#!/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');
const ICONS_JSON = path.join(ROOT, 'node_modules', '@iconify-json', 'mdi', 'icons.json');
const OUT_FILE = path.join(ROOT, 'src', 'lib', 'iconify-mdi-subset.generated.json');

/**
 * 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 = [
  // PostActions: dynamic share/copy state
  'share-variant-outline',
  'link-variant',
  // Search: file-type fallback
  'file-outline',
  // Common social icons editors pick (Header.svelte: social.icon)
  'facebook',
  'instagram',
  'twitter',
  'youtube',
  'linkedin',
  'mastodon',
  'github',
  'email',
  'email-outline',
  'phone',
  'whatsapp',
  'telegram',
  'import-contacts',
  'arrow-top-right',
  'open-in-new',
  'card-account-details-outline',
  'qrcode',
  'sort-alphabetical-ascending',
  'account-group-outline',
  // Common file-type icons (FilesBlock: f.iconName)
  'file-pdf-box',
  'file-word-box',
  'file-excel-box',
  'file-image',
  'file-video',
  'file-music',
  // Tag/link/banner fallbacks (LinkListBlock, Tags, DeadlineBannerBlock)
  'link',
  'tag-outline',
  'flag-outline',
  'information-outline',
  // OrganisationsMapBlock: activate-overlay
  'cursor-default-click-outline',
  // CalendarBlock: social-image modal button
  'image-outline',
  // StellingnahmeGenerator: KI-Regeln-Accordion + Detail-Anpassen
  'tune-variant',
  'tune',
  'check-decagram',
];

const STATIC_PATTERN = /icon="mdi:([a-z0-9-]+)"/g;

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() {
  const found = new Set();
  for (const file of walk(SRC_DIR)) {
    const content = fs.readFileSync(file, 'utf8');
    let m;
    while ((m = STATIC_PATTERN.exec(content)) !== null) {
      found.add(m[1]);
    }
  }
  return found;
}

function main() {
  if (!fs.existsSync(ICONS_JSON)) {
    console.error(
      `[generate-icons] missing ${ICONS_JSON} — run \`npm install\` first.`,
    );
    process.exit(1);
  }
  const collection = JSON.parse(fs.readFileSync(ICONS_JSON, 'utf8'));
  const wanted = new Set([...scanStatic(), ...EXTRA_ICONS]);

  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(OUT_FILE, JSON.stringify(subset, null, 2) + '\n');

  const sizeBefore = fs.statSync(ICONS_JSON).size;
  const sizeAfter = fs.statSync(OUT_FILE).size;
  console.log(
    `[generate-icons] ${Object.keys(icons).length} icons + ${Object.keys(aliases).length} aliases → ${path.relative(ROOT, OUT_FILE)}`,
  );
  console.log(
    `[generate-icons] ${(sizeBefore / 1024 / 1024).toFixed(2)} MB → ${(sizeAfter / 1024).toFixed(1)} KB (${((1 - sizeAfter / sizeBefore) * 100).toFixed(1)}% smaller)`,
  );
  if (missing.length) {
    console.warn(
      `[generate-icons] ${missing.length} icon(s) not found in MDI: ${missing.join(', ')}`,
    );
  }
}

main();