import os from 'os';
import path from 'path';

import { File } from '@google-cloud/storage';

import { getBucket, copyFile } from '../../resize_image/buckets';
import { isAlreadyPendingCompression } from '../../resize_image/compress';

import { getDestFileName, isCompressableFile } from './copy_files.rules';
import { Logger } from './logger';

export const getAllBucketFilesAndCopy = async ({ folder = '' } = {}): Promise<number> => {
    const logFilePath = path.join(os.tmpdir(), 'minify_all_images.log');
    const logger = new Logger({ filePath: logFilePath });

    const bucketName = process.env.TARGET_BUCKET;

    if (bucketName === undefined) {
        // TODO: Better Error handling
        logger.error('TARGET_BUCKET is not defined');
        throw new Error('TARGET_BUCKET is not defined');
    }

    logger.log(`Processing files in ${bucketName}, folder ${folder}`);

    const bucket = await getBucket(bucketName);

    let count = 0;

    return new Promise((resolve, reject) => {
        bucket
            .getFilesStream()
            .on('error', function (this: ReadableStream, error: Error) {
                logger.error(error);
                this.cancel();
                reject(error);
            })
            .on('data', function (file: File) {
                if (isCompressableFile(file) && file.name.includes(folder) && !isAlreadyPendingCompression(file.name)) {
                    count += 1;
                    logger.log(`${file.name} -> ${getDestFileName(file.name)}\n`);
                    return copyFile(file, getDestFileName(file.name)).catch((error) => logger.error(error));
                }
                return null;
            })
            .on('end', function () {
                logger.log(`Processed ${count} files`);
                logger.close();
                resolve(count);
            });
    });
};