#!/usr/bin/env node
/**
 * Tree-shake @iconify-json/mdi: scan src/ for `icon="mdi:..."` references and
 * emit a minimal IconifyJSON containing only those icons. Saves ~3 MB in the
 * client bundle vs. shipping the full 7000+ icon collection.
 *
 * Dynamic icons (from CMS data, conditional names) cannot be detected
 * statically — list them under EXTRA_ICONS below. Anything missing falls
 * through to the iconify API at runtime, which adds a network roundtrip but
 * does not break.
 *
 * Run via `npm run generate:icons`. Hooked into `prebuild`.
 */

import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const ROOT = path.resolve(__dirname, '..');
const SRC_DIR = path.join(ROOT, 'src');

/**
 * Icons that appear via dynamic bindings (CMS data, conditional expressions)
 * and would otherwise miss the static scan. Add new ones here when editors
 * pick icons that appear blank — better than shipping the full collection.
 */
const EXTRA_ICONS = [
  // Brand/Logo-Icons ohne Lucide-Pendant (Editors picken sie als social.icon)
  'google',
  'whatsapp',
  'mastodon',
  'telegram',
  // Sprach-Logos (CodeBlock: dynamische language->icon-Map, kein literal icon="")
  'language-javascript',
  'language-python',
  'language-rust',
];

/**
 * Lucide-Icons aus CMS-Daten (Header social.icon, FilesBlock file types, …) +
 * dynamische Bindings, die der statische Scan nicht findet.
 */
const EXTRA_LUCIDE = [
  // Nav / Header social.icon (CMS)
  'calendar-1',
  'contact-round',
  'search',
  'x',
  'cloud',
  'mail',
  'facebook',
  'youtube',
  'map',
  'video',
  'instagram',
  'twitter',
  'linkedin',
  'github',
  'phone',
  // PostActions / Links
  'share-2',
  'link',
  'external-link',
  'arrow-up-right',
  // Kontakt/Verzeichnis
  'id-card',
  'qr-code',
  'arrow-down-a-z',
  'users',
  // File-type icons (FilesBlock: dynamic f.iconName)
  'file',
  'file-text',
  'file-spreadsheet',
  'file-image',
  'file-video',
  'file-music',
  'file-down',
  'presentation',
  // Tag/flag/info/format fallbacks
  'tag',
  'flag',
  'info',
  'type',
  'image',
  // Windkarte / Map / Generator
  'fan',
  'mouse-pointer-click',
  'sliders-horizontal',
  'badge-check',
];

function walk(dir) {
  const out = [];
  for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
    if (entry.name === 'node_modules' || entry.name.startsWith('.')) continue;
    const full = path.join(dir, entry.name);
    if (entry.isDirectory()) {
      out.push(...walk(full));
    } else if (/\.(svelte|ts|tsx|js|mjs)$/.test(entry.name)) {
      out.push(full);
    }
  }
  return out;
}

function scanStatic(prefix) {
  const pattern = new RegExp(`icon="${prefix}:([a-z0-9-]+)"`, 'g');
  const found = new Set();
  for (const file of walk(SRC_DIR)) {
    const content = fs.readFileSync(file, 'utf8');
    let m;
    while ((m = pattern.exec(content)) !== null) {
      found.add(m[1]);
    }
  }
  return found;
}

/** Build a tree-shaken subset for one Iconify collection. */
function buildSubset({ prefix, pkg, outFile, extra }) {
  const iconsJson = path.join(ROOT, 'node_modules', '@iconify-json', pkg, 'icons.json');
  if (!fs.existsSync(iconsJson)) {
    console.error(`[generate-icons] missing ${iconsJson} — run \`npm install\` first.`);
    process.exit(1);
  }
  const collection = JSON.parse(fs.readFileSync(iconsJson, 'utf8'));
  const wanted = new Set([...scanStatic(prefix), ...extra]);

  const icons = {};
  const aliases = {};
  const missing = [];

  for (const name of wanted) {
    if (collection.icons[name]) {
      icons[name] = collection.icons[name];
    } else if (collection.aliases?.[name]) {
      aliases[name] = collection.aliases[name];
      const parent = collection.aliases[name].parent;
      if (parent && collection.icons[parent] && !icons[parent]) {
        icons[parent] = collection.icons[parent];
      }
    } else {
      missing.push(name);
    }
  }

  const subset = {
    prefix: collection.prefix,
    width: collection.width,
    height: collection.height,
    icons,
    ...(Object.keys(aliases).length ? { aliases } : {}),
  };
  fs.writeFileSync(outFile, JSON.stringify(subset, null, 2) + '\n');

  const sizeAfter = fs.statSync(outFile).size;
  console.log(
    `[generate-icons] ${prefix}: ${Object.keys(icons).length} icons + ${Object.keys(aliases).length} aliases → ${path.relative(ROOT, outFile)} (${(sizeAfter / 1024).toFixed(1)} KB)`,
  );
  if (missing.length) {
    console.warn(`[generate-icons] ${prefix}: ${missing.length} not found: ${missing.join(', ')}`);
  }
}

function main() {
  buildSubset({
    prefix: 'mdi',
    pkg: 'mdi',
    outFile: path.join(ROOT, 'src', 'lib', 'iconify-mdi-subset.generated.json'),
    extra: EXTRA_ICONS,
  });
  buildSubset({
    prefix: 'lucide',
    pkg: 'lucide',
    outFile: path.join(ROOT, 'src', 'lib', 'iconify-lucide-subset.generated.json'),
    extra: EXTRA_LUCIDE,
  });
}

main();