/lib/bookkeeping/account-backfill', () => ({
  backfillStandardBASAccounts: (...args: unknown[]) => mockBackfill(...args),
}))

describe('validateBalance', () => {
  it('balanced entry (debit == credit) → valid: true', () => {
    const lines: CreateJournalEntryLineInput[] = [
      { account_number: '1930', debit_amount: 1000, credit_amount: 0 },
      { account_number: '3001', debit_amount: 0, credit_amount: 1000 },
    ]

    const result = validateBalance(lines)
    expect(result.valid).toBe(true)
    expect(result.totalDebit).toBe(1000)
    expect(result.totalCredit).toBe(1000)
  })

  it('unbalanced entry → valid: false', () => {
    const lines: CreateJournalEntryLineInput[] = [
      { account_number: '1930', debit_amount: 1000, credit_amount: 0 },
      { account_number: '3001', debit_amount: 0, credit_amount: 500 },
    ]

    const result = validateBalance(lines)
    expect(result.valid).toBe(false)
    expect(result.totalDebit).toBe(1000)
    expect(result.totalCredit).toBe(500)
  })

  it('zero amounts → valid: false (roundedDebit must be > 0)', () => {
    const lines: CreateJournalEntryLineInput[] = [
      { account_number: '1930', debit_amount: 0, credit_amount: 0 },
      { account_number: '3001', debit_amount: 0, credit_amount: 0 },
    ]

    const result = validateBalance(lines)
    expect(result.valid).toBe(false)
    expect(result.totalDebit).toBe(0)
    expect(result.totalCredit).toBe(0)
  })

  it('floating point edge case (33.33 + 33.33 + 33.34) → valid: true', () => {
    const lines: CreateJournalEntryLineInput[] = [
      { account_number: '1930', debit_amount: 33.33, credit_amount: 0 },
      { account_number: '1930', debit_amount: 33.33, credit_amount: 0 },
      { account_number: '1930', debit_amount: 33.34, credit_amount: 0 },
      { account_number: '3001', debit_amount: 0, credit_amount: 100 },
    ]

    const result = validateBalance(lines)
    expect(result.valid).toBe(true)
    expect(result.totalDebit).toBe(100)
    expect(result.totalCredit).toBe(100)
  })

  it('single line (only debit, no credit) → valid: false', () => {
    const lines: CreateJournalEntryLineInput[] = [
      { account_number: '1930', debit_amount: 500, credit_amount: 0 },
    ]

    const result = validateBalance(lines)
    expect(result.valid).toBe(false)
  })
})

describe('getSwedishLocalDate', () => {
  it('returns a date string in YYYY-MM-DD format', () => {
    const date = getSwedishLocalDate()
    expect(date).toMatch(/^\d{4}-\d{2}-\d{2}$/)
  })

  it('returns a valid date', () => {
    const date = getSwedishLocalDate()
    const parsed = new Date(date)
    expect(parsed.toString()).not.toBe('Invalid Date')
  })
})

describe('createDraftEntry: cancelled status on line-insert failure', () => {
  it('sets status to cancelled (not delete) when line insert fails', async () => {
    const updateMock = vi.fn().mockReturnValue({ eq: vi.fn().mockResolvedValue({ error: null }) })

    const supabase = {
      from: vi.fn().mockImplementation((table: string) => {
        if (table === 'fiscal_periods') {
          return {
            select: vi.fn().mockReturnValue({
              eq: vi.fn().mockReturnValue({
                eq: vi.fn().mockReturnValue({
                  single: vi.fn().mockResolvedValue({
                    data: { name: 'FY 2024', period_start: '2024-01-01', period_end: '2024-12-31' },
                    error: null,
                  }),
                }),
              }),
            }),
          }
        }
        if (table === 'journal_entries') {
          return {
            insert: vi.fn().mockReturnValue({
              select: vi.fn().mockReturnValue({
                single: vi.fn().mockResolvedValue({
                  data: { id: 'entry-1', user_id: 'user-1', status: 'draft' as JournalEntryStatus },
                  error: null,
                }),
              }),
            }),
            update: updateMock,
            delete: vi.fn().mockReturnValue({ eq: vi.fn().mockResolvedValue({ error: null }) }),
          }
        }
        if (table === 'journal_entry_lines') {
          return {
            insert: vi.fn().mockResolvedValue({ error: { message: 'Line insert failed' } }),
          }
        }
        if (table === 'chart_of_accounts') {
          return {
            select: vi.fn().mockReturnValue({
              eq: vi.fn().mockReturnValue({
                in: vi.fn().mockReturnValue({
                  eq: vi.fn().mockResolvedValue({
                    data: [{ account_number: '1930', id: 'acc-1' }, { account_number: '3001', id: 'acc-2' }],
                    error: null,
                  }),
                }),
              }),
            }),
          }
        }
        return createMockChain()
      }),
    }

    await expect(
      createDraftEntry(supabase as never, 'company-1', 'user-1', {
        fiscal_period_id: 'period-1',
        entry_date: '2024-01-01',
        description: 'Test',
        source_type: 'manual',
        lines: [
          { account_number: '1930', debit_amount: 1000, credit_amount: 0 },
          { account_number: '3001', debit_amount: 0, credit_amount: 1000 },
        ],
      })
    ).rejects.toThrow(BookkeepingDatabaseError)

    // Should call update with cancelled status, NOT delete
    expect(updateMock).toHaveBeenCalledWith({ status: 'cancelled' })
  })
})

describe('createDraftEntry: date/period cross-validation', () => {
  function buildSupabase(periodData: { name: string; period_start: string; period_end: string } | null) {
    return {
      from: vi.fn().mockImplementation((table: string) => {
        if (table === 'fiscal_periods') {
          return {
            select: vi.fn().mockReturnValue({
              eq: vi.fn().mockReturnValue({
                eq: vi.fn().mockReturnValue({
                  single: vi.fn().mockResolvedValue({
                    data: periodData,
                    error: periodData ? null : { message: 'Not found' },
                  }),
                }),
              }),
            }),
          }
        }
        if (table === 'chart_of_accounts') {
          return {
            select: vi.fn().mockReturnValue({
              eq: vi.fn().mockReturnValue({
                in: vi.fn().mockReturnValue({
                  eq: vi.fn().mockResolvedValue({
                    data: [{ account_number: '1930', id: 'acc-1' }, { account_number: '3001', id: 'acc-2' }],
                    error: null,
                  }),
                }),
              }),
            }),
          }
        }
        if (table === 'journal_entries') {
          return {
            insert: vi.fn().mockReturnValue({
              select: vi.fn().mockReturnValue({
                single: vi.fn().mockResolvedValue({
                  data: { id: 'entry-1', status: 'draft' },
                  error: null,
                }),
              }),
            }),
            select: vi.fn().mockReturnValue({
              eq: vi.fn().mockReturnValue({
                single: vi.fn().mockResolvedValue({
                  data: { id: 'entry-1', status: 'draft', lines: [] },
                  error: null,
                }),
              }),
            }),
          }
        }
        if (table === 'journal_entry_lines') {
          return {
            insert: vi.fn().mockResolvedValue({ error: null }),
          }
        }
        return createMockChain()
      }),
    }
  }

  const validLines = [
    { account_number: '1930', debit_amount: 1000, credit_amount: 0 },
    { account_number: '3001', debit_amount: 0, credit_amount: 1000 },
  ]

  it('rejects entry date before period start', async () => {
    const supabase = buildSupabase({
      name: 'FY 2025',
      period_start: '2025-01-01',
      period_end: '2025-12-31',
    })

    await expect(
      createDraftEntry(supabase as never, 'company-1', 'user-1', {
        fiscal_period_id: 'period-1',
        entry_date: '2024-12-15',
        description: 'Test',
        source_type: 'manual',
        lines: validLines,
      })
    ).rejects.toThrow('Entry date 2024-12-15 is outside fiscal period "FY 2025"')
  })

  it('rejects entry date after period end', async () => {
    const supabase = buildSupabase({
      name: 'FY 2025',
      period_start: '2025-01-01',
      period_end: '2025-12-31',
    })

    await expect(
      createDraftEntry(supabase as never, 'company-1', 'user-1', {
        fiscal_period_id: 'period-1',
        entry_date: '2026-01-15',
        description: 'Test',
        source_type: 'manual',
        lines: validLines,
      })
    ).rejects.toThrow('Entry date 2026-01-15 is outside fiscal period "FY 2025"')
  })

  it('accepts entry date within period', async () => {
    const supabase = buildSupabase({
      name: 'FY 2025',
      period_start: '2025-01-01',
      period_end: '2025-12-31',
    })

    const result = await createDraftEntry(supabase as never, 'company-1', 'user-1', {
      fiscal_period_id: 'period-1',
      entry_date: '2025-06-15',
      description: 'Test',
      source_type: 'manual',
      lines: validLines,
    })

    expect(result).toBeDefined()
    expect(result.id).toBe('entry-1')
  })

  it('accepts entry date on period start boundary', async () => {
    const supabase = buildSupabase({
      name: 'FY 2025',
      period_start: '2025-01-01',
      period_end: '2025-12-31',
    })

    const result = await createDraftEntry(supabase as never, 'company-1', 'user-1', {
      fiscal_period_id: 'period-1',
      entry_date: '2025-01-01',
      description: 'Test',
      source_type: 'manual',
      lines: validLines,
    })

    expect(result).toBeDefined()
  })

  it('accepts entry date on period end boundary', async () => {
    const supabase = buildSupabase({
      name: 'FY 2025',
      period_start: '2025-01-01',
      period_end: '2025-12-31',
    })

    const result = await createDraftEntry(supabase as never, 'company-1', 'user-1', {
      fiscal_period_id: 'period-1',
      entry_date: '2025-12-31',
      description: 'Test',
      source_type: 'manual',
      lines: validLines,
    })

    expect(result).toBeDefined()
  })

  it('throws when fiscal period not found', async () => {
    const supabase = buildSupabase(null)

    await expect(
      createDraftEntry(supabase as never, 'company-1', 'user-1', {
        fiscal_period_id: 'nonexistent',
        entry_date: '2025-06-15',
        description: 'Test',
        source_type: 'manual',
        lines: validLines,
      })
    ).rejects.toThrow('Fiscal period not found')
  })
})

describe('JournalEntryStatus type includes cancelled', () => {
  it('cancelled is a valid JournalEntryStatus value', () => {
    const status: JournalEntryStatus = 'cancelled'
    expect(['draft', 'posted', 'reversed', 'cancelled']).toContain(status)
  })
})

describe('createDraftEntry: on-demand BAS account backfill', () => {
  // Engine seeds standard BAS accounts missing from the chart instead of
  // failing (June 2026 incident: 3740 öresavrundning missing → payment
  // voucher dead end). Non-seedable numbers still throw.

  beforeEach(() => {
    mockBackfill.mockClear()
  })

  function buildSupabase(opts: { chartByCall: { account_number: string; id: string }[][] }) {
    let chartCall = 0
    return {
      from: vi.fn().mockImplementation((table: string) => {
        if (table === 'fiscal_periods') {
          return {
            select: vi.fn().mockReturnValue({
              eq: vi.fn().mockReturnValue({
                eq: vi.fn().mockReturnValue({
                  single: vi.fn().mockResolvedValue({
                    data: { name: 'FY 2026', period_start: '2026-01-01', period_end: '2026-12-31' },
                    error: null,
                  }),
                }),
              }),
            }),
          }
        }
        if (table === 'chart_of_accounts') {
          const result = opts.chartByCall[Math.min(chartCall++, opts.chartByCall.length - 1)]
          return {
            select: vi.fn().mockReturnValue({
              eq: vi.fn().mockReturnValue({
                in: vi.fn().mockReturnValue({
                  eq: vi.fn().mockResolvedValue({ data: result, error: null }),
                }),
              }),
            }),
          }
        }
        if (table === 'journal_entries') {
          return {
            insert: vi.fn().mockReturnValue({
              select: vi.fn().mockReturnValue({
                single: vi.fn().mockResolvedValue({
                  data: { id: 'entry-1', status: 'draft' },
                  error: null,
                }),
              }),
            }),
            select: vi.fn().mockReturnValue({
              eq: vi.fn().mockReturnValue({
                single: vi.fn().mockResolvedValue({
                  data: { id: 'entry-1', status: 'draft', lines: [] },
                  error: null,
                }),
              }),
            }),
          }
        }
        if (table === 'journal_entry_lines') {
          return { insert: vi.fn().mockResolvedValue({ error: null }) }
        }
        return createMockChain()
      }),
    }
  }

  const LINES: CreateJournalEntryLineInput[] = [
    { account_number: '2440', debit_amount: 11231.25, credit_amount: 0 },
    { account_number: '1930', debit_amount: 0, credit_amount: 11231 },
    { account_number: '3740', debit_amount: 0, credit_amount: 0.25 },
  ]

  it('seeds a missing standard BAS account and proceeds', async () => {
    mockBackfill.mockResolvedValue(['3740'])
    const supabase = buildSupabase({
      chartByCall: [
        // First resolution: 3740 missing
        [{ account_number: '2440', id: 'acc-1' }, { account_number: '1930', id: 'acc-2' }],
        // Re-resolution after backfill: all present
        [
          { account_number: '2440', id: 'acc-1' },
          { account_number: '1930', id: 'acc-2' },
          { account_number: '3740', id: 'acc-3' },
        ],
      ],
    })

    const entry = await createDraftEntry(supabase as never, 'company-1', 'user-1', {
      fiscal_period_id: 'period-1',
      entry_date: '2026-06-08',
      description: 'Utbetalning leverantörsfaktura',
      source_type: 'supplier_invoice_paid',
      lines: LINES,
    })

    expect(entry.id).toBe('entry-1')
    expect(mockBackfill).toHaveBeenCalledWith(expect.anything(), 'company-1', 'user-1', ['3740'])
  })

  it('still throws AccountsNotInChartError when the account is not seedable', async () => {
    mockBackfill.mockResolvedValue([])
    const supabase = buildSupabase({
      chartByCall: [
        [{ account_number: '2440', id: 'acc-1' }, { account_number: '1930', id: 'acc-2' }],
      ],
    })

    await expect(
      createDraftEntry(supabase as never, 'company-1', 'user-1', {
        fiscal_period_id: 'period-1',
        entry_date: '2026-06-08',
        description: 'Utbetalning leverantörsfaktura',
        source_type: 'supplier_invoice_paid',
        lines: LINES,
      })
    ).rejects.toThrow(AccountsNotInChartError)

    expect(mockBackfill).toHaveBeenCalledTimes(1)
  })
})

describe('reverseEntry: entry_date defaults to original entry date', () => {
  it('uses original entry_date when no reversalDate is provided', async () => {
    const original = {
      id: 'entry-1',
      company_id: 'company-1',
      status: 'posted',
      fiscal_period_id: 'period-1',
      voucher_series: 'A',
      voucher_number: 3,
      entry_date: '2024-11-15',
      description: 'Hyra november',
      source_type: 'manual',
      source_id: null,
      lines: [
        { account_number: '5010', debit_amount: 10000, credit_amount: 0 },
        { account_number: '1930', debit_amount: 0, credit_amount: 10000 },
      ],
    }
    const reversal = { id: 'reversal-1', reverses_id: 'entry-1' }

    let jeCall = 0
    const jeResults = [
      { data: original, error: null },
      { data: reversal, error: null },
      { data: null, error: null },
      { data: [{ id: 'entry-1' }], error: null },
      { data: { ...reversal, lines: [] }, error: null },
    ]

    let insertedEntryDate: string | undefined
    function jeBuilder() {
      const b: Record<string, unknown> = {}
      for (const m of ['select', 'eq', 'in', 'update']) b[m] = vi.fn().mockReturnValue(b)
      b.insert = vi.fn().mockImplementation((payload: unknown) => {
        const p = payload as Record<string, unknown>
        if (p.entry_date !== undefined) insertedEntryDate = p.entry_date as string
        return b
      })
      b.single = vi.fn().mockImplementation(async () => jeResults[jeCall++])
      b.then = (resolve: (v: unknown) => void) => resolve(jeResults[jeCall++])
      return b
    }

    const supabase = {
      rpc: vi.fn().mockResolvedValue({ data: 4, error: null }),
      from: vi.fn().mockImplementation((table: string) => {
        if (table === 'journal_entries') return jeBuilder()
        if (table === 'chart_of_accounts') {
          const b: Record<string, unknown> = {}
          for (const m of ['select', 'eq', 'in']) b[m] = vi.fn().mockReturnValue(b)
          b.then = (resolve: (v: unknown) => void) =>
            resolve({ data: [{ id: 'acc-5010', account_number: '5010' }, { id: 'acc-1930', account_number: '1930' }], error: null })
          return b
        }
        if (table === 'journal_entry_lines') return { insert: vi.fn().mockResolvedValue({ error: null }) }
        return createMockChain()
      }),
    }

    await reverseEntry(supabase as never, 'company-1', 'user-1', 'entry-1')

    expect(insertedEntryDate).toBe('2024-11-15')
  })

  it('uses explicit reversalDate when provided', async () => {
    const original = {
      id: 'entry-1',
      company_id: 'company-1',
      status: 'posted',
      fiscal_period_id: 'period-1',
      voucher_series: 'A',
      voucher_number: 3,
      entry_date: '2024-11-15',
      description: 'Hyra november',
      source_type: 'manual',
      source_id: null,
      lines: [
        { account_number: '5010', debit_amount: 10000, credit_amount: 0 },
        { account_number: '1930', debit_amount: 0, credit_amount: 10000 },
      ],
    }
    const reversal = { id: 'reversal-1', reverses_id: 'entry-1' }

    let jeCall = 0
    const jeResults = [
      { data: original, error: null },
      { data: reversal, error: null },
      { data: null, error: null },
      { data: [{ id: 'entry-1' }], error: null },
      { data: { ...reversal, lines: [] }, error: null },
    ]

    let insertedEntryDate: string | undefined
    function jeBuilder() {
      const b: Record<string, unknown> = {}
      for (const m of ['select', 'eq', 'in', 'update']) b[m] = vi.fn().mockReturnValue(b)
      b.insert = vi.fn().mockImplementation((payload: unknown) => {
        const p = payload as Record<string, unknown>
        if (p.entry_date !== undefined) insertedEntryDate = p.entry_date as string
        return b
      })
      b.single = vi.fn().mockImplementation(async () => jeResults[jeCall++])
      b.then = (resolve: (v: unknown) => void) => resolve(jeResults[jeCall++])
      return b
    }

    const supabase = {
      rpc: vi.fn().mockResolvedValue({ data: 4, error: null }),
      from: vi.fn().mockImplementation((table: string) => {
        if (table === 'journal_entries') return jeBuilder()
        if (table === 'chart_of_accounts') {
          const b: Record<string, unknown> = {}
          for (const m of ['select', 'eq', 'in']) b[m] = vi.fn().mockReturnValue(b)
          b.then = (resolve: (v: unknown) => void) =>
            resolve({ data: [{ id: 'acc-5010', account_number: '5010' }, { id: 'acc-1930', account_number: '1930' }], error: null })
          return b
        }
        if (table === 'journal_entry_lines') return { insert: vi.fn().mockResolvedValue({ error: null }) }
        return createMockChain()
      }),
    }

    await reverseEntry(supabase as never, 'company-1', 'user-1', 'entry-1', '2025-01-01')

    expect(insertedEntryDate).toBe('2025-01-01')
  })
})

describe('reverseEntry: storno guard', () => {
  // BFL 5 kap 5§: a storno-of-a-storno makes the original verifikat's
  // cancellation chain ambiguous, so stornos are never reversible. A
  // correction entry, by contrast, is a regular live verifikation (it can be
  // a duplicate of an affärshändelse booked by another verifikat) and must
  // stay reversible: the guard covers 'storno' only.
  function supabaseReturningOriginal(original: Record<string, unknown>) {
    return {
      rpc: vi.fn(),
      from: vi.fn().mockImplementation((table: string) => {
        if (table === 'journal_entries') {
          const b: Record<string, unknown> = {}
          for (const m of ['select', 'eq', 'in', 'update', 'insert']) b[m] = vi.fn().mockReturnValue(b)
          b.single = vi.fn().mockResolvedValue({ data: original, error: null })
          return b
        }
        return createMockChain()
      }),
    }
  }

  it(`throws CannotReverseStornoError for source_type 'storno'`, async () => {
    const original = {
      id: 'entry-1',
      company_id: 'company-1',
      status: 'posted',
      fiscal_period_id: 'period-1',
      voucher_series: 'A',
      voucher_number: 3,
      entry_date: '2024-11-15',
      description: 'Makulering: Hyra november',
      source_type: 'storno',
      source_id: null,
      lines: [
        { account_number: '1930', debit_amount: 10000, credit_amount: 0 },
        { account_number: '5010', debit_amount: 0, credit_amount: 10000 },
      ],
    }
    const supabase = supabaseReturningOriginal(original)

    await expect(
      reverseEntry(supabase as never, 'company-1', 'user-1', 'entry-1'),
    ).rejects.toBeInstanceOf(CannotReverseStornoError)

    // No reversal was written: the guard fires before any voucher number is drawn.
    expect(supabase.rpc).not.toHaveBeenCalled()
  })

  it(`reverses a correction entry like any regular verifikat`, async () => {
    // A rättelseverifikation that turned out to duplicate another booking
    // (support case 2026-07-26) is nullified with a normal storno; the
    // correction_of_id link keeps the chain traceable.
    const original = {
      id: 'entry-1',
      company_id: 'company-1',
      status: 'posted',
      fiscal_period_id: 'period-1',
      voucher_series: 'A',
      voucher_number: 3,
      entry_date: '2024-11-15',
      description: 'Rättelse: Hyra november',
      source_type: 'correction',
      source_id: null,
      correction_of_id: 'entry-0',
      lines: [
        { account_number: '5010', debit_amount: 10000, credit_amount: 0 },
        { account_number: '1930', debit_amount: 0, credit_amount: 10000 },
      ],
    }
    const reversal = { id: 'reversal-1', reverses_id: 'entry-1' }

    let jeCall = 0
    const jeResults = [
      { data: original, error: null },
      { data: reversal, error: null },
      { data: null, error: null },
      { data: [{ id: 'entry-1' }], error: null },
      { data: { ...reversal, lines: [] }, error: null },
    ]

    let insertedEntry: Record<string, unknown> | undefined
    function jeBuilder() {
      const b: Record<string, unknown> = {}
      for (const m of ['select', 'eq', 'in', 'update']) b[m] = vi.fn().mockReturnValue(b)
      b.insert = vi.fn().mockImplementation((payload: unknown) => {
        insertedEntry = payload as Record<string, unknown>
        return b
      })
      b.single = vi.fn().mockImplementation(async () => jeResults[jeCall++])
      b.then = (resolve: (v: unknown) => void) => resolve(jeResults[jeCall++])
      return b
    }

    const supabase = {
      rpc: vi.fn().mockResolvedValue({ data: 4, error: null }),
      from: vi.fn().mockImplementation((table: string) => {
        if (table === 'journal_entries') return jeBuilder()
        if (table === 'chart_of_accounts') {
          const b: Record<string, unknown> = {}
          for (const m of ['select', 'eq', 'in']) b[m] = vi.fn().mockReturnValue(b)
          b.then = (resolve: (v: unknown) => void) =>
            resolve({ data: [{ id: 'acc-5010', account_number: '5010' }, { id: 'acc-1930', account_number: '1930' }], error: null })
          return b
        }
        if (table === 'journal_entry_lines') return { insert: vi.fn().mockResolvedValue({ error: null }) }
        return createMockChain()
      }),
    }

    await reverseEntry(supabase as never, 'company-1', 'user-1', 'entry-1')

    expect(insertedEntry).toBeDefined()
    expect(insertedEntry!.source_type).toBe('storno')
    expect(insertedEntry!.reverses_id).toBe('entry-1')
    expect(insertedEntry!.description).toBe('Makulering: Rättelse: Hyra november')
  })
})

describe('reverseEntry: bank transaction unlink', () => {
  // After a reversal the booked bank transaction must return to "Att bokföra"
  // (journal_entry_id cleared) so the user can book it again. The agent paths
  // in lib/pending-operations/commit.ts did this manually; the engine now owns
  // it so the dashboard reverse route behaves the same.
  it('clears transactions.journal_entry_id for rows booked by the reversed entry', async () => {
    const original = {
      id: 'entry-1',
      company_id: 'company-1',
      status: 'posted',
      fiscal_period_id: 'period-1',
      voucher_series: 'A',
      voucher_number: 7,
      entry_date: '2026-02-02',
      description: 'ALMI AB - Innovationslån',
      source_type: 'manual',
      source_id: null,
      lines: [
        { account_number: '1930', debit_amount: 1000, credit_amount: 0 },
        { account_number: '2350', debit_amount: 0, credit_amount: 1000 },
      ],
    }
    const reversal = { id: 'reversal-1', reverses_id: 'entry-1', source_type: 'storno' }

    let jeCall = 0
    const jeResults = [
      { data: original, error: null },                   // fetch original (.single)
      { data: reversal, error: null },                   // insert reversal (.single)
      { data: null, error: null },                       // post reversal (await)
      { data: [{ id: 'entry-1' }], error: null },        // CAS original → reversed (await)
      { data: { ...reversal, lines: [] }, error: null }, // fetch complete (.single)
    ]
    function jeBuilder() {
      const b: Record<string, unknown> = {}
      for (const m of ['select', 'eq', 'in', 'update', 'insert']) {
        b[m] = vi.fn().mockReturnValue(b)
      }
      b.single = vi.fn().mockImplementation(async () => jeResults[jeCall++])
      b.then = (resolve: (v: unknown) => void) => resolve(jeResults[jeCall++])
      return b
    }

    const txUpdatePayloads: unknown[] = []
    const txFilters: Record<string, unknown> = {}

    const supabase = {
      rpc: vi.fn().mockResolvedValue({ data: 8, error: null }),
      from: vi.fn().mockImplementation((table: string) => {
        if (table === 'journal_entries') return jeBuilder()
        if (table === 'chart_of_accounts') {
          const b: Record<string, unknown> = {}
          for (const m of ['select', 'eq', 'in']) b[m] = vi.fn().mockReturnValue(b)
          b.then = (resolve: (v: unknown) => void) =>
            resolve({
              data: [
                { id: 'acc-1930', account_number: '1930' },
                { id: 'acc-2350', account_number: '2350' },
              ],
              error: null,
            })
          return b
        }
        if (table === 'journal_entry_lines') {
          return { insert: vi.fn().mockResolvedValue({ error: null }) }
        }
        if (table === 'transactions') {
          const b: Record<string, unknown> = {}
          b.update = vi.fn().mockImplementation((payload: unknown) => {
            txUpdatePayloads.push(payload)
            return b
          })
          b.eq = vi.fn().mockImplementation((col: string, val: unknown) => {
            txFilters[col] = val
            return b
          })
          b.then = (resolve: (v: unknown) => void) => resolve({ error: null })
          return b
        }
        return createMockChain()
      }),
    }

    const result = await reverseEntry(supabase as never, 'company-1', 'user-1', 'entry-1')

    expect(result.id).toBe('reversal-1')
    expect(txUpdatePayloads).toEqual([{ journal_entry_id: null }])
    expect(txFilters).toMatchObject({ company_id: 'company-1', journal_entry_id: 'entry-1' })
  })
})

describe('reverseEntry: opening balance unlink', () => {
  // Reversing a period's IB verifikat must also drop the period's pointer to
  // it. getOpeningBalances() reads the linked entry's lines with no status
  // filter, so a still-linked cancelled IB keeps showing in the Balansrapport,
  // and year-end refuses to run while the pointer is non-null: the storno its
  // own error message asks for could never satisfy it. See engine.pg.test.ts
  // for why the flag must fall before the pointer.
  function buildSupabase(sourceType: string) {
    const original = {
      id: 'entry-1',
      company_id: 'company-1',
      status: 'posted',
      fiscal_period_id: 'period-1',
      voucher_series: 'A',
      voucher_number: 1,
      entry_date: '2026-01-01',
      description: 'Ingående balanser från SIE-import',
      source_type: sourceType,
      source_id: null,
      lines: [
        { account_number: '1930', debit_amount: 1000, credit_amount: 0 },
        { account_number: '2350', debit_amount: 0, credit_amount: 1000 },
      ],
    }
    const reversal = { id: 'reversal-1', reverses_id: 'entry-1', source_type: 'storno' }

    let jeCall = 0
    const jeResults = [
      { data: original, error: null },
      { data: reversal, error: null },
      { data: null, error: null },
      { data: [{ id: 'entry-1' }], error: null },
      { data: { ...reversal, lines: [] }, error: null },
    ]
    function jeBuilder() {
      const b: Record<string, unknown> = {}
      for (const m of ['select', 'eq', 'in', 'update', 'insert']) {
        b[m] = vi.fn().mockReturnValue(b)
      }
      b.single = vi.fn().mockImplementation(async () => jeResults[jeCall++])
      b.then = (resolve: (v: unknown) => void) => resolve(jeResults[jeCall++])
      return b
    }

    const fpUpdates: unknown[] = []
    const fpFilters: Record<string, unknown>[] = []

    const supabase = {
      rpc: vi.fn().mockResolvedValue({ data: 2, error: null }),
      from: vi.fn().mockImplementation((table: string) => {
        if (table === 'journal_entries') return jeBuilder()
        if (table === 'chart_of_accounts') {
          const b: Record<string, unknown> = {}
          for (const m of ['select', 'eq', 'in']) b[m] = vi.fn().mockReturnValue(b)
          b.then = (resolve: (v: unknown) => void) =>
            resolve({
              data: [
                { id: 'acc-1930', account_number: '1930' },
                { id: 'acc-2350', account_number: '2350' },
              ],
              error: null,
            })
          return b
        }
        if (table === 'journal_entry_lines') {
          return { insert: vi.fn().mockResolvedValue({ error: null }) }
        }
        if (table === 'fiscal_periods') {
          const b: Record<string, unknown> = {}
          const filters: Record<string, unknown> = {}
          b.update = vi.fn().mockImplementation((payload: unknown) => {
            fpUpdates.push(payload)
            fpFilters.push(filters)
            return b
          })
          b.eq = vi.fn().mockImplementation((col: string, val: unknown) => {
            filters[col] = val
            return b
          })
          b.then = (resolve: (v: unknown) => void) => resolve({ error: null })
          return b
        }
        if (table === 'transactions') {
          const b: Record<string, unknown> = {}
          for (const m of ['update', 'eq']) b[m] = vi.fn().mockReturnValue(b)
          b.then = (resolve: (v: unknown) => void) => resolve({ error: null })
          return b
        }
        return createMockChain()
      }),
    }

    return { supabase, fpUpdates, fpFilters }
  }

  it('clears the period IB link, flag before pointer, for an opening_balance entry', async () => {
    const { supabase, fpUpdates, fpFilters } = buildSupabase('opening_balance')

    const result = await reverseEntry(supabase as never, 'company-1', 'user-1', 'entry-1')

    expect(result.id).toBe('reversal-1')
    // Order matters: enforce_opening_balance_immutability rejects the pointer
    // write while opening_balances_set is still true.
    expect(fpUpdates).toEqual([{ opening_balances_set: false }, { opening_balance_entry_id: null }])
    // Scoped to this entry, so a period pointing elsewhere is untouched.
    for (const f of fpFilters) {
      expect(f).toMatchObject({ company_id: 'company-1', opening_balance_entry_id: 'entry-1' })
    }
  })

  it('leaves fiscal_periods untouched for a non-opening_balance entry', async () => {
    const { supabase, fpUpdates } = buildSupabase('manual')

    await reverseEntry(supabase as never, 'company-1', 'user-1', 'entry-1')

    expect(fpUpdates).toEqual([])
  })
})