#!/usr/bin/env node
/**
 * Build quiXzoom Asia pages from templates + translations
 * Outputs to dist/ with versioned assets
 */

const fs = require('fs');
const path = require('path');

const LANGUAGES = [
  { code: 'zh-cn', name: 'Simplified Chinese', currency: 'CNY', symbol: '¥' },
  { code: 'zh-tw', name: 'Traditional Chinese', currency: 'TWD', symbol: 'NT$' },
  { code: 'ja', name: 'Japanese', currency: 'JPY', symbol: '¥' },
  { code: 'ko', name: 'Korean', currency: 'KRW', symbol: '₩' },
  { code: 'th', name: 'Thai', currency: 'THB', symbol: '฿' },
  { code: 'vi', name: 'Vietnamese', currency: 'VND', symbol: '₫' },
  { code: 'id', name: 'Indonesian', currency: 'IDR', symbol: 'Rp' },
  { code: 'ms', name: 'Malay', currency: 'MYR', symbol: 'RM' },
  { code: 'hi', name: 'Hindi', currency: 'INR', symbol: '₹' },
];

const VERSION = process.env.VERSION || require('../package.json').version;
const BUILD_TIME = new Date().toISOString();

function loadTemplate() {
  return fs.readFileSync(path.join(__dirname, '../src/template.html'), 'utf8');
}

function loadTranslations(langCode) {
  const transPath = path.join(__dirname, `../src/translations/${langCode}.json`);
  if (!fs.existsSync(transPath)) {
    console.error(`❌ Missing translations: ${langCode}`);
    process.exit(1);
  }
  return JSON.parse(fs.readFileSync(transPath, 'utf8'));
}

function interpolate(template, vars) {
  // First pass: interpolate vars that contain other placeholders
  let result = template;
  let changed = true;
  let passes = 0;
  const MAX_PASSES = 5;

  while (changed && passes < MAX_PASSES) {
    changed = false;
    passes++;
    result = result.replace(/\{\{(\w+)\}\}/g, (match, key) => {
      if (vars[key] === undefined) {
        return match; // keep placeholder for next pass or final check
      }
      const value = vars[key];
      if (value.includes('{{')) {
        changed = true;
      }
      return value;
    });
  }

  // Final check for remaining placeholders
  const remaining = result.match(/\{\{(\w+)\}\}/g);
  if (remaining) {
    const unique = [...new Set(remaining.map(m => m.slice(2, -2)))].filter(k => vars[k] === undefined);
    for (const key of unique) {
      console.warn(`⚠️  Missing translation key: ${key}`);
    }
  }

  return result;
}

function build() {
  console.log(`🔨 Building quiXzoom Asia v${VERSION}...\n`);

  const distDir = path.join(__dirname, '../dist');
  if (fs.existsSync(distDir)) {
    fs.rmSync(distDir, { recursive: true });
  }
  fs.mkdirSync(distDir, { recursive: true });

  const template = loadTemplate();

  // Build root language selector
  const rootHtml = fs.readFileSync(path.join(__dirname, '../src/index.html'), 'utf8')
    .replace('{{VERSION}}', VERSION)
    .replace('{{BUILD_TIME}}', BUILD_TIME);
  fs.writeFileSync(path.join(distDir, 'index.html'), rootHtml);

  // Build each language
  for (const lang of LANGUAGES) {
    console.log(`  📄 ${lang.code} — ${lang.name}`);

    const translations = loadTranslations(lang.code);
    translations.VERSION = VERSION;
    translations.BUILD_TIME = BUILD_TIME;
    translations.LANG_CODE = lang.code;
    translations.LANG_NAME = lang.name;
    translations.CURRENCY = lang.currency;
    translations.CURRENCY_SYMBOL = lang.symbol;

    const html = interpolate(template, translations);
    const langDir = path.join(distDir, lang.code);
    fs.mkdirSync(langDir, { recursive: true });
    fs.writeFileSync(path.join(langDir, 'index.html'), html);
  }

  // Copy static assets
  const assets = ['favicon.svg', 'apple-touch-icon.svg'];
  for (const asset of assets) {
    const src = path.join(__dirname, `../src/${asset}`);
    if (fs.existsSync(src)) {
      fs.copyFileSync(src, path.join(distDir, asset));
    }
  }

  // Write build manifest
  const manifest = {
    version: VERSION,
    buildTime: BUILD_TIME,
    languages: LANGUAGES.map(l => l.code),
    gitCommit: process.env.GIT_COMMIT || 'unknown',
    gitBranch: process.env.GIT_BRANCH || 'unknown',
  };
  fs.writeFileSync(path.join(distDir, 'manifest.json'), JSON.stringify(manifest, null, 2));

  console.log(`\n✅ Build complete: ${distDir}/`);
  console.log(`   ${LANGUAGES.length + 1} pages generated`);
}

build();