#!/usr/bin/env node
/**
 * CSS Build Script
 * Concatenates modular CSS files from src/styles/ into style.css
 *
 * Usage: node scripts/build-css.js
 *
 * File order matters! Files are concatenated in alphabetical order.
 * Prefix files with numbers to control order: _01_variables.css, _02_panel.css, etc.
 */

import fs from 'fs-extra';
import path from 'path';
import { fileURLToPath } from 'url';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
const rootDir = path.resolve(__dirname, '..');
const stylesDir = path.join(rootDir, 'src', 'styles');
const outputFile = path.join(rootDir, 'style.css');

async function buildCSS() {
    console.log('Building CSS from src/styles/...');

    // Read all CSS files from src/styles/
    const files = await fs.readdir(stylesDir);
    const cssFiles = files
        .filter(f => f.endsWith('.css'))
        .sort() // Alphabetical order (use _01_, _02_ prefix for control)
        .map(f => path.join(stylesDir, f));

    if (cssFiles.length === 0) {
        console.error('No CSS files found in src/styles/');
        process.exit(1);
    }

    console.log(`Found ${cssFiles.length} CSS files:`);
    cssFiles.forEach(f => console.log(`  - ${path.basename(f)}`));

    // Read and concatenate all files
    const contents = [];
    for (const file of cssFiles) {
        const content = await fs.readFile(file, 'utf-8');
        const basename = path.basename(file);
        contents.push(`/* ============================================ */`);
        contents.push(`/* ${basename} */`);
        contents.push(`/* ============================================ */`);
        contents.push('');
        contents.push(content);
        contents.push('');
    }

    const combined = contents.join('\n');

    // Write to style.css
    await fs.writeFile(outputFile, combined, 'utf-8');

    const stats = await fs.stat(outputFile);
    const lines = combined.split('\n').length;
    const sizeKB = (stats.size / 1024).toFixed(1);

    console.log(`\n✅ Built ${outputFile}`);
    console.log(`   Lines: ${lines}`);
    console.log(`   Size: ${sizeKB} KB`);
}

buildCSS().catch(err => {
    console.error('Build failed:', err);
    process.exit(1);
});