/**
 * @file features/layout/components/header.tsx
 * @description 애플리케이션 상단 헤더 컴포넌트
 */

import Link from "next/link";
import { User } from "@supabase/supabase-js";
import { AUTH_ROUTES } from "@/features/auth/constants";
import { UserMenu } from "@/features/layout/components/user-menu";
import { ThemeToggle } from "@/components/theme-toggle";
import { Button } from "@/components/ui/button";
import { SessionTimer } from "@/features/auth/components/session-timer";
import { cn } from "@/lib/utils";
import { Logo } from "@/features/layout/components/Logo";


import { MarketIndices } from "@/features/layout/components/market-indices";

interface HeaderProps {
  /** 현재 로그인 사용자 정보(null 가능) */
  user: User | null;
  /** 대시보드 링크 버튼 노출 여부 */
  showDashboardLink?: boolean;
  /** 홈 랜딩에서 배경과 자연스럽게 섞이는 헤더 모드 */
  blendWithBackground?: boolean;
}

/**
 * 글로벌 헤더 컴포넌트
 * @param user Supabase User 객체
 * @param showDashboardLink 대시보드 버튼 노출 여부
 * @param blendWithBackground 홈 랜딩 전용 반투명 모드
 * @returns Header JSX
 * @see app/(home)/page.tsx 홈 랜딩에서 blendWithBackground=true로 호출
 */
export function Header({
  user,
  showDashboardLink = false,
  blendWithBackground = false,
}: HeaderProps) {
  return (
    <header
      className={cn(
        "fixed inset-x-0 top-0 z-50 w-full",
        blendWithBackground
          ? "text-white"
          : "border-b border-border/40 bg-background/80 backdrop-blur-xl supports-backdrop-filter:bg-background/60",
      )}
    >
      {blendWithBackground && (
        <div
          aria-hidden="true"
          className="pointer-events-none absolute inset-x-0 top-0 h-24 bg-linear-to-b from-black/70 via-black/35 to-transparent"
        />
      )}

      <div
        className={cn(
          "relative z-10 flex h-16 w-full items-center justify-between px-4 md:px-6",
          blendWithBackground
            ? "bg-black/30 backdrop-blur-xl supports-backdrop-filter:bg-black/20"
            : "",
        )}
      >
        {/* ========== LEFT: LOGO SECTION ========== */}
        <Link href={AUTH_ROUTES.HOME} className="group flex items-center gap-2">
          <Logo
            variant="full"
            className="h-10 text-xl transition-transform duration-200 group-hover:scale-105"
            blendWithBackground={blendWithBackground}
          />
        </Link>

        {/* ========== CENTER: MARKET INDICES ========== */}
        {!blendWithBackground && user && (
          <div className="absolute left-1/2 top-1/2 -translate-x-1/2 -translate-y-1/2">
            <MarketIndices />
          </div>
        )}

        {/* ========== RIGHT: ACTION SECTION ========== */}
        <div
          className={cn(
            "flex items-center gap-2 sm:gap-3",
            blendWithBackground ? "text-white" : "",
          )}
        >
          <ThemeToggle
            className={cn(
              blendWithBackground
                ? "rounded-full border border-white/40 bg-black/50 text-white! backdrop-blur-md hover:bg-black/65 focus-visible:ring-white/80"
                : "",
            )}
            iconClassName={blendWithBackground ? "text-white!" : undefined}
          />

          {user ? (
            <>
              <SessionTimer blendWithBackground={blendWithBackground} />

              {showDashboardLink && (
                <Button
                  asChild
                  variant="ghost"
                  size="sm"
                  className={cn(
                    "hidden font-medium sm:inline-flex",
                    blendWithBackground
                      ? "rounded-full border border-white/40 bg-black/50 text-white! backdrop-blur-md [text-shadow:0_1px_8px_rgba(0,0,0,0.45)] hover:bg-black/65 hover:text-white!"
                      : "",
                  )}
                >
                  <Link href={AUTH_ROUTES.DASHBOARD}>시작하기</Link>
                </Button>
              )}

              <UserMenu user={user} blendWithBackground={blendWithBackground} />
            </>
          ) : (
            <div className="flex items-center gap-2">
              <Button
                asChild
                variant="ghost"
                size="sm"
                className={cn(
                  "hidden sm:inline-flex",
                  blendWithBackground
                    ? "rounded-full border border-white/40 bg-black/50 text-white! backdrop-blur-md hover:bg-black/65 hover:text-white!"
                    : "",
                )}
              >
                <Link href={AUTH_ROUTES.LOGIN}>로그인</Link>
              </Button>
              <Button
                asChild
                size="sm"
                className={cn(
                  "rounded-full px-6",
                  blendWithBackground
                    ? "bg-brand-500/90 text-white shadow-lg shadow-brand-700/40 hover:bg-brand-400"
                    : "",
                )}
              >
                <Link href={AUTH_ROUTES.SIGNUP}>회원가입</Link>
              </Button>
            </div>
          )}
        </div>
      </div>
    </header>
  );
}