// /components/files/fileService.js

const path = require('path');
const config = require('../../config/config');
const {
  uploadToTempBucket,
  commitTempFile,
  generatePresignedUrl,
  deleteFromBucket
} = require('../../utils/s3Client');
const AppError = require('../../utils/AppError');

const uploadTempFile = async (fileBuffer, originalName, mimeType) => {
  if (!fileBuffer || !originalName) {
    throw new AppError('FILE_REQUIRED');
  }

  const ext = path.extname(originalName);
  const uniquePrefix = `${Date.now()}-${Math.round(Math.random() * 1E9)}`;
  const tempFileName = `temp-${uniquePrefix}${ext}`;

  const result = await uploadToTempBucket(fileBuffer, tempFileName, mimeType);
  return {
    tempFileName: result.tempFileName,
    originalName,
    mimeType,
    bucket: result.bucket
  };
};

const getPresignedUrl = async (filename, bucket = null) => {
  if (!filename) {
    throw new AppError('VALIDATION_FAILED', null, 'Filename is required');
  }

  const targetBucket = bucket || config.S3_TEMP_BUCKET;
  const signedUrl = await generatePresignedUrl(filename, targetBucket);
  return {
    filename,
    bucket: targetBucket,
    presignedUrl: signedUrl,
    signedUrl,
    expiresInSeconds: config.SIGNED_URL_EXPIRES_IN
  };
};

const commitFile = async (tempFileName, targetFileName = null, targetBucket = 'certificates') => {
  return commitTempFile(tempFileName, targetFileName, targetBucket);
};

const deleteFile = async (filename, bucket = null) => {
  return deleteFromBucket(filename, bucket || config.S3_TEMP_BUCKET);
};

module.exports = {
  uploadTempFile,
  getPresignedUrl,
  commitFile,
  deleteFile
};