import { NextRequest } from 'next/server';
import { prisma } from '@/lib/prisma';
import { getServerSession } from "next-auth";
import { authOptions } from "../../auth/authOptions";
import { FactureSchema } from "@/lib/validations/schemas";
import { successResponse, errorResponse, unauthorizedResponse, validationErrorResponse } from "@/lib/api-response";
import { z } from "zod";

export async function GET(req: NextRequest, { params }: { params: Promise<{ id: string }> }) {
  try {
    const session = await getServerSession(authOptions);
    if (!session) return unauthorizedResponse();

    const resolvedParams = await params;
    const { id } = resolvedParams;
    const facture = await prisma.facture.findUnique({
      where: { id },
      include: { partner: true },
    });
    if (!facture) return errorResponse('Facture non trouvée', undefined, 404);
    return successResponse(facture);
  } catch (error: any) {
    return errorResponse("Error fetching facture", error.message);
  }
}

export async function PUT(req: NextRequest, { params }: { params: Promise<{ id: string }> }) {
  try {
    const session = await getServerSession(authOptions);
    if (!session || (session.user.role !== "MANAGER" && session.user.role !== "ADMIN")) {
      return unauthorizedResponse();
    }

    const resolvedParams = await params;
    const { id } = resolvedParams;

    // Liste blanche des champs autorisés pour la mise à jour
    const allowedFields = [
      "type", "titre", "montant", "partenaireId", "clientId",
      "dateReception", "echeance", "statut", "remarque", "pdfPath", "datePaiement"
    ];

    let updateData: any = {};
    const contentType = req.headers.get("content-type") || "";

    if (contentType.includes("application/json")) {
      const data = await req.json();
      
      const PartialFactureSchema = FactureSchema.partial();
      try {
        PartialFactureSchema.parse(data);
      } catch (validationError: any) {
        if (validationError instanceof z.ZodError) {
          return validationErrorResponse(validationError);
        }
      }

      for (const key of allowedFields) {
        if (data[key] !== undefined) {
          if (["montant"].includes(key)) updateData[key] = parseFloat(data[key]);
          else if (["partenaireId", "clientId"].includes(key)) updateData[key] = parseInt(data[key], 10);
          else if (["dateReception", "echeance", "datePaiement"].includes(key)) updateData[key] = new Date(data[key]);
          else updateData[key] = data[key];
        }
      }
    } else if (contentType.includes("multipart/form-data")) {
      const formData = await req.formData();
      for (const key of allowedFields) {
        const value = formData.get(key);
        if (value !== null && value !== undefined && value !== "") {
          if (["montant"].includes(key)) updateData[key] = parseFloat(value as string);
          else if (["partenaireId", "clientId"].includes(key)) updateData[key] = parseInt(value as string, 10);
          else if (["dateReception", "echeance", "datePaiement"].includes(key)) updateData[key] = new Date(value as string);
          else updateData[key] = value;
        }
      }
    } else {
      return errorResponse("Type de contenu non supporté", undefined, 400);
    }

    const facture = await prisma.facture.update({
      where: { id },
      data: updateData,
      include: { client: true, partner: true },
    });
    return successResponse(facture);
  } catch (error: any) {
    return errorResponse("Erreur lors de la modification", error.message);
  }
}

export async function DELETE(req: NextRequest, { params }: { params: Promise<{ id: string }> }) {
  try {
    const session = await getServerSession(authOptions);
    if (!session || (session.user.role !== "MANAGER" && session.user.role !== "ADMIN")) {
      return unauthorizedResponse();
    }

    const resolvedParams = await params;
    const { id } = resolvedParams;
    await prisma.facture.delete({ where: { id } });
    return successResponse({ success: true });
  } catch (error: any) {
    return errorResponse("Erreur lors de la suppression", error.message);
  }
}