import {
  initEditors, switchMode, getEditorValues, setEditorValues,
  setOnChange, getCurrentMode, getCssType, setCssType,
  relayoutEditors,
  MODE_TABS, MODE_TO_JS_TYPE, JS_TYPE_TO_MODE,
} from './editors.js';
import { renderPreview } from './preview.js';
import { initConsole, clearConsole } from './console-panel.js';
import { compileCss } from './preprocessors.js';
import { compileJs } from './js-preprocessors.js';
import { createFiddle, loadFiddle, updateFiddle, listTags } from './api.js';
import { getPref, setPref } from './preferences.js';
import { initEmmet } from './emmet.js';
import { initKeybindings } from './keybindings.js';
import { initResizer, clearInlineSizes } from './resizer.js';
import { exportHtml } from './export.js';
import { showQrModal } from './qr.js';

let currentId = null;
let debounceTimer = null;
let currentTags = [];
let currentResources = [];

const $ = (sel) => document.querySelector(sel);

const STARTER_TEMPLATES = {
  'html-css-js': { html: '', css: '', js: '' },
  'typescript': {
    html: '<div id="app"></div>',
    css: '',
    js: `interface Greeting {\n  name: string;\n  message: string;\n}\n\nconst greet = (g: Greeting): string => \`\${g.message}, \${g.name}!\`;\n\nconst result = greet({ name: "World", message: "Hello" });\ndocument.getElementById("app")!.innerHTML = \`<h1>\${result}</h1>\`;\nconsole.log(result);`,
  },
  'react': {
    js: `const App = () => {\n  const [count, setCount] = React.useState(0);\n  return (\n    <div>\n      <h1>Hello React</h1>\n      <button onClick={() => setCount(c => c + 1)}>Count: {count}</button>\n    </div>\n  );\n};\n\nReactDOM.createRoot(document.getElementById('root')).render(<App />);`,
    css: '',
    html: '',
  },
  'react-ts': {
    js: `const App: React.FC = () => {\n  const [count, setCount] = React.useState<number>(0);\n  return (\n    <div>\n      <h1>Hello React + TypeScript</h1>\n      <button onClick={() => setCount(c => c + 1)}>Count: {count}</button>\n    </div>\n  );\n};\n\nReactDOM.createRoot(document.getElementById('root')!).render(<App />);`,
    css: '',
    html: '',
  },
  'vue': {
    js: `<template>\n  <div>\n    <h1>{{ msg }}</h1>\n    <button @click="count++">Count: {{ count }}</button>\n  </div>\n</template>\n\n<script>\nconst component = {\n  data() {\n    return {\n      msg: 'Hello Vue!',\n      count: 0,\n    };\n  },\n};\n</script>`,
    css: '',
  },
  'svelte': {
    js: `<script>\n  let count = 0;\n</script>\n\n<h1>Hello Svelte</h1>\n<button on:click={() => count++}>Count: {count}</button>\n\n<style>\n  h1 { color: #ff3e00; }\n  button { padding: 8px 16px; cursor: pointer; }\n</style>`,
    css: '',
  },
  'markdown': {
    js: `# Hello Markdown\n\nThis is a **Markdown** fiddle. Write your content here and see it rendered in the preview.\n\n## Features\n\n- Headers, **bold**, *italic*\n- Lists (ordered and unordered)\n- Code blocks with syntax highlighting\n- Links, images, and more\n\n### Code Example\n\n\`\`\`javascript\nconst greeting = "Hello, World!";\nconsole.log(greeting);\n\`\`\`\n\n> Blockquotes work too!\n\n| Column 1 | Column 2 |\n|----------|----------|\n| Cell A   | Cell B   |`,
    css: `body {\n  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;\n  max-width: 720px;\n  margin: 0 auto;\n  padding: 24px;\n  line-height: 1.6;\n  color: #1a1a1a;\n}\n\nh1, h2, h3 { margin-top: 1.5em; margin-bottom: 0.5em; }\nh1 { border-bottom: 2px solid #eee; padding-bottom: 0.3em; }\n\ncode {\n  background: #f4f4f4;\n  padding: 2px 6px;\n  border-radius: 3px;\n  font-size: 0.9em;\n}\n\npre {\n  background: #f4f4f4;\n  padding: 16px;\n  border-radius: 6px;\n  overflow-x: auto;\n}\n\npre code { background: none; padding: 0; }\n\nblockquote {\n  border-left: 4px solid #ddd;\n  margin: 1em 0;\n  padding: 0.5em 1em;\n  color: #555;\n}\n\ntable {\n  border-collapse: collapse;\n  width: 100%;\n  margin: 1em 0;\n}\n\nth, td {\n  border: 1px solid #ddd;\n  padding: 8px 12px;\n  text-align: left;\n}\n\nth { background: #f4f4f4; font-weight: 600; }`,
  },
  'wasm': {
    html: '<h1>WebAssembly Demo</h1>\n<div id="output"></div>',
    css: `body {\n  font-family: monospace;\n  padding: 24px;\n  background: #1a1a2e;\n  color: #0f0;\n}\n\nh1 { color: #00d4ff; margin-bottom: 16px; }\n#output { white-space: pre; font-size: 14px; line-height: 1.8; }`,
    js: `// Inline WebAssembly "add" module (no external URL needed)\n// WAT source: (module (func (export "add") (param i32 i32) (result i32) local.get 0 local.get 1 i32.add))\nconst wasmBytes = new Uint8Array([\n  0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00,\n  0x01, 0x07, 0x01, 0x60, 0x02, 0x7f, 0x7f, 0x01, 0x7f,\n  0x03, 0x02, 0x01, 0x00,\n  0x07, 0x07, 0x01, 0x03, 0x61, 0x64, 0x64, 0x00, 0x00,\n  0x0a, 0x09, 0x01, 0x07, 0x00, 0x20, 0x00, 0x20, 0x01, 0x6a, 0x0b\n]);\n\nconst out = document.getElementById('output');\n\ntry {\n  const { instance } = await WebAssembly.instantiate(wasmBytes);\n  const add = instance.exports.add;\n\n  out.textContent = [\n    \`WASM loaded successfully!\`,\n    \`\`,\n    \`add(2, 3) = \${add(2, 3)}\`,\n    \`add(100, 200) = \${add(100, 200)}\`,\n    \`add(-5, 10) = \${add(-5, 10)}\`,\n  ].join('\\n');\n} catch (e) {\n  out.textContent = 'Error: ' + e.message;\n}`,
  },
};

function getTailwindChecked() {
  const cb = $('#tailwind-checkbox');
  return cb ? cb.checked : false;
}

async function run() {
  const mode = getCurrentMode();
  const { html, css, js } = getEditorValues();
  const cssType = getCssType();

  try {
    const compiledCss = await compileCss(css, cssType);
    const result = await compileJs(js, mode);
    clearConsole();

    // Show warnings from compilation (e.g., Svelte)
    if (result.warnings && result.warnings.length) {
      result.warnings.forEach((w) => {
        window.postMessage({ type: 'console', method: 'warn', args: [w] }, '*');
      });
    }

    const options = {
      tailwind: getTailwindChecked(),
      isModule: result.isModule || false,
      renderedHtml: result.renderedHtml || null,
      previewTheme: getPref('previewTheme'),
      resources: currentResources,
    };

    renderPreview(html, compiledCss, result.js, mode, result.extraCss || '', options);
  } catch (e) {
    clearConsole();
    renderPreview(html, '', '', mode, '', { tailwind: getTailwindChecked(), previewTheme: getPref('previewTheme'), resources: currentResources });
    window.postMessage({ type: 'console', method: 'error', args: [`Compile error: ${e.message}`] }, '*');
  }
}

function scheduleRun() {
  if (!getPref('autoRun')) return;
  clearTimeout(debounceTimer);
  debounceTimer = setTimeout(run, 500);
}

function showToast(msg) {
  const toast = $('#share-toast');
  toast.textContent = msg;
  toast.classList.remove('hidden');
  setTimeout(() => toast.classList.add('hidden'), 3000);
}

async function save() {
  const { html, css, js } = getEditorValues();
  const title = $('#title-input').value || 'Untitled';
  const css_type = getCssType();
  const js_type = MODE_TO_JS_TYPE[getCurrentMode()] || 'javascript';
  const listed = $('#listed-checkbox').checked ? 1 : 0;
  const tags = currentTags.slice();
  const options = JSON.stringify({ tailwind: getTailwindChecked(), resources: currentResources });
  try {
    if (currentId) {
      await updateFiddle(currentId, { title, html, css, css_type, js, js_type, listed, options, tags });
      showToast(`Saved! Share: ${location.origin}/f/${currentId}`);
    } else {
      const result = await createFiddle({ title, html, css, css_type, js, js_type, listed, options, tags });
      currentId = result.id;
      history.pushState(null, '', `/f/${currentId}`);
      showToast(`Saved! Share: ${location.origin}/f/${currentId}`);
    }
  } catch (e) {
    showToast(`Save failed: ${e.message}`);
  }
}

async function fork() {
  const { html, css, js } = getEditorValues();
  const title = ($('#title-input').value || 'Untitled') + ' (fork)';
  const css_type = getCssType();
  const js_type = MODE_TO_JS_TYPE[getCurrentMode()] || 'javascript';
  const listed = $('#listed-checkbox').checked ? 1 : 0;
  const tags = currentTags.slice();
  const options = JSON.stringify({ tailwind: getTailwindChecked(), resources: currentResources });
  try {
    const result = await createFiddle({ title, html, css, css_type, js, js_type, listed, options, tags });
    currentId = result.id;
    $('#title-input').value = title;
    history.pushState(null, '', `/f/${currentId}`);
    showToast(`Forked! New URL: ${location.origin}/f/${currentId}`);
  } catch (e) {
    showToast(`Fork failed: ${e.message}`);
  }
}

async function loadFromUrl() {
  const match = location.pathname.match(/^\/f\/([a-zA-Z0-9_-]+)$/);
  if (!match) return;
  try {
    const fiddle = await loadFiddle(match[1]);
    currentId = fiddle.id;
    $('#title-input').value = fiddle.title;

    // Restore mode from js_type
    const mode = JS_TYPE_TO_MODE[fiddle.js_type] || 'html-css-js';
    $('#framework-mode').value = mode;
    switchMode(mode);

    // Restore CSS type
    setCssType(fiddle.css_type || 'css');

    // Restore listed/tags
    $('#listed-checkbox').checked = fiddle.listed !== 0;
    currentTags = (fiddle.tags || []).map(t => t.name);
    renderTags();

    // Restore options (tailwind checkbox, resources)
    const opts = JSON.parse(fiddle.options || '{}');
    const twCb = $('#tailwind-checkbox');
    if (twCb) twCb.checked = !!opts.tailwind;
    currentResources = opts.resources || [];
    renderResourceList();

    setEditorValues(fiddle);
    setTimeout(run, 100);
  } catch (e) {
    showToast(`Failed to load fiddle: ${e.message}`);
  }
}

function handleModeChange(newMode) {
  const oldMode = getCurrentMode();
  if (newMode === oldMode) return;

  switchMode(newMode);

  // Insert starter template if editors are empty
  const { html, css, js } = getEditorValues();
  if (!html && !css && !js) {
    const template = STARTER_TEMPLATES[newMode];
    if (template) {
      setEditorValues(template);
    }
  }

  scheduleRun();
}

function applyLayout(layout) {
  const grid = $('.grid');
  // Remove all layout classes
  grid.classList.remove('layout-top-bottom', 'layout-editor-only', 'layout-preview-only');
  // Clear resizer inline styles when switching layouts
  clearInlineSizes();

  if (layout === 'top-bottom') grid.classList.add('layout-top-bottom');
  else if (layout === 'editor-only') grid.classList.add('layout-editor-only');
  else if (layout === 'preview-only') grid.classList.add('layout-preview-only');

  setPref('layout', layout);
  // Give DOM time to reflow then relayout editors
  requestAnimationFrame(() => relayoutEditors());
}

async function init() {
  // Load Emmet before editors so completion providers are registered
  await initEmmet();

  initEditors('html-css-js');
  setOnChange(scheduleRun);
  initConsole();
  initResizer();
  initKeybindings();

  // Auto-run checkbox
  const autoRunCb = $('#auto-run-checkbox');
  autoRunCb.checked = getPref('autoRun');
  autoRunCb.addEventListener('change', (e) => setPref('autoRun', e.target.checked));

  // Tailwind checkbox
  const twCb = $('#tailwind-checkbox');
  if (twCb) {
    twCb.addEventListener('change', () => scheduleRun());
  }

  // Layout selector
  const layoutSel = $('#layout-mode');
  const savedLayout = getPref('layout') || 'default';
  layoutSel.value = savedLayout;
  if (savedLayout !== 'default') applyLayout(savedLayout);
  layoutSel.addEventListener('change', (e) => applyLayout(e.target.value));

  // Mode selector
  $('#framework-mode').addEventListener('change', (e) => {
    handleModeChange(e.target.value);
  });

  // Toolbar buttons
  $('#btn-run').addEventListener('click', run);
  $('#btn-save').addEventListener('click', save);
  $('#btn-fork').addEventListener('click', fork);

  // Keyboard shortcuts
  document.addEventListener('keydown', (e) => {
    if ((e.ctrlKey || e.metaKey) && e.key === 's') {
      e.preventDefault();
      save();
    }
    if ((e.ctrlKey || e.metaKey) && e.key === 'Enter') {
      e.preventDefault();
      run();
    }
    // Escape closes any open modal
    if (e.key === 'Escape') {
      document.querySelectorAll('.modal-overlay:not(.hidden)').forEach(m => m.classList.add('hidden'));
    }
    // ? key opens shortcuts (only when not typing in an input/editor)
    if (e.key === '?' && !e.ctrlKey && !e.metaKey) {
      const tag = document.activeElement?.tagName;
      if (tag !== 'INPUT' && tag !== 'TEXTAREA' && !document.activeElement?.closest('.editor-area')) {
        e.preventDefault();
        $('#shortcuts-modal').classList.remove('hidden');
      }
    }
  });

  // Tags input
  const tagsInput = $('#tags-input');
  tagsInput.addEventListener('keydown', (e) => {
    if (e.key === 'Enter' || e.key === ',') {
      e.preventDefault();
      const val = tagsInput.value.trim().replace(/,/g, '');
      if (val && !currentTags.includes(val)) {
        currentTags.push(val);
        renderTags();
      }
      tagsInput.value = '';
    }
  });

  // Load tag suggestions
  loadTagSuggestions();

  // Export & QR buttons
  $('#btn-export').addEventListener('click', async () => {
    const mode = getCurrentMode();
    const { html, css, js } = getEditorValues();
    const cssType = getCssType();
    const title = $('#title-input').value || 'Untitled';
    try {
      const compiledCss = await compileCss(css, cssType);
      const result = await compileJs(js, mode);
      exportHtml({
        title, html, css: compiledCss, js: result.js, mode,
        extraCss: result.extraCss,
        tailwind: getTailwindChecked(),
        isModule: result.isModule || false,
        renderedHtml: result.renderedHtml || null,
        previewTheme: getPref('previewTheme'),
        resources: currentResources,
      });
    } catch (e) {
      showToast(`Export failed: ${e.message}`);
    }
  });

  $('#btn-qr').addEventListener('click', () => {
    const url = currentId ? `${location.origin}/f/${currentId}` : location.href;
    showQrModal(url);
  });

  // Preview theme selector
  const themeSel = $('#preview-theme');
  const savedTheme = getPref('previewTheme');
  themeSel.value = savedTheme;
  themeSel.addEventListener('change', (e) => {
    setPref('previewTheme', e.target.value);
    scheduleRun();
  });

  // Resources modal
  const resModal = $('#resources-modal');
  $('#btn-resources').addEventListener('click', () => resModal.classList.remove('hidden'));
  $('#resources-modal-close').addEventListener('click', () => resModal.classList.add('hidden'));
  resModal.addEventListener('click', (e) => { if (e.target === resModal) resModal.classList.add('hidden'); });

  $('#btn-add-css').addEventListener('click', () => {
    const input = $('#resource-css-input');
    const url = input.value.trim();
    if (url) { currentResources.push({ type: 'css', url }); input.value = ''; renderResourceList(); scheduleRun(); }
  });
  $('#btn-add-js').addEventListener('click', () => {
    const input = $('#resource-js-input');
    const url = input.value.trim();
    if (url) { currentResources.push({ type: 'js', url }); input.value = ''; renderResourceList(); scheduleRun(); }
  });
  $('#resource-css-input').addEventListener('keydown', (e) => { if (e.key === 'Enter') $('#btn-add-css').click(); });
  $('#resource-js-input').addEventListener('keydown', (e) => { if (e.key === 'Enter') $('#btn-add-js').click(); });

  // Shortcuts modal
  const scModal = $('#shortcuts-modal');
  $('#btn-shortcuts').addEventListener('click', () => scModal.classList.remove('hidden'));
  $('#shortcuts-modal-close').addEventListener('click', () => scModal.classList.add('hidden'));
  scModal.addEventListener('click', (e) => { if (e.target === scModal) scModal.classList.add('hidden'); });

  // Load fiddle from URL if present
  loadFromUrl();

  // Handle browser back/forward
  window.addEventListener('popstate', () => {
    currentId = null;
    loadFromUrl();
  });
}

function renderTags() {
  const container = $('#tags-display');
  container.innerHTML = '';
  for (const tag of currentTags) {
    const pill = document.createElement('span');
    pill.className = 'tag-pill';
    pill.innerHTML = `${tag}<button class="tag-remove">&times;</button>`;
    pill.querySelector('.tag-remove').addEventListener('click', () => {
      currentTags = currentTags.filter(t => t !== tag);
      renderTags();
    });
    container.appendChild(pill);
  }
}

function renderResourceList() {
  const container = $('#resource-list');
  container.innerHTML = '';
  currentResources.forEach((r, i) => {
    const item = document.createElement('div');
    item.className = 'resource-item';
    item.innerHTML = `<span class="resource-type ${r.type}">${r.type}</span><span class="resource-url" title="${r.url}">${r.url}</span><button class="resource-remove">&times;</button>`;
    item.querySelector('.resource-remove').addEventListener('click', () => {
      currentResources.splice(i, 1);
      renderResourceList();
      scheduleRun();
    });
    container.appendChild(item);
  });
}

async function loadTagSuggestions() {
  try {
    const { tags } = await listTags();
    const datalist = $('#tags-datalist');
    datalist.innerHTML = '';
    for (const t of tags) {
      const opt = document.createElement('option');
      opt.value = t.name;
      datalist.appendChild(opt);
    }
  } catch (_) { /* ignore */ }
}

init();