'use client'

import { useState, useEffect, use } from 'react'
import { useRouter } from 'next/navigation'
import { Navigation } from '@/components/Navigation'
import { ProtectedRoute } from '@/components/ProtectedRoute'
import { flashcardsService, type Flashcard } from '@/lib/services/flashcards'

interface FlashcardDetailPageProps {
  params: Promise<{
    id: string
  }>
}

export default function FlashcardDetailPage({ params }: FlashcardDetailPageProps) {
  const { id } = use(params)

  return (
    <ProtectedRoute>
      <FlashcardDetailContent cardId={id} />
    </ProtectedRoute>
  )
}

function FlashcardDetailContent({ cardId }: { cardId: string }) {
  const router = useRouter()
  const [flashcard, setFlashcard] = useState<Flashcard | null>(null)
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState<string | null>(null)
  const [isEditing, setIsEditing] = useState(false)
  const [editedCard, setEditedCard] = useState<any>(null)

  // 假資料 - 用於展示效果
  const mockCards: {[key: string]: any} = {
    'mock1': {
      id: 'mock1',
      word: 'hello',
      translation: '你好',
      partOfSpeech: 'interjection',
      pronunciation: '/həˈloʊ/',
      definition: 'A greeting word used when meeting someone or beginning a phone conversation',
      example: 'Hello, how are you today?',
      exampleTranslation: '你好，你今天怎麼樣？',
      masteryLevel: 95,
      timesReviewed: 15,
      isFavorite: true,
      nextReviewDate: '2025-09-21',
      cardSet: { name: '基礎詞彙', color: 'bg-blue-500' },
      difficultyLevel: 'A1',
      createdAt: '2025-09-17',
      synonyms: ['hi', 'greetings', 'good day']
    },
    'mock2': {
      id: 'mock2',
      word: 'elaborate',
      translation: '詳細說明',
      partOfSpeech: 'verb',
      pronunciation: '/ɪˈlæbərət/',
      definition: 'To explain something in more detail; to develop or present a theory, policy, or system in further detail',
      example: 'Could you elaborate on your proposal?',
      exampleTranslation: '你能詳細說明一下你的提案嗎？',
      masteryLevel: 45,
      timesReviewed: 5,
      isFavorite: false,
      nextReviewDate: '2025-09-19',
      cardSet: { name: '高級詞彙', color: 'bg-purple-500' },
      difficultyLevel: 'B2',
      createdAt: '2025-09-14',
      synonyms: ['explain', 'detail', 'expand', 'clarify']
    }
  }

  // 載入詞卡資料
  useEffect(() => {
    const loadFlashcard = async () => {
      try {
        setLoading(true)

        // 首先檢查是否為假資料
        if (mockCards[cardId]) {
          setFlashcard(mockCards[cardId])
          setEditedCard(mockCards[cardId])
          setLoading(false)
          return
        }

        // 載入真實詞卡
        const result = await flashcardsService.getFlashcard(cardId)
        if (result.success && result.data) {
          setFlashcard(result.data)
          setEditedCard(result.data)
        } else {
          throw new Error(result.error || '詞卡不存在')
        }
      } catch (err) {
        setError('載入詞卡時發生錯誤')
      } finally {
        setLoading(false)
      }
    }

    loadFlashcard()
  }, [cardId])

  // 獲取CEFR等級顏色
  const getCEFRColor = (level: string) => {
    switch (level) {
      case 'A1': return 'bg-green-100 text-green-700 border-green-200'
      case 'A2': return 'bg-blue-100 text-blue-700 border-blue-200'
      case 'B1': return 'bg-yellow-100 text-yellow-700 border-yellow-200'
      case 'B2': return 'bg-orange-100 text-orange-700 border-orange-200'
      case 'C1': return 'bg-red-100 text-red-700 border-red-200'
      case 'C2': return 'bg-purple-100 text-purple-700 border-purple-200'
      default: return 'bg-gray-100 text-gray-700 border-gray-200'
    }
  }

  // 獲取例句圖片
  const getExampleImage = (word: string) => {
    const imageMap: {[key: string]: string} = {
      'hello': '/images/examples/bring_up.png',
      'elaborate': '/images/examples/instinct.png',
      'beautiful': '/images/examples/warrant.png'
    }
    return imageMap[word?.toLowerCase()] || '/images/examples/bring_up.png'
  }

  // 處理收藏切換
  const handleToggleFavorite = async () => {
    if (!flashcard) return

    try {
      // 假資料處理
      if (flashcard.id.startsWith('mock')) {
        const updated = { ...flashcard, isFavorite: !flashcard.isFavorite }
        setFlashcard(updated)
        setEditedCard(updated)
        alert(`${flashcard.isFavorite ? '已取消收藏' : '已加入收藏'}「${flashcard.word}」`)
        return
      }

      // 真實API調用
      const result = await flashcardsService.toggleFavorite(flashcard.id)
      if (result.success) {
        setFlashcard(prev => prev ? { ...prev, isFavorite: !prev.isFavorite } : null)
        alert(`${flashcard.isFavorite ? '已取消收藏' : '已加入收藏'}「${flashcard.word}」`)
      }
    } catch (error) {
      alert('操作失敗，請重試')
    }
  }

  // 處理編輯保存
  const handleSaveEdit = async () => {
    if (!flashcard || !editedCard) return

    try {
      // 假資料處理
      if (flashcard.id.startsWith('mock')) {
        setFlashcard(editedCard)
        setIsEditing(false)
        alert('詞卡更新成功！')
        return
      }

      // 真實API調用
      const result = await flashcardsService.updateFlashcard(flashcard.id, {
        word: editedCard.word,
        translation: editedCard.translation,
        definition: editedCard.definition,
        pronunciation: editedCard.pronunciation,
        partOfSpeech: editedCard.partOfSpeech,
        example: editedCard.example,
        exampleTranslation: editedCard.exampleTranslation,
        difficultyLevel: editedCard.difficultyLevel
      })

      if (result.success) {
        setFlashcard(editedCard)
        setIsEditing(false)
        alert('詞卡更新成功！')
      } else {
        alert(result.error || '更新失敗')
      }
    } catch (error) {
      alert('更新失敗，請重試')
    }
  }

  // 處理刪除
  const handleDelete = async () => {
    if (!flashcard) return

    if (!confirm(`確定要刪除詞卡「${flashcard.word}」嗎？`)) {
      return
    }

    try {
      // 假資料處理
      if (flashcard.id.startsWith('mock')) {
        alert('詞卡已刪除（模擬）')
        router.push('/flashcards')
        return
      }

      // 真實API調用
      const result = await flashcardsService.deleteFlashcard(flashcard.id)
      if (result.success) {
        alert('詞卡已刪除')
        router.push('/flashcards')
      } else {
        alert(result.error || '刪除失敗')
      }
    } catch (error) {
      alert('刪除失敗，請重試')
    }
  }

  if (loading) {
    return (
      <div className="min-h-screen bg-gray-50 flex items-center justify-center">
        <div className="text-lg text-gray-600">載入中...</div>
      </div>
    )
  }

  if (error || !flashcard) {
    return (
      <div className="min-h-screen bg-gray-50 flex items-center justify-center">
        <div className="text-center">
          <div className="text-red-600 text-lg mb-4">{error || '詞卡不存在'}</div>
          <button
            onClick={() => router.push('/flashcards')}
            className="px-4 py-2 bg-primary text-white rounded-lg hover:bg-primary-hover transition-colors"
          >
            返回詞卡列表
          </button>
        </div>
      </div>
    )
  }

  return (
    <div className="min-h-screen bg-gradient-to-br from-blue-50 to-indigo-100">
      <Navigation />

      <div className="max-w-4xl mx-auto px-4 py-8">
        {/* 導航欄 */}
        <div className="flex items-center justify-between mb-6">
          <div className="flex items-center gap-3">
            <button
              onClick={() => router.push('/flashcards')}
              className="text-gray-600 hover:text-gray-900 flex items-center gap-2"
            >
              <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15 19l-7-7 7-7" />
              </svg>
              返回詞卡列表
            </button>
          </div>
        </div>

        {/* 主要詞卡內容 - 學習功能風格 */}
        <div className="bg-white rounded-xl shadow-lg overflow-hidden mb-6 relative">
          {/* CEFR標籤 - 右上角 */}
          <div className="absolute top-4 right-4 z-10">
            <span className={`px-3 py-1 rounded-full text-sm font-medium border ${getCEFRColor((flashcard as any).difficultyLevel || 'A1')}`}>
              {(flashcard as any).difficultyLevel || 'A1'}
            </span>
          </div>

          {/* 標題區 */}
          <div className="bg-gradient-to-br from-blue-50 to-indigo-50 p-6 border-b border-blue-200">
            <div className="pr-16">
              <h1 className="text-4xl font-bold text-gray-900 mb-3">{flashcard.word}</h1>
              <div className="flex items-center gap-3">
                <span className="text-sm bg-gray-100 text-gray-700 px-3 py-1 rounded-full">
                  {flashcard.partOfSpeech}
                </span>
                <span className="text-lg text-gray-600">{flashcard.pronunciation}</span>
                <button className="w-10 h-10 bg-blue-600 rounded-full flex items-center justify-center text-white hover:bg-blue-700 transition-colors">
                  <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15.536 8.464a5 5 0 010 7.072m2.828-9.9a9 9 0 010 12.728M5.586 15H4a1 1 0 01-1-1v-4a1 1 0 011-1h1.586l4.707-4.707C10.923 3.663 12 4.109 12 5v14c0 .891-1.077 1.337-1.707.707L5.586 15z" />
                  </svg>
                </button>
              </div>
            </div>

            {/* 學習統計 */}
            <div className="grid grid-cols-3 gap-4 text-center mt-4">
              <div className="bg-white bg-opacity-60 rounded-lg p-3">
                <div className="text-2xl font-bold text-gray-900">{flashcard.masteryLevel}%</div>
                <div className="text-sm text-gray-600">掌握程度</div>
              </div>
              <div className="bg-white bg-opacity-60 rounded-lg p-3">
                <div className="text-2xl font-bold text-gray-900">{flashcard.timesReviewed}</div>
                <div className="text-sm text-gray-600">複習次數</div>
              </div>
              <div className="bg-white bg-opacity-60 rounded-lg p-3">
                <div className="text-2xl font-bold text-gray-900">
                  {Math.ceil((new Date(flashcard.nextReviewDate).getTime() - new Date().getTime()) / (1000 * 60 * 60 * 24))}
                </div>
                <div className="text-sm text-gray-600">天後複習</div>
              </div>
            </div>
          </div>

          {/* 內容區 - 學習卡片風格 */}
          <div className="p-6 space-y-6">
            {/* 翻譯區塊 */}
            <div className="bg-green-50 rounded-lg p-4 border border-green-200">
              <h3 className="font-semibold text-green-900 mb-3 text-left">中文翻譯</h3>
              {isEditing ? (
                <input
                  type="text"
                  value={editedCard?.translation || ''}
                  onChange={(e) => setEditedCard((prev: any) => ({ ...prev, translation: e.target.value }))}
                  className="w-full p-3 border border-green-300 rounded-lg focus:ring-2 focus:ring-green-500 bg-white"
                  placeholder="輸入中文翻譯"
                />
              ) : (
                <p className="text-green-800 font-medium text-left text-lg">
                  {flashcard.translation}
                </p>
              )}
            </div>

            {/* 定義區塊 */}
            <div className="bg-gray-50 rounded-lg p-4 border border-gray-200">
              <h3 className="font-semibold text-gray-900 mb-3 text-left">英文定義</h3>
              {isEditing ? (
                <textarea
                  value={editedCard?.definition || ''}
                  onChange={(e) => setEditedCard((prev: any) => ({ ...prev, definition: e.target.value }))}
                  className="w-full p-3 border border-gray-300 rounded-lg focus:ring-2 focus:ring-blue-500 bg-white h-20 resize-none"
                  placeholder="輸入英文定義"
                />
              ) : (
                <p className="text-gray-700 text-left leading-relaxed">
                  {flashcard.definition}
                </p>
              )}
            </div>

            {/* 例句區塊 */}
            <div className="bg-blue-50 rounded-lg p-4 border border-blue-200">
              <h3 className="font-semibold text-blue-900 mb-3 text-left">例句</h3>

              {/* 例句圖片 */}
              <div className="mb-4">
                <img
                  src={getExampleImage(flashcard.word)}
                  alt={`${flashcard.word} example`}
                  className="w-full max-w-md mx-auto rounded-lg border border-blue-300"
                />
              </div>

              <div className="space-y-3">
                {isEditing ? (
                  <>
                    <textarea
                      value={editedCard?.example || ''}
                      onChange={(e) => setEditedCard((prev: any) => ({ ...prev, example: e.target.value }))}
                      className="w-full p-3 border border-blue-300 rounded-lg focus:ring-2 focus:ring-blue-500 bg-white h-16 resize-none"
                      placeholder="輸入英文例句"
                    />
                    <textarea
                      value={editedCard?.exampleTranslation || ''}
                      onChange={(e) => setEditedCard((prev: any) => ({ ...prev, exampleTranslation: e.target.value }))}
                      className="w-full p-3 border border-blue-300 rounded-lg focus:ring-2 focus:ring-blue-500 bg-white h-16 resize-none"
                      placeholder="輸入例句翻譯"
                    />
                  </>
                ) : (
                  <>
                    <div className="relative">
                      <p className="text-blue-800 text-left italic text-lg pr-12">
                        "{flashcard.example}"
                      </p>
                      <div className="absolute bottom-0 right-0">
                        <button className="w-10 h-10 bg-blue-600 rounded-full flex items-center justify-center text-white hover:bg-blue-700 transition-colors">
                          <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15.536 8.464a5 5 0 010 7.072m2.828-9.9a9 9 0 010 12.728M5.586 15H4a1 1 0 01-1-1v-4a1 1 0 011-1h1.586l4.707-4.707C10.923 3.663 12 4.109 12 5v14c0 .891-1.077 1.337-1.707.707L5.586 15z" />
                          </svg>
                        </button>
                      </div>
                    </div>
                    <p className="text-blue-700 text-left text-base">
                      "{flashcard.exampleTranslation}"
                    </p>
                  </>
                )}
              </div>
            </div>

            {/* 同義詞區塊 */}
            {(flashcard as any).synonyms && (flashcard as any).synonyms.length > 0 && (
              <div className="bg-purple-50 rounded-lg p-4 border border-purple-200">
                <h3 className="font-semibold text-purple-900 mb-3 text-left">同義詞</h3>
                <div className="flex flex-wrap gap-2">
                  {(flashcard as any).synonyms.map((synonym: string, index: number) => (
                    <span
                      key={index}
                      className="bg-white text-purple-700 px-3 py-1 rounded-full text-sm border border-purple-200 font-medium"
                    >
                      {synonym}
                    </span>
                  ))}
                </div>
              </div>
            )}

            {/* 詞卡資訊 */}
            <div className="bg-gray-50 rounded-lg p-4 border border-gray-200">
              <h3 className="font-semibold text-gray-900 mb-3 text-left">詞卡資訊</h3>
              <div className="grid grid-cols-2 gap-4 text-sm">
                <div>
                  <span className="text-gray-600">詞性:</span>
                  <span className="ml-2 font-medium">{flashcard.partOfSpeech}</span>
                </div>
                <div>
                  <span className="text-gray-600">創建時間:</span>
                  <span className="ml-2 font-medium">{new Date(flashcard.createdAt).toLocaleDateString()}</span>
                </div>
                <div>
                  <span className="text-gray-600">下次複習:</span>
                  <span className="ml-2 font-medium">{new Date(flashcard.nextReviewDate).toLocaleDateString()}</span>
                </div>
                <div>
                  <span className="text-gray-600">複習次數:</span>
                  <span className="ml-2 font-medium">{flashcard.timesReviewed} 次</span>
                </div>
              </div>
            </div>
          </div>

          {/* 編輯模式的操作按鈕 */}
          {isEditing && (
            <div className="px-6 pb-6">
              <div className="flex gap-3">
                <button
                  onClick={handleSaveEdit}
                  className="flex-1 bg-green-600 text-white py-3 rounded-lg font-medium hover:bg-green-700 transition-colors flex items-center justify-center gap-2"
                >
                  <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 13l4 4L19 7" />
                  </svg>
                  保存修改
                </button>
                <button
                  onClick={() => {
                    setIsEditing(false)
                    setEditedCard(flashcard)
                  }}
                  className="flex-1 bg-gray-500 text-white py-3 rounded-lg font-medium hover:bg-gray-600 transition-colors"
                >
                  取消編輯
                </button>
              </div>
            </div>
          )}
        </div>

        {/* 底部操作區 - 平均延展按鈕 */}
        <div className="flex gap-3">
          <button
            onClick={handleToggleFavorite}
            className={`flex-1 py-3 rounded-lg font-medium transition-colors ${
              flashcard.isFavorite
                ? 'bg-yellow-100 text-yellow-700 border border-yellow-300 hover:bg-yellow-200'
                : 'bg-gray-100 text-gray-600 border border-gray-300 hover:bg-yellow-50 hover:text-yellow-600'
            }`}
          >
            <div className="flex items-center justify-center gap-2">
              <svg className="w-4 h-4" fill={flashcard.isFavorite ? "currentColor" : "none"} stroke="currentColor" viewBox="0 0 24 24">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M11.049 2.927c.3-.921 1.603-.921 1.902 0l1.519 4.674a1 1 0 00.95.69h4.915c.969 0 1.371 1.24.588 1.81l-3.976 2.888a1 1 0 00-.363 1.118l1.518 4.674c.3.922-.755 1.688-1.538 1.118l-3.976-2.888a1 1 0 00-1.176 0l-3.976 2.888c-.783.57-1.838-.197-1.538-1.118l1.518-4.674a1 1 0 00-.363-1.118l-3.976-2.888c-.784-.57-.38-1.81.588-1.81h4.914a1 1 0 00.951-.69l1.519-4.674z" />
              </svg>
              {flashcard.isFavorite ? '已收藏' : '收藏'}
            </div>
          </button>

          <button
            onClick={() => setIsEditing(!isEditing)}
            className={`flex-1 py-3 rounded-lg font-medium transition-colors ${
              isEditing
                ? 'bg-gray-100 text-gray-700 border border-gray-300'
                : 'bg-blue-100 text-blue-700 border border-blue-300 hover:bg-blue-200'
            }`}
          >
            <div className="flex items-center justify-center gap-2">
              <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M11 5H6a2 2 0 00-2 2v11a2 2 0 002 2h11a2 2 0 002-2v-5m-1.414-9.414a2 2 0 112.828 2.828L11.828 15H9v-2.828l8.586-8.586z" />
              </svg>
              {isEditing ? '取消編輯' : '編輯詞卡'}
            </div>
          </button>

          <button
            onClick={handleDelete}
            className="flex-1 py-3 bg-red-600 text-white rounded-lg font-medium hover:bg-red-700 transition-colors"
          >
            <div className="flex items-center justify-center gap-2">
              <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 7l-.867 12.142A2 2 0 0116.138 21H7.862a2 2 0 01-1.995-1.858L5 7m5 4v6m4-6v6m1-10V4a1 1 0 00-1-1h-4a1 1 0 00-1 1v3M4 7h16" />
              </svg>
              刪除詞卡
            </div>
          </button>
        </div>
      </div>
    </div>
  )
}