import { NextResponse } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from "@/app/api/auth/options";
import { prisma } from '@/lib/prisma';
import { deleteMissionLogo } from '@/lib/mission-uploads';

// Helper function to check authentication
async function checkAuth(request: Request) {
  const session = await getServerSession(authOptions);
  if (!session?.user?.id) {
    console.error('Unauthorized access attempt:', {
      url: request.url,
      method: request.method,
      headers: Object.fromEntries(request.headers)
    });
    return { authorized: false, userId: null };
  }
  return { authorized: true, userId: session.user.id };
}

// GET endpoint to retrieve a mission by ID
export async function GET(request: Request, props: { params: Promise<{ missionId: string }> }) {
  const params = await props.params;
  try {
    const { authorized, userId } = await checkAuth(request);
    if (!authorized || !userId) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const { missionId } = params;
    if (!missionId) {
      return NextResponse.json({ error: 'Mission ID is required' }, { status: 400 });
    }

    // Get mission with detailed info
    const mission = await prisma.mission.findFirst({
      where: {
        id: missionId,
        OR: [
          { creatorId: userId },
          { missionUsers: { some: { userId } } }
        ]
      },
      include: {
        creator: {
          select: {
            id: true,
            email: true
          }
        },
        missionUsers: {
          select: {
            id: true,
            role: true,
            user: {
              select: {
                id: true,
                email: true
              }
            }
          }
        },
        attachments: {
          select: {
            id: true,
            filename: true,
            filePath: true,
            fileType: true,
            fileSize: true,
            createdAt: true
          },
          orderBy: { createdAt: 'desc' }
        }
      }
    });

    if (!mission) {
      return NextResponse.json({ error: 'Mission not found or access denied' }, { status: 404 });
    }

    return NextResponse.json(mission);
  } catch (error) {
    console.error('Error retrieving mission:', error);
    return NextResponse.json({ 
      error: 'Internal server error', 
      details: error instanceof Error ? error.message : String(error) 
    }, { status: 500 });
  }
}

// PUT endpoint to update a mission
export async function PUT(request: Request, props: { params: Promise<{ missionId: string }> }) {
  const params = await props.params;
  try {
    const { authorized, userId } = await checkAuth(request);
    if (!authorized || !userId) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const { missionId } = params;
    if (!missionId) {
      return NextResponse.json({ error: 'Mission ID is required' }, { status: 400 });
    }

    // Check if mission exists and user has access to modify it
    const existingMission = await prisma.mission.findFirst({
      where: {
        id: missionId,
        OR: [
          { creatorId: userId },
          { missionUsers: { some: { userId, role: { in: ['gardien-temps', 'gardien-parole'] } } } }
        ]
      }
    });

    if (!existingMission) {
      return NextResponse.json({ error: 'Mission not found or not authorized to update' }, { status: 404 });
    }

    // Parse the request body
    const body = await request.json();
    const { 
      name,
      logo,
      oddScope,
      niveau,
      intention,
      missionType,
      donneurDOrdre,
      projection,
      services,
      participation,
      profils,
      guardians,
      volunteers
    } = body;

    // Update the mission data
    const updatedMission = await prisma.mission.update({
      where: { id: missionId },
      data: {
        name,
        logo,
        oddScope: oddScope || undefined,
        niveau,
        intention,
        missionType,
        donneurDOrdre,
        projection,
        services: services || undefined,
        participation,
        profils: profils || undefined
      }
    });

    // Update guardians if provided
    if (guardians) {
      // Get current guardians
      const currentGuardians = await prisma.missionUser.findMany({
        where: {
          missionId,
          role: { in: ['gardien-temps', 'gardien-parole', 'gardien-memoire'] }
        }
      });

      // Delete all guardians
      if (currentGuardians.length > 0) {
        await prisma.missionUser.deleteMany({
          where: {
            missionId,
            role: { in: ['gardien-temps', 'gardien-parole', 'gardien-memoire'] }
          }
        });
      }

      // Add new guardians
      const guardianRoles = ['gardien-temps', 'gardien-parole', 'gardien-memoire'];
      const guardianEntries = Object.entries(guardians)
        .filter(([role, userId]) => guardianRoles.includes(role) && userId)
        .map(([role, userId]) => ({
          role,
          userId: userId as string,
          missionId
        }));
      
      if (guardianEntries.length > 0) {
        await prisma.missionUser.createMany({
          data: guardianEntries
        });
      }
    }

    // Update volunteers if provided
    if (volunteers) {
      // Get current volunteers
      const currentVolunteers = await prisma.missionUser.findMany({
        where: {
          missionId,
          role: 'volontaire'
        }
      });

      // Delete all volunteers
      if (currentVolunteers.length > 0) {
        await prisma.missionUser.deleteMany({
          where: {
            missionId,
            role: 'volontaire'
          }
        });
      }

      // Add new volunteers
      if (volunteers.length > 0) {
        const volunteerEntries = volunteers.map((userId: string) => ({
          role: 'volontaire',
          userId,
          missionId
        }));
        
        await prisma.missionUser.createMany({
          data: volunteerEntries
        });
      }
    }

    return NextResponse.json({
      success: true,
      mission: {
        id: updatedMission.id,
        name: updatedMission.name,
        updatedAt: updatedMission.updatedAt
      }
    });
  } catch (error) {
    console.error('Error updating mission:', error);
    return NextResponse.json({ 
      error: 'Internal server error', 
      details: error instanceof Error ? error.message : String(error) 
    }, { status: 500 });
  }
}

// DELETE endpoint to remove a mission
export async function DELETE(request: Request, props: { params: Promise<{ missionId: string }> }) {
  const params = await props.params;
  try {
    const { authorized, userId } = await checkAuth(request);
    if (!authorized || !userId) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const { missionId } = params;
    if (!missionId) {
      return NextResponse.json({ error: 'Mission ID is required' }, { status: 400 });
    }

    // Check if mission exists and user is the creator
    const mission = await prisma.mission.findFirst({
      where: {
        id: missionId,
        creatorId: userId  // Only creator can delete a mission
      },
      include: {
        attachments: true
      }
    });

    if (!mission) {
      return NextResponse.json({ error: 'Mission not found or not authorized to delete' }, { status: 404 });
    }

    // Delete logo if exists
    if (mission.logo) {
      try {
        await deleteMissionLogo(mission.logo);
      } catch (error) {
        console.error('Error deleting mission logo:', error);
        // Continue deletion even if logo deletion fails
      }
    }

    // Delete mission (cascade will handle missionUsers and attachments)
    await prisma.mission.delete({
      where: { id: missionId }
    });

    return NextResponse.json({ success: true });
  } catch (error) {
    console.error('Error deleting mission:', error);
    return NextResponse.json({ 
      error: 'Internal server error', 
      details: error instanceof Error ? error.message : String(error) 
    }, { status: 500 });
  }
}