import { Injectable } from '@nestjs/common';
import { diskStorage } from 'multer';
import { extname, join } from 'path';
import * as fs from 'fs';

@Injectable()
export class FilesService {
  // Method to configure Multer's storage
  getMulterStorage() {
    return diskStorage({
      destination: (req, file, cb) => {
        // Define the upload path
        const uploadPath = './uploads';
        
        // Create the upload directory if it doesn't exist
        if (!fs.existsSync(uploadPath)) {
          fs.mkdirSync(uploadPath, { recursive: true });
        }

        // Set the destination directory for file storage
        cb(null, uploadPath);
      },
      filename: (req, file, cb) => {
        // Generate a unique file name based on the current timestamp
        const fileName = Date.now() + extname(file.originalname);
        cb(null, fileName);
      },
    });
  }

  // Method to filter file types based on MIME type and extension
  fileFilter(req, file, cb) {
    const allowedImageTypes = ['image/jpeg', 'image/png', 'image/gif', 'image/jpg'];
    const allowedVideoTypes = ['video/mp4', 'video/avi', 'video/mov'];

    // Check if the file is an image or a video
    if (allowedImageTypes.includes(file.mimetype) || allowedVideoTypes.includes(file.mimetype)) {
      return cb(null, true); // Allow the file
    } else {
      return cb(new Error('Only images (jpg, png, gif) and videos (mp4, avi, mov) are allowed!'), false); // Reject the file
    }
  }

  // Helper method to categorize the uploaded files into images and videos
  categorizeFiles(files: Express.Multer.File[]): { image: string[]; video: string[] } {
    const categorizedFiles = {
      image: [],
      video: [],
    };

    // Categorize files based on their extensions
    files.forEach(file => {
      const ext = extname(file.originalname).toLowerCase();
      if (['.jpg', '.jpeg', '.png', '.gif'].includes(ext)) {
        categorizedFiles.image.push(file.path); // Categorize as image
      } else if (['.mp4', '.avi', '.mov'].includes(ext)) {
        categorizedFiles.video.push(file.path); // Categorize as video
      }
    });

    return categorizedFiles;
  }
}