import { useParams, Link } from 'react-router-dom';
import { useQuery, keepPreviousData } from '@tanstack/react-query';
import { useEffect, useState, useRef } from 'react';
import { motion, AnimatePresence } from 'framer-motion';
import { Calendar, Clock, ChevronLeft, Link2, X, ChevronRight } from 'lucide-react';
import { getSchedule } from '@/api';
import { decodeHtmlEntities, formatFullDate, formatTime, formatXDateTimeWithTime } from '@/utils';
import Birthday from './Birthday';

/**
 * URL을 링크로 변환하는 함수
 */
function linkifyText(text) {
  if (!text) return null;

  // URL 패턴: http(s)://로 시작하거나 일반적인 단축 URL 도메인
  const urlPattern = /(https?:\/\/[^\s]+|(?:bit\.ly|youtu\.be|t\.co|goo\.gl|tinyurl\.com)\/[^\s]+)/gi;

  const parts = [];
  let lastIndex = 0;
  let match;

  while ((match = urlPattern.exec(text)) !== null) {
    if (match.index > lastIndex) {
      parts.push(text.slice(lastIndex, match.index));
    }

    let url = match[0];
    const href = url.startsWith('http') ? url : `https://${url}`;

    parts.push(
      <a key={match.index} href={href} target="_blank" rel="noopener noreferrer" className="text-blue-500 hover:underline">
        {url}
      </a>
    );

    lastIndex = match.index + match[0].length;
  }

  if (lastIndex < text.length) {
    parts.push(text.slice(lastIndex));
  }

  return parts.length > 0 ? parts : text;
}

/**
 * 특수 일정 ID 파싱
 * @param {string} id - 일정 ID
 * @returns {object|null} { type, year, nameEn } 또는 null
 */
function parseSpecialId(id) {
  // birthday-{year}-{nameEn} 형식
  const birthdayMatch = id.match(/^birthday-(\d{4})-(.+)$/);
  if (birthdayMatch) {
    return { type: 'birthday', year: birthdayMatch[1], nameEn: birthdayMatch[2] };
  }

  // debut-{year} 형식
  const debutMatch = id.match(/^debut-(\d{4})$/);
  if (debutMatch) {
    return { type: 'debut', year: debutMatch[1] };
  }

  // anniversary-{year} 형식
  const anniversaryMatch = id.match(/^anniversary-(\d{4})$/);
  if (anniversaryMatch) {
    return { type: 'anniversary', year: anniversaryMatch[1] };
  }

  return null;
}

/**
 * 전체화면 시 자동 가로 회전 훅 (숏츠가 아닐 때만)
 */
function useFullscreenOrientation(isShorts) {
  useEffect(() => {
    if (isShorts) return;

    const handleFullscreenChange = async () => {
      const isFullscreen = !!document.fullscreenElement;

      if (isFullscreen) {
        try {
          if (screen.orientation && screen.orientation.lock) {
            await screen.orientation.lock('landscape');
          }
        } catch (e) {
          // 지원하지 않는 브라우저
        }
      } else {
        try {
          if (screen.orientation && screen.orientation.unlock) {
            screen.orientation.unlock();
          }
        } catch (e) {
          // 무시
        }
      }
    };

    document.addEventListener('fullscreenchange', handleFullscreenChange);
    document.addEventListener('webkitfullscreenchange', handleFullscreenChange);

    return () => {
      document.removeEventListener('fullscreenchange', handleFullscreenChange);
      document.removeEventListener('webkitfullscreenchange', handleFullscreenChange);
    };
  }, [isShorts]);
}

/**
 * Mobile 예정 일정 Placeholder 컴포넌트
 */
function MobileScheduledPlaceholder({ bannerUrl }) {
  return (
    <div className="relative aspect-video bg-gradient-to-br from-gray-800 to-gray-900 rounded-xl overflow-hidden shadow-lg">
      {/* 배경: 배너 이미지 또는 패턴 */}
      {bannerUrl ? (
        <div
          className="absolute inset-0 bg-cover bg-center"
          style={{ backgroundImage: `url(${bannerUrl})` }}
        >
          <div className="absolute inset-0 bg-gradient-to-t from-black/70 via-transparent to-transparent" />
        </div>
      ) : (
        <div className="absolute inset-0 opacity-5">
          <div className="absolute inset-0" style={{
            backgroundImage: `url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='1'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E")`,
          }} />
        </div>
      )}

      {/* 하단 텍스트 */}
      <div className="absolute bottom-0 left-0 right-0 p-4">
        <div className="flex items-center gap-2 text-white/90">
          <Clock size={16} className="text-amber-400" />
          <span className="text-base font-medium">업로드 예정</span>
        </div>
      </div>
    </div>
  );
}

/**
 * Mobile 유튜브 섹션
 */
function MobileYoutubeSection({ schedule }) {
  const videoId = schedule.videoId;
  const isShorts = schedule.videoType === 'shorts';
  const isScheduled = !videoId; // videoId가 없으면 예정 일정

  // 숏츠가 아닐 때만 가로 회전 (숏츠는 전체화면에서 세로 유지)
  useFullscreenOrientation(isShorts);
  const members = schedule.members || [];
  const isFullGroup = members.length === 5;

  return (
    <div className="space-y-4">
      {/* 영상 임베드 또는 예정 Placeholder */}
      <motion.div initial={{ opacity: 0, scale: 0.98 }} animate={{ opacity: 1, scale: 1 }} transition={{ delay: 0.1 }}>
        {isScheduled ? (
          <MobileScheduledPlaceholder bannerUrl={schedule.bannerUrl} />
        ) : (
          <div className="relative bg-gray-900 rounded-xl overflow-hidden shadow-lg aspect-video">
            <iframe
              src={`https://www.youtube.com/embed/${videoId}?rel=0`}
              title={schedule.title}
              allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; fullscreen; web-share"
              allowFullScreen
              className="absolute inset-0 w-full h-full"
            />
          </div>
        )}
      </motion.div>

      {/* 영상 정보 */}
      <motion.div
        initial={{ opacity: 0, y: 10 }}
        animate={{ opacity: 1, y: 0 }}
        transition={{ delay: 0.2 }}
        className="bg-gradient-to-br from-gray-100 to-gray-200/80 rounded-xl p-4"
      >
        <div className="flex items-center gap-2 mb-3">
          <h1 className="font-bold text-gray-900 text-base leading-relaxed">{decodeHtmlEntities(schedule.title)}</h1>
          {isScheduled && (
            <span className="flex-shrink-0 px-2 py-0.5 bg-amber-100 text-amber-700 text-xs font-semibold rounded-full">
              예정
            </span>
          )}
        </div>

        {/* 메타 정보 */}
        <div className={`flex flex-wrap items-center gap-3 text-xs text-gray-500 ${members.length > 0 || !isScheduled ? 'mb-3' : ''}`}>
          <div className="flex items-center gap-1">
            <Calendar size={12} />
            <span>{formatXDateTimeWithTime(schedule.date, schedule.time)}</span>
          </div>
          {schedule.channelName && (
            <div className="flex items-center gap-1">
              <Link2 size={12} />
              <span>{schedule.channelName}</span>
            </div>
          )}
        </div>

        {/* 멤버 목록 */}
        {members.length > 0 && (
          <div className="flex flex-wrap gap-1.5 mb-4">
            {isFullGroup ? (
              <span className="px-2.5 py-1 bg-primary/10 text-primary text-xs font-medium rounded-full">
                프로미스나인
              </span>
            ) : (
              members.map((member) => (
                <span key={member.id} className="px-2.5 py-1 bg-primary/10 text-primary text-xs font-medium rounded-full">
                  {member.name}
                </span>
              ))
            )}
          </div>
        )}

        {/* 유튜브에서 보기 버튼 (예정 일정이 아닐 때만) */}
        {!isScheduled && (
          <div className="pt-4 border-t border-gray-300/50">
            <a
              href={schedule.videoUrl}
              target="_blank"
              rel="noopener noreferrer"
              className="flex items-center justify-center gap-2 w-full py-3 bg-red-500 active:bg-red-600 text-white rounded-xl font-medium transition-colors"
            >
              <svg className="w-5 h-5" viewBox="0 0 24 24" fill="currentColor">
                <path d="M23.498 6.186a3.016 3.016 0 0 0-2.122-2.136C19.505 3.545 12 3.545 12 3.545s-7.505 0-9.377.505A3.017 3.017 0 0 0 .502 6.186C0 8.07 0 12 0 12s0 3.93.502 5.814a3.016 3.016 0 0 0 2.122 2.136c1.871.505 9.376.505 9.376.505s7.505 0 9.377-.505a3.015 3.015 0 0 0 2.122-2.136C24 15.93 24 12 24 12s0-3.93-.502-5.814zM9.545 15.568V8.432L15.818 12l-6.273 3.568z" />
              </svg>
              YouTube에서 보기
            </a>
          </div>
        )}
      </motion.div>
    </div>
  );
}

/**
 * Mobile X(트위터) 섹션
 */
function MobileXSection({ schedule }) {
  const profile = schedule.profile;
  const username = profile?.username || 'realfromis_9';
  const displayName = profile?.displayName || username;
  const avatarUrl = profile?.avatarUrl;

  // 라이트박스 상태
  const [lightboxOpen, setLightboxOpen] = useState(false);
  const [lightboxIndex, setLightboxIndex] = useState(0);
  const historyPushedRef = useRef(false);

  const openLightbox = (index) => {
    setLightboxIndex(index);
    setLightboxOpen(true);
    window.history.pushState({ lightbox: true }, '');
    historyPushedRef.current = true;
  };

  const closeLightbox = () => {
    setLightboxOpen(false);
    if (historyPushedRef.current) {
      historyPushedRef.current = false;
      window.history.back();
    }
  };

  const goToPrev = () => {
    if (schedule.imageUrls?.length > 1) {
      setLightboxIndex((lightboxIndex - 1 + schedule.imageUrls.length) % schedule.imageUrls.length);
    }
  };

  const goToNext = () => {
    if (schedule.imageUrls?.length > 1) {
      setLightboxIndex((lightboxIndex + 1) % schedule.imageUrls.length);
    }
  };

  // 라이트박스 열릴 때 body 스크롤 방지
  useEffect(() => {
    if (lightboxOpen) {
      document.body.style.overflow = 'hidden';
    } else {
      document.body.style.overflow = '';
    }
    return () => {
      document.body.style.overflow = '';
    };
  }, [lightboxOpen]);

  // 뒤로가기 처리 (하드웨어 백버튼)
  useEffect(() => {
    const handlePopState = () => {
      if (lightboxOpen) {
        historyPushedRef.current = false;
        setLightboxOpen(false);
      }
    };

    window.addEventListener('popstate', handlePopState);
    return () => window.removeEventListener('popstate', handlePopState);
  }, [lightboxOpen]);


  return (
    <>
      <motion.div
        initial={{ opacity: 0, y: 10 }}
        animate={{ opacity: 1, y: 0 }}
        transition={{ delay: 0.1 }}
        className="bg-white rounded-xl border border-gray-200 overflow-hidden"
      >
        {/* 헤더 */}
        <div className="p-4 pb-0">
          <div className="flex items-center gap-3">
            {avatarUrl ? (
              <img src={avatarUrl} alt={displayName} className="w-10 h-10 rounded-full object-cover" />
            ) : (
              <div className="w-10 h-10 rounded-full bg-gradient-to-br from-gray-700 to-gray-900 flex items-center justify-center">
                <span className="text-white font-bold">{displayName.charAt(0).toUpperCase()}</span>
              </div>
            )}
            <div className="flex-1 min-w-0">
              <div className="flex items-center gap-1.5">
                <span className="font-bold text-gray-900 text-sm truncate">{displayName}</span>
                <svg className="w-4 h-4 text-blue-500 flex-shrink-0" viewBox="0 0 24 24" fill="currentColor">
                  <path d="M22.25 12c0-1.43-.88-2.67-2.19-3.34.46-1.39.2-2.9-.81-3.91s-2.52-1.27-3.91-.81c-.66-1.31-1.91-2.19-3.34-2.19s-2.67.88-3.34 2.19c-1.39-.46-2.9-.2-3.91.81s-1.27 2.52-.81 3.91C2.63 9.33 1.75 10.57 1.75 12s.88 2.67 2.19 3.34c-.46 1.39-.2 2.9.81 3.91s2.52 1.27 3.91.81c.66 1.31 1.91 2.19 3.34 2.19s2.67-.88 3.34-2.19c1.39.46 2.9.2 3.91-.81s1.27-2.52.81-3.91c1.31-.67 2.19-1.91 2.19-3.34zm-11.07 4.57l-3.84-3.84 1.27-1.27 2.57 2.57 5.39-5.39 1.27 1.27-6.66 6.66z" />
                </svg>
              </div>
              <span className="text-xs text-gray-500 -mt-0.5 block">@{username}</span>
            </div>
          </div>
        </div>

        {/* 본문 */}
        <div className="p-4">
          <p className="text-gray-900 text-[15px] leading-relaxed whitespace-pre-wrap">
            {linkifyText(decodeHtmlEntities(schedule.content || schedule.title))}
          </p>
        </div>

        {/* 이미지 */}
        {schedule.imageUrls?.length > 0 && (
          <div className="px-4 pb-3">
            {schedule.imageUrls.length === 1 ? (
              <img
                src={schedule.imageUrls[0]}
                alt=""
                className="w-full rounded-xl border border-gray-100 cursor-pointer active:opacity-80 transition-opacity"
                onClick={() => openLightbox(0)}
              />
            ) : (
              <div className="grid gap-1 rounded-xl overflow-hidden border border-gray-100 grid-cols-2">
                {schedule.imageUrls.slice(0, 4).map((url, i) => (
                  <img
                    key={i}
                    src={url}
                    alt=""
                    className={`w-full object-cover cursor-pointer active:opacity-80 transition-opacity ${
                      schedule.imageUrls.length === 3 && i === 0 ? 'row-span-2 h-full' : 'aspect-square'
                    }`}
                    onClick={() => openLightbox(i)}
                  />
                ))}
              </div>
            )}
          </div>
        )}

        {/* 날짜/시간 */}
        <div className="px-4 py-3 border-t border-gray-100">
          <span className="text-gray-500 text-sm">{formatXDateTimeWithTime(schedule.date, schedule.time)}</span>
        </div>

        {/* X에서 보기 버튼 */}
        <div className="px-4 py-3 border-t border-gray-100 bg-gray-50/50">
          <a
            href={schedule.postUrl}
            target="_blank"
            rel="noopener noreferrer"
            className="flex items-center justify-center gap-2 w-full py-2.5 bg-gray-900 active:bg-black text-white rounded-full font-medium transition-colors"
          >
            <svg className="w-4 h-4" viewBox="0 0 24 24" fill="currentColor">
              <path d="M18.244 2.25h3.308l-7.227 8.26 8.502 11.24H16.17l-5.214-6.817L4.99 21.75H1.68l7.73-8.835L1.254 2.25H8.08l4.713 6.231zm-1.161 17.52h1.833L7.084 4.126H5.117z" />
            </svg>
            X에서 보기
          </a>
        </div>
      </motion.div>

      {/* 모바일 라이트박스 */}
      <AnimatePresence>
        {lightboxOpen && schedule.imageUrls?.length > 0 && (
          <motion.div
            initial={{ opacity: 0 }}
            animate={{ opacity: 1 }}
            exit={{ opacity: 0 }}
            className="fixed inset-0 bg-black z-50 flex items-center justify-center"
            onClick={closeLightbox}
          >
            <button className="absolute top-4 right-4 p-2 text-white/70 z-10" onClick={closeLightbox}>
              <X size={28} />
            </button>

            <motion.img
              key={lightboxIndex}
              src={schedule.imageUrls[lightboxIndex]}
              alt=""
              className="max-w-full max-h-full object-contain"
              initial={{ opacity: 0, scale: 0.95 }}
              animate={{ opacity: 1, scale: 1 }}
              onClick={(e) => e.stopPropagation()}
            />

            {schedule.imageUrls.length > 1 && (
              <>
                <button
                  className="absolute left-2 top-1/2 -translate-y-1/2 p-2 text-white/70"
                  onClick={(e) => {
                    e.stopPropagation();
                    goToPrev();
                  }}
                >
                  <ChevronLeft size={32} />
                </button>
                <button
                  className="absolute right-2 top-1/2 -translate-y-1/2 p-2 text-white/70"
                  onClick={(e) => {
                    e.stopPropagation();
                    goToNext();
                  }}
                >
                  <ChevronRight size={32} />
                </button>
              </>
            )}

            {schedule.imageUrls.length > 1 && (
              <div className="absolute bottom-6 left-1/2 -translate-x-1/2 flex gap-2">
                {schedule.imageUrls.map((_, i) => (
                  <button
                    key={i}
                    className={`w-2 h-2 rounded-full transition-colors ${i === lightboxIndex ? 'bg-white' : 'bg-white/40'}`}
                    onClick={(e) => {
                      e.stopPropagation();
                      setLightboxIndex(i);
                    }}
                  />
                ))}
              </div>
            )}
          </motion.div>
        )}
      </AnimatePresence>
    </>
  );
}

/**
 * Mobile 기본 섹션
 */
function MobileDefaultSection({ schedule }) {
  return (
    <div className="bg-white rounded-xl p-4 shadow-sm">
      <h1 className="font-bold text-gray-900 text-base mb-3">{decodeHtmlEntities(schedule.title)}</h1>
      <div className="flex items-center gap-3 text-xs text-gray-500">
        <div className="flex items-center gap-1">
          <Calendar size={12} />
          <span>{formatFullDate(schedule.date)}</span>
        </div>
        {schedule.time && (
          <div className="flex items-center gap-1">
            <Clock size={12} />
            <span>{formatTime(schedule.time)}</span>
          </div>
        )}
      </div>
      {schedule.description && (
        <p className="mt-3 text-sm text-gray-600 whitespace-pre-wrap">{decodeHtmlEntities(schedule.description)}</p>
      )}
    </div>
  );
}

/**
 * Mobile 일정 상세 페이지
 */
function MobileScheduleDetail() {
  const { id } = useParams();

  // 특수 일정 ID 체크
  const specialId = parseSpecialId(id);
  if (specialId?.type === 'birthday') {
    return <Birthday year={specialId.year} nameEn={specialId.nameEn} />;
  }

  // 모바일 레이아웃 활성화
  useEffect(() => {
    document.documentElement.classList.add('mobile-layout');
    return () => {
      document.documentElement.classList.remove('mobile-layout');
    };
  }, []);

  const {
    data: schedule,
    isLoading,
    error,
  } = useQuery({
    queryKey: ['schedule', id],
    queryFn: () => getSchedule(id),
    placeholderData: keepPreviousData,
    retry: false,
  });

  if (isLoading && !schedule) {
    return (
      <div className="mobile-layout-container bg-gray-50">
        <div className="mobile-content flex items-center justify-center">
          <div className="w-8 h-8 border-2 border-primary border-t-transparent rounded-full animate-spin" />
        </div>
      </div>
    );
  }

  if (error || !schedule) {
    return (
      <div className="mobile-layout-container bg-gradient-to-br from-gray-50 to-gray-100">
        <div className="mobile-content flex items-center justify-center px-6">
          <div className="text-center">
            <motion.div
              initial={{ opacity: 0, scale: 0.5 }}
              animate={{ opacity: 1, scale: 1 }}
              transition={{ duration: 0.5, type: 'spring', stiffness: 100 }}
              className="mb-6"
            >
              <div className="w-24 h-24 mx-auto bg-gradient-to-br from-primary/10 to-primary/5 rounded-2xl flex items-center justify-center">
                <Calendar size={48} className="text-primary/40" />
              </div>
            </motion.div>

            <motion.div
              initial={{ opacity: 0, y: 20 }}
              animate={{ opacity: 1, y: 0 }}
              transition={{ delay: 0.2, duration: 0.5 }}
              className="mb-6"
            >
              <h2 className="text-xl font-bold text-gray-800 mb-2">일정을 찾을 수 없습니다</h2>
              <p className="text-gray-500 text-sm leading-relaxed">
                요청하신 일정이 존재하지 않거나
                <br />
                삭제되었을 수 있습니다.
              </p>
            </motion.div>

            <motion.div
              initial={{ opacity: 0 }}
              animate={{ opacity: 1 }}
              transition={{ delay: 0.4, duration: 0.5 }}
              className="flex justify-center gap-1.5 mb-8"
            >
              {[...Array(5)].map((_, i) => (
                <motion.div
                  key={i}
                  className="w-1.5 h-1.5 rounded-full bg-primary"
                  animate={{
                    y: [0, -6, 0],
                    opacity: [0.3, 1, 0.3],
                  }}
                  transition={{
                    duration: 1.2,
                    repeat: Infinity,
                    delay: i * 0.15,
                    ease: 'easeInOut',
                  }}
                />
              ))}
            </motion.div>

            <motion.div
              initial={{ opacity: 0, y: 20 }}
              animate={{ opacity: 1, y: 0 }}
              transition={{ delay: 0.5, duration: 0.5 }}
              className="flex flex-col gap-3"
            >
              <button
                onClick={() => window.history.back()}
                className="flex items-center justify-center gap-2 w-full px-6 py-3 border-2 border-primary text-primary rounded-full font-medium active:bg-primary active:text-white transition-colors"
              >
                <ChevronLeft size={18} />
                이전 페이지
              </button>
              <Link
                to="/schedule"
                className="flex items-center justify-center gap-2 w-full px-6 py-3 bg-gradient-to-r from-primary to-primary-dark text-white rounded-full font-medium active:opacity-90 transition-opacity"
              >
                <Calendar size={18} />
                일정 목록
              </Link>
            </motion.div>
          </div>
        </div>
      </div>
    );
  }

  // 카테고리별 섹션 렌더링
  const categoryName = schedule.category?.name;
  const renderCategorySection = () => {
    switch (categoryName) {
      case '유튜브':
        return <MobileYoutubeSection schedule={schedule} />;
      case 'X':
        return <MobileXSection schedule={schedule} />;
      default:
        return <MobileDefaultSection schedule={schedule} />;
    }
  };

  return (
    <div className="mobile-layout-container bg-gray-50">
      {/* 헤더 */}
      <div className="flex-shrink-0 bg-white border-b border-gray-100">
        <div className="flex items-center justify-center h-14 px-4">
          <span className="text-sm font-medium" style={{ color: schedule.category?.color }}>
            {schedule.category?.name}
          </span>
        </div>
      </div>

      {/* 메인 컨텐츠 */}
      <div className="mobile-content p-4">{renderCategorySection()}</div>
    </div>
  );
}

export default MobileScheduleDetail;