/* PDF 转换页：上传 epub + 进度轮询 + 下载 + 用户软删。
   复用 common.js 的 el/toast/fmtBytes/fmtTime/api 工具。
   state.items 缓存当前用户任务列表；轮询未完成任务进度直至终态。 */
(function () {
  "use strict";
  const { el, toast, fmtBytes, fmtTime, api } = window.ZK;
  const dropzone = document.getElementById("dropzone");
  const fileInput = document.getElementById("fileInput");
  const uploadProgress = document.getElementById("uploadProgress");
  const uploadName = document.getElementById("uploadName");
  const uploadBar = document.getElementById("uploadBar");
  const refreshBtn = document.getElementById("refresh");
  const countEl = document.getElementById("count");
  const listEl = document.getElementById("list");

  const state = { items: [], polling: null };

  refreshBtn.addEventListener("click", () => load());

  // ---------- 上传 ----------
  dropzone.addEventListener("dragover", (e) => {
    e.preventDefault();
    dropzone.classList.add("is-drag");
  });
  dropzone.addEventListener("dragleave", () => dropzone.classList.remove("is-drag"));
  dropzone.addEventListener("drop", (e) => {
    e.preventDefault();
    dropzone.classList.remove("is-drag");
    if (e.dataTransfer.files.length) handleFile(e.dataTransfer.files[0]);
  });
  fileInput.addEventListener("change", () => {
    if (fileInput.files.length) handleFile(fileInput.files[0]);
    fileInput.value = "";
  });

  function handleFile(file) {
    const name = file.name || "";
    if (!name.toLowerCase().endsWith(".epub")) {
      toast("仅支持 epub 文件", "err");
      return;
    }
    if (file.size > 250 * 1024 * 1024) {
      toast("文件超过 250MB 上限", "err");
      return;
    }
    uploadFile(file);
  }

  function uploadFile(file) {
    uploadProgress.classList.remove("hidden");
    uploadName.textContent = file.name;
    uploadBar.style.width = "0%";
    const xhr = new XMLHttpRequest();
    xhr.open("POST", "/api/pdf/jobs");
    xhr.upload.onprogress = (e) => {
      if (e.lengthComputable) {
        uploadBar.style.width = Math.round((e.loaded / e.total) * 100) + "%";
      }
    };
    xhr.onload = () => {
      uploadProgress.classList.add("hidden");
      if (xhr.status === 200) {
        toast("已提交，转换中…");
        load();
      } else {
        let msg = "上传失败";
        try {
          const b = JSON.parse(xhr.responseText);
          msg = b.detail || msg;
        } catch {}
        toast(msg, "err");
      }
    };
    xhr.onerror = () => {
      uploadProgress.classList.add("hidden");
      toast("网络错误", "err");
    };
    const fd = new FormData();
    fd.append("file", file);
    xhr.send(fd);
  }

  // ---------- 列表 ----------
  async function load() {
    listEl.innerHTML = '<div class="skel">加载中…</div>';
    countEl.textContent = "";
    try {
      const res = await api("/api/pdf/jobs");
      if (!res.ok) throw new Error("HTTP " + res.status);
      const body = await res.json();
      state.items = body.items || [];
      countEl.textContent = `共 ${body.total} 个任务`;
      render();
      schedulePoll();
    } 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">还没有任务。上传一个 epub 试试吧。</div>';
      return;
    }
    const tbl = el("table", { class: "jobs-table" });
    tbl.appendChild(el("thead", null,
      el("tr", null,
        el("th", { class: "col-name" }, "文件名"),
        el("th", { class: "col-size" }, "大小"),
        el("th", { class: "col-status" }, "状态"),
        el("th", { class: "col-time" }, "创建时间"),
        el("th", { class: "col-act" }, "操作")
      )
    ));
    const tbody = el("tbody", null);
    for (const j of state.items) tbody.appendChild(renderRow(j));
    tbl.appendChild(tbody);
    listEl.innerHTML = "";
    listEl.appendChild(tbl);
  }

  function renderRow(j) {
    return el("tr", { dataset: { id: j.id } },
      el("td", { class: "col-name" }, j.source_filename),
      el("td", { class: "col-size mono" }, fmtBytes(j.source_size)),
      el("td", { class: "col-status" }, statusCell(j)),
      el("td", { class: "col-time muted" }, fmtTime(j.created_at)),
      el("td", { class: "col-act" }, actionsCell(j))
    );
  }

  function statusCell(j) {
    if (j.status === "done") return el("span", { class: "tag ok" }, "完成");
    if (j.status === "failed") return el("span", { class: "tag err", title: j.error_message || "" }, "失败");
    // pending / converting 显示进度条
    const wrap = el("span", { class: "prog" });
    wrap.appendChild(el("span", { class: "prog__label" }, j.status === "converting" ? "转换中" : "排队中"));
    wrap.appendChild(el("span", { class: "bar bar--sm" },
      el("span", { class: "bar__fill", style: "width:" + (j.progress || 0) + "%" })
    ));
    return wrap;
  }

  function actionsCell(j) {
    const cell = el("span", null);
    if (j.status === "done") {
      cell.appendChild(el("a", { class: "btn primary", href: `/api/pdf/jobs/${j.id}/download`, download: "" }, "下载"));
    }
    cell.appendChild(el("button", { class: "btn danger", onclick: () => removeOne(j) }, "删除"));
    return cell;
  }

  // ---------- 轮询未完成任务 ----------
  function schedulePoll() {
    if (state.polling) clearInterval(state.polling);
    const pending = state.items.filter((j) => j.status === "pending" || j.status === "converting");
    if (!pending.length) return;
    state.polling = setInterval(async () => {
      let stillPending = false;
      for (const j of pending) {
        try {
          const res = await api(`/api/pdf/jobs/${j.id}`);
          if (res.ok) {
            const fresh = await res.json();
            Object.assign(j, fresh);
          }
        } catch {}
        if (j.status === "pending" || j.status === "converting") stillPending = true;
      }
      render();
      if (!stillPending) {
        clearInterval(state.polling);
        state.polling = null;
      }
    }, 1500);
  }

  async function removeOne(j) {
    if (!confirm(`确定删除「${j.source_filename}」？\n删除后将不再显示（管理员仍可见，需管理员彻底删除才会清除）。`)) return;
    try {
      const res = await api(`/api/pdf/jobs/${j.id}`, { method: "DELETE" });
      if (!res.ok) throw new Error("HTTP " + res.status);
      await load();
      toast("已删除");
    } catch (e) {
      toast("删除失败：" + (e.message || e), "err");
    }
  }

  load();
})();