// 播放页评论：只读列表 + 「查看更多评论」追加翻页
(function () {
  var commentsRoot = document.querySelector("[data-play-comments]");
  if (!commentsRoot) return;

  var listEl = document.querySelector("[data-comment-list]");
  var totalEl = document.querySelector("[data-comment-total-label]");
  var moreBtn = document.querySelector("[data-comment-more]");
  var loadingMore = false;
  var PAGE_SIZE = 4;

  function toast(message, type) {
    if (typeof window.showToast === "function") {
      window.showToast(message, type);
      return;
    }
  }

  function toInt(v, fallback) {
    var n = parseInt(v, 10);
    return isNaN(n) ? fallback || 0 : n;
  }

  function escapeHtml(s) {
    return String(s == null ? "" : s)
      .replace(/&/g, "&")
      .replace(/</g, "&lt;")
      .replace(/>/g, "&gt;")
      .replace(/"/g, "&quot;");
  }

  function getPageSize() {
    return Math.max(
      1,
      toInt(commentsRoot.getAttribute("data-comment-size"), PAGE_SIZE)
    );
  }

  function getPage() {
    return Math.max(
      1,
      toInt(commentsRoot.getAttribute("data-comment-page"), 1)
    );
  }

  function getLoaded() {
    if (!listEl) return 0;
    return listEl.querySelectorAll(".play-comment:not(.play-comment--empty)").length;
  }

  function setPagerState(page, loaded, total) {
    if (page != null) commentsRoot.setAttribute("data-comment-page", String(page));
    if (loaded != null) commentsRoot.setAttribute("data-comment-loaded", String(loaded));
    if (total != null) commentsRoot.setAttribute("data-comment-total", String(total));
    syncMoreButton(total != null ? total : toInt(commentsRoot.getAttribute("data-comment-total"), 0));
  }

  function syncMoreButton(total) {
    if (!moreBtn) return;
    var loaded = getLoaded();
    var hasMore = total > loaded;
    if (hasMore) {
      moreBtn.hidden = false;
      moreBtn.removeAttribute("hidden");
    } else {
      moreBtn.hidden = true;
      moreBtn.setAttribute("hidden", "");
    }
  }

  function formatTime(raw) {
    var s = String(raw || "").trim();
    if (!s) return "刚刚";
    var d = new Date(s);
    if (isNaN(d.getTime())) return s;
    return (
      d.getFullYear() +
      "/" +
      (d.getMonth() + 1) +
      "/" +
      d.getDate() +
      " " +
      String(d.getHours()).padStart(2, "0") +
      ":" +
      String(d.getMinutes()).padStart(2, "0")
    );
  }

  function renderCommentItem(item) {
    item = item || {};
    var avatar = String(item.userAvatar || "").trim();
    var name = escapeHtml(item.userName || "匿名用户");
    var text = escapeHtml(item.text || "");
    var time = escapeHtml(formatTime(item.createdAt));
    var like = toInt(item.countLike, 0);
    var avatarHtml = avatar
      ? '<img class="play-comment__avatar lazy" src="/static/images/placeholder.png?v=2" data-src="' +
        escapeHtml(avatar) +
        '" alt="" loading="lazy" decoding="async">'
      : '<img class="play-comment__avatar" src="/static/images/placeholder.png?v=2" data-src="/static/images/profile/avatar.png" alt="" loading="lazy" decoding="async">';
    var children = Array.isArray(item.children) ? item.children : [];
    var replies = children
      .map(function (child) {
        var cName = escapeHtml(child.userName || "用户");
        var replyTo = child.replyUserName
          ? " 回复 " + escapeHtml(child.replyUserName)
          : "";
        return (
          '<div class="play-comment__reply">' +
          cName +
          replyTo +
          "：" +
          escapeHtml(child.text || "") +
          "</div>"
        );
      })
      .join("");
    var commentId = escapeHtml(item.id || "");
    return (
      '<li class="play-comment" data-comment-id="' +
      commentId +
      '">' +
      avatarHtml +
      '<div class="play-comment__body">' +
      '<div class="play-comment__meta">' +
      '<span class="play-comment__name">' +
      name +
      "</span>" +
      '<span class="play-comment__time">' +
      time +
      "</span>" +
      "</div>" +
      '<p class="play-comment__text">' +
      text +
      "</p>" +
      replies +
      '<div class="play-comment__actions">' +
      '<span class="play-comment__action">' +
      '<img class="icon" src="/static/images/placeholder.png?v=2" data-src="/static/images/heart.svg" alt="" loading="lazy" decoding="async">' +
      "<span>" +
      escapeHtml(like) +
      "</span>" +
      "</span>" +
      "</div></div></li>"
    );
  }

  function getLoadedIds() {
    var ids = Object.create(null);
    if (!listEl) return ids;
    listEl.querySelectorAll(".play-comment[data-comment-id]").forEach(function (el) {
      var id = String(el.getAttribute("data-comment-id") || "").trim();
      if (id) ids[id] = true;
    });
    return ids;
  }

  function updateTotal(n) {
    if (!totalEl) return;
    totalEl.textContent = n > 0 ? n + " 条" : "暂无评论";
  }

  // 下一页追加到现有列表底部，不替换已展示评论。
  function appendList(list, totalCount) {
    if (!listEl) return;
    list = Array.isArray(list) ? list : [];
    var total =
      typeof totalCount === "number"
        ? totalCount
        : toInt(commentsRoot.getAttribute("data-comment-total"), 0);
    if (typeof totalCount === "number") {
      updateTotal(totalCount);
    }
    if (!list.length) {
      setPagerState(getPage(), getLoaded(), total);
      return;
    }

    var empty = listEl.querySelector(".play-comment--empty");
    if (empty) empty.remove();

    var existing = getLoadedIds();
    var fresh = list.filter(function (item) {
      var id = String((item && item.id) || "").trim();
      return id && !existing[id];
    });
    if (!fresh.length) {
      setPagerState(getPage(), getLoaded(), total);
      return;
    }

    var wrap = document.createElement("ul");
    wrap.innerHTML = fresh.map(renderCommentItem).join("");
    var nodes = [];
    while (wrap.firstChild) {
      nodes.push(wrap.firstChild);
      listEl.appendChild(wrap.firstChild);
    }
    if (typeof window.initLazyImages === "function") {
      nodes.forEach(function (node) {
        if (node && node.nodeType === 1) window.initLazyImages(node);
      });
      window.initLazyImages(listEl);
    }
    setPagerState(getPage(), getLoaded(), total);
  }

  function fetchCommentPage(pageNum) {
    if (!window.HttpRequest || typeof window.HttpRequest.get !== "function") {
      return Promise.reject(new Error("评论服务未就绪"));
    }
    var objectId = toInt(commentsRoot.getAttribute("data-object-id"), 0);
    var objectType = toInt(commentsRoot.getAttribute("data-object-type"), 10);
    if (objectId <= 0) return Promise.reject(new Error("缺少评论对象"));
    var pageSize = getPageSize();
    return window.HttpRequest.get("/api/comment/list", {
      params: {
        objectId: objectId,
        objectType: objectType,
        pageNum: pageNum,
        pageSize: pageSize,
        sortOrder: 1,
      },
    }).then(function (res) {
      if (!res || Number(res.code) !== 200 || !res.data) {
        throw new Error((res && (res.tip || res.msg)) || "加载失败");
      }
      return res.data;
    });
  }

  function loadMoreComments() {
    if (loadingMore || !moreBtn) return;
    var nextPage = getPage() + 1;
    loadingMore = true;
    moreBtn.disabled = true;
    fetchCommentPage(nextPage)
      .then(function (data) {
        var list = data.list || [];
        var total = toInt(data.totalCount, 0);
        commentsRoot.setAttribute("data-comment-page", String(nextPage));
        // 只追加，绝不 renderList 整表替换
        appendList(list, total);
      })
      .catch(function (err) {
        toast((err && err.message) || "加载失败，请稍后重试", "error");
      })
      .finally(function () {
        loadingMore = false;
        if (moreBtn) moreBtn.disabled = false;
      });
  }

  if (moreBtn) {
    moreBtn.addEventListener("click", function (event) {
      event.preventDefault();
      loadMoreComments();
    });
  }
})();