/**
 * AKSRT Archive AJAX Filter
 */
(function () {
  "use strict";

  function initArchiveFilter(root) {
    var scope = root || document;
    var bar = scope.querySelector(".archive-filter-bar--ajax[data-ajax-archive]");
    if (!bar || bar.dataset.aksrtArchiveInit === "1") return;
    bar.dataset.aksrtArchiveInit = "1";

    var archiveType = bar.dataset.ajaxArchive || "category";
    var termId = parseInt(bar.dataset.termId, 10) || 0;
    var wrap = scope.querySelector("[data-ajax-wrap]");
    if (!wrap) return;

    var loading = wrap.querySelector(".archive__ajax-loading");
    var REST_BASE = "/wp-json/aksrt/v1/archive/posts";
    var emptyText = archiveType === "tag" ? "该标签下暂无文章" : "该分类下暂无文章";

    var state = {
      filter_cat: "",
      filter_tag: "",
      sort: "date",
      page: 1
    };

    var activeCat = bar.querySelector("[data-filter-cat].is-active");
    if (activeCat) state.filter_cat = activeCat.dataset.filterCat || "";
    var activeTag = bar.querySelector("[data-filter-tag].is-active");
    if (activeTag) state.filter_tag = activeTag.dataset.filterTag || "";
    var activeSort = bar.querySelector("[data-filter-sort].is-active");
    if (activeSort) state.sort = activeSort.dataset.filterSort || "date";

    function buildUrl() {
      var params = new URLSearchParams();
      params.set("archive_type", archiveType);
      params.set("term_id", String(termId));
      if (state.filter_cat) params.set("filter_cat", state.filter_cat);
      if (state.filter_tag) params.set("filter_tag", state.filter_tag);

      params.set("sort", state.sort || "date");
      params.set("page", String(state.page));
      return REST_BASE + "?" + params.toString();
    }

    function updateActiveChips() {
      bar.querySelectorAll("[data-filter-cat]").forEach(function (el) {
        el.classList.toggle("is-active", (el.dataset.filterCat || "") === state.filter_cat);
      });
      bar.querySelectorAll("[data-filter-tag]").forEach(function (el) {
        el.classList.toggle("is-active", (el.dataset.filterTag || "") === state.filter_tag);
      });
      bar.querySelectorAll("[data-filter-sort]").forEach(function (el) {
        el.classList.toggle("is-active", (el.dataset.filterSort || "date") === state.sort);
      });
    }

    function showLoading() {
      if (loading) loading.classList.add("is-loading");
      wrap.classList.add("is-loading");
    }

    function hideLoading() {
      if (loading) loading.classList.remove("is-loading");
      wrap.classList.remove("is-loading");
    }

    function rebuildEmptyState() {
      var noResults = document.createElement("div");
      noResults.className = "no-results content-stream__empty";
      noResults.innerHTML = "<p>" + emptyText + "</p>";
      wrap.appendChild(noResults);
    }

    function fetchPosts(pushState) {
      showLoading();
      fetch(buildUrl(), {
        method: "GET",
        headers: { Accept: "application/json" },
        credentials: "same-origin"
      })
        .then(function (r) {
          if (!r.ok) throw new Error("HTTP " + r.status);
          return r.json();
        })
        .then(function (data) {
          hideLoading();
          if (data.html !== undefined) {
            var children = Array.from(wrap.children);
            children.forEach(function (child) {
              if (child !== loading) wrap.removeChild(child);
            });
            if (data.html) {
              var temp = document.createElement("div");
              temp.innerHTML = data.html;
              while (temp.firstChild) wrap.appendChild(temp.firstChild);
              } else {
                rebuildEmptyState();
              }
              // legacy 事件顺序：先 post_ajax.ed，再全局 auto_fun 重扫
              wrap.dispatchEvent(new CustomEvent("post_ajax.ed", { bubbles: true }));
              if (typeof window.auto_fun === "function") window.auto_fun();
            }
          if (pushState !== false) {
            var url = new URL(window.location.href);
            url.searchParams.delete("orderby");
            url.searchParams.delete("order");
            url.searchParams.delete("paged");
            url.searchParams.delete("aksrt_filter_cat");
            url.searchParams.delete("aksrt_filter_tag");
            if (state.filter_cat) url.searchParams.set("aksrt_filter_cat", state.filter_cat);
            if (state.filter_tag) url.searchParams.set("aksrt_filter_tag", state.filter_tag);
            if (state.sort) url.searchParams.set("orderby", state.sort);
            if (state.page > 1) url.searchParams.set("paged", String(state.page));
            history.pushState({ aksrtArchive: true, state: Object.assign({}, state) }, "", url.toString());
          }
        })
        .catch(function () {
          hideLoading();
        });
    }

    bar.addEventListener("click", function (e) {
      var chip = e.target.closest("[data-filter-cat], [data-filter-tag], [data-filter-sort]");
      if (!chip) return;
      e.preventDefault();

      var changed = false;
      if (chip.dataset.filterCat !== undefined) {
        var newCat = chip.dataset.filterCat;
        if (newCat !== state.filter_cat) {
          state.filter_cat = newCat;
          changed = true;
        }
      }
      if (chip.dataset.filterTag !== undefined) {
        var newTag = chip.dataset.filterTag;
        if (newTag !== state.filter_tag) {
          state.filter_tag = newTag;
          changed = true;
        }
      }
      if (chip.dataset.filterSort !== undefined) {
        var newSort = chip.dataset.filterSort || "date";
        if (newSort !== state.sort) {
          state.sort = newSort;
          changed = true;
        }
      }

      if (changed) {
        state.page = 1;
        updateActiveChips();
        fetchPosts(true);
      }
    });

    wrap.addEventListener("click", function (e) {
      var pageLink = e.target.closest(".pagination a, .nav-links a, a.page-numbers");
      if (!pageLink || !wrap.contains(pageLink)) return;
      var href = pageLink.getAttribute("href");
      if (!href) return;

      var match = href.match(/[?&]paged=(\d+)/);
      if (match) {
        e.preventDefault();
        state.page = parseInt(match[1], 10) || 1;
        fetchPosts(true);
      }
    });

    window.addEventListener("popstate", function (e) {
      if (e.state && e.state.aksrtArchive) {
        state = Object.assign(state, e.state.state);
        updateActiveChips();
        fetchPosts(false);
      }
    });
  }

  function init(root) {
    initArchiveFilter(root);
  }

  if (document.readyState === "loading") {
    document.addEventListener("DOMContentLoaded", function () { init(); });
  } else {
    init();
  }
  // AJAX 注入新内容后由 auto_fun 重扫（bar 级 data 标记保证幂等）。
  if (window.jQuery) {
    window.jQuery(document).on("auto_fun", function () { init(); });
  }
})();