const REFRESH_MS = 60_000;

const tableState = {
  yesterday: {
    items: [],
    meta: {},
    sortKey: "rank",
    sortDir: "asc",
  },
  today: {
    items: [],
    meta: {},
    sortKey: "rank",
    sortDir: "asc",
  },
};

const SORT_KEYS = {
  rank: (r) => Number(r.rank) || 0,
  symbol: (r) => String(r.symbol || ""),
  quote_volume: (r) => Number(r.quote_volume) || 0,
  price_change_pct: (r) => Number(r.price_change_pct) || 0,
  tags: (r) => {
    let score = 0;
    if (r.is_high_volume) score += 2;
    if (r.is_high_change) score += 1;
    return score;
  },
};

function formatPeriod(start, end) {
  const fmt = (s) => s.replace("T", " ").slice(0, 16);
  return `${fmt(start)} ~ ${fmt(end)}`;
}

function tagText(row) {
  const tags = [];
  if (row.is_high_volume) tags.push("千万+");
  if (row.is_high_change) tags.push("涨跌5%+");
  return tags.join(" ") || "";
}

function renderTags(row) {
  const parts = [];
  if (row.is_high_volume) {
    parts.push('<span class="tag tag-vol">千万+</span>');
  }
  if (row.is_high_change) {
    parts.push('<span class="tag tag-chg">涨跌5%+</span>');
  }
  return parts.length ? parts.join("") : "—";
}

function pctClass(pct) {
  if (pct > 0) return "pct-up";
  if (pct < 0) return "pct-down";
  return "";
}

function sortItems(items, key, dir) {
  const getter = SORT_KEYS[key] || SORT_KEYS.rank;
  const sorted = [...items].sort((a, b) => {
    const va = getter(a);
    const vb = getter(b);
    if (typeof va === "string") {
      return dir === "asc" ? va.localeCompare(vb) : vb.localeCompare(va);
    }
    return dir === "asc" ? va - vb : vb - va;
  });
  return sorted;
}

function updateSortHeaders(tableId) {
  const table = document.querySelector(`table[data-table="${tableId}"]`);
  if (!table) return;
  const { sortKey, sortDir } = tableState[tableId];
  table.querySelectorAll("th.sortable").forEach((th) => {
    th.classList.remove("sorted-asc", "sorted-desc");
    const key = th.dataset.sort;
    if (key === sortKey) {
      th.classList.add(sortDir === "asc" ? "sorted-asc" : "sorted-desc");
    }
  });
}

function renderTable(tableId, tbody) {
  const state = tableState[tableId];
  const items = sortItems(state.items, state.sortKey, state.sortDir);

  if (!items.length) {
    tbody.innerHTML = '<tr><td colspan="5" class="loading">暂无数据</td></tr>';
    updateSortHeaders(tableId);
    return;
  }

  tbody.innerHTML = items
    .map((row, idx) => {
      const highlight =
        row.is_high_volume || row.is_high_change ? " row-highlight" : "";
      const pct = row.price_change_pct ?? 0;
      const displayRank =
        state.sortKey === "rank" && state.sortDir === "asc"
          ? row.rank
          : idx + 1;
      return `<tr class="${highlight}">
        <td class="rank">${displayRank}</td>
        <td><strong>${row.symbol}</strong></td>
        <td data-value="${row.quote_volume ?? 0}">${row.quote_volume_fmt || row.quote_volume}</td>
        <td class="${pctClass(pct)}" data-value="${pct}">${row.price_change_pct_fmt || pct.toFixed(2) + "%"}</td>
        <td data-value="${tagText(row)}">${renderTags(row)}</td>
      </tr>`;
    })
    .join("");

  updateSortHeaders(tableId);
}

function setTableData(tableId, data) {
  tableState[tableId].items = data.items || [];
  tableState[tableId].meta = {
    period_start: data.period_start,
    period_end: data.period_end,
    updated_at: data.updated_at,
  };
  const tbody = document.getElementById(`${tableId}-body`);
  renderTable(tableId, tbody);
}

function toggleSort(tableId, key) {
  const state = tableState[tableId];
  if (state.sortKey === key) {
    state.sortDir = state.sortDir === "asc" ? "desc" : "asc";
  } else {
    state.sortKey = key;
    state.sortDir = key === "symbol" ? "asc" : "desc";
  }
  const tbody = document.getElementById(`${tableId}-body`);
  renderTable(tableId, tbody);
}

function resetSort(tableId) {
  tableState[tableId].sortKey = "rank";
  tableState[tableId].sortDir = "asc";
  const tbody = document.getElementById(`${tableId}-body`);
  renderTable(tableId, tbody);
}

function exportCsv(tableId) {
  const state = tableState[tableId];
  if (!state.items.length) {
    alert("暂无数据可导出");
    return;
  }
  const items = sortItems(state.items, state.sortKey, state.sortDir);
  const header = [
    "排名",
    "合约",
    "成交额显示",
    "成交额USDT",
    "涨跌幅%",
    "千万+",
    "涨跌5%+",
    "标记",
  ];
  const rows = items.map((r, i) => [
    state.sortKey === "rank" && state.sortDir === "asc" ? r.rank : i + 1,
    r.symbol,
    r.quote_volume_fmt || "",
    r.quote_volume ?? "",
    r.price_change_pct ?? "",
    r.is_high_volume ? "是" : "否",
    r.is_high_change ? "是" : "否",
    tagText(r),
  ]);

  const escape = (v) => `"${String(v).replace(/"/g, '""')}"`;
  const csv = [header, ...rows].map((row) => row.map(escape).join(",")).join("\n");
  const blob = new Blob(["\ufeff" + csv], { type: "text/csv;charset=utf-8" });
  const url = URL.createObjectURL(blob);
  const a = document.createElement("a");
  const period = state.meta.period_start
    ? state.meta.period_start.slice(0, 10)
    : tableId;
  a.href = url;
  a.download = `binance-top30-${tableId}-${period}.csv`;
  a.click();
  URL.revokeObjectURL(url);
}

document.querySelectorAll("th.sortable").forEach((th) => {
  th.addEventListener("click", () => {
    const table = th.closest("table");
    const tableId = table?.dataset.table;
    const key = th.dataset.sort;
    if (tableId && key) toggleSort(tableId, key);
  });
});

document.querySelectorAll("[data-export]").forEach((btn) => {
  btn.addEventListener("click", () => exportCsv(btn.dataset.export));
});

document.querySelectorAll("[data-reset]").forEach((btn) => {
  btn.addEventListener("click", () => resetSort(btn.dataset.reset));
});

async function loadYesterday() {
  const body = document.getElementById("yesterday-body");
  body.innerHTML = '<tr><td colspan="5" class="loading">加载中…</td></tr>';
  try {
    const res = await fetch("/api/yesterday/top30");
    const data = await res.json();
    document.getElementById("yesterday-period").textContent = formatPeriod(
      data.period_start,
      data.period_end
    );
    document.getElementById("yesterday-updated").textContent =
      "更新: " + (data.updated_at || "").replace("T", " ").slice(0, 19);
    setTableData("yesterday", data);
  } catch (e) {
    body.innerHTML = `<tr><td colspan="5" class="error">加载失败: ${e.message}</td></tr>`;
  }
}

async function loadToday() {
  const body = document.getElementById("today-body");
  try {
    const res = await fetch("/api/today/top30");
    const data = await res.json();
    document.getElementById("today-period").textContent = formatPeriod(
      data.period_start,
      data.period_end
    );
    document.getElementById("today-updated").textContent =
      "更新: " + (data.updated_at || "").replace("T", " ").slice(0, 19);
    setTableData("today", data);
    document.getElementById("status").textContent = "今日数据已刷新";
  } catch (e) {
    body.innerHTML = `<tr><td colspan="5" class="error">加载失败: ${e.message}</td></tr>`;
    document.getElementById("status").textContent = e.message;
  }
}

document.getElementById("btn-refresh").addEventListener("click", async () => {
  document.getElementById("status").textContent = "刷新中…";
  await fetch("/api/refresh/today", { method: "POST" });
  await loadToday();
});

loadYesterday();
loadToday();
setInterval(loadToday, REFRESH_MS);