const accountHealthText = document.querySelector("#accountHealthText");
const refreshBtn = document.querySelector("#refreshBtn");
const accountForm = document.querySelector("#accountForm");
const accountQuery = document.querySelector("#accountQuery");
const accountStatus = document.querySelector("#accountStatus");
const accountMeta = document.querySelector("#accountMeta");
const accountRows = document.querySelector("#accountRows");

function fmtHours(value) {
  return Number(value || 0).toLocaleString("zh-CN", { maximumFractionDigits: 2 });
}

function fmtTime(seconds) {
  if (!seconds) return "未知";
  return new Date(seconds * 1000).toLocaleString("zh-CN", { hour12: false });
}

function escapeHtml(value) {
  return String(value ?? "")
    .replaceAll("&", "&")
    .replaceAll("<", "&lt;")
    .replaceAll(">", "&gt;")
    .replaceAll('"', "&quot;")
    .replaceAll("'", "&#039;");
}

function metric(label, value) {
  return `<div class="metric"><span>${escapeHtml(label)}</span><strong>${escapeHtml(value)}</strong></div>`;
}

function statusClass(status) {
  if (status === "欠费") return "debt";
  if (status === "预警") return "warning";
  if (status === "正常") return "normal";
  return "closed";
}

function renderPayments(payments) {
  if (!payments.length) return "暂无";
  return payments.map((item) => `${escapeHtml(item.date)}：${fmtHours(item.hours)} 小时`).join("<br>");
}

async function fetchJson(url) {
  const response = await fetch(url, { cache: "no-store" });
  if (!response.ok) {
    let detail = `${response.status} ${response.statusText}`;
    try {
      const payload = await response.json();
      detail = payload.detail || detail;
    } catch (_error) {
      detail = response.statusText || detail;
    }
    throw new Error(detail);
  }
  return response.json();
}

function renderSummary(summary, count) {
  accountMeta.innerHTML = [
    metric("当前结果", `${count} 人`),
    metric("欠费", summary.debt),
    metric("预警", summary.warning),
    metric("正常", summary.normal),
  ].join("");
}

async function loadAccountHealth() {
  try {
    const data = await fetchJson("/api/account-health");
    accountHealthText.textContent = `账户 ${data.accounts_count} 人；数据更新时间 ${fmtTime(data.accounts.mtime)}`;
  } catch (error) {
    accountHealthText.textContent = `读取失败：${error.message}`;
  }
}

async function loadAccounts() {
  accountRows.innerHTML = `<tr><td colspan="5" class="empty">正在读取</td></tr>`;
  const params = new URLSearchParams();
  if (accountQuery.value.trim()) params.set("q", accountQuery.value.trim());
  if (accountStatus.value) params.set("status", accountStatus.value);
  try {
    const data = await fetchJson(`/api/accounts?${params.toString()}`);
    renderSummary(data.summary, data.count);
    accountRows.innerHTML = data.accounts
      .map(
        (row) => `<tr>
          <td>${escapeHtml(row.student)}<br><small>${escapeHtml(row.student_id)}</small></td>
          <td><span class="status ${statusClass(row.account_status)}">${escapeHtml(row.account_status)}</span></td>
          <td class="num">${fmtHours(row.remaining)}</td>
          <td>${renderPayments(row.payments)}</td>
          <td class="note-cell">${escapeHtml(row.note || "")}</td>
        </tr>`,
      )
      .join("");
    if (!data.accounts.length) {
      accountRows.innerHTML = `<tr><td colspan="5" class="empty">没有符合条件的账户</td></tr>`;
    }
  } catch (error) {
    accountRows.innerHTML = `<tr><td colspan="5" class="empty">读取失败：${escapeHtml(error.message)}</td></tr>`;
  }
}

accountForm.addEventListener("submit", (event) => {
  event.preventDefault();
  loadAccounts();
});

accountStatus.addEventListener("change", loadAccounts);

refreshBtn.addEventListener("click", () => {
  loadAccountHealth();
  loadAccounts();
});

loadAccountHealth();
loadAccounts();