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

// Helper function to check if user can manage files (creator or gardien)
// Also checks if mission is closed (closed missions cannot be modified)
async function checkCanManage(userId: string, missionId: string): Promise<{ canManage: boolean; isClosed: boolean }> {
  const mission = await prisma.mission.findFirst({
    where: { id: missionId },
    select: {
      creatorId: true,
      isClosed: true,
      missionUsers: {
        where: { userId },
        select: { role: true }
      }
    }
  });

  if (!mission) return { canManage: false, isClosed: false };
  
  // If mission is closed, no one can manage files
  if (mission.isClosed) {
    return { canManage: false, isClosed: true };
  }
  
  // Creator can always manage
  if (mission.creatorId === userId) return { canManage: true, isClosed: false };
  
  // Gardiens can manage
  const userRole = mission.missionUsers[0]?.role;
  const canManage = userRole === 'gardien-temps' || userRole === 'gardien-parole' || userRole === 'gardien-memoire';
  return { canManage, isClosed: false };
}

export async function POST(
  request: Request,
  { params }: { params: Promise<{ missionId: string }> }
) {
  try {
    const session = await getServerSession(authOptions);
    if (!session?.user?.id) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const { missionId } = await params;
    const userId = session.user.id;

    // Check if user can manage files and if mission is closed
    const { canManage, isClosed } = await checkCanManage(userId, missionId);
    if (isClosed) {
      return NextResponse.json({ error: 'Mission is closed: files cannot be uploaded to closed missions' }, { status: 403 });
    }
    if (!canManage) {
      return NextResponse.json({ error: 'Forbidden: You do not have permission to upload files' }, { status: 403 });
    }

    const formData = await request.formData();
    const file = formData.get('file') as File;
    const path = formData.get('path') as string || 'attachments';

    if (!file) {
      return NextResponse.json({ error: 'File is required' }, { status: 400 });
    }

    // Use the existing uploadMissionAttachment function from mission-uploads.ts
    // This ensures we use the exact same S3 client configuration and logic
    console.log(`[POST /api/missions/${missionId}/files/upload] Uploading file:`, {
      fileName: file.name,
      fileSize: file.size,
      fileType: file.type,
      path: path
    });

    // Upload using the proven function from mission-uploads.ts
    let uploadResult;
    try {
      uploadResult = await uploadMissionAttachment(userId, missionId, file);
      console.log(`[POST /api/missions/${missionId}/files/upload] Upload successful:`, {
        filePath: uploadResult.filePath
      });
    } catch (uploadError: any) {
      console.error(`[POST /api/missions/${missionId}/files/upload] Upload failed:`, {
        error: uploadError.message,
        code: uploadError.Code,
        fileName: file.name
      });
      throw uploadError;
    }

    // Create attachment record in database
    let attachment;
    try {
      attachment = await prisma.attachment.create({
        data: {
          filename: uploadResult.filename,
          filePath: uploadResult.filePath,
          fileType: uploadResult.fileType,
          fileSize: uploadResult.fileSize,
          missionId: missionId,
          uploaderId: userId
        }
      });
      console.log(`[POST /api/missions/${missionId}/files/upload] Attachment record created:`, {
        attachmentId: attachment.id
      });
    } catch (dbError: any) {
      console.error(`[POST /api/missions/${missionId}/files/upload] Database error:`, {
        error: dbError.message,
        fileName: file.name
      });
      // File was uploaded but DB record creation failed - still return success but log the error
      // The file exists in S3 even if the DB record doesn't
    }

    return NextResponse.json({
      success: true,
      file: {
        type: 'file',
        name: uploadResult.filename,
        path: uploadResult.filePath,
        key: uploadResult.filePath,
        size: uploadResult.fileSize,
        lastModified: new Date().toISOString()
      }
    });
  } catch (error: any) {
    console.error('Error uploading file:', error);
    return NextResponse.json(
      { error: 'Failed to upload file', details: error.message },
      { status: 500 }
    );
  }
}