export const dynamic = 'force-dynamic'

import { NextRequest, NextResponse } from 'next/server'
import { getSession } from '@/lib/auth/get-session'
import { withUser, asAdmin } from '@/lib/db/with-user'
import { writeAuditLog } from '@/lib/db/audit'
import { incidents, auditLog } from '@/lib/db/schema'
import { eq, and, gte, sql } from 'drizzle-orm'
import { createDeepSeekClient } from '@/lib/claude/client'
import { getApiKey } from '@/lib/settings'

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 })

  // Rate limit
  const since = new Date(Date.now() - 60_000)
  const [rateRow] = await asAdmin(db =>
    db.select({ cnt: sql<number>`count(*)` }).from(auditLog)
      .where(and(
        eq(auditLog.changedBy, session.sub),
        eq(auditLog.action, 'ai_triage_suggest'),
        gte(auditLog.changedAt, since),
      ))
  )
  if (Number(rateRow?.cnt ?? 0) > 0)
    return NextResponse.json({ error: 'Rate limited — please wait 60 seconds' }, { status: 429 })

  const deepseekKey = await getApiKey('DEEPSEEK_API_KEY')
  const client = createDeepSeekClient(deepseekKey)

  const [incident] = await withUser(session.sub, async tx =>
    tx.select({
      incidentType: incidents.incidentType,
      description: incidents.description,
      injuryInvolved: incidents.injuryInvolved,
      assetInvolved: incidents.assetInvolved,
      medicalStatus: incidents.medicalStatus,
    })
    .from(incidents).where(eq(incidents.id, id)).limit(1)
  )
  if (!incident) return NextResponse.json({ error: 'Not found' }, { status: 404 })

  let res: Awaited<ReturnType<typeof client.chat.completions.create>>
  try {
    res = await client.chat.completions.create({
      model: 'deepseek-v4-pro',
      max_tokens: 1024,
      tools: [{
        type: 'function',
        function: {
          name: 'suggest_triage',
          description: 'Suggest severity rating and NADOPOD 2004 DOSH classification for a warehouse incident',
          parameters: {
            type: 'object',
            properties: {
              severity: { type: 'number', description: '1=minor, 2=low, 3=moderate, 4=serious, 5=critical/fatality' },
              is_fatality: { type: 'boolean' },
              is_serious_bodily_injury: { type: 'boolean', description: 'Fracture, amputation, blindness, serious burn, or similar' },
              is_dangerous_occurrence: { type: 'boolean', description: 'Structural collapse, explosion, fire, scaffold collapse, etc.' },
              is_occupational_disease: { type: 'boolean', description: 'Disease arising from workplace exposure' },
              rationale: { type: 'string', description: 'One-sentence rationale citing NADOPOD 2004 where applicable' },
            },
            required: [
              'severity', 'is_fatality', 'is_serious_bodily_injury',
              'is_dangerous_occurrence', 'is_occupational_disease', 'rationale',
            ],
          },
        },
      }],
      tool_choice: { type: 'function', function: { name: 'suggest_triage' } },
      messages: [{
        role: 'user',
        content: `You are an HSE triage specialist for a Malaysian 3PL warehouse. Assess this incident under NADOPOD 2004.

Incident type: ${incident.incidentType}
Description: ${incident.description}
Injury involved: ${incident.injuryInvolved ? 'yes' : 'no'}
Medical status: ${incident.medicalStatus ?? 'N/A'}
Asset/equipment involved: ${incident.assetInvolved ? 'yes' : 'no'}

Suggest severity (1–5) and tick the appropriate NADOPOD 2004 flags. Give a one-sentence rationale.`,
      }],
    })
  } catch {
    return NextResponse.json({ error: 'AI service unavailable' }, { status: 503 })
  }

  const call = res.choices[0]?.message?.tool_calls?.[0]
  if (!call || call.type !== 'function') return NextResponse.json({ error: 'AI suggestion failed' }, { status: 500 })

  let input: {
    severity?: unknown
    is_fatality?: unknown
    is_serious_bodily_injury?: unknown
    is_dangerous_occurrence?: unknown
    is_occupational_disease?: unknown
    rationale?: unknown
  }
  try { input = JSON.parse(call.function.arguments) }
  catch { return NextResponse.json({ error: 'AI returned unexpected structure' }, { status: 500 }) }

  if (
    typeof input.severity !== 'number' ||
    typeof input.is_fatality !== 'boolean' ||
    typeof input.is_serious_bodily_injury !== 'boolean' ||
    typeof input.is_dangerous_occurrence !== 'boolean' ||
    typeof input.is_occupational_disease !== 'boolean' ||
    typeof input.rationale !== 'string'
  ) {
    return NextResponse.json({ error: 'AI returned unexpected structure' }, { status: 500 })
  }

  await withUser(session.sub, async tx => {
    await writeAuditLog(tx, 'incidents', id, 'ai_triage_suggest', { suggestion: input, model: 'deepseek-v4-pro' })
  })

  return NextResponse.json(input)
}