import { NextResponse } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from "@/app/api/auth/options";
import { PrismaClient } from '@prisma/client';
import { prisma } from '@/lib/prisma';
import { 
  uploadMissionLogo, 
  uploadMissionAttachment, 
  generateMissionLogoUploadUrl,
  generateMissionAttachmentUploadUrl
} from '@/lib/mission-uploads';
import { getPublicUrl, S3_CONFIG } from '@/lib/s3';

// 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 };
}

// Generate presigned URL for direct upload to S3/Minio
export async function GET(request: Request) {
  try {
    const { authorized, userId } = await checkAuth(request);
    if (!authorized || !userId) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const { searchParams } = new URL(request.url);
    const missionId = searchParams.get('missionId');
    const type = searchParams.get('type'); // 'logo' or 'attachment'
    const filename = searchParams.get('filename');
    
    if (!missionId || !type || !filename) {
      return NextResponse.json({ 
        error: 'Missing required parameters', 
        required: { missionId: true, type: true, filename: true },
        received: { missionId: !!missionId, type: !!type, filename: !!filename }
      }, { status: 400 });
    }

    // Verify that the mission exists and user has access to it
    const mission = await prisma.mission.findUnique({
      where: { id: missionId },
      select: { id: true, creatorId: true }
    });

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

    // Currently only allow creator to upload files
    // You can modify this to include other roles if needed
    if (mission.creatorId !== userId) {
      return NextResponse.json({ error: 'Not authorized to upload to this mission' }, { status: 403 });
    }

    let result;
    if (type === 'logo') {
      // For logo, we expect filename to contain the file extension (e.g., '.jpg')
      const fileExtension = filename.substring(filename.lastIndexOf('.'));
      result = await generateMissionLogoUploadUrl(userId, missionId, fileExtension);
    } else if (type === 'attachment') {
      result = await generateMissionAttachmentUploadUrl(userId, missionId, filename);
    } else {
      return NextResponse.json({ error: 'Invalid upload type' }, { status: 400 });
    }

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

// Handle file upload (server-side)
export async function POST(request: Request) {
  console.log('=== File upload request received ===');
  
  try {
    console.log('Checking authentication...');
    const { authorized, userId } = await checkAuth(request);
    if (!authorized || !userId) {
      console.log('Authentication failed');
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }
    console.log('User authenticated:', userId);

    // Parse the form data
    console.log('Parsing form data...');
    const formData = await request.formData();
    const missionId = formData.get('missionId') as string;
    const type = formData.get('type') as string; // 'logo' or 'attachment'
    const file = formData.get('file') as File;
    
    console.log('Form data received:', { 
      missionId, 
      type, 
      fileExists: !!file,
      fileName: file?.name,
      fileSize: file?.size,
      fileType: file?.type
    });

    if (!missionId || !type || !file) {
      console.log('Missing required fields:', { missionId: !!missionId, type: !!type, file: !!file });
      return NextResponse.json({ 
        error: 'Missing required fields', 
        required: { missionId: true, type: true, file: true },
        received: { missionId: !!missionId, type: !!type, file: !!file }
      }, { status: 400 });
    }

    // Verify that the mission exists and user has access to it
    console.log('Verifying mission access...');
    const mission = await prisma.mission.findUnique({
      where: { id: missionId },
      select: { id: true, creatorId: true }
    });

    if (!mission) {
      console.log('Mission not found:', missionId);
      return NextResponse.json({ error: 'Mission not found' }, { status: 404 });
    }

    // Currently only allow creator to upload files
    if (mission.creatorId !== userId) {
      console.log('User not authorized to upload to this mission', { userId, creatorId: mission.creatorId });
      return NextResponse.json({ error: 'Not authorized to upload to this mission' }, { status: 403 });
    }
    console.log('Mission access verified');

    if (type === 'logo') {
      console.log('Processing logo upload...');
      try {
        // Upload logo file to Minio
        const { filePath } = await uploadMissionLogo(userId, missionId, file);
        console.log('Logo uploaded successfully to path:', filePath);
        
        // Generate public URL
        const publicUrl = getPublicUrl(filePath, S3_CONFIG.bucket);
        console.log('Public URL for logo:', publicUrl);
        
        // Update mission record with logo path
        console.log('Updating mission record with logo path...');
        await prisma.mission.update({
          where: { id: missionId },
          data: { logo: filePath }
        });
        console.log('Mission record updated');
        
        return NextResponse.json({ 
          success: true, 
          filePath,
          publicUrl
        });
      } catch (logoError) {
        console.error('Error in logo upload process:', logoError);
        return NextResponse.json({ 
          error: 'Logo upload failed', 
          details: logoError instanceof Error ? logoError.message : String(logoError) 
        }, { status: 500 });
      }
    } 
    else if (type === 'attachment') {
      // Upload attachment file to Minio
      console.log('Processing attachment upload...');
      try {
        const { filename, filePath, fileType, fileSize } = await uploadMissionAttachment(
          userId, 
          missionId, 
          file
        );
        console.log('Attachment uploaded successfully to path:', filePath);
        
        // Generate public URL
        const publicUrl = getPublicUrl(filePath, S3_CONFIG.bucket);
        console.log('Public URL for attachment:', publicUrl);
        
        // Create attachment record in database
        console.log('Creating attachment record in database...');
        const attachment = await prisma.attachment.create({
          data: {
            filename,
            filePath,
            fileType,
            fileSize,
            missionId,
            uploaderId: userId
          }
        });
        console.log('Attachment record created:', attachment.id);
        
        return NextResponse.json({ 
          success: true, 
          attachment: {
            id: attachment.id,
            filename: attachment.filename,
            filePath: attachment.filePath,
            publicUrl,
            fileType: attachment.fileType,
            fileSize: attachment.fileSize,
            createdAt: attachment.createdAt
          }
        });
      } catch (attachmentError) {
        console.error('Error in attachment upload process:', attachmentError);
        return NextResponse.json({ 
          error: 'Attachment upload failed', 
          details: attachmentError instanceof Error ? attachmentError.message : String(attachmentError) 
        }, { status: 500 });
      }
    } 
    else {
      console.log('Invalid upload type:', type);
      return NextResponse.json({ error: 'Invalid upload type' }, { status: 400 });
    }
  } catch (error) {
    console.error('Unhandled error in upload process:', error);
    return NextResponse.json({ 
      error: 'Internal server error', 
      details: error instanceof Error ? error.message : String(error) 
    }, { status: 500 });
  }
}