/* schedule.js — filters, pagination, table render, CSV export */

const PAGE_SIZE = 100;
let currentOffset = 0;
let currentTotal = 0;

// ── init ──────────────────────────────────────────────────────────────────────

document.addEventListener("DOMContentLoaded", () => {
  // Default date range: last 7 days
  const today = new Date();
  const week  = new Date(today);
  week.setDate(today.getDate() - 7);
  document.getElementById("f-date-from").value = fmtDate(week);
  document.getElementById("f-date-to").value   = fmtDate(today);

  loadData();
});

// ── filter helpers ────────────────────────────────────────────────────────────

function getFilters() {
  return {
    date_from:     document.getElementById("f-date-from").value || "",
    date_to:       document.getElementById("f-date-to").value   || "",
    airport:       document.getElementById("f-airport").value,
    direction:     document.getElementById("f-direction").value,
    flight_number: document.getElementById("f-flight").value.trim(),
    time_from:     document.getElementById("f-time-from").value || "",
    time_to:       document.getElementById("f-time-to").value   || "",
  };
}

function buildQuery(extra = {}) {
  const f = { ...getFilters(), limit: PAGE_SIZE, offset: currentOffset, ...extra };
  return Object.entries(f)
    .filter(([, v]) => v !== "" && v !== "all")
    .map(([k, v]) => `${encodeURIComponent(k)}=${encodeURIComponent(v)}`)
    .join("&");
}

function applyFilters() {
  currentOffset = 0;
  loadData();
}

function resetFilters() {
  document.getElementById("f-date-from").value   = "";
  document.getElementById("f-date-to").value     = "";
  document.getElementById("f-airport").value     = "all";
  document.getElementById("f-direction").value   = "all";
  document.getElementById("f-flight").value      = "";
  document.getElementById("f-time-from").value   = "";
  document.getElementById("f-time-to").value     = "";
  currentOffset = 0;
  loadData();
}

// ── pagination ────────────────────────────────────────────────────────────────

function prevPage() {
  if (currentOffset <= 0) return;
  currentOffset = Math.max(0, currentOffset - PAGE_SIZE);
  loadData();
}

function nextPage() {
  if (currentOffset + PAGE_SIZE >= currentTotal) return;
  currentOffset += PAGE_SIZE;
  loadData();
}

function updatePagination() {
  const page  = Math.floor(currentOffset / PAGE_SIZE) + 1;
  const pages = Math.max(1, Math.ceil(currentTotal / PAGE_SIZE));
  document.getElementById("page-info").textContent   = `Стр. ${page} / ${pages}`;
  document.getElementById("total-info").textContent  = `Всего: ${currentTotal.toLocaleString("ru")}`;
  document.getElementById("btn-prev").disabled = currentOffset <= 0;
  document.getElementById("btn-next").disabled = currentOffset + PAGE_SIZE >= currentTotal;
}

// ── data load ─────────────────────────────────────────────────────────────────

async function loadData() {
  setLoading(true);
  try {
    const resp = await fetch(`/api/schedule/data?${buildQuery()}`);
    if (!resp.ok) throw new Error(`HTTP ${resp.status}`);
    const data = await resp.json();
    currentTotal = data.total || 0;
    renderTable(data.flights || []);
    renderCards(data.flights || []);
    updatePagination();
    document.getElementById("last-updated").textContent =
      "Обновлено: " + new Date().toLocaleTimeString("ru");
  } catch (e) {
    showError(e.message);
  } finally {
    setLoading(false);
  }
}

// ── render table ──────────────────────────────────────────────────────────────

function renderTable(flights) {
  const tbody = document.getElementById("table-body");
  if (!flights.length) {
    tbody.innerHTML = `<tr><td colspan="10" class="state-msg">Нет данных по выбранным фильтрам</td></tr>`;
    return;
  }

  tbody.innerHTML = flights.map(f => {
    const dirIcon = f.direction === "departure"
      ? `<span class="dir-icon dir-dep" title="Вылет">↑</span>`
      : `<span class="dir-icon dir-arr" title="Прилёт">↓</span>`;

    const route = routeStr(f);
    const sched = fmtTime(f.scheduled_at);
    const actual = f.actual_at ? fmtTime(f.actual_at) : "—";
    const delay  = delayCell(f.delay_min);
    const badge  = statusBadge(f.status);
    const dateStr = fmtDateShort(f.scheduled_at);

    return `<tr>
      <td>${dateStr}</td>
      <td><strong>${esc(f.flight_number)}</strong></td>
      <td>${esc(f.airline || "—")}</td>
      <td>${esc(f.airport)}</td>
      <td>${dirIcon}</td>
      <td>${esc(route)}</td>
      <td>${sched}</td>
      <td>${actual}</td>
      <td>${delay}</td>
      <td>${badge}</td>
    </tr>`;
  }).join("");
}

// ── render cards (mobile) ─────────────────────────────────────────────────────

function renderCards(flights) {
  const container = document.getElementById("cards-container");
  if (!flights.length) {
    container.innerHTML = `<div class="state-msg">Нет данных по выбранным фильтрам</div>`;
    return;
  }

  container.innerHTML = flights.map(f => {
    const dirLabel = f.direction === "departure" ? "↑ Вылет" : "↓ Прилёт";
    const dirClass = f.direction === "departure" ? "dir-dep" : "dir-arr";
    const route    = routeStr(f);
    const sched    = fmtTime(f.scheduled_at);
    const actual   = f.actual_at ? fmtTime(f.actual_at) : "—";
    const delay    = f.delay_min != null ? `${f.delay_min > 0 ? "+" : ""}${f.delay_min} мин` : "—";
    const badge    = statusBadge(f.status);

    return `<div class="card">
      <div class="card-header">
        <div>
          <div class="card-flight">${esc(f.flight_number)}</div>
          <div class="card-airline">${esc(f.airline || "—")}</div>
        </div>
        ${badge}
      </div>
      <div class="card-row"><span>Аэропорт</span><span>${esc(f.airport)}</span></div>
      <div class="card-row"><span>Направление</span><span class="${dirClass}">${dirLabel}</span></div>
      <div class="card-row"><span>Маршрут</span><span>${esc(route)}</span></div>
      <div class="card-row"><span>Запланировано</span><span>${sched}</span></div>
      <div class="card-row"><span>Фактически</span><span>${actual}</span></div>
      <div class="card-row"><span>Задержка</span><span>${delay}</span></div>
    </div>`;
  }).join("");
}

// ── CSV export ────────────────────────────────────────────────────────────────

function exportCsv() {
  const qs = buildQuery({ limit: 100000, offset: 0 });
  window.location.href = `/api/schedule/export?${qs}`;
}

// ── helpers ───────────────────────────────────────────────────────────────────

function routeStr(f) {
  const o = f.origin      || "";
  const d = f.destination || "";
  if (!o && !d) return "—";
  if (!o) return `→ ${d}`;
  if (!d) return `${o} →`;
  return `${o} → ${d}`;
}

function statusBadge(status) {
  const map = {
    scheduled: "badge-scheduled",
    departed:  "badge-departed",
    arrived:   "badge-arrived",
    delayed:   "badge-delayed",
    cancelled: "badge-cancelled",
  };
  const cls = map[status] || "badge-scheduled";
  const labels = {
    scheduled: "По расписанию",
    departed:  "Вылетел",
    arrived:   "Прилетел",
    delayed:   "Задержан",
    cancelled: "Отменён",
  };
  return `<span class="badge ${cls}">${labels[status] || status || "—"}</span>`;
}

function delayCell(min) {
  if (min == null) return "—";
  if (min > 0) return `<span class="delay-pos">+${min}</span>`;
  if (min < 0) return `<span class="delay-neg">${min}</span>`;
  return "0";
}

function fmtDate(d) {
  return d.toISOString().slice(0, 10);
}

function fmtDateShort(iso) {
  if (!iso) return "—";
  return iso.slice(0, 10);
}

function fmtTime(iso) {
  if (!iso) return "—";
  try {
    return new Date(iso).toLocaleTimeString("ru", { hour: "2-digit", minute: "2-digit", timeZone: "Europe/Moscow" });
  } catch { return iso.slice(11, 16); }
}

function esc(s) {
  if (!s) return "—";
  return String(s)
    .replace(/&/g, "&amp;")
    .replace(/</g, "&lt;")
    .replace(/>/g, "&gt;");
}

function setLoading(on) {
  if (on) {
    document.getElementById("table-body").innerHTML =
      `<tr><td colspan="10" class="state-msg">Загрузка…</td></tr>`;
    document.getElementById("cards-container").innerHTML =
      `<div class="state-msg">Загрузка…</div>`;
  }
}

function showError(msg) {
  document.getElementById("table-body").innerHTML =
    `<tr><td colspan="10" class="state-msg" style="color:#f85149">Ошибка: ${esc(msg)}</td></tr>`;
  document.getElementById("cards-container").innerHTML =
    `<div class="state-msg" style="color:#f85149">Ошибка: ${esc(msg)}</div>`;
}