/**
 * MetonaEditor Styles - 编辑器样式
 * @module styles
 * @version 0.1.8
 * @description 编辑器 UI 样式注入与管理
 */

import { THEMES } from './constants.js';

let styleElement = null;

/**
 * 生成 CSS 样式
 */
const generateCSS = () => {
  return `
    /* ============ CSS 变量默认值（被 themes.js 动态覆盖） ============ */
    :root {
      --md-bg: #ffffff;
      --md-text: #1f2937;
      --md-border: rgba(0, 0, 0, 0.08);
      --md-shadow: 0 10px 36px -10px rgba(0,0,0,0.18), 0 4px 14px -4px rgba(0,0,0,0.08);
      --md-hover-shadow: 0 14px 48px -10px rgba(0,0,0,0.22), 0 6px 18px -4px rgba(0,0,0,0.10);
      --md-toolbar-bg: rgba(248, 249, 250, 0.92);
      --md-textarea-bg: #ffffff;
      --md-preview-bg: #ffffff;
      --md-code-bg: rgba(243, 244, 246, 1);
      --md-code-text: #1f2937;
      --md-accent: #3b82f6;
      --md-muted: #6b7280;
      --md-radius: 10px;
      --md-font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
      --md-mono: "SF Mono", "Cascadia Code", "Consolas", "Liberation Mono", "Courier New", monospace;
    }

    /* ============ 容器 ============ */
    .me-wrapper {
      display: flex;
      flex-direction: column;
      box-sizing: border-box;
      border: 1px solid var(--md-border);
      border-radius: var(--md-radius);
      overflow: hidden;
      background: var(--md-bg);
      color: var(--md-text);
      box-shadow: var(--md-shadow);
      font-family: var(--md-font);
      font-size: 14px;
      line-height: 1.6;
      position: relative;
      transition: box-shadow 0.25s ease, border-color 0.25s ease;
      width: 100%;
    }
    .me-wrapper:hover { box-shadow: var(--md-hover-shadow); }
    .me-wrapper.me-disabled { opacity: 0.6; pointer-events: none; }
    .me-wrapper * { box-sizing: border-box; }
    .me-wrapper.me-fullscreen {
      position: fixed;
      top: 0; left: 0; right: 0; bottom: 0;
      width: 100vw; height: 100vh;
      z-index: 9999;
      border-radius: 0;
      border: 0;
    }

    /* ============ 工具栏 ============ */
    .me-toolbar {
      display: flex;
      align-items: center;
      flex-wrap: wrap;
      gap: 2px;
      padding: 6px 8px;
      background: var(--md-toolbar-bg);
      border-bottom: 1px solid var(--md-border);
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
      min-height: 40px;
    }
    .me-btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      width: 30px; height: 30px;
      padding: 0;
      border: 0;
      border-radius: 6px;
      background: transparent;
      color: var(--md-text);
      cursor: pointer;
      transition: background 0.15s ease, color 0.15s ease, transform 0.1s ease;
      flex-shrink: 0;
    }
    .me-btn:hover { background: var(--md-code-bg); color: var(--md-accent); }
    .me-btn:active { transform: scale(0.92); }
    .me-btn.me-active { background: var(--md-accent); color: #fff; }
    .me-btn:disabled { opacity: 0.35; cursor: not-allowed; pointer-events: none; }
    .me-btn:focus-visible { outline: 2px solid var(--md-accent); outline-offset: 1px; }
    .me-btn svg { width: 17px; height: 17px; display: block; }
    .me-btn span { font-size: 12px; font-weight: 500; }

    .me-toolbar-sep {
      display: inline-block;
      width: 1px; height: 20px;
      background: var(--md-border);
      margin: 0 4px;
      flex-shrink: 0;
    }
    .me-toolbar-group {
      display: inline-flex;
      gap: 2px;
      margin-left: auto;
      padding-left: 6px;
      border-left: 1px solid var(--md-border);
    }
    .me-toolbar-group .me-btn { width: auto; padding: 0 8px; }
    .me-toolbar-group .me-btn span { font-size: 12px; }

    /* ============ 主体布局 ============ */
    .me-body {
      display: flex;
      flex: 1;
      min-height: 0;
      position: relative;
    }
    .me-editor-pane, .me-preview-pane {
      flex: 1 1 50%;
      min-width: 0;
      overflow: hidden;
      position: relative;
    }

    /* ============ 编辑区内层（v0.1.7） ============ */
    .me-editor-inner { display: flex; height: 100%; overflow: hidden; position: relative; }
    .me-gutter {
      flex: 0 0 auto;
      min-width: 36px;
      padding: 16px 8px 16px 6px;
      overflow: hidden;
      background: var(--md-code-bg);
      border-right: 1px solid var(--md-border);
      color: var(--md-muted);
      font-family: var(--md-mono);
      font-size: 13.5px;
      line-height: 1.7;
      text-align: right;
      user-select: none;
      white-space: pre;
    }
    .me-gutter-line { padding-right: 4px; }
    .me-gutter-active {
      color: var(--md-accent);
      font-weight: 600;
      background: rgba(59, 130, 246, 0.08);
      border-radius: 3px;
    }

    .me-divider {
      flex: 0 0 1px;
      background: var(--md-border);
      cursor: col-resize;
      position: relative;
    }
    .me-divider::after {
      content: '';
      position: absolute;
      top: 0; bottom: 0; left: -3px; right: -3px;
    }
    .me-divider:hover { background: var(--md-accent); }

    /* 编辑区 */
    .me-textarea {
      width: 100%;
      height: 100%;
      padding: 16px 18px;
      border: 0;
      outline: 0;
      resize: none;
      background: var(--md-textarea-bg);
      color: var(--md-text);
      font-family: var(--md-mono);
      font-size: 13.5px;
      line-height: 1.7;
      tab-size: 2;
      -moz-tab-size: 2;
      display: block;
      white-space: pre-wrap;
      word-wrap: break-word;
    }
    .me-textarea::placeholder { color: var(--md-muted); opacity: 0.7; }
    .me-textarea:focus { outline: 0; }

    /* 预览区 */
    .me-preview-pane { overflow: auto; background: var(--md-preview-bg); }
    .me-preview {
      padding: 18px 22px;
      max-width: 100%;
      word-wrap: break-word;
      overflow-wrap: break-word;
    }

    /* 模式切换 */
    .me-body.me-mode-edit .me-preview-pane,
    .me-body.me-mode-edit .me-divider { display: none; }
    .me-body.me-mode-edit .me-editor-pane { flex: 1 1 100%; }
    .me-body.me-mode-preview .me-editor-pane,
    .me-body.me-mode-preview .me-divider { display: none; }
    .me-body.me-mode-preview .me-preview-pane { flex: 1 1 100%; }

    /* ============ 预览区排版 ============ */
    .me-preview > :first-child { margin-top: 0; }
    .me-preview > :last-child { margin-bottom: 0; }
    .me-preview h1, .me-preview h2, .me-preview h3,
    .me-preview h4, .me-preview h5, .me-preview h6 {
      margin: 1.4em 0 0.6em;
      font-weight: 650;
      line-height: 1.3;
    }
    .me-preview h1 { font-size: 1.9em; padding-bottom: 0.3em; border-bottom: 1px solid var(--md-border); }
    .me-preview h2 { font-size: 1.55em; padding-bottom: 0.3em; border-bottom: 1px solid var(--md-border); }
    .me-preview h3 { font-size: 1.3em; }
    .me-preview h4 { font-size: 1.12em; }
    .me-preview h5 { font-size: 1em; }
    .me-preview h6 { font-size: 0.9em; color: var(--md-muted); }
    .me-preview p { margin: 0.7em 0; }
    .me-preview a { color: var(--md-accent); text-decoration: none; }
    .me-preview a:hover { text-decoration: underline; }
    .me-preview strong { font-weight: 650; }
    .me-preview em { font-style: italic; }
    .me-preview del { text-decoration: line-through; opacity: 0.75; }
    .me-preview ul, .me-preview ol { margin: 0.6em 0; padding-left: 1.6em; }
    .me-preview li { margin: 0.25em 0; }
    .me-preview li.me-task-item { list-style: none; margin-left: -1.4em; }
    .me-preview li.me-task-item input { margin-right: 0.5em; vertical-align: middle; }
    .me-preview blockquote {
      margin: 0.8em 0;
      padding: 0.4em 1em;
      border-left: 3px solid var(--md-accent);
      background: var(--md-code-bg);
      border-radius: 0 6px 6px 0;
      color: var(--md-text);
    }
    .me-preview blockquote > :first-child { margin-top: 0; }
    .me-preview blockquote > :last-child { margin-bottom: 0; }
    .me-preview hr {
      border: 0;
      height: 1px;
      background: var(--md-border);
      margin: 1.6em 0;
    }
    .me-preview code {
      font-family: var(--md-mono);
      font-size: 0.88em;
      padding: 0.15em 0.4em;
      background: var(--md-code-bg);
      color: var(--md-code-text);
      border-radius: 4px;
    }
    .me-preview pre {
      margin: 0.9em 0;
      padding: 14px 16px;
      background: var(--md-code-bg);
      border-radius: 8px;
      overflow-x: auto;
      border: 1px solid var(--md-border);
    }
    .me-preview pre code {
      padding: 0;
      background: transparent;
      color: var(--md-code-text);
      font-size: 0.9em;
      line-height: 1.6;
      border-radius: 0;
    }
    .me-preview img {
      max-width: 100%;
      height: auto;
      border-radius: 6px;
      vertical-align: middle;
    }
    .me-table-wrap { overflow-x: auto; margin: 0.9em 0; }
    .me-preview table {
      border-collapse: collapse;
      width: 100%;
      font-size: 0.93em;
      display: block;
    }
    .me-preview th, .me-preview td {
      border: 1px solid var(--md-border);
      padding: 7px 12px;
      text-align: left;
    }
    .me-preview th {
      background: var(--md-code-bg);
      font-weight: 600;
    }
    .me-preview tr:nth-child(even) td { background: var(--md-code-bg); }
    .me-preview tr:nth-child(even) td { background-color: color-mix(in srgb, var(--md-code-bg) 40%, transparent); }

    /* ============ 状态栏 ============ */
    .me-statusbar {
      display: flex;
      align-items: center;
      justify-content: flex-end;
      gap: 14px;
      padding: 4px 12px;
      border-top: 1px solid var(--md-border);
      background: var(--md-toolbar-bg);
      color: var(--md-muted);
      font-size: 12px;
      min-height: 26px;
    }
    .me-statusbar:empty { display: none; }

    /* ============ 响应式 ============ */
    @media (max-width: 768px) {
      .me-body.me-mode-split {
        flex-direction: column;
      }
      .me-body.me-mode-split .me-divider {
        flex: 0 0 1px;
        width: 100%;
        height: 1px;
        cursor: row-resize;
      }
      .me-body.me-mode-split .me-divider::after {
        top: -3px; bottom: -3px; left: 0; right: 0;
      }
      .me-body.me-mode-split .me-editor-pane,
      .me-body.me-mode-split .me-preview-pane {
        flex: 1 1 50%;
        width: 100%;
      }
      .me-toolbar { padding: 4px; }
      .me-btn { width: 28px; height: 28px; }
      .me-preview { padding: 14px; }
      .me-textarea { padding: 12px; font-size: 13px; }
    }

    /* ============ 无障碍 ============ */
    .me-wrapper:focus-within {
      border-color: var(--md-accent);
    }
    .me-textarea:focus-visible { outline: 0; }

    /* ============ 动画 ============ */
    @media (prefers-reduced-motion: reduce) {
      .me-wrapper, .me-btn, .me-textarea { transition: none !important; }
    }

    /* ============ 全屏模式优化 ============ */
    .me-wrapper.me-fullscreen .me-preview,
    .me-wrapper.me-fullscreen .me-textarea { font-size: 15px; }

    /* ============ 只读模式 ============ */
    .me-wrapper.me-readonly .me-textarea {
      background: var(--md-code-bg);
      cursor: default;
      opacity: 0.88;
    }
    .me-wrapper.me-readonly .me-toolbar {
      opacity: 0.45; pointer-events: none;
    }

    /* ============ 高亮标记 ============ */
    .me-preview mark {
      background: rgba(250, 204, 21, 0.3);
      color: inherit;
      padding: 0.1em 0.2em;
      border-radius: 3px;
    }

    /* ============ 上标/下标 ============ */
    .me-preview sup { font-size: 0.75em; vertical-align: super; line-height: 1; }
    .me-preview sub { font-size: 0.75em; vertical-align: sub; line-height: 1; }

    /* ============ 数学公式 ============ */
    .me-preview .me-math-block {
      display: block;
      margin: 1.2em 0;
      padding: 12px 16px;
      background: var(--md-code-bg);
      border-radius: 8px;
      overflow-x: auto;
      font-family: var(--md-mono);
      font-size: 0.95em;
      text-align: center;
    }
    .me-preview .me-math-inline {
      font-family: var(--md-mono);
      font-size: 0.95em;
      padding: 0.05em 0.2em;
    }

    /* ============ 定义列表 ============ */
    .me-preview dl { margin: 0.8em 0; }
    .me-preview dt { font-weight: 650; margin: 0.6em 0 0.2em; }
    .me-preview dd { margin: 0 0 0.3em 1.6em; color: var(--md-text); }

    /* ============ 脚注 ============ */
    .me-preview .me-footnote-ref a {
      font-size: 0.75em;
      vertical-align: super;
      text-decoration: none;
      color: var(--md-accent);
    }
    .me-preview .me-footnotes {
      margin-top: 2em;
      border-top: 1px solid var(--md-border);
      padding-top: 0.8em;
      font-size: 0.9em;
      color: var(--md-muted);
    }
    .me-preview .me-footnotes hr { display: none; }
    .me-preview .me-footnotes ol { padding-left: 1.2em; }
    .me-preview .me-footnote-item { margin: 0.3em 0; }
    .me-preview .me-footnote-backref {
      text-decoration: none;
      color: var(--md-accent);
      margin-right: 0.4em;
    }

    /* ============ Toast 通知（v0.1.6） ============ */
    .me-toast {
      position: absolute;
      bottom: 16px;
      right: 16px;
      z-index: 30;
      display: flex;
      align-items: center;
      gap: 8px;
      padding: 10px 16px;
      border-radius: 8px;
      font-size: 13px;
      pointer-events: auto;
      cursor: pointer;
      opacity: 0;
      transform: translateY(12px);
      transition: opacity 0.3s ease, transform 0.3s ease;
      box-shadow: 0 6px 20px rgba(0,0,0,0.15);
      max-width: 360px;
    }
    .me-toast.me-toast-enter { opacity: 1; transform: translateY(0); }
    .me-toast.me-toast-leave { opacity: 0; transform: translateY(12px); }
    .me-toast-success { background: #10b981; color: #fff; }
    .me-toast-error   { background: #ef4444; color: #fff; }
    .me-toast-warning { background: #f59e0b; color: #fff; }
    .me-toast-info    { background: var(--md-accent, #3b82f6); color: #fff; }
    .me-toast-icon { font-weight: 700; font-size: 16px; flex-shrink: 0; }
    .me-toast-msg  { line-height: 1.4; }

    /* ============ 右键菜单（v0.1.6） ============ */
    .me-context-menu {
      position: fixed;
      z-index: 40;
      min-width: 180px;
      padding: 4px 0;
      background: var(--md-bg);
      border: 1px solid var(--md-border);
      border-radius: 8px;
      box-shadow: 0 8px 28px rgba(0,0,0,0.18);
      font-size: 13px;
    }
    .me-context-menu-item {
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 6px 14px;
      cursor: pointer;
      color: var(--md-text);
      transition: background 0.1s;
    }
    .me-context-menu-item:hover { background: var(--md-code-bg); color: var(--md-accent); }
    .me-context-menu-sep {
      height: 1px;
      background: var(--md-border);
      margin: 4px 0;
    }
    .me-context-menu-shortcut {
      color: var(--md-muted);
      font-size: 11px;
      margin-left: 24px;
    }

    /* ============ 大纲面板（v0.1.7） ============ */
    .me-outline {
      position: absolute;
      top: 0; right: 0;
      width: 220px;
      height: 100%;
      overflow-y: auto;
      background: var(--md-preview-bg);
      border-left: 1px solid var(--md-border);
      padding: 12px 14px;
      font-size: 13px;
      z-index: 15;
    }
    .me-outline-title {
      font-weight: 650;
      margin-bottom: 8px;
      padding-bottom: 6px;
      border-bottom: 1px solid var(--md-border);
      color: var(--md-text);
    }
    .me-outline ul { list-style: none; padding: 0; margin: 0; }
    .me-outline li { margin: 2px 0; }
    .me-outline a {
      color: var(--md-muted);
      text-decoration: none;
      display: block;
      padding: 2px 6px;
      border-radius: 4px;
      transition: background 0.1s, color 0.1s;
    }
    .me-outline a:hover { background: var(--md-code-bg); color: var(--md-accent); }
    .me-outline-l1 a { font-weight: 600; color: var(--md-text); }
    .me-outline-l2 a { padding-left: 12px; }
    .me-outline-l3 a { padding-left: 20px; font-size: 12px; }
    .me-outline-l4 a { padding-left: 28px; font-size: 12px; }

    /* ============ 打印样式 ============ */
    @media print {
      .me-wrapper { border: 0 !important; box-shadow: none !important; }
      .me-toolbar, .me-statusbar, .me-divider { display: none !important; }
      .me-body.me-mode-split .me-editor-pane { display: none; }
      .me-body.me-mode-split .me-preview-pane { flex: 1 1 100% !important; }
      .me-preview { padding: 0 !important; font-size: 11pt; }
      .me-wrapper.me-fullscreen { position: static !important; width: auto !important; height: auto !important; }
    }
  `;
};

/**
 * 注入样式（单例）
 */
export const injectStyles = () => {
  if (typeof document === 'undefined') return;
  if (styleElement && document.getElementById('metona-editor-styles')) return;

  const css = generateCSS();
  styleElement = document.createElement('style');
  styleElement.id = 'metona-editor-styles';
  styleElement.textContent = css.replace(/\s+/g, ' ');
  document.head.appendChild(styleElement);
};

/**
 * 更新样式
 */
export const updateStyles = () => {
  if (!styleElement) { injectStyles(); return; }
  styleElement.textContent = generateCSS().replace(/\s+/g, ' ');
};

/**
 * 移除样式
 */
export const removeStyles = () => {
  if (styleElement && styleElement.parentNode) {
    styleElement.parentNode.removeChild(styleElement);
  }
  styleElement = null;
};

/**
 * 获取系统主题
 */
export const getSystemTheme = () => {
  if (typeof window === 'undefined') return 'light';
  return window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light';
};

/**
 * 监听系统主题变化
 */
export const watchSystemTheme = (callback) => {
  if (typeof window === 'undefined' || !window.matchMedia) return () => {};
  const mediaQuery = window.matchMedia('(prefers-color-scheme: dark)');
  const handler = (e) => callback(e.matches ? 'dark' : 'light');
  mediaQuery.addEventListener('change', handler);
  return () => mediaQuery.removeEventListener('change', handler);
};

export { THEMES };
export default { injectStyles, updateStyles, removeStyles, getSystemTheme, watchSystemTheme };