import { NextRequest, NextResponse } from 'next/server'
import { prisma } from '@/lib/db'
import { getSession, isAdmin } from '@/lib/auth'
import { getProjectWithTenantCheck } from '@/lib/tenant'
import QRCode from 'qrcode'

// Helper: create a rapport record and return JSON response
async function createRapport(projectId: string, data: any, tenantId: string, userId: string, req: NextRequest) {
  // Einsatz-Nummer: one unique number per project (not per rapport)
  const existingRapport = await (prisma as any).rapport.findFirst({
    where: { projectId },
    orderBy: { createdAt: 'asc' },
    select: { reportNumber: true },
  })

  let reportNumber: string
  if (existingRapport?.reportNumber) {
    reportNumber = existingRapport.reportNumber
  } else {
    const year = new Date().getFullYear()
    const prefix = `${year}-`
    const lastRapport = await (prisma as any).rapport.findFirst({
      where: { tenantId, reportNumber: { startsWith: prefix } },
      orderBy: { reportNumber: 'desc' },
      select: { reportNumber: true },
    })
    let nextNum = 1
    if (lastRapport?.reportNumber) {
      const lastNum = parseInt(lastRapport.reportNumber.split('-')[1])
      if (!isNaN(lastNum)) nextNum = lastNum + 1
    }
    reportNumber = `${prefix}${String(nextNum).padStart(4, '0')}`
  }

  data.reportNumber = reportNumber

  const rapport = await (prisma as any).rapport.create({
    data: { reportNumber, data, projectId, tenantId, createdById: userId },
  })

  // Generate QR code
  const baseUrl = process.env.NEXTAUTH_URL || req.headers.get('origin') || `${req.headers.get('x-forwarded-proto') || 'https'}://${req.headers.get('host')}` || 'http://localhost:3000'
  const rapportUrl = `${baseUrl}/rapport/${rapport.token}`
  let qrCodeDataUri = ''
  try {
    qrCodeDataUri = await QRCode.toDataURL(rapportUrl, { width: 200, margin: 1, color: { dark: '#1a1a1a', light: '#ffffff' } })
  } catch (e) {
    console.warn('QR code generation failed:', e)
  }

  if (qrCodeDataUri) {
    data.qrCodeUrl = qrCodeDataUri
    await (prisma as any).rapport.update({ where: { id: rapport.id }, data: { data } })
  }

  return NextResponse.json({
    id: rapport.id,
    reportNumber: rapport.reportNumber,
    token: rapport.token,
    qrCodeUrl: qrCodeDataUri,
  })
}

// GET: List rapports for a project
export async function GET(req: NextRequest) {
  try {
    const user = await getSession()
    if (!user) return NextResponse.json({ error: 'Nicht autorisiert' }, { status: 401 })

    const { searchParams } = new URL(req.url)
    const projectId = searchParams.get('projectId')

    if (!projectId) {
      return NextResponse.json({ error: 'projectId erforderlich' }, { status: 400 })
    }

    // Mandanten-Isolation: nur Rapporte von Projekten des eigenen Tenants
    const project = await getProjectWithTenantCheck(projectId, user)
    if (!project) {
      return NextResponse.json({ error: 'Projekt nicht gefunden' }, { status: 404 })
    }

    const rapports = await (prisma as any).rapport.findMany({
      where: { projectId },
      orderBy: { createdAt: 'desc' },
      select: {
        id: true,
        reportNumber: true,
        token: true,
        generatedAt: true,
        createdAt: true,
        createdBy: { select: { name: true } },
      },
    })

    return NextResponse.json({ rapports })
  } catch (error) {
    console.error('Error fetching rapports:', error)
    return NextResponse.json({ error: 'Serverfehler' }, { status: 500 })
  }
}

// POST: Create a new rapport
export async function POST(req: NextRequest) {
  try {
    const user = await getSession()
    if (!user) return NextResponse.json({ error: 'Nicht autorisiert' }, { status: 401 })
    if (user.role === 'VIEWER') return NextResponse.json({ error: 'Keine Berechtigung' }, { status: 403 })

    let body: any
    try {
      body = await req.json()
    } catch (parseErr: any) {
      console.error('[Rapport] Body parse error:', parseErr?.message)
      return NextResponse.json({ error: 'Request zu gross oder ungültig: ' + (parseErr?.message || 'Body konnte nicht gelesen werden') }, { status: 400 })
    }
    const { projectId, data } = body || {}

    if (!projectId || !data) {
      console.error('[Rapport] Missing fields — projectId:', !!projectId, 'data:', !!data, 'body keys:', Object.keys(body || {}))
      return NextResponse.json({ error: `Felder fehlen (projectId=${!!projectId}, data=${!!data})` }, { status: 400 })
    }

    // Mandanten-Isolation: Rapport nur für ein Projekt des eigenen Tenants anlegen
    const project = await getProjectWithTenantCheck(projectId, user)
    if (!project) {
      return NextResponse.json({ error: 'Projekt nicht gefunden' }, { status: 404 })
    }

    let tenantId = project?.tenantId || user.tenantId || null
    if (!tenantId) {
      const membership = await (prisma as any).tenantMembership.findFirst({
        where: { userId: user.id },
        select: { tenantId: true },
      })
      tenantId = membership?.tenantId || null
    }

    console.log('[Rapport] Creating rapport — project:', projectId, 'tenant:', tenantId || '(none)')
    return await createRapport(projectId, data, tenantId, user.id, req)
  } catch (error: any) {
    console.error('[Rapport] Error:', error?.message || error)
    if (error?.code === 'P2002') {
      return NextResponse.json({ error: 'Rapportnummer existiert bereits' }, { status: 409 })
    }
    return NextResponse.json({ error: error?.message || 'Serverfehler' }, { status: 500 })
  }
}