import _ from 'lodash';
import path from 'path';
import chokidar from 'chokidar';
import logger from './logger';

export function watchDir(dir: string, onFileChange: (filePaths: string[]) => void, throttleDelay = 1000): chokidar.FSWatcher {
    const fullDir = path.resolve(process.cwd(), dir);
    logger.debug('Watch dir for changes: ' + fullDir);
    const watcher = chokidar.watch('.', {
        cwd: fullDir,
        ignored: (filePath) => {
            return (
                filePath.includes(`/.git/`) ||
                filePath.includes(`/.next/`) ||
                filePath.includes(`/.cache/`) ||
                filePath.includes(`/.stackbit/cache`) ||
                filePath.includes(`/node_modules`) ||
                ((filePath.includes(`/.`) || filePath.startsWith(`.`)) && !(filePath.includes(`/.stackbit`) || filePath.startsWith(`.stackbit`)))
            );
        },
        persistent: true,
        ignoreInitial: true
    });
    let changedFiles: string[] = [];
    const throttledFileChange = _.throttle(() => {
        if (changedFiles.length) {
            onFileChange(changedFiles);
            changedFiles = [];
        }
    }, throttleDelay);
    const handleFileChange = (filePath: string) => {
        if (!changedFiles.includes(filePath)) {
            changedFiles.push(filePath);
        }
        throttledFileChange();
    };
    watcher
        .on('add', handleFileChange)
        .on('change', handleFileChange)
        .on('unlink', handleFileChange)
        .on('addDir', handleFileChange)
        .on('unlinkDir', handleFileChange);

    return watcher;
}