const multer = require('multer');
const path = require('path');
const { v4: uuidv4 } = require('uuid');

// Configure storage for profile images
const profileImageStorage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, path.join(__dirname, '../uploads/profiles'));
  },
  filename: function (req, file, cb) {
    // Generate unique filename: uuid + original extension
    const uniqueId = uuidv4();
    const ext = path.extname(file.originalname);
    cb(null, `${uniqueId}${ext}`);
  }
});

// File filter to accept only images
const imageFileFilter = (req, file, cb) => {
  // Accept images only
  const allowedMimes = ['image/jpeg', 'image/jpg', 'image/png', 'image/gif', 'image/webp'];
  if (allowedMimes.includes(file.mimetype)) {
    cb(null, true);
  } else {
    cb(new Error('Invalid file type. Only JPEG, PNG, GIF and WebP images are allowed.'), false);
  }
};

// Create multer upload middleware for profile images
const uploadProfileImage = multer({
  storage: profileImageStorage,
  fileFilter: imageFileFilter,
  limits: {
    fileSize: 5 * 1024 * 1024 // 5MB limit
  }
}).single('profileImage');

// Configure storage for message images
const messageImageStorage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, path.join(__dirname, '../uploads/messages'));
  },
  filename: function (req, file, cb) {
    // Generate unique filename: uuid + original extension
    const uniqueId = uuidv4();
    const ext = path.extname(file.originalname);
    cb(null, `${uniqueId}${ext}`);
  }
});

// Create multer upload middleware for message images
const uploadMessageImage = multer({
  storage: messageImageStorage,
  fileFilter: imageFileFilter,
  limits: {
    fileSize: 5 * 1024 * 1024 // 5MB limit
  }
}).single('image');

// Configure storage for forum images
const forumImageStorage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, path.join(__dirname, '../uploads/forum'));
  },
  filename: function (req, file, cb) {
    const uniqueId = uuidv4();
    const ext = path.extname(file.originalname);
    cb(null, `${uniqueId}${ext}`);
  }
});

// Factory function to create forum image upload middleware
const createForumImageUpload = (maxFiles) => {
  return multer({
    storage: forumImageStorage,
    fileFilter: imageFileFilter,
    limits: {
      fileSize: 5 * 1024 * 1024 // 5MB limit per file
    }
  }).array('images', maxFiles);
};

// Create multer upload middleware for forum post images (up to 5 images)
const uploadForumPostImages = createForumImageUpload(5);

// Create multer upload middleware for forum comment images (up to 3 images)
const uploadForumCommentImages = createForumImageUpload(3);

module.exports = {
  uploadProfileImage,
  uploadMessageImage,
  uploadForumPostImages,
  uploadForumCommentImages
};