import { readdir } from 'fs/promises';
import { spawn } from 'child_process';
import path from 'path';
import { fileURLToPath } from 'url';
import * as gulp from 'gulp';
import { rm } from 'fs/promises';

// Get the current file's directory
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

// Define input and output directories
const SRC_DIR = path.join(__dirname, 'src');
const BIN_DIR = path.join(SRC_DIR, 'bin');
const DIST_DIR = path.join(__dirname, 'dist');

// Function to bundle a single file using esbuild
async function buildFile(entryFile) {
    const outputFile = path.join(
        DIST_DIR,
        path.basename(entryFile).replace(/\.ts$/, '.mjs')
    );
    console.log(`Building: ${entryFile} → ${outputFile}`);

    // Define the esbuild command and arguments
    const command = 'esbuild';
    const args = [
        entryFile,
        '--bundle',
        '--platform=node',
        '--format=esm',
        '--minify',
        '--loader:.cfg=text',
        '--loader:.ini=text',
        '--outfile=' + outputFile,
    ];

    // Execute the esbuild command as a child process
    return new Promise((resolve, reject) => {
        const child = spawn(command, args, { stdio: 'inherit' });
        child.on('close', code => {
            if (code === 0) {
                resolve();
            } else {
                reject(new Error(`Build failed for ${entryFile} with exit code ${code}`));
            }
        });
    });
}

// Get all files in the src/bin directory
async function getEntryFiles() {
    const files = await readdir(BIN_DIR);
    return files.map(file => path.join(BIN_DIR, file));
}

// Build all entry files
async function buildAll() {
    const entryFiles = await getEntryFiles();
    for (const entry of entryFiles) {
        await buildFile(entry);
    }
}

// Clean the output directory
async function clean() {
    try {
        console.log(`Cleaning dist directory: ${DIST_DIR}`);
        await rm(DIST_DIR, { recursive: true, force: true });
    } catch (err) {
        console.error('Error cleaning dist directory:', err.message);
    }
}

const task = gulp.series(clean, buildAll);

// Watch for file changes and rebuild
export async function watch() {
    await task();
    console.log('Watching for changes...');
    await gulp.watch(SRC_DIR + '/**/*', task);
}

// Export tasks for Gulp
export default task; // Default task