import { NextRequest, NextResponse } from 'next/server'
import { PrismaClient } from '@prisma/client'
import { requireAdmin } from '@/lib/require-admin'

// Prisma client instance
const prisma = new PrismaClient()

// Validation function for privacy policy data
function validatePrivacyPolicyData(data: any) {
  const errors: string[] = []
  
  // Required fields validation
  if (!data.title?.trim()) errors.push('Title ist erforderlich')
  if (!data.responsible?.trim()) errors.push('Verantwortlicher ist erforderlich')
  if (!data.contactDPO?.trim()) errors.push('Kontaktdaten des Datenschutzbeauftragten sind erforderlich')
  if (!data.dataSubjectsRights?.trim()) errors.push('Betroffenen-Rechte sind erforderlich')
  if (!data.complaintRight?.trim()) errors.push('Beschwerderecht ist erforderlich')
  if (!data.withdrawalRight?.trim()) errors.push('Widerrufsrecht ist erforderlich')
  if (!data.processingDescription?.trim()) errors.push('Verarbeitungstätigkeit ist erforderlich')
  if (!data.recipients?.trim()) errors.push('Empfänger sind erforderlich')
  
  // Optional boolean validation
  if (data.isPublic !== undefined && typeof data.isPublic !== 'boolean') {
    errors.push('isPublic muss ein Boolean-Wert sein')
  }
  
  return errors
}

// GET /api/privacy-policies/[id] - returns a single privacy policy
export async function GET(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const { id: rawId } = await params
    const id = parseInt(rawId)
    
    // Validate ID is a number
    if (isNaN(id)) {
      return NextResponse.json(
        { error: 'Ungültige ID' },
        { status: 400 }
      )
    }
    
    // Find privacy policy by ID
    const policy = await prisma.privacyPolicy.findUnique({
      where: { id }
    })
    
    if (!policy) {
      return NextResponse.json(
        { error: 'Datenschutzerklärung nicht gefunden' },
        { status: 404 }
      )
    }
    
    return NextResponse.json(policy)
  } catch (error) {
    console.error('Error fetching privacy policy:', error)
    return NextResponse.json(
      { error: 'Fehler beim Abrufen der Datenschutzerklärung' },
      { status: 500 }
    )
  }
}

// PUT /api/privacy-policies/[id] - updates a privacy policy (Admin)
export async function PUT(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const denied = await requireAdmin()
    if (denied) return denied

    const { id: rawId } = await params
    const id = parseInt(rawId)
    const data = await request.json()
    
    // Validate ID is a number
    if (isNaN(id)) {
      return NextResponse.json(
        { error: 'Ungültige ID' },
        { status: 400 }
      )
    }
    
    // Validate required fields
    const validationErrors = validatePrivacyPolicyData(data)
    if (validationErrors.length > 0) {
      return NextResponse.json(
        { error: 'Validierungsfehler', details: validationErrors },
        { status: 400 }
      )
    }
    
    // Check if policy exists
    const existingPolicy = await prisma.privacyPolicy.findUnique({
      where: { id }
    })
    
    if (!existingPolicy) {
      return NextResponse.json(
        { error: 'Datenschutzerklärung nicht gefunden' },
        { status: 404 }
      )
    }
    
    // Update privacy policy
    const updatedPolicy = await prisma.privacyPolicy.update({
      where: { id },
      data: {
        title: data.title.trim(),
        responsible: data.responsible.trim(),
        contactDPO: data.contactDPO.trim(),
        dataSubjectsRights: data.dataSubjectsRights.trim(),
        complaintRight: data.complaintRight.trim(),
        withdrawalRight: data.withdrawalRight.trim(),
        processingDescription: data.processingDescription.trim(),
        processingPurposes: data.processingPurposes?.trim() || null,
        legalBasis: data.legalBasis?.trim() || null,
        recipients: data.recipients.trim(),
        storageDuration: data.storageDuration?.trim() || null,
        dataSource: data.dataSource?.trim() || null,
        provisionObligation: data.provisionObligation?.trim() || null,
        provisionConsequences: data.provisionConsequences?.trim() || null,
        isPublic: data.isPublic !== undefined ? data.isPublic : existingPolicy.isPublic
      }
    })
    
    return NextResponse.json(updatedPolicy)
  } catch (error) {
    console.error('Error updating privacy policy:', error)
    return NextResponse.json(
      { error: 'Fehler beim Aktualisieren der Datenschutzerklärung' },
      { status: 500 }
    )
  }
}

// DELETE /api/privacy-policies/[id] - deletes a privacy policy (Admin)
export async function DELETE(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    const denied = await requireAdmin()
    if (denied) return denied

    const { id: rawId } = await params
    const id = parseInt(rawId)
    
    // Validate ID is a number
    if (isNaN(id)) {
      return NextResponse.json(
        { error: 'Ungültige ID' },
        { status: 400 }
      )
    }
    
    // Check if policy exists
    const existingPolicy = await prisma.privacyPolicy.findUnique({
      where: { id }
    })
    
    if (!existingPolicy) {
      return NextResponse.json(
        { error: 'Datenschutzerklärung nicht gefunden' },
        { status: 404 }
      )
    }
    
    // Delete privacy policy
    await prisma.privacyPolicy.delete({
      where: { id }
    })
    
    return NextResponse.json(
      { message: 'Datenschutzerklärung erfolgreich gelöscht' },
      { status: 200 }
    )
  } catch (error) {
    console.error('Error deleting privacy policy:', error)
    return NextResponse.json(
      { error: 'Fehler beim Löschen der Datenschutzerklärung' },
      { status: 500 }
    )
  }
}