/**
 * 模板库页面 — V21 设计系统
 * 页面头部 + 工具栏（搜索+分类胶囊按钮组）+ 4列模板卡片网格 + 空状态
 * 使用 mock 数据，CSS 变量，V21 组件
 */
import React, { useState } from "react";
import { Button } from "@/components/ui";
import "./templates.css";

/* ============================================================
 * Mock 数据
 * ============================================================ */
type TemplateCategory = "口播" | "种草" | "产品" | "品牌";

interface TemplateItem {
  id: string;
  name: string;
  category: TemplateCategory;
  usageCount: number;
  isFavorite: boolean;
  gradient: string;
  codeSnippet: string;
}

const categories: Array<"全部" | TemplateCategory> = [
  "全部",
  "口播",
  "种草",
  "产品",
  "品牌",
];

const mockTemplates: TemplateItem[] = [
  {
    id: "tpl-1",
    name: "商品口播模板",
    category: "口播",
    usageCount: 128,
    isFavorite: true,
    gradient: "linear-gradient(135deg, #6366f1, #8b5cf6)",
    codeSnippet:
      "# 商品口播脚本\n## 开场白\n大家好，今天给大家推荐...\n## 产品介绍\n这款产品的特点是...",
  },
  {
    id: "tpl-2",
    name: "种草笔记视频模板",
    category: "种草",
    usageCount: 96,
    isFavorite: false,
    gradient: "linear-gradient(135deg, #10b981, #059669)",
    codeSnippet:
      "# 种草视频\n## 使用场景\n早上出门前的护肤步骤...\n## 产品亮点\n温和不刺激，适合敏感肌...",
  },
  {
    id: "tpl-3",
    name: "新品发布展示模板",
    category: "产品",
    usageCount: 74,
    isFavorite: false,
    gradient: "linear-gradient(135deg, #0ea5e9, #0284c7)",
    codeSnippet:
      "# 新品发布\n## 产品概览\n全新升级，性能提升50%...\n## 核心功能\nAI智能识别，一键优化...",
  },
  {
    id: "tpl-4",
    name: "品牌故事宣传片",
    category: "品牌",
    usageCount: 52,
    isFavorite: true,
    gradient: "linear-gradient(135deg, #f59e0b, #d97706)",
    codeSnippet:
      "# 品牌故事\n## 品牌起源\n2020年，我们从一个想法开始...\n## 品牌理念\n让创作更简单...",
  },
  {
    id: "tpl-5",
    name: "知识分享口播模板",
    category: "口播",
    usageCount: 215,
    isFavorite: false,
    gradient: "linear-gradient(135deg, #8b5cf6, #7c3aed)",
    codeSnippet:
      "# 知识分享\n## 主题引入\n今天我们来聊一个很多人问的问题...\n## 核心内容\n第一点，第二点，第三点...",
  },
  {
    id: "tpl-6",
    name: "好物推荐种草模板",
    category: "种草",
    usageCount: 183,
    isFavorite: true,
    gradient: "linear-gradient(135deg, #059669, #047857)",
    codeSnippet:
      "# 好物推荐\n## 痛点引入\n你是不是也有这样的困扰...\n## 解决方案\n直到我发现了这个神器...",
  },
  {
    id: "tpl-7",
    name: "产品对比评测模板",
    category: "产品",
    usageCount: 67,
    isFavorite: false,
    gradient: "linear-gradient(135deg, #0284c7, #0369a1)",
    codeSnippet:
      "# 产品对比\n## 对比维度\n外观、性能、价格、体验...\n## 总结推荐\n综合来看，A适合...B适合...",
  },
  {
    id: "tpl-8",
    name: "品牌活动预热模板",
    category: "品牌",
    usageCount: 41,
    isFavorite: false,
    gradient: "linear-gradient(135deg, #d97706, #b45309)",
    codeSnippet:
      "# 活动预热\n## 悬念引入\n倒计时3天，惊喜即将揭晓...\n## 活动亮点\n福利一、福利二、福利三...",
  },
];

/* ============================================================
 * 组件
 * ============================================================ */
const TemplateLibrary: React.FC = () => {
  const [searchText, setSearchText] = useState("");
  const [activeCategory, setActiveCategory] = useState<
    "全部" | TemplateCategory
  >("全部");
  const [favorites, setFavorites] = useState<Set<string>>(
    () => new Set(mockTemplates.filter((t) => t.isFavorite).map((t) => t.id)),
  );

  /** 切换收藏 */
  const toggleFavorite = (id: string, e: React.MouseEvent) => {
    e.stopPropagation();
    setFavorites((prev) => {
      const next = new Set(prev);
      if (next.has(id)) {
        next.delete(id);
      } else {
        next.add(id);
      }
      return next;
    });
  };

  /** 过滤模板 */
  const filtered = mockTemplates.filter((t) => {
    const matchSearch =
      !searchText ||
      t.name.toLowerCase().includes(searchText.toLowerCase()) ||
      t.codeSnippet.toLowerCase().includes(searchText.toLowerCase());
    const matchCategory =
      activeCategory === "全部" || t.category === activeCategory;
    return matchSearch && matchCategory;
  });

  return (
    <div className="xx-templates-page">
      {/* ── 页面头部 ──────────────────────────────────────────── */}
      <div className="xx-templates-header">
        <div className="xx-templates-header-text">
          <h2>模板库</h2>
          <p>选择模板快速开始创作，支持自定义修改</p>
        </div>
        <Button buttonType="primary" buttonSize="md">
          + 创建模板
        </Button>
      </div>

      {/* ── 工具栏：搜索 + 分类按钮组 ─────────────────────────── */}
      <div className="xx-templates-toolbar">
        <div className="xx-templates-search">
          <span className="xx-templates-search-icon">🔍</span>
          <input
            className="xx-templates-search-input"
            type="text"
            placeholder="搜索模板名称或内容..."
            value={searchText}
            onChange={(e) => setSearchText(e.target.value)}
          />
        </div>
        <div className="xx-templates-categories">
          {categories.map((cat) => (
            <button
              key={cat}
              className={`xx-templates-cat-btn${activeCategory === cat ? " active" : ""}`}
              onClick={() => setActiveCategory(cat)}
            >
              {cat}
            </button>
          ))}
        </div>
      </div>

      {/* ── 模板卡片网格 ──────────────────────────────────────── */}
      {filtered.length === 0 ? (
        <div className="xx-templates-empty">
          <div className="xx-templates-empty-icon">📭</div>
          <h3>
            {searchText || activeCategory !== "全部"
              ? "未找到匹配的模板"
              : "暂无模板"}
          </h3>
          <p>
            {searchText || activeCategory !== "全部"
              ? "试试调整搜索条件或切换分类"
              : "点击上方「创建模板」开始创作"}
          </p>
        </div>
      ) : (
        <div className="xx-templates-grid">
          {filtered.map((tpl) => (
            <div key={tpl.id} className="xx-template-card">
              {/* 缩略图 */}
              <div className="xx-template-thumb">
                <div
                  className="xx-template-thumb-bg"
                  style={{ background: tpl.gradient }}
                >
                  {tpl.codeSnippet}
                </div>
                <div className="xx-template-thumb-overlay" />
                <button
                  className={`xx-template-fav-btn${favorites.has(tpl.id) ? " is-favorite" : ""}`}
                  onClick={(e) => toggleFavorite(tpl.id, e)}
                  title={favorites.has(tpl.id) ? "取消收藏" : "收藏"}
                >
                  {favorites.has(tpl.id) ? "★" : "☆"}
                </button>
              </div>

              {/* 信息区 */}
              <div className="xx-template-info">
                <div className="xx-template-info-top">
                  <h4 className="xx-template-name">{tpl.name}</h4>
                  <span
                    className={`xx-template-category-pill xx-template-category-pill--${tpl.category}`}
                  >
                    {tpl.category}
                  </span>
                </div>
                <div className="xx-template-meta">
                  <span className="xx-template-usage">
                    已使用 {tpl.usageCount} 次
                  </span>
                  <button className="xx-template-use-btn">使用此模板</button>
                </div>
              </div>
            </div>
          ))}
        </div>
      )}
    </div>
  );
};

export default TemplateLibrary;