export const dynamic = 'force-dynamic'

import { NextRequest, NextResponse } from 'next/server'
import { getSession } from '@/lib/auth/get-session'
import { withUser } from '@/lib/db/with-user'
import { writeAuditLog } from '@/lib/db/audit'
import { incidents, investigations } from '@/lib/db/schema'
import { eq, and, sql } from 'drizzle-orm'

export async function POST(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  const { id } = await params
  const session = await getSession()
  if (!session) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
  if (!['hse', 'admin'].includes(session.role))
    return NextResponse.json({ error: 'Forbidden' }, { status: 403 })

  const [incident] = await withUser(session.sub, async tx =>
    tx.select({ status: incidents.status }).from(incidents).where(eq(incidents.id, id)).limit(1)
  )
  if (!incident) return NextResponse.json({ error: 'Not found' }, { status: 404 })
  if (incident.status !== 'triaged')
    return NextResponse.json({ error: 'Incident must be triaged first' }, { status: 409 })

  const [existingCount] = await withUser(session.sub, async tx =>
    tx.select({ cnt: sql<number>`count(*)` }).from(investigations).where(eq(investigations.incidentId, id))
  )
  if (Number(existingCount?.cnt ?? 0) > 0)
    return NextResponse.json({ error: 'Investigation already exists for this incident' }, { status: 409 })

  const body = await request.json()
  const method: 'five_why' | 'fishbone' | 'other' = body.method ?? 'five_why'

  let invId!: string
  await withUser(session.sub, async tx => {
    const [inv] = await tx.insert(investigations).values({
      incidentId: id,
      investigatorId: session.sub,
      method,
      findingsText: body.findings_text ?? null,
      rootCauseSummary: body.root_cause_summary ?? null,
      fiveWhySteps: method === 'five_why' ? (body.five_why_steps ?? []) : null,
      fishboneCategories: method === 'fishbone' ? (body.fishbone_categories ?? []) : null,
      alcoholTestResult: body.alcohol_test_result ?? null,
      urineTestResult: body.urine_test_result ?? null,
      witnessStatementRefs: Array.isArray(body.witness_statement_refs) ? body.witness_statement_refs : [],
    }).returning({ id: investigations.id })

    if (!inv) throw new Error('Insert failed')
    invId = inv.id

    await tx.update(incidents).set({ status: 'investigating' }).where(eq(incidents.id, id))
    await writeAuditLog(tx, 'incidents', id, 'investigation_started', {
      status: 'investigating', investigation_id: inv.id,
    })
  })

  return NextResponse.json({ id: invId })
}

export async function PATCH(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  const { id } = await params
  const session = await getSession()
  if (!session) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
  if (!['hse', 'admin'].includes(session.role))
    return NextResponse.json({ error: 'Forbidden' }, { status: 403 })

  const body = await request.json()
  const { investigation_id, complete, ...fields } = body

  if (!investigation_id) return NextResponse.json({ error: 'investigation_id required' }, { status: 422 })

  const updateData: Partial<typeof investigations.$inferInsert> = {
    findingsText: fields.findings_text ?? null,
    rootCauseSummary: fields.root_cause_summary ?? null,
    fiveWhySteps: fields.five_why_steps ?? null,
    fishboneCategories: fields.fishbone_categories ?? null,
    alcoholTestResult: fields.alcohol_test_result ?? null,
    urineTestResult: fields.urine_test_result ?? null,
    witnessStatementRefs: Array.isArray(fields.witness_statement_refs) ? fields.witness_statement_refs : [],
  }
  if (complete) updateData.completedAt = new Date()

  await withUser(session.sub, async tx => {
    await tx.update(investigations)
      .set(updateData)
      .where(and(eq(investigations.id, investigation_id), eq(investigations.incidentId, id)))

    if (complete) {
      await tx.update(incidents).set({ status: 'capa_pending' }).where(eq(incidents.id, id))
      await writeAuditLog(tx, 'incidents', id, 'investigation_completed', { status: 'capa_pending' })
    }
  })

  return NextResponse.json({ ok: true })
}