"use client";

import Link from "next/link";
import { usePathname } from "next/navigation";
import clsx from "clsx";
import { LogIn, UserRound, RotateCw, BookOpen, Sparkles } from "lucide-react";
import { useDashboardStore } from "@/hooks/useDashboardStore";
import { useI18n } from "@/hooks/useI18n";

function parseExpiryInfo(raw?: string | null) {
  const text = String(raw || "").trim();
  if (!text) return null;
  const dt = new Date(text);
  if (Number.isNaN(dt.getTime())) return null;
  const diffMs = dt.getTime() - Date.now();
  const daysLeft = Math.ceil(diffMs / 86_400_000);
  return {
    date: dt,
    daysLeft,
    expired: diffMs <= 0,
  };
}

export function HeaderBar() {
  const store = useDashboardStore();
  const { locale, setLocale, t } = useI18n();
  const pathname = usePathname();
  const isAuthenticated = store.proAccess.authenticated;
  const docsHref = "/docs/intro";
  const docsActive = pathname?.startsWith("/docs");
  const trialPromoLabel =
    locale === "en-US"
      ? "New users get 3-day Pro trial"
      : "新用户可免费体验 3 天 Pro";

  const accountHref = isAuthenticated
    ? "/account"
    : "/auth/login?next=%2Faccount";
  const accountLabel = isAuthenticated
    ? t("header.account")
    : t("header.signIn");
  const accountAria = isAuthenticated
    ? t("header.accountAria")
    : t("header.signInAria");
  const effectiveExpiry = store.proAccess.subscriptionActive
    ? store.proAccess.subscriptionTotalExpiresAt ||
      store.proAccess.subscriptionExpiresAt
    : store.proAccess.subscriptionExpiresAt;
  const expiryInfo = parseExpiryInfo(effectiveExpiry);
  const isTrialPlan = /trial/i.test(
    String(store.proAccess.subscriptionPlanCode || ""),
  );
  const showRenewReminder =
    isAuthenticated &&
    !store.proAccess.loading &&
    ((store.proAccess.subscriptionActive &&
      expiryInfo &&
      expiryInfo.daysLeft <= 3) ||
      (!store.proAccess.subscriptionActive && Boolean(expiryInfo)));
  const renewReminderLabel = !showRenewReminder
    ? ""
    : !store.proAccess.subscriptionActive
      ? isTrialPlan
        ? locale === "en-US"
          ? "Trial ended"
          : "试用已结束"
        : locale === "en-US"
          ? "Pro expired"
          : "Pro 已到期"
      : isTrialPlan
        ? locale === "en-US"
          ? `Trial ${Math.max(expiryInfo?.daysLeft || 0, 0)}d left`
          : `试用剩余 ${Math.max(expiryInfo?.daysLeft || 0, 0)} 天`
        : locale === "en-US"
          ? `Pro ${Math.max(expiryInfo?.daysLeft || 0, 0)}d left`
          : `Pro 还剩 ${Math.max(expiryInfo?.daysLeft || 0, 0)} 天`;

  return (
    <header className="header">
      <div className="brand">
        <h1>PolyWeather</h1>
        <span className="subtitle">{t("header.subtitle")}</span>
      </div>

      <div className="header-right">
        <div
          className="lang-switch"
          role="group"
          aria-label={t("header.langAria")}
        >
          <button
            type="button"
            className={clsx("lang-btn", locale === "zh-CN" && "active")}
            onClick={() => setLocale("zh-CN")}
          >
            {t("header.langZh")}
          </button>
          <button
            type="button"
            className={clsx("lang-btn", locale === "en-US" && "active")}
            onClick={() => setLocale("en-US")}
          >
            {t("header.langEn")}
          </button>
        </div>

        <Link
          href={docsHref}
          className={clsx("info-btn", docsActive && "active")}
          title={t("header.docsAria")}
          aria-label={t("header.docsAria")}
        >
          <BookOpen size={14} strokeWidth={2} />
          {t("header.docs")}
        </Link>

        <Link
          href="/account"
          className="trial-promo-badge"
          title={trialPromoLabel}
          aria-label={trialPromoLabel}
        >
          <Sparkles size={12} strokeWidth={2} />
          <span>{trialPromoLabel}</span>
        </Link>

        <Link
          href={accountHref}
          className="account-btn"
          title={accountAria}
          aria-label={accountAria}
        >
          {isAuthenticated ? <UserRound size={14} /> : <LogIn size={14} />}
          <span>{accountLabel}</span>
        </Link>

        {showRenewReminder ? (
          <Link
            href="/account"
            className={clsx(
              "account-renew-badge",
              !store.proAccess.subscriptionActive && "expired",
            )}
            title={renewReminderLabel}
            aria-label={renewReminderLabel}
          >
            <span>{renewReminderLabel}</span>
          </Link>
        ) : null}

        <div className="live-badge" id="liveBadge">
          <span className="pulse-dot" />
          <span>{t("header.live")}</span>
        </div>

        <button
          type="button"
          className={clsx(
            "refresh-btn",
            store.loadingState.refresh && "spinning",
          )}
          title={t("header.refreshAria")}
          aria-label={t("header.refreshAria")}
          onClick={() => void store.refreshAll()}
        >
          <RotateCw size={16} strokeWidth={2} />
        </button>
      </div>
    </header>
  );
}