export const dynamic = 'force-dynamic'

import { NextRequest, NextResponse } from 'next/server'
import { aliasedTable } from 'drizzle-orm'
import { getSession } from '@/lib/auth/get-session'
import { withUser } from '@/lib/db/with-user'
import { incidents, sites, users } from '@/lib/db/schema'
import { eq } from 'drizzle-orm'
import { buildJkkp6Pdf, buildJkkp7Pdf, type JkkpIncident } from '@/lib/pdf/jkkp'
import { computeDoshObligation } from '@/lib/incidents/dosh'

export async function GET(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  const { id } = await params
  const form = request.nextUrl.searchParams.get('form')
  if (form !== 'jkkp6' && form !== 'jkkp7')
    return NextResponse.json({ error: 'form must be jkkp6 or jkkp7' }, { status: 422 })

  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 reporterAlias = aliasedTable(users, 'reporter')

  const [incident] = await withUser(session.sub, async tx =>
    tx.select({
      referenceNo: incidents.referenceNo,
      incidentType: incidents.incidentType,
      description: incidents.description,
      reportedAt: incidents.reportedAt,
      severity: incidents.severity,
      lostDays: incidents.lostDays,
      isFatality: incidents.isFatality,
      isSeriousBodilyInjury: incidents.isSeriousBodilyInjury,
      isDangerousOccurrence: incidents.isDangerousOccurrence,
      isOccupationalDisease: incidents.isOccupationalDisease,
      siteName: sites.name,
      reporterName: reporterAlias.name,
    })
    .from(incidents)
    .leftJoin(sites, eq(incidents.siteId, sites.id))
    .leftJoin(reporterAlias, eq(incidents.reportedBy, reporterAlias.id))
    .where(eq(incidents.id, id))
    .limit(1)
  )

  if (!incident) return NextResponse.json({ error: 'Not found' }, { status: 404 })

  const dosh = computeDoshObligation({
    is_fatality: incident.isFatality,
    is_serious_bodily_injury: incident.isSeriousBodilyInjury,
    is_dangerous_occurrence: incident.isDangerousOccurrence,
    is_occupational_disease: incident.isOccupationalDisease,
    lost_days: incident.lostDays,
  })

  const required = form === 'jkkp6' ? dosh.requires_jkkp6 : dosh.requires_jkkp7
  if (!required) return NextResponse.json({ error: 'This form is not required for this incident' }, { status: 400 })

  const jkkpIncident: JkkpIncident = {
    reference_no: incident.referenceNo,
    incident_type: incident.incidentType,
    description: incident.description,
    reported_at: incident.reportedAt instanceof Date ? incident.reportedAt.toISOString() : (incident.reportedAt as string),
    severity: incident.severity,
    is_fatality: incident.isFatality,
    is_serious_bodily_injury: incident.isSeriousBodilyInjury,
    is_dangerous_occurrence: incident.isDangerousOccurrence,
    lost_days: incident.lostDays,
    site_name: incident.siteName ?? 'Unknown',
    reporter_name: incident.reporterName ?? 'Unknown',
  }

  const pdfBytes = form === 'jkkp6'
    ? await buildJkkp6Pdf(jkkpIncident)
    : await buildJkkp7Pdf(jkkpIncident)

  const ref = jkkpIncident.reference_no ?? id
  return new NextResponse(Buffer.from(pdfBytes), {
    headers: {
      'Content-Type': 'application/pdf',
      'Content-Disposition': `attachment; filename="${form}-${ref}.pdf"`,
    },
  })
}