/**
 * AKSRT Code Block Enhancements
 *
 * Integrates EnlighterJS for syntax highlighting and adds
 * copy-to-clipboard buttons and language labels to code blocks.
 * No jQuery dependency — pure vanilla JS.
 *
 * @package AKSRT
 */

(function () {
  'use strict';

  var BASE_URI = (window.aksrtData && window.aksrtData.themeUri) || '';
  var STYLE_ID = 'aksrt-enlighter-css';
  var ENLIGHTER_LOADED = false;

  function getHighlightSettings() {
    return (window.aksrtData && window.aksrtData.codeHighlight) || {};
  }

  function isDarkTheme(value) {
    if (typeof value === 'boolean') return value;
    return document.documentElement.classList.contains('dark') ||
           document.documentElement.getAttribute('data-theme') === 'dark';
  }

  function getThemeName(isDark) {
    var settings = getHighlightSettings();
    return isDarkTheme(isDark) ? (settings.darkTheme || 'monokai') : (settings.lightTheme || 'enlighter');
  }

  function applyEnlighterTheme(isDark) {
    var settings = getHighlightSettings();
    if (settings.enabled === false) return;

    var theme = getThemeName(isDark);
    document.querySelectorAll('.enlighter-default').forEach(function (el) {
      el.className = el.className.replace(/\benlighter-t-[\w-]+\b/g, '').replace(/\s+/g, ' ').trim();
      el.classList.add('enlighter-t-' + theme);
    });
  }

  window.AksrtPrecodeApplyTheme = applyEnlighterTheme;

  // ── Copy Button Styles ──

  var COPY_STYLE_ID = 'aksrt-precode-style';

  function injectCopyStyle() {
    if (document.getElementById(COPY_STYLE_ID)) return;
    var style = document.createElement('style');
    style.id = COPY_STYLE_ID;
    style.textContent =
      '.aksrt-code-copy{position:absolute;top:6px;right:8px;border:none;background:rgba(255,255,255,0.08);color:#a6adc8;cursor:pointer;padding:3px 10px;border-radius:6px;font-size:12px;z-index:10;transition:all 0.2s;backdrop-filter:blur(4px);}' +
      '.aksrt-code-copy:hover{background:rgba(255,255,255,0.15);color:#cdd6f4;}' +
      '.aksrt-code-copy.is-copied{color:#a6e3a1;}' +
      '.enlighter-default{position:relative;}' +
      '.enlighter-default .aksrt-code-copy{top:4px;right:4px;}' +
      'pre{position:relative;}' +
      'pre .aksrt-code-copy{top:8px;right:8px;}';
    document.head.appendChild(style);
  }

  // ── EnlighterJS CSS Injection ──

  function injectEnlighterCSS() {
    if (document.getElementById(STYLE_ID)) return;
    var link = document.createElement('link');
    link.id = STYLE_ID;
    link.rel = 'stylesheet';
    link.href = BASE_URI + '/assets/js/enlighter/enlighterjs.min.css';
    document.head.appendChild(link);
  }

  // ── EnlighterJS Loader ──

  function loadEnlighterJS(callback) {
    if (ENLIGHTER_LOADED && window.EnlighterJS) {
      callback();
      return;
    }

    injectEnlighterCSS();

    var script = document.createElement('script');
    script.src = BASE_URI + '/assets/js/enlighter/enlighterjs.min.js';
    script.onload = function () {
      ENLIGHTER_LOADED = true;
      callback();
    };
    script.onerror = function () {
      // Fallback: just add copy buttons without highlighting
      addCopyButtonsPlain();
    };
    document.head.appendChild(script);
  }

  // ── Copy to Clipboard ──

  function copyToClipboard(text, btn) {
    if (navigator.clipboard && navigator.clipboard.writeText) {
      navigator.clipboard.writeText(text).then(function () {
        showCopied(btn);
      });
    } else {
      var ta = document.createElement('textarea');
      ta.value = text;
      ta.style.cssText = 'position:fixed;left:-9999px;';
      document.body.appendChild(ta);
      ta.select();
      try { document.execCommand('copy'); showCopied(btn); } catch (e) { /* ignore */ }
      document.body.removeChild(ta);
    }
  }

  function showCopied(btn) {
    btn.textContent = '已复制';
    btn.classList.add('is-copied');
    setTimeout(function () {
      btn.textContent = '复制';
      btn.classList.remove('is-copied');
    }, 1500);
  }

  function createCopyButton(text) {
    var btn = document.createElement('button');
    btn.className = 'aksrt-code-copy';
    btn.textContent = '复制';
    btn.type = 'button';
    btn.addEventListener('click', function () {
      copyToClipboard(text, btn);
    });
    return btn;
  }

  // ── EnlighterJS Integration ──

  function initEnlighter() {
    if (!window.EnlighterJS) return;

    // Get settings from aksrtData or use defaults
    var settings = getHighlightSettings();
    if (settings.enabled === false) return;  // 后台关闭代码高亮

    var lineNumbers = settings.lineNumbers === true;
    var showButtons = settings.showButtons !== false;
    var maxHeight = settings.maxHeight || 400;

    var currentTheme = getThemeName();

    // Find all code blocks that haven't been processed
    var blocks = document.querySelectorAll('pre > code:not(.enlighter-origin)');
    if (blocks.length === 0) return;

    // Process each block
    blocks.forEach(function (code) {
      var pre = code.parentElement;
      if (!pre || pre.dataset.aksrtEnhanced) return;

      // Get raw text before EnlighterJS processes it
      var rawText = code.textContent;

      // Apply EnlighterJS
      try {
        EnlighterJS.enlight(code, {
          theme: currentTheme,
          linenumbers: lineNumbers,
          indent: 2,
          textOverflow: 'scroll',
          rawcodeDbclick: true,
          rawButton: showButtons,
          infoButton: showButtons,
          windowButton: showButtons
        });
      } catch (e) {
        // If EnlighterJS fails, keep the plain block
      }

      // Add copy button after EnlighterJS processing
      var container = pre.querySelector('.enlighter-default') || pre;
      container.appendChild(createCopyButton(rawText));
      pre.dataset.aksrtEnhanced = '1';

      // Apply max-height
      if (maxHeight > 0) {
        pre.style.maxHeight = maxHeight + 'px';
        pre.style.overflow = 'auto';
      }
    });

    applyEnlighterTheme();
  }

  // ── Fallback: Plain code blocks with copy buttons ──

  function addCopyButtonsPlain() {
    var blocks = document.querySelectorAll('pre > code');
    blocks.forEach(function (code) {
      var pre = code.parentElement;
      if (!pre || pre.dataset.aksrtEnhanced) return;
      pre.style.position = 'relative';
      pre.appendChild(createCopyButton(code.textContent));
      pre.dataset.aksrtEnhanced = '1';
    });
  }

  // ── Main Init ──

  function init() {
    injectCopyStyle();

    // Check if there are any code blocks on the page
    var blocks = document.querySelectorAll('pre > code');
    if (blocks.length === 0) return;

    // Load EnlighterJS and initialize
    loadEnlighterJS(initEnlighter);
  }

  window.AksrtFrontend.register('aksrt-precode', function () {
    init();
  });
})();