/**
 * 知资札记 - 文章详情页逻辑
 */
(function () {
  'use strict';

  const API_BASE = '/api/zhizi_notes';
  const STORAGE_KEY = 'zhizi_notes_theme';
  const $ = function (sel) { return document.querySelector(sel); };

  let articleId = null;
  let isFavorited = false;

  // ── 解析 URL 参数 ──
  function getParam(name) {
    const params = new URLSearchParams(window.location.search);
    return params.get(name);
  }

  // ── Toast ──
  function showToast(msg, type) {
    type = type || 'info';
    const t = $('#zd-toast');
    if (!t) return;
    t.textContent = msg;
    t.className = 'zs-toast ' + type + ' show';
    clearTimeout(t._timer);
    t._timer = setTimeout(function () { t.classList.remove('show'); }, type === 'error' ? 4000 : 2000);
  }

  // ── 暗黑模式 ──
  function initTheme() {
    const saved = localStorage.getItem(STORAGE_KEY);
    if (saved === 'dark') {
      document.documentElement.setAttribute('data-theme', 'dark');
    }
    const btn = $('#zs-theme-btn');
    if (btn) {
      btn.textContent = saved === 'dark' ? '☀️' : '🌙';
      btn.addEventListener('click', function () {
        const isDark = document.documentElement.getAttribute('data-theme') === 'dark';
        if (isDark) {
          document.documentElement.removeAttribute('data-theme');
          localStorage.setItem(STORAGE_KEY, 'light');
          btn.textContent = '🌙';
        } else {
          document.documentElement.setAttribute('data-theme', 'dark');
          localStorage.setItem(STORAGE_KEY, 'dark');
          btn.textContent = '☀️';
        }
      });
    }
  }

  // ── API ──
  async function apiGet(path) {
    try {
      const res = await fetch(API_BASE + path, { credentials: 'same-origin' });
      return await res.json();
    } catch (e) { return { ok: false, error: e.message }; }
  }

  async function apiPost(path, body) {
    try {
      const res = await fetch(API_BASE + path, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        credentials: 'same-origin',
        body: JSON.stringify(body)
      });
      return await res.json();
    } catch (e) { return { ok: false, error: e.message }; }
  }

  // ── 加载详情 ──
  async function loadDetail() {
    articleId = getParam('id');
    if (!articleId) {
      showError('缺少文章ID');
      return;
    }

    const data = await apiGet('/articles/' + articleId);
    const loading = $('#zd-loading');
    if (loading) loading.style.display = 'none';

    if (!data.ok) {
      showError(data.error || '文章不存在');
      return;
    }

    renderArticle(data.data);
  }

  function showError(msg) {
    const loading = $('#zd-loading');
    const error = $('#zd-error');
    if (loading) loading.style.display = 'none';
    if (error) {
      error.style.display = 'block';
      $('#zd-error-msg').textContent = msg;
    }
  }

  // ── 渲染文章 ──
  function renderArticle(article) {
    const articleEl = $('#zd-article');
    if (!articleEl) return;
    articleEl.style.display = 'block';

    // 标题
    $('#zd-title').textContent = article.title;
    document.title = article.title + ' · 知资札记';

    // 元信息
    $('#zd-category').textContent = article.category || '未分类';
    $('#zd-source').textContent = article.source ? '来源：' + article.source : '';
    $('#zd-date').textContent = (article.created_at || '').slice(0, 10);
    $('#zd-views').textContent = (article.views || 0) + ' 阅读';

    // 收藏按钮
    isFavorited = article.fav_count > 0;
    updateFavBtn();
    const favBtn = $('#zd-fav-btn');
    if (favBtn) {
      favBtn.addEventListener('click', function () { toggleFavorite(); });
    }

    // 标签
    const tagsEl = $('#zd-tags');
    try {
      const tags = JSON.parse(article.tags_json || '[]');
      if (tags.length > 0 && tagsEl) {
        tagsEl.innerHTML = '';
        tags.forEach(function (t) {
          const span = document.createElement('span');
          span.className = 'zd-tag';
          span.textContent = t;
          tagsEl.appendChild(span);
        });
      } else if (tagsEl) {
        tagsEl.style.display = 'none';
      }
    } catch (e) { if (tagsEl) tagsEl.style.display = 'none'; }

    // 封面图
    if (article.cover_url) {
      const cover = $('#zd-cover');
      const coverImg = $('#zd-cover-img');
      if (cover) cover.style.display = 'block';
      if (coverImg) coverImg.src = article.cover_url;
    }

    // 正文
    const contentEl = $('#zd-content');
    if (contentEl) {
      contentEl.innerHTML = article.content || article.content_plain || '';
    }

    // 图片集
    if (article.images && article.images.length > 0) {
      const gallery = $('#zd-gallery');
      const grid = $('#zd-gallery-grid');
      if (gallery) gallery.style.display = 'block';
      if (grid) {
        grid.innerHTML = '';
        article.images.forEach(function (img) {
          const item = document.createElement('div');
          item.className = 'gallery-item';
          const imgEl = document.createElement('img');
          imgEl.src = '/uploads/zhizi_notes/' + img.filename;
          imgEl.alt = img.original_name || '';
          imgEl.loading = 'lazy';
          item.appendChild(imgEl);
          grid.appendChild(item);
        });
      }
    }
  }

  // ── 收藏切换 ──
  async function toggleFavorite() {
    const data = await apiPost('/articles/' + articleId + '/toggle_favorite', {});
    if (data.ok) {
      isFavorited = data.data ? data.data.favorited : !isFavorited;
      updateFavBtn();
      showToast(isFavorited ? '已收藏' : '已取消收藏', isFavorited ? 'success' : 'info');
    } else {
      showToast('操作失败：' + (data.error || '未知错误'), 'error');
    }
  }

  function updateFavBtn() {
    const btn = $('#zd-fav-btn');
    if (!btn) return;
    if (isFavorited) {
      btn.classList.add('favorited');
      btn.textContent = '♥';
    } else {
      btn.classList.remove('favorited');
      btn.textContent = '♡';
    }
  }

  // ── 初始化 ──
  function init() {
    initTheme();
    loadDetail();

    // 返回按钮
    const backBtn = $('#zd-back');
    if (backBtn) {
      backBtn.addEventListener('click', function () {
        if (document.referrer && document.referrer.indexOf('/tools/zhizi_notes') !== -1) {
          history.back();
        } else {
          location.href = '/tools/zhizi_notes/index.html';
        }
      });
    }
  }

  document.addEventListener('DOMContentLoaded', init);
})();