/**
 * Home flow:
 * - range mode: start~end, skip TW holidays/weekends
 * - list mode: exact dates, fill even on holidays
 * Preview/fill: Teams meetings + GitLab issues → PTS
 */

function setDefaultDates() {
  const today = todayStr();
  document.getElementById("startDate").value = today;
  document.getElementById("endDate").value = today;
}

function getDateMode() {
  const checked = document.querySelector('input[name="dateMode"]:checked');
  return checked ? checked.value : "range";
}

function getDateRange() {
  const start = document.getElementById("startDate")?.value || todayStr();
  let end = document.getElementById("endDate")?.value || start;
  if (end < start) {
    document.getElementById("endDate").value = start;
    document.getElementById("startDate").value = end;
    return { start: end, end: start };
  }
  return { start, end };
}

function getDateListText() {
  return (document.getElementById("dateList")?.value || "").trim();
}

function parseDateList(text) {
  const dates = [];
  for (const line of text.split(/\n+/)) {
    const t = line.trim();
    if (!t || t.startsWith("#")) continue;
    for (const part of t.split(/[\s,;]+/)) {
      const d = part.trim();
      if (/^\d{4}-\d{2}-\d{2}$/.test(d)) dates.push(d);
    }
  }
  return [...new Set(dates)].sort();
}

function setRangeToToday() {
  const today = todayStr();
  document.getElementById("startDate").value = today;
  document.getElementById("endDate").value = today;
  updateRangeMeta();
}

function updateDateModeUI() {
  const mode = getDateMode();
  document.getElementById("rangePanel")?.classList.toggle("hidden", mode !== "range");
  document.getElementById("listPanel")?.classList.toggle("hidden", mode !== "list");
  updateRangeMeta();
}

function updateRangeMeta() {
  const el = document.getElementById("rangeMeta");
  if (!el) return;
  if (getDateMode() === "list") {
    const dates = parseDateList(getDateListText());
    el.textContent = dates.length
      ? `指定 ${dates.length} 天（含假日也填）：${dates.join("、")}`
      : "請輸入至少一個日期";
    return;
  }
  const { start, end } = getDateRange();
  el.textContent = `區間 ${start} → ${end}（自動跳過週末／台灣假日）`;
}

function setActionStatus(text, ok) {
  const el = document.getElementById("actionStatus");
  if (!el) return;
  el.textContent = text || "";
  el.className = "settings-status" + (ok === true ? " ok" : ok === false ? " err" : "");
}

function escapeHtml(text) {
  return String(text)
    .replace(/&/g, "&amp;")
    .replace(/</g, "&lt;")
    .replace(/>/g, "&gt;")
    .replace(/"/g, "&quot;");
}

async function refreshConn() {
  const line = document.getElementById("connLine");
  try {
    const data = await api("/api/status");
    const teams = data.teams_calendar || {};
    const parts = [
      data.has_pts_session ? "工時 ✓" : "工時 ✗",
      data.gitlab_configured && !data.gitlab_error ? "任務 ✓" : "任務 ✗",
      data.teams_calendar_enabled ? (teams.connected ? "行事曆 ✓" : "行事曆 ✗") : "行事曆 關",
    ];
    if (line) {
      line.textContent = parts.join(" · ");
      if (data.gitlab_error) line.textContent += " — " + data.gitlab_error;
    }
  } catch (err) {
    if (line) line.textContent = err.message;
  }
}

function renderPlan(data, { filled } = {}) {
  const root = document.getElementById("planView");
  if (!root) return;

  const workdays = data.workdays || [];
  const plan = data.plan || {};
  const meetings = data.analysis?.meetings || data.meetings || {};
  const source = data.source || "";
  const gitlabN = data.gitlab_task_count ?? "—";

  const meetingNote =
    meetings.enabled === false
      ? "會議未啟用"
      : meetings.error
        ? `會議：${meetings.error}`
        : meetings.meeting_count != null
          ? `會議 ${meetings.meeting_count} 場 · ${meetings.meeting_hours_total ?? 0}h`
          : "";

  if (!workdays.length && !Object.keys(plan).length) {
    root.innerHTML = `<p class="hint">沒有可填日期。區間模式會跳過假日；指定多日請確認日期格式。</p>`;
    return;
  }

  const days = workdays.length ? workdays : Object.keys(plan).sort();
  const dayBlocks = days
    .map((day) => {
      const entries = plan[day] || [];
      if (!entries.length) {
        return `<div class="plan-day">
          <div class="plan-day-head"><strong>${escapeHtml(day)}</strong><span class="muted-inline">無項目</span></div>
        </div>`;
      }
      const hours = entries.reduce((s, e) => s + Number(e.take_hours || 0), 0);
      const rows = entries
        .map((e) => {
          const desc = String(e.description || "");
          const isMeeting =
            (e.pts_task_name || "").toLowerCase().includes("meet") ||
            desc.toLowerCase().includes("meeting") ||
            desc.toLowerCase().includes("attended");
          const tag = isMeeting
            ? '<span class="tag">會議</span>'
            : e.gitlab_task_id
              ? '<span class="tag">GitLab</span>'
              : "";
          return `<li class="plan-row">
            <span class="meeting-hours">${escapeHtml(String(e.take_hours))}h</span>
            <span class="meeting-subject">${tag}${escapeHtml(e.pts_task_name || "")} · ${escapeHtml(desc)}</span>
          </li>`;
        })
        .join("");
      return `<div class="plan-day">
        <div class="plan-day-head">
          <strong>${escapeHtml(day)}</strong>
          <span class="muted-inline">${entries.length} 筆 · ${hours}h</span>
        </div>
        <ul class="meeting-items">${rows}</ul>
      </div>`;
    })
    .join("");

  const title = filled ? "已填寫" : "預覽";
  const dry = data.dry_run ? "（試跑）" : "";
  root.innerHTML = `
    <div class="meetings-summary">
      ${pill(title + dry, source || "ok", true)}
      ${pill("天數", String(days.length), null)}
      ${pill("GitLab", String(gitlabN), null)}
      ${meetingNote ? pill("Teams", meetingNote, meetings.error ? false : null) : ""}
    </div>
    <div class="meetings-list">${dayBlocks}</div>
  `;
}

async function runPreview() {
  const mode = getDateMode();
  setActionStatus("預覽中…");
  document.getElementById("planView").innerHTML = `<p class="hint">會議 + GitLab 分配中…</p>`;

  try {
    let data;
    if (mode === "list") {
      const dates = parseDateList(getDateListText());
      if (!dates.length) throw new Error("請至少輸入一個日期（YYYY-MM-DD）");
      data = await api("/api/preview/dates", {
        method: "POST",
        body: JSON.stringify({ dates_text: dates.join("\n") }),
      });
      document.getElementById("rangeMeta").textContent =
        `指定 ${dates.length} 天（含假日）：${dates.join("、")}`;
    } else {
      const { start, end } = getDateRange();
      data = await api(
        `/api/preview?start_date=${encodeURIComponent(start)}&end_date=${encodeURIComponent(end)}`
      );
      document.getElementById("rangeMeta").textContent =
        `區間 ${start} → ${end} · 工作日 ${(data.workdays || []).length} 天（已跳過假日）`;
    }
    renderPlan(data, { filled: false });
    setActionStatus("預覽完成（尚未送出）", true);
  } catch (err) {
    document.getElementById("planView").innerHTML =
      `<p class="settings-status err">${escapeHtml(err.message)}</p>`;
    setActionStatus(err.message, false);
  }
}

async function runFill() {
  const mode = getDateMode();
  const dryRun = document.getElementById("dryRun").checked;
  setActionStatus(`${dryRun ? "試跑" : "填寫"}中…`);
  document.getElementById("planView").innerHTML = `<p class="hint">處理中…</p>`;

  try {
    let data;
    if (mode === "list") {
      const dates = parseDateList(getDateListText());
      if (!dates.length) throw new Error("請至少輸入一個日期（YYYY-MM-DD）");
      data = await api("/api/fill/dates", {
        method: "POST",
        body: JSON.stringify({
          dates_text: dates.join("\n"),
          dry_run: dryRun,
          skip_existing: true,
        }),
      });
      document.getElementById("rangeMeta").textContent =
        `指定 ${dates.length} 天` + (dryRun ? " · 試跑" : " · 已送出");
    } else {
      const { start, end } = getDateRange();
      data = await api("/api/fill/range", {
        method: "POST",
        body: JSON.stringify({
          start_date: start,
          end_date: end,
          dry_run: dryRun,
          skip_existing: true,
        }),
      });
      document.getElementById("rangeMeta").textContent =
        `區間 ${start} → ${end}` + (dryRun ? " · 試跑" : " · 已送出");
    }

    if (data.plan || data.workdays) {
      renderPlan({ ...data, dry_run: dryRun }, { filled: !dryRun });
    } else {
      document.getElementById("planView").innerHTML = `
        <div class="meetings-summary">
          ${pill(dryRun ? "試跑完成" : "填寫完成", "ok", true)}
          ${pill("新增", String((data.created || []).length), null)}
          ${pill("略過", String((data.skipped || []).length), null)}
        </div>
        <pre class="preview">${escapeHtml(JSON.stringify(data, null, 2))}</pre>
      `;
    }
    setActionStatus(dryRun ? "試跑完成" : "填寫完成", true);
    await refreshConn();
  } catch (err) {
    document.getElementById("planView").innerHTML =
      `<p class="settings-status err">${escapeHtml(err.message)}</p>`;
    setActionStatus(err.message, false);
  }
}

document.querySelectorAll('input[name="dateMode"]').forEach((el) => {
  el.addEventListener("change", updateDateModeUI);
});
document.getElementById("setTodayBtn")?.addEventListener("click", setRangeToToday);
document.getElementById("previewBtn")?.addEventListener("click", () => runPreview().catch(console.error));
document.getElementById("fillBtn")?.addEventListener("click", () => runFill().catch(console.error));
document.getElementById("startDate")?.addEventListener("change", updateRangeMeta);
document.getElementById("endDate")?.addEventListener("change", updateRangeMeta);
document.getElementById("dateList")?.addEventListener("input", updateRangeMeta);

setDefaultDates();
updateDateModeUI();
refreshConn().catch(console.error);