import Router from 'koa-router';
import multer from '@koa/multer';
import path from 'path';
import fs from 'fs';

const router = new Router({
  prefix: '/api/files'
});

const uploadDir = path.join(process.cwd(), 'uploads');
if (!fs.existsSync(uploadDir)) {
  fs.mkdirSync(uploadDir, { recursive: true });
}

const storage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, uploadDir);
  },
  filename: (req, file, cb) => {
    const uniqueSuffix = Date.now() + '-' + Math.round(Math.random() * 1E9);
    cb(null, uniqueSuffix + '-' + file.originalname);
  }
});

const upload = multer({ storage });

const fileTransfers = new Map();

router.get('/info', async (ctx) => {
  ctx.body = {
    message: 'File API endpoint'
  };
});

router.post('/metadata', async (ctx) => {
  const { fileId, name, size, type, senderId, receiverId } = ctx.request.body;
  
  fileTransfers.set(fileId, {
    fileId,
    name,
    size,
    type,
    senderId,
    receiverId,
    progress: 0,
    status: 'pending',
    createdAt: new Date()
  });

  ctx.body = {
    success: true,
    fileId,
    message: 'File metadata registered'
  };
});

router.get('/metadata/:fileId', async (ctx) => {
  const { fileId } = ctx.params;
  const fileData = fileTransfers.get(fileId);
  
  if (!fileData) {
    ctx.status = 404;
    ctx.body = {
      error: 'File not found'
    };
    return;
  }

  ctx.body = fileData;
});

router.put('/progress/:fileId', async (ctx) => {
  const { fileId } = ctx.params;
  const { progress, status } = ctx.request.body;
  
  const fileData = fileTransfers.get(fileId);
  if (fileData) {
    fileData.progress = progress;
    if (status) {
      fileData.status = status;
    }
    
    ctx.io?.to(fileData.senderId).emit('file-progress', {
      fileId,
      progress,
      status
    });
    ctx.io?.to(fileData.receiverId).emit('file-progress', {
      fileId,
      progress,
      status
    });
  }

  ctx.body = {
    success: true,
    fileId,
    progress
  };
});

router.delete('/:fileId', async (ctx) => {
  const { fileId } = ctx.params;
  fileTransfers.delete(fileId);
  
  ctx.body = {
    success: true,
    message: 'File transfer cancelled'
  };
});

router.get('/transfers', async (ctx) => {
  const { userId } = ctx.query;
  
  const transfers = Array.from(fileTransfers.values()).filter(
    transfer => transfer.senderId === userId || transfer.receiverId === userId
  );
  
  ctx.body = transfers;
});

export default router;