"""主页：上传入口 + 最近 10 个任务的实时进度。

共享 _shared.py 的 BASE_CSS / SHARED_JS / 上传协议 JS。
页面专属：refreshList（拉取最近任务）、makeTaskCard、pollTask（轮询进行中任务）。
"""

from __future__ import annotations

from ._shared import POLL_INTERVAL, render_page, render_upload_js

RECENT_LIMIT = 10
LIST_REFRESH_INTERVAL = 5000

_PAGE_JS = f"""
const POLL_INTERVAL = {POLL_INTERVAL};
const LIST_REFRESH_INTERVAL = {LIST_REFRESH_INTERVAL};
const RECENT_LIMIT = {RECENT_LIMIT};

const tasksEl = document.getElementById("tasks");
const emptyEl = document.getElementById("empty");
let pollingIds = new Set();

// 初始化上传区
initUpload(document.getElementById("drop"), document.getElementById("file-input"), tasksEl);

// ==================== 最近任务列表 ====================

async function refreshList() {{
  try {{
    const r = await fetch("/api/tasks?limit=" + RECENT_LIMIT);
    if (!r.ok) return;
    const data = await r.json();
    renderTasks(data.tasks);
  }} catch (e) {{}}
}}

function renderTasks(tasks) {{
  tasksEl.querySelectorAll(".server-task").forEach(el => el.remove());
  const hasUploadCards = tasksEl.querySelector(".upload-task") !== null;
  emptyEl.style.display = (tasks.length === 0 && !hasUploadCards) ? "block" : "none";

  for (const task of tasks) {{
    tasksEl.appendChild(makeTaskCard(task));
  }}
  // 对进行中的任务启动轮询
  for (const task of tasks) {{
    if (ACTIVE_STATES.includes(task.status) && !pollingIds.has(task.id)) {{
      pollingIds.add(task.id);
      pollTask(task.id);
    }}
  }}
}}

function downloadLinks(taskId) {{
  return `<a href="/api/tasks/${{taskId}}/subtitle?type=bilingual" class="dl">双语 SRT</a>`
    + ` <a href="/api/tasks/${{taskId}}/subtitle?type=en" class="dl">英</a>`
    + ` <a href="/api/tasks/${{taskId}}/subtitle?type=zh" class="dl">中</a>`;
}}

function makeTaskCard(task) {{
  const el = document.createElement("div");
  el.className = "card task server-task";
  el.dataset.taskId = task.id;
  el.innerHTML = renderTaskInner(task);
  return el;
}}

function renderTaskInner(task) {{
  const label = STATUS_LABEL[task.status] || task.status;
  const stateClass = task.status === "done" ? "state-done"
    : task.status === "failed" ? "state-fail" : "state-running";
  const created = new Date(task.created_at).toLocaleString();

  let body;
  if (task.status === "done") {{
    body = `<div class="task-meta"><b>完成</b> · ${{downloadLinks(task.id)}}</div>`;
  }} else if (task.status === "failed") {{
    body = `<div class="task-meta fail-msg">${{escapeHtml(task.error || "未知错误")}}</div>`;
  }} else {{
    body = `<div class="bar"><div class="fill" style="width:${{task.progress}}%"></div><span class="pct">${{task.progress.toFixed(0)}}%</span></div>`;
  }}
  return `
    <div class="task-head">
      <span class="fname">#${{task.id}} ${{escapeHtml(task.filename)}}</span>
      <span class="fstate ${{stateClass}}">${{label}}</span>
    </div>
    ${{body}}
    <div class="task-time">${{created}}</div>`;
}}

async function pollTask(taskId) {{
  const tick = async () => {{
    try {{
      const r = await fetch("/api/tasks/" + taskId);
      if (!r.ok) {{ pollingIds.delete(taskId); return; }}
      const task = await r.json();
      const card = tasksEl.querySelector('.server-task[data-task-id="' + taskId + '"]');
      if (!card) {{ pollingIds.delete(taskId); return; }}

      card.innerHTML = renderTaskInner(task);

      if (task.status === "done" || task.status === "failed") {{
        pollingIds.delete(taskId);
        return;
      }}
      setTimeout(tick, POLL_INTERVAL);
    }} catch (e) {{
      setTimeout(tick, POLL_INTERVAL);
    }}
  }};
  tick();
}}

// 启动
refreshList();
setInterval(refreshList, LIST_REFRESH_INTERVAL);
"""

_BODY = """
<h1>音频转字幕</h1>
<p class="sub">上传视频或音频文件，自动生成双语（英/中）SRT 字幕。支持大文件分片上传与断点续传。</p>

<div id="drop" class="drop">
  <p class="drop-hint">把文件拖到这里，或</p>
  <label class="btn">选择文件<input id="file-input" type="file" multiple hidden></label>
</div>

<h2>最近任务</h2>
<div id="tasks" class="tasks"></div>
<div id="empty" class="empty" style="display:none">暂无任务，上传文件后这里会显示进度。</div>
"""


def render() -> str:
    # 上传完成后刷新任务列表，让新任务出现在卡片中
    upload_js = render_upload_js(on_complete="refreshList();")
    return render_page(
        title="audio2text — 音频转字幕",
        nav_active="home",
        body=_BODY,
        page_js=upload_js + _PAGE_JS,
    )