/* 文件浏览页：分页拉取 /api/admin/files、复选框多选 + 全选、批量下载/删除、复制 sha。
   state.items 缓存当前页数据；切换页/页大小重新拉取；删除后若当前页空则回退一页。 */
(function () {
  "use strict";
  const { el, toast, copyText, fmtBytes, fmtTime, api } = window.ZK;
  const listEl = document.getElementById("list");
  const countEl = document.getElementById("count");
  const refreshBtn = document.getElementById("refresh");
  const pageSizeSel = document.getElementById("pageSize");
  const batchbar = document.getElementById("batchbar");
  const selCountEl = document.getElementById("selCount");
  const batchDownloadBtn = document.getElementById("batchDownload");
  const batchDeleteBtn = document.getElementById("batchDelete");
  const clearSelBtn = document.getElementById("clearSel");
  const pagerEl = document.getElementById("pager");

  // 分页状态
  const state = {
    page: 1,            // 从 1 开始
    pageSize: 100,      // 数字或 "all"
    total: 0,
    items: [],
    selected: new Set(), // 选中的 file id
  };

  refreshBtn.addEventListener("click", () => load(state.page));
  pageSizeSel.addEventListener("change", () => {
    const v = pageSizeSel.value;
    state.pageSize = v === "all" ? "all" : Number(v);
    state.page = 1;
    load(1);
  });
  batchDownloadBtn.addEventListener("click", batchDownload);
  batchDeleteBtn.addEventListener("click", batchDelete);
  clearSelBtn.addEventListener("click", () => {
    state.selected.clear();
    renderSelection();
  });

  function effectiveLimit() {
    return state.pageSize === "all" ? 10000 : state.pageSize;
  }
  function totalPages() {
    if (state.pageSize === "all") return 1;
    return Math.max(1, Math.ceil(state.total / state.pageSize));
  }

  async function load(page) {
    state.page = Math.max(1, page);
    const limit = effectiveLimit();
    const offset = (state.page - 1) * (state.pageSize === "all" ? 0 : state.pageSize);
    listEl.innerHTML = '<div class="skel">加载中…</div>';
    countEl.textContent = "";
    pagerEl.classList.add("hidden");
    try {
      const res = await api(`/api/admin/files?limit=${limit}&offset=${offset}`);
      if (!res.ok) throw new Error("HTTP " + res.status);
      const body = await res.json();
      state.items = body.items || [];
      state.total = body.total || 0;
      // 删除后当前页可能空且不是首页：回退一页
      if (state.items.length === 0 && state.page > 1) {
        load(state.page - 1);
        return;
      }
      countEl.textContent = `共 ${state.total} 个文件`;
      render();
      renderPager();
    } catch (e) {
      listEl.innerHTML = '<div class="empty">加载失败：' + (e.message || e) + "</div>";
    }
  }

  function render() {
    if (!state.items.length) {
      listEl.innerHTML = '<div class="empty">还没有文件。去 <a class="link" href="/api/upload">上传</a> 一个吧。</div>';
      renderSelection();
      return;
    }
    const allChecked = state.items.length > 0 && state.items.every((f) => state.selected.has(f.id));
    const table = el("table", { class: "files-table" });
    const thead = el("thead", null,
      el("tr", null,
        el("th", { class: "col-sel" },
          el("input", { type: "checkbox", id: "selectAll", checked: allChecked })
        ),
        el("th", { class: "col-name" }, "文件名 / SHA-256"),
        el("th", { class: "col-size" }, "大小"),
        el("th", { class: "col-src" }, "来源"),
        el("th", { class: "col-time" }, "上传时间"),
        el("th", { class: "col-act" }, "操作")
      )
    );
    const tbody = el("tbody", null);
    for (const f of state.items) {
      const checked = state.selected.has(f.id);
      const row = el("tr", { class: checked ? "sel" : "", dataset: { id: f.id } },
        el("td", { class: "col-sel" },
          el("input", { type: "checkbox", class: "row-sel", checked, dataset: { id: f.id } })
        ),
        el("td", { class: "col-name" },
          el("div", { class: "fname" }, f.original_filename),
          el("span", { class: "sha mono sha-short", title: "点击复制完整 SHA-256" }, shortSha(f.sha256))
        ),
        el("td", { class: "col-size mono" }, fmtBytes(f.size_bytes)),
        el("td", { class: "col-src" }, el("span", { class: "tag" }, f.source || "-")),
        el("td", { class: "col-time muted" }, fmtTime(f.uploaded_at)),
        el("td", { class: "col-act" },
          el("a", { class: "btn primary", href: `/api/admin/files/${f.id}/download`, download: "" }, "下载"),
          el("button", { class: "btn danger", onclick: () => removeOne(f) }, "删除")
        )
      );
      const shaNode = row.querySelector(".sha-short");
      shaNode.addEventListener("click", async () => {
        const ok = await copyText(f.sha256);
        toast(ok ? "已复制 SHA-256" : "复制失败");
      });
      const cb = row.querySelector(".row-sel");
      cb.addEventListener("change", () => toggleSelect(f.id, cb.checked));
      tbody.appendChild(row);
    }
    table.appendChild(thead);
    table.appendChild(tbody);
    listEl.innerHTML = "";
    listEl.appendChild(table);

    document.getElementById("selectAll").addEventListener("change", (e) => {
      const on = e.target.checked;
      for (const f of state.items) {
        if (on) state.selected.add(f.id);
        else state.selected.delete(f.id);
      }
      render();
      renderSelection();
    });
    renderSelection();
  }

  function toggleSelect(id, on) {
    if (on) state.selected.add(id);
    else state.selected.delete(id);
    render();
    renderSelection();
  }

  function renderSelection() {
    const n = state.selected.size;
    selCountEl.textContent = n;
    batchbar.classList.toggle("hidden", n === 0);
    // 更新全选框状态（不重新渲染表格，只改 checkbox）
    const sa = document.getElementById("selectAll");
    if (sa) {
      sa.checked = state.items.length > 0 && state.items.every((f) => state.selected.has(f.id));
    }
  }

  function renderPager() {
    if (state.pageSize === "all" || totalPages() <= 1) {
      pagerEl.classList.add("hidden");
      return;
    }
    pagerEl.classList.remove("hidden");
    pagerEl.innerHTML = "";
    const tp = totalPages();
    const cur = state.page;
    const mk = (label, page, opts = {}) => {
      const b = el("button", {
        class: "btn" + (page === cur && !opts.ellipsis ? " is-current" : ""),
        onclick: () => load(page),
      }, String(label));
      if (opts.disabled) b.disabled = true;
      return b;
    };
    pagerEl.appendChild(mk("‹", cur - 1, { disabled: cur <= 1 }));
    // 页码：始终显示首页、末页、当前页前后各 1 页，其余用省略号
    const pages = new Set([1, tp, cur, cur - 1, cur + 1]);
    const sorted = [...pages].filter((p) => p >= 1 && p <= tp).sort((a, b) => a - b);
    let last = 0;
    for (const p of sorted) {
      if (p - last > 1) pagerEl.appendChild(el("span", { class: "pager-ellipsis" }, "…"));
      pagerEl.appendChild(mk(p, p));
      last = p;
    }
    pagerEl.appendChild(mk("›", cur + 1, { disabled: cur >= tp }));
    pagerEl.appendChild(el("span", { class: "pager-info" }, `第 ${cur}/${tp} 页`));
  }

  function shortSha(sha) {
    if (!sha) return "-";
    return sha.length > 16 ? sha.slice(0, 12) + "…" + sha.slice(-4) : sha;
  }

  async function removeOne(f) {
    if (!confirm(`确定删除「${f.original_filename}」？\n此操作不可恢复，将同时删除磁盘文件。`)) return;
    try {
      const res = await api(`/api/admin/files/${f.id}`, { method: "DELETE" });
      if (!res.ok) throw new Error("HTTP " + res.status);
      state.selected.delete(f.id);
      // 删除后重新加载当前页（后续行会自动上移补位）
      await load(state.page);
      toast("已删除");
    } catch (e) {
      toast("删除失败：" + (e.message || e), "err");
    }
  }

  async function batchDelete() {
    const ids = [...state.selected];
    if (!ids.length) return;
    if (!confirm(`确定删除选中的 ${ids.length} 个文件？\n此操作不可恢复，将同时删除磁盘文件。`)) return;
    batchDeleteBtn.disabled = true;
    try {
      const res = await api("/api/admin/files/batch-delete", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ ids }),
      });
      if (!res.ok) throw new Error("HTTP " + res.status);
      const body = await res.json();
      state.selected.clear();
      await load(state.page);
      const miss = body.not_found && body.not_found.length;
      toast(`已删除 ${body.deleted} 个` + (miss ? `，${miss} 个未找到` : ""));
    } catch (e) {
      toast("批量删除失败：" + (e.message || e), "err");
    } finally {
      batchDeleteBtn.disabled = false;
    }
  }

  async function batchDownload() {
    const ids = [...state.selected];
    if (!ids.length) return;
    if (ids.length > 20) {
      if (!confirm(`将下载 ${ids.length} 个文件，浏览器可能弹出多个下载提示。继续？`)) return;
    }
    // 逐个触发下载：同源 Basic Auth 凭据由浏览器自动带上
    for (const id of ids) {
      const a = document.createElement("a");
      a.href = `/api/admin/files/${id}/download`;
      a.download = "";
      document.body.appendChild(a);
      a.click();
      a.remove();
      // 间隔 150ms，避免浏览器拦截并发下载
      await new Promise((r) => setTimeout(r, 150));
    }
    toast(`已触发 ${ids.length} 个下载`);
  }

  load(1);
})();