// ==UserScript==
// @name         Game Datacards - Image Export/Import (ZIP)
// @namespace    local
// @match        https://game-datacards.eu/*
// @grant        none
// @version      2.1
// @run-at       document-idle
// @require      https://cdn.jsdelivr.net/npm/fflate@0.8.3/umd/index.js
// @downloadURL  https://git.luxick.de/luxick/scripts/raw/branch/master/js/datacards-import-export.user.js
// @updateURL    https://git.luxick.de/luxick/scripts/raw/branch/master/js/datacards-import-export.user.js
// ==/UserScript==

(function () {
  'use strict';

  const DB_NAME = 'CardImagesDB';
  const STORE = 'images';

  function openDB() {
    return new Promise((resolve, reject) => {
      const req = indexedDB.open(DB_NAME);
      req.onsuccess = () => resolve(req.result);
      req.onerror = () => reject(req.error);
    });
  }

  function getAll(db) {
    return new Promise((resolve, reject) => {
      const tx = db.transaction(STORE, 'readonly');
      const req = tx.objectStore(STORE).getAll();
      req.onsuccess = () => resolve(req.result);
      req.onerror = () => reject(req.error);
    });
  }

  function putAll(db, records) {
    return new Promise((resolve, reject) => {
      const tx = db.transaction(STORE, 'readwrite');
      const store = tx.objectStore(STORE);
      records.forEach((r) => store.put(r));
      tx.oncomplete = () => resolve();
      tx.onerror = () => reject(tx.error);
    });
  }

  function blobToU8(blob) {
    return new Promise((resolve, reject) => {
      const reader = new FileReader();
      reader.onloadend = () => resolve(new Uint8Array(reader.result));
      reader.onerror = () => reject(reader.error);
      reader.readAsArrayBuffer(blob);
    });
  }

  function extFromType(type) {
    if (!type) return 'bin';
    const map = { 'image/png': 'png', 'image/jpeg': 'jpg', 'image/webp': 'webp', 'image/gif': 'gif' };
    return map[type] || type.split('/')[1] || 'bin';
  }

  async function doExport() {
    const db = await openDB();
    const records = await getAll(db);
    if (!records.length) {
      alert('No images found in the database.');
      return;
    }

    const files = {};
    const manifest = [];

    for (const rec of records) {
      if (!(rec.image instanceof Blob)) {
        console.warn('Record image is not a Blob, skipping binary for', rec.id);
      }
      const ext = extFromType(rec.type || (rec.image && rec.image.type));
      const imgName = `images/${rec.id}.${ext}`;

      if (rec.image instanceof Blob) {
        files[imgName] = await blobToU8(rec.image);
      }

      const meta = { ...rec };
      delete meta.image;
      meta.__file = imgName;
      manifest.push(meta);
    }

    files['manifest.json'] = fflate.strToU8(JSON.stringify(manifest, null, 2));

    const zipped = fflate.zipSync(files, { level: 6 });
    const blob = new Blob([zipped], { type: 'application/zip' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = 'game-datacards-images.zip';
    a.click();
    URL.revokeObjectURL(url);
    console.log(`Exported ${records.length} images to ZIP.`);
  }

  async function doImport() {
    const input = document.createElement('input');
    input.type = 'file';
    input.accept = '.zip,application/zip';
    input.onchange = async () => {
      const file = input.files[0];
      if (!file) return;

      const buf = new Uint8Array(await file.arrayBuffer());
      const entries = fflate.unzipSync(buf);

      if (!entries['manifest.json']) {
        alert('No manifest.json in the ZIP. Cannot import.');
        return;
      }

      const manifest = JSON.parse(fflate.strFromU8(entries['manifest.json']));
      const records = [];

      for (const meta of manifest) {
        const rec = { ...meta };
        const fileName = meta.__file;
        delete rec.__file;

        if (fileName && entries[fileName]) {
          rec.image = new Blob([entries[fileName]], { type: rec.type || 'application/octet-stream' });
          rec.size = entries[fileName].byteLength;
        }
        records.push(rec);
      }

      const db = await openDB();
      await putAll(db, records);
      alert(`Imported ${records.length} images. Reload the page to see them.`);
    };
    input.click();
  }

  const EXPORT_ICON =
    '<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"></path><polyline points="7 10 12 15 17 10"></polyline><line x1="12" x2="12" y1="15" y2="3"></line></svg>';

  const IMPORT_ICON =
    '<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"></path><polyline points="17 8 12 3 7 8"></polyline><line x1="12" x2="12" y1="3" y2="15"></line></svg>';

  function mkBtn(id, title, iconSvg, fn) {
    const b = document.createElement('button');
    b.id = id;
    b.className = 'app-header-icon-btn';
    b.title = title;
    b.setAttribute('aria-label', title);
    b.innerHTML = iconSvg;
    b.onclick = () => fn().catch((e) => alert('Error: ' + e.message));
    return b;
  }

  function addButtons() {
    if (document.getElementById('gdc-img-export')) return true;

    const settingsBtn = document.querySelector('.app-header-settings-btn');
    if (!settingsBtn) return false;

    // Wrap our two buttons in a header group so spacing matches the rest.
    const group = document.createElement('div');
    group.className = 'app-header-group';
    group.appendChild(mkBtn('gdc-img-export', 'Export card images', EXPORT_ICON, doExport));
    group.appendChild(mkBtn('gdc-img-import', 'Import card images', IMPORT_ICON, doImport));

    // Insert the group right before the settings button's group,
    // so the buttons sit to the left of the cog.
    const settingsGroup = settingsBtn.closest('.app-header-group');
    settingsGroup.parentNode.insertBefore(group, settingsGroup);
    return true;
  }

  // The app renders after load, so retry until the header exists.
  if (!addButtons()) {
    const obs = new MutationObserver(() => {
      if (addButtons()) obs.disconnect();
    });
    obs.observe(document.body, { childList: true, subtree: true });
  }
})();