/**
 * 모드팩 페이지 - GitHub Release 스타일
 */
import React, { useState } from 'react';
import { Download, Package, ChevronDown, ChevronUp, Calendar, HardDrive, Gamepad2, Box, Image } from 'lucide-react';
import { motion, AnimatePresence } from 'framer-motion';


// 파일 크기 포맷
const formatFileSize = (bytes) => {
  if (bytes < 1024) return `${bytes} B`;
  if (bytes < 1048576) return `${(bytes / 1024).toFixed(1)} KB`;
  if (bytes < 1073741824) return `${(bytes / 1048576).toFixed(1)} MB`;
  return `${(bytes / 1073741824).toFixed(2)} GB`;
};

// 날짜 포맷
const formatDate = (dateString) => {
  const date = new Date(dateString);
  return date.toLocaleDateString('ko-KR', {
    year: 'numeric',
    month: 'long',
    day: 'numeric',
  });
};

// 모드팩 카드 컴포넌트
const ModpackCard = ({ modpack, isLatest }) => {
  const [showChangelog, setShowChangelog] = useState(false);
  const [showContents, setShowContents] = useState(false);

  const totalMods = modpack.contents.mods.length;
  const totalResourcepacks = modpack.contents.resourcepacks.length;
  const totalShaderpacks = modpack.contents.shaderpacks.length;

  return (
    <div className={`bg-zinc-900 border rounded-2xl overflow-hidden ${isLatest ? 'border-mc-green' : 'border-zinc-800'}`}>
      {/* 헤더 */}
      <div className="p-5">
        {/* 상단: 아이콘 + 버전 정보 + 다운로드 버튼 */}
        <div className="flex items-center gap-3 mb-3">
          <div className={`p-2.5 rounded-xl ${isLatest ? 'bg-mc-green/20' : 'bg-zinc-800'}`}>
            <Package className={isLatest ? 'text-mc-green' : 'text-zinc-400'} size={24} />
          </div>
          <div className="flex-1 min-w-0">
            <div className="flex items-center gap-2">
              <h3 className="text-xl font-bold text-white">v{modpack.version}</h3>
              {isLatest && (
                <span className="px-2 py-0.5 bg-mc-green/20 text-mc-green text-xs font-medium rounded-full">
                  최신
                </span>
              )}
            </div>
            <p className="text-sm text-zinc-400 mt-0.5 truncate">{modpack.name}</p>
          </div>
          
          {/* PC: 오른쪽에 다운로드 버튼 */}
          <a 
            href={`/api/modpacks/${modpack.id}/download`}
            className="hidden sm:flex items-center gap-2 px-4 py-2.5 bg-mc-green hover:bg-mc-green/80 text-white font-medium rounded-xl transition-colors shrink-0"
          >
            <Download size={18} />
            <span>다운로드</span>
          </a>
        </div>
        
        {/* 모바일: 전체 너비 다운로드 버튼 */}
        <a 
          href={`/api/modpacks/${modpack.id}/download`}
          className="flex sm:hidden items-center justify-center gap-2 w-full px-4 py-2.5 bg-mc-green hover:bg-mc-green/80 text-white font-medium rounded-xl transition-colors"
        >
          <Download size={18} />
          <span>다운로드</span>
        </a>

        {/* 메타 정보 */}
        <div className="flex flex-wrap gap-x-4 gap-y-2 mt-4 text-sm text-zinc-400">
          <div className="flex items-center gap-1.5">
            <Gamepad2 size={14} />
            <span>MC {modpack.minecraftVersion}</span>
          </div>
          <div className="flex items-center gap-1.5">
            <Box size={14} />
            <span>{modpack.modLoader}</span>
          </div>
          <div className="flex items-center gap-1.5">
            <HardDrive size={14} />
            <span>{formatFileSize(modpack.fileSize)}</span>
          </div>
          <div className="flex items-center gap-1.5">
            <Calendar size={14} />
            <span>{formatDate(modpack.createdAt)}</span>
          </div>
        </div>

        {/* 포함 콘텐츠 요약 */}
        <div className="flex flex-wrap gap-2 mt-4">
          {totalMods > 0 && (
            <span className="px-2.5 py-1 bg-blue-500/20 text-blue-400 text-xs rounded-lg">
              모드 {totalMods}개
            </span>
          )}
          {totalResourcepacks > 0 && (
            <span className="px-2.5 py-1 bg-purple-500/20 text-purple-400 text-xs rounded-lg">
              리소스팩 {totalResourcepacks}개
            </span>
          )}
          {totalShaderpacks > 0 && (
            <span className="px-2.5 py-1 bg-orange-500/20 text-orange-400 text-xs rounded-lg">
              쉐이더 {totalShaderpacks}개
            </span>
          )}
        </div>
      </div>

      {/* 변경 로그 토글 */}
      <button 
        onClick={() => setShowChangelog(!showChangelog)}
        className="w-full flex items-center justify-between px-5 py-3 bg-zinc-800/50 hover:bg-zinc-800 text-zinc-300 text-sm transition-colors border-t border-zinc-800"
      >
        <span>체인지 로그</span>
        {showChangelog ? <ChevronUp size={16} /> : <ChevronDown size={16} />}
      </button>

      {/* 변경 로그 내용 */}
      <AnimatePresence>
        {showChangelog && (
          <motion.div
            initial={{ height: 0, opacity: 0 }}
            animate={{ height: 'auto', opacity: 1 }}
            exit={{ height: 0, opacity: 0 }}
            transition={{ duration: 0.2, ease: 'easeInOut' }}
            className="overflow-hidden"
          >
            <div className="px-5 py-4 bg-zinc-800/30 border-t border-zinc-800">
              <div className="prose prose-invert max-w-none">
                {modpack.changelog.split('\n').map((line, i) => {
                  if (line.startsWith('###')) {
                    return <h4 key={i} className="text-white font-semibold mt-2 mb-2">{line.replace('### ', '')}</h4>;
                  }
                  if (line.startsWith('- ')) {
                    return <p key={i} className="text-zinc-400 my-1.5 pl-4">• {line.replace('- ', '')}</p>;
                  }
                  return null;
                })}
              </div>
            </div>
          </motion.div>
        )}
      </AnimatePresence>

      {/* 포함 콘텐츠 토글 */}
      <button 
        onClick={() => setShowContents(!showContents)}
        className="w-full flex items-center justify-between px-5 py-3 bg-zinc-800/50 hover:bg-zinc-800 text-zinc-300 text-sm transition-colors border-t border-zinc-800"
      >
        <span>포함된 콘텐츠</span>
        {showContents ? <ChevronUp size={16} /> : <ChevronDown size={16} />}
      </button>

      {/* 포함 콘텐츠 내용 */}
      <AnimatePresence>
        {showContents && (
          <motion.div
            initial={{ height: 0, opacity: 0 }}
            animate={{ height: 'auto', opacity: 1 }}
            exit={{ height: 0, opacity: 0 }}
            transition={{ duration: 0.2, ease: 'easeInOut' }}
            className="overflow-hidden"
          >
            <div className="px-5 py-4 bg-zinc-800/30 border-t border-zinc-800">
              {/* 모드 */}
              {modpack.contents.mods.length > 0 && (
                <div className="mb-6">
                  <h4 className="text-white font-medium text-sm mb-3 flex items-center gap-2">
                    <Box size={14} className="text-blue-400" />
                    모드 ({modpack.contents.mods.length}개)
                  </h4>
                  <div className="grid grid-cols-1 sm:grid-cols-2 gap-2">
                    {[...modpack.contents.mods].sort((a, b) => {
                      const titleA = (typeof a === 'object' ? a.title : a).toLowerCase();
                      const titleB = (typeof b === 'object' ? b.title : b).toLowerCase();
                      return titleA.localeCompare(titleB);
                    }).map((mod, i) => {
                      // mod가 객체인 경우 (Modrinth 연동 후) vs 문자열인 경우 (현재)
                      const isObject = typeof mod === 'object';
                      const title = isObject ? mod.title : mod;
                      const version = isObject ? mod.version : null;
                      const iconUrl = isObject ? mod.icon_url : null;
                      const slug = isObject ? mod.slug : null;
                      
                      const content = (
                        <div className={`flex items-center gap-3 p-3 bg-zinc-800/80 rounded-xl border border-zinc-700/50 transition-all h-[68px] ${slug ? 'hover:bg-blue-500/10 hover:border-blue-500/30 cursor-pointer' : ''}`}>
                          {/* 아이콘 */}
                          <div className="w-12 h-12 rounded-lg bg-zinc-700 flex items-center justify-center overflow-hidden flex-shrink-0">
                            {iconUrl ? (
                              <img src={iconUrl} alt="" className="w-full h-full object-cover" />
                            ) : (
                              <Box size={20} className="text-blue-400" />
                            )}
                          </div>
                          {/* 정보 */}
                          <div className="min-w-0 flex-1">
                            <p className="text-white font-medium truncate">{title}</p>
                            <p className="text-zinc-500 text-sm truncate h-5">{version || ''}</p>
                          </div>
                        </div>
                      );
                      
                      return slug ? (
                        <a key={i} href={`https://modrinth.com/mod/${slug}`} target="_blank" rel="noopener noreferrer">
                          {content}
                        </a>
                      ) : (
                        <div key={i}>{content}</div>
                      );
                    })}
                  </div>
                </div>
              )}

              {/* 리소스팩 */}
              {modpack.contents.resourcepacks.length > 0 && (
                <div className="mb-6">
                  <h4 className="text-white font-medium text-sm mb-3 flex items-center gap-2">
                    <Image size={14} className="text-purple-400" />
                    리소스팩 ({modpack.contents.resourcepacks.length}개)
                  </h4>
                  <div className="grid grid-cols-1 sm:grid-cols-2 gap-2">
                    {[...modpack.contents.resourcepacks].sort((a, b) => {
                      const titleA = (typeof a === 'object' ? a.title : a).toLowerCase();
                      const titleB = (typeof b === 'object' ? b.title : b).toLowerCase();
                      return titleA.localeCompare(titleB);
                    }).map((pack, i) => {
                      const isObject = typeof pack === 'object';
                      const title = isObject ? pack.title : pack;
                      const version = isObject ? pack.version : null;
                      const iconUrl = isObject ? pack.icon_url : null;
                      const slug = isObject ? pack.slug : null;
                      
                      const content = (
                        <div className={`flex items-center gap-3 p-3 bg-zinc-800/80 rounded-xl border border-zinc-700/50 transition-all h-[68px] ${slug ? 'hover:bg-purple-500/10 hover:border-purple-500/30 cursor-pointer' : ''}`}>
                          <div className="w-12 h-12 rounded-lg bg-zinc-700 flex items-center justify-center overflow-hidden flex-shrink-0">
                            {iconUrl ? (
                              <img src={iconUrl} alt="" className="w-full h-full object-cover" />
                            ) : (
                              <Image size={20} className="text-purple-400" />
                            )}
                          </div>
                          <div className="min-w-0 flex-1">
                            <p className="text-white font-medium truncate">{title}</p>
                            <p className="text-zinc-500 text-sm truncate h-5">{version || ''}</p>
                          </div>
                        </div>
                      );
                      
                      return slug ? (
                        <a key={i} href={`https://modrinth.com/resourcepack/${slug}`} target="_blank" rel="noopener noreferrer">
                          {content}
                        </a>
                      ) : (
                        <div key={i}>{content}</div>
                      );
                    })}
                  </div>
                </div>
              )}

              {/* 쉐이더 */}
              {modpack.contents.shaderpacks.length > 0 && (
                <div>
                  <h4 className="text-white font-medium text-sm mb-3 flex items-center gap-2">
                    <span className="text-orange-400">✨</span>
                    쉐이더 ({modpack.contents.shaderpacks.length}개)
                  </h4>
                  <div className="grid grid-cols-1 sm:grid-cols-2 gap-2">
                    {[...modpack.contents.shaderpacks].sort((a, b) => {
                      const titleA = (typeof a === 'object' ? a.title : a).toLowerCase();
                      const titleB = (typeof b === 'object' ? b.title : b).toLowerCase();
                      return titleA.localeCompare(titleB);
                    }).map((shader, i) => {
                      const isObject = typeof shader === 'object';
                      const title = isObject ? shader.title : shader;
                      const version = isObject ? shader.version : null;
                      const iconUrl = isObject ? shader.icon_url : null;
                      const slug = isObject ? shader.slug : null;
                      
                      const content = (
                        <div className={`flex items-center gap-3 p-3 bg-zinc-800/80 rounded-xl border border-zinc-700/50 transition-all ${slug ? 'hover:bg-orange-500/10 hover:border-orange-500/30 cursor-pointer' : ''}`}>
                          <div className="w-12 h-12 rounded-lg bg-zinc-700 flex items-center justify-center overflow-hidden flex-shrink-0">
                            {iconUrl ? (
                              <img src={iconUrl} alt="" className="w-full h-full object-cover" />
                            ) : (
                              <span className="text-xl">✨</span>
                            )}
                          </div>
                          <div className="min-w-0 flex-1">
                            <p className="text-white font-medium truncate">{title}</p>
                            {version && <p className="text-zinc-500 text-sm truncate">{version}</p>}
                          </div>
                        </div>
                      );
                      
                      return slug ? (
                        <a key={i} href={`https://modrinth.com/shader/${slug}`} target="_blank" rel="noopener noreferrer">
                          {content}
                        </a>
                      ) : (
                        <div key={i}>{content}</div>
                      );
                    })}
                  </div>
                </div>
              )}
            </div>
          </motion.div>
        )}
      </AnimatePresence>
    </div>
  );
};

export default function Modpack() {
  const [modpacks, setModpacks] = useState([]);
  const [loading, setLoading] = useState(true);

  // API에서 모드팩 목록 가져오기
  React.useEffect(() => {
    const fetchModpacks = async () => {
      try {
        const res = await fetch('/api/modpacks');
        const data = await res.json();
        // API 응답을 UI 형식에 맞게 변환
        const formatted = data.map(mp => ({
          id: mp.id,
          version: mp.version,
          name: mp.name,
          minecraftVersion: mp.minecraft_version,
          modLoader: mp.mod_loader,
          changelog: mp.changelog || '',
          fileSize: mp.file_size,
          createdAt: mp.created_at,
          contents: mp.contents || { mods: [], resourcepacks: [], shaderpacks: [] },
        }));
        setModpacks(formatted);
      } catch (error) {
        console.error('모드팩 목록 로드 실패:', error);
      } finally {
        setLoading(false);
      }
    };
    fetchModpacks();
  }, []);

  if (loading) {
    return (
      <div className="min-h-screen bg-mc-dark p-4 sm:p-6 flex items-center justify-center">
        <div className="text-zinc-400">로딩 중...</div>
      </div>
    );
  }

  return (
    <div className="min-h-screen bg-mc-dark p-4 sm:p-6">
      <div className="max-w-4xl mx-auto">
        {/* 헤더 */}
        <div className="mb-6">
          <h1 className="text-2xl font-bold text-white flex items-center gap-3">
            <Package className="text-mc-green" />
            모드팩
          </h1>
          <p className="text-zinc-400 mt-1">서버 접속에 필요한 모드팩을 다운로드하세요</p>
        </div>

        {/* 모드팩 목록 */}
        <div className="space-y-4">
          {modpacks.map((modpack, index) => (
            <ModpackCard key={modpack.id} modpack={modpack} isLatest={index === 0} />
          ))}
        </div>

        {/* 빈 상태 (모드팩이 없을 때) */}
        {modpacks.length === 0 && (
          <div className="text-center py-16">
            <Package className="mx-auto text-zinc-600 mb-4" size={48} />
            <p className="text-zinc-400">등록된 모드팩이 없습니다</p>
          </div>
        )}
      </div>
    </div>
  );
}