Feat/change fiscal year (#300)

* feat: enhance journal entry handling with follow-up entries and related RPC

* fix: improve validation for journal entry lines to ensure proper submission criteria

* fix: enhance OAuth error handling and user feedback in Arcim migration process

* fix: add OAuth error translation for user-friendly feedback in Fortnox integration

* feat: add fiscal period editor and related API for entry count

* feat: enforce calendar year for individual firms and improve fiscal period validation

app/api/bookkeeping/fiscal-periods/[id]/entry-count/__tests__/route.test.ts

@@ -0,0 +1,73 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+
+vi.mock('@/lib/supabase/server', () => ({
+  createClient: vi.fn(),
+}))
+vi.mock('@/lib/company/context', () => ({
+  requireCompanyId: vi.fn().mockResolvedValue('company-1'),
+}))
+
+import { createClient } from '@/lib/supabase/server'
+import { createQueuedMockSupabase } from '@/tests/helpers'
+import { GET } from '../route'
+
+function mkReq() {
+  return new Request('http://localhost/api/bookkeeping/fiscal-periods/period-1/entry-count')
+}
+
+function mkParams(id = 'period-1') {
+  return { params: Promise.resolve({ id }) }
+}
+
+describe('GET /api/bookkeeping/fiscal-periods/[id]/entry-count', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('returns 401 when unauthenticated', async () => {
+    const { supabase } = createQueuedMockSupabase()
+    supabase.auth.getUser.mockResolvedValue({ data: { user: null } })
+    vi.mocked(createClient).mockResolvedValue(supabase as never)
+
+    const res = await GET(mkReq(), mkParams())
+    expect(res.status).toBe(401)
+  })
+
+  it('returns 404 when period does not belong to company', async () => {
+    const { supabase, enqueue } = createQueuedMockSupabase()
+    supabase.auth.getUser.mockResolvedValue({ data: { user: { id: 'user-1' } } })
+    enqueue({ data: null, error: null })
+    vi.mocked(createClient).mockResolvedValue(supabase as never)
+
+    const res = await GET(mkReq(), mkParams())
+    expect(res.status).toBe(404)
+  })
+
+  it('returns posted count on happy path', async () => {
+    const { supabase, enqueue } = createQueuedMockSupabase()
+    supabase.auth.getUser.mockResolvedValue({ data: { user: { id: 'user-1' } } })
+    // fiscal_periods lookup
+    enqueue({ data: { id: 'period-1' }, error: null })
+    // journal_entries count
+    enqueue({ count: 3, error: null })
+    vi.mocked(createClient).mockResolvedValue(supabase as never)
+
+    const res = await GET(mkReq(), mkParams())
+    expect(res.status).toBe(200)
+    const body = await res.json()
+    expect(body.data.posted_count).toBe(3)
+  })
+
+  it('returns 0 when no posted entries exist', async () => {
+    const { supabase, enqueue } = createQueuedMockSupabase()
+    supabase.auth.getUser.mockResolvedValue({ data: { user: { id: 'user-1' } } })
+    enqueue({ data: { id: 'period-1' }, error: null })
+    enqueue({ count: 0, error: null })
+    vi.mocked(createClient).mockResolvedValue(supabase as never)
+
+    const res = await GET(mkReq(), mkParams())
+    expect(res.status).toBe(200)
+    const body = await res.json()
+    expect(body.data.posted_count).toBe(0)
+  })
+})

app/api/bookkeeping/fiscal-periods/[id]/entry-count/route.ts

@@ -0,0 +1,42 @@
+import { createClient } from '@/lib/supabase/server'
+import { NextResponse } from 'next/server'
+import { requireCompanyId } from '@/lib/company/context'
+
+export async function GET(
+  _request: Request,
+  { params }: { params: Promise<{ id: string }> }
+) {
+  const { id } = await params
+  const supabase = await createClient()
+  const { data: { user } } = await supabase.auth.getUser()
+
+  if (!user) {
+    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+  }
+
+  const companyId = await requireCompanyId(supabase, user.id)
+
+  const { data: period, error: fetchError } = await supabase
+    .from('fiscal_periods')
+    .select('id')
+    .eq('id', id)
+    .eq('company_id', companyId)
+    .maybeSingle()
+
+  if (fetchError || !period) {
+    return NextResponse.json({ error: 'Räkenskapsår hittades inte' }, { status: 404 })
+  }
+
+  const { count, error: countError } = await supabase
+    .from('journal_entries')
+    .select('id', { count: 'exact', head: true })
+    .eq('company_id', companyId)
+    .eq('fiscal_period_id', id)
+    .in('status', ['posted', 'reversed'])
+
+  if (countError) {
+    return NextResponse.json({ error: countError.message }, { status: 500 })
+  }
+
+  return NextResponse.json({ data: { posted_count: count ?? 0 } })
+}

app/api/bookkeeping/fiscal-periods/[id]/route.ts

@@ -1,7 +1,7 @@
 import { createClient } from '@/lib/supabase/server'
 import { NextResponse } from 'next/server'
 import { validateBody } from '@/lib/api/validate'
-import { validatePeriodDuration } from '@/lib/bookkeeping/validate-period-duration'
+import { validatePeriodDuration, parseDateParts } from '@/lib/bookkeeping/validate-period-duration'
 import { requireCompanyId } from '@/lib/company/context'
 import { requireWritePermission } from '@/lib/auth/require-write'
 import { z } from 'zod'
@@ -72,6 +72,24 @@ export async function PATCH(
     const newStart = body.period_start || period.period_start
     const newEnd = body.period_end || period.period_end
 
+    // Enskild firma must use calendar year per BFL 3 kap.
+    const { data: companyRow } = await supabase
+      .from('companies')
+      .select('entity_type')
+      .eq('id', companyId)
+      .single()
+
+    if (companyRow?.entity_type === 'enskild_firma') {
+      const s = parseDateParts(newStart)
+      const e = parseDateParts(newEnd)
+      if (s.month !== 1 || s.day !== 1 || e.month !== 12 || e.day !== 31) {
+        return NextResponse.json(
+          { error: 'Enskild firma måste använda kalenderår (1 januari – 31 december) enligt BFL 3 kap.' },
+          { status: 400 }
+        )
+      }
+    }
+
     // First period for this company may start on any day (BFL 3 kap.)
     const { count: earlierCount } = await supabase
       .from('fiscal_periods')