import { useState, useRef, useEffect } from "react";
import { Link, useLocation } from "react-router-dom";
import CategoryBadge from "@/components/common/CategoryBadge";

/** 경로 → breadcrumb 레이블 매핑 (정적 경로) */
const pathLabels: Record<string, string> = {
  "/dashboard": "대시보드",
  "/services": "서비스 관리",
  "/services/register": "서비스 등록",
  "/messages": "메시지 관리",
  "/messages/register": "메시지 등록",
  "/statistics": "발송 통계",
  "/statistics/history": "발송 이력",
  "/devices": "기기 관리",
  "/tags": "태그 관리",
  "/settings": "마이 페이지",
  "/settings/profile": "프로필 수정",
  "/settings/notifications": "알림",
};

/**
 * 동적 경로 패턴 매칭 규칙
 * pattern으로 pathname을 매칭 → crumbs 함수가 추가할 브레드크럼 배열 반환
 */
const dynamicPatterns: {
  pattern: RegExp;
  crumbs: (match: RegExpMatchArray) => { path: string; label: string }[];
}[] = [
  {
    // /services/:id 또는 /services/:id/edit (register 제외)
    pattern: /^\/services\/(?!register$)([^/]+)(\/edit)?$/,
    crumbs: (match) => {
      const id = match[1];
      const isEdit = !!match[2];
      const result = [{ path: `/services/${id}`, label: "서비스 상세" }];
      if (isEdit) {
        result.push({ path: `/services/${id}/edit`, label: "서비스 수정" });
      }
      return result;
    },
  },
];

/** pathname → breadcrumb 배열 생성 */
function buildBreadcrumbs(pathname: string) {
  const segments = pathname.split("/").filter(Boolean);
  const crumbs: { path: string; label: string }[] = [];

  // 1) 정적 경로 매칭 (누적 경로 기반)
  let currentPath = "";
  for (const segment of segments) {
    currentPath += `/${segment}`;
    const label = pathLabels[currentPath];
    if (label) {
      crumbs.push({ path: currentPath, label });
    }
  }

  // 2) 동적 경로 패턴 매칭
  for (const { pattern, crumbs: buildDynamic } of dynamicPatterns) {
    const match = pathname.match(pattern);
    if (match) {
      crumbs.push(...buildDynamic(match));
    }
  }

  return crumbs;
}

/* ── 알림 더미 데이터 ── */
interface NotificationItem {
  variant: "success" | "warning" | "error" | "info" | "default";
  icon: string;
  category: string;
  title: string;
  description: string;
  time: string;
}

const MOCK_NOTIFICATIONS: NotificationItem[] = [
  { variant: "success", icon: "check_circle", category: "발송", title: "마케팅 발송", description: "마케팅 캠페인 발송이 완료되었습니다 (1,234건 중 1,230건 성공)", time: "14:30" },
  { variant: "warning", icon: "verified", category: "인증서", title: "iOS Production", description: "인증서가 7일 후 만료 예정입니다. 갱신이 필요합니다.", time: "09:15" },
  { variant: "error", icon: "error", category: "실패", title: "프로모션 알림", description: "FCM 토큰 만료로 인해 320건 발송에 실패했습니다", time: "1일 전" },
  { variant: "info", icon: "cloud", category: "서비스", title: "마케팅 발송", description: "신규 서비스가 정상 등록되었습니다", time: "2일 전" },
  { variant: "default", icon: "settings", category: "시스템", title: "SPMS", description: "정기 점검이 완료되어 정상 운영 중입니다", time: "3일 전" },
];

export default function AppHeader() {
  const { pathname } = useLocation();
  const crumbs = buildBreadcrumbs(pathname);
  const [notiOpen, setNotiOpen] = useState(false);
  const notiRef = useRef<HTMLDivElement>(null);

  // 외부 클릭 시 드롭다운 닫기
  useEffect(() => {
    function handleClick(e: MouseEvent) {
      if (notiRef.current && !notiRef.current.contains(e.target as Node)) {
        setNotiOpen(false);
      }
    }
    document.addEventListener("click", handleClick);
    return () => document.removeEventListener("click", handleClick);
  }, []);

  // 페이지 이동 시 닫기
  useEffect(() => {
    setNotiOpen(false);
  }, [pathname]);

  return (
    <header className="fixed left-64 right-0 top-0 z-40 flex h-16 items-center justify-between border-b border-gray-200 bg-white px-10 shadow-sm">
      {/* 브레드크럼 (다단계) */}
      <nav className="flex min-w-0 flex-1 items-center overflow-hidden text-sm">
        {crumbs.length === 0 ? (
          <span className="font-medium text-foreground">Home</span>
        ) : (
          <>
            <Link to="/" className="flex-shrink-0 whitespace-nowrap text-gray-500 transition-colors hover:text-primary">Home</Link>
            {crumbs.map((crumb, i) => {
              const isLast = i === crumbs.length - 1;
              return (
                <span key={crumb.path} className="flex flex-shrink-0 items-center">
                  <span className="material-symbols-outlined mx-2 text-base text-gray-300">chevron_right</span>
                  {isLast ? (
                    <span className="whitespace-nowrap font-medium text-foreground">{crumb.label}</span>
                  ) : (
                    <Link to={crumb.path} className="whitespace-nowrap text-gray-500 transition-colors hover:text-primary">
                      {crumb.label}
                    </Link>
                  )}
                </span>
              );
            })}
          </>
        )}
      </nav>

      {/* 우측 아이콘 */}
      <div className="ml-auto flex flex-shrink-0 items-center gap-5 pl-4 text-gray-400">
        {/* 알림 버튼 + 드롭다운 */}
        <div className="relative" ref={notiRef}>
          <button
            onClick={() => setNotiOpen((v) => !v)}
            className="group relative transition-colors hover:text-primary"
          >
            <span className="material-symbols-outlined text-2xl group-hover:animate-pulse">
              notifications
            </span>
            <span className="absolute right-0.5 top-0.5 size-2 rounded-full border-2 border-white bg-red-500" />
          </button>

          {/* 알림 드롭다운 패널 */}
          {notiOpen && (
            <div className="absolute right-0 top-full mt-2 w-96 overflow-hidden rounded-xl border border-gray-200 bg-white shadow-lg z-50">
              {/* 헤더 */}
              <div className="flex items-center justify-between border-b border-gray-100 px-4 py-3">
                <h3 className="text-sm font-bold text-foreground">알림</h3>
                <Link
                  to="/settings/notifications"
                  className="text-xs font-medium text-primary transition-colors hover:text-[#1d4ed8]"
                >
                  전체 보기
                </Link>
              </div>

              {/* 알림 목록 */}
              <div className="overflow-y-auto" style={{ maxHeight: 200, overscrollBehavior: "contain" }}>
                {MOCK_NOTIFICATIONS.map((noti, i) => (
                  <div
                    key={i}
                    className="cursor-pointer border-b border-gray-50 px-4 py-3 transition-colors hover:bg-gray-50"
                  >
                    <div className="mb-1 flex items-center gap-2">
                      <CategoryBadge variant={noti.variant} icon={noti.icon} label={noti.category} />
                      <p className="flex-1 truncate text-xs font-bold text-foreground">{noti.title}</p>
                      <span className="flex-shrink-0 text-[10px] text-gray-400">{noti.time}</span>
                    </div>
                    <p className="truncate text-[11px] text-gray-500">{noti.description}</p>
                  </div>
                ))}
              </div>
            </div>
          )}
        </div>

        {/* 구분선 */}
        <div className="h-6 w-px bg-gray-200" />

        {/* 프로필 */}
        <Link
          to="/settings"
          className="flex items-center gap-2 transition-colors hover:text-primary"
        >
          <span className="material-symbols-outlined text-2xl">account_circle</span>
        </Link>
      </div>
    </header>
  );
}