'use client'

import { useState, useMemo, useCallback } from 'react'
import { ProtectedRoute } from '@/components/ProtectedRoute'
import { Navigation } from '@/components/Navigation'
import { ClickableTextV2 } from '@/components/ClickableTextV2'
import { flashcardsService } from '@/lib/services/flashcards'
import { Play } from 'lucide-react'
import Link from 'next/link'

// 常數定義
const CEFR_LEVELS = ['A1', 'A2', 'B1', 'B2', 'C1', 'C2'] as const
const MAX_MANUAL_INPUT_LENGTH = 300

// 工具函數
const getLevelIndex = (level: string): number => {
  return CEFR_LEVELS.indexOf(level as typeof CEFR_LEVELS[number])
}

const getTargetLearningRange = (userLevel: string): string => {
  const ranges: Record<string, string> = {
    'A1': 'A2-B1', 'A2': 'B1-B2', 'B1': 'B2-C1',
    'B2': 'C1-C2', 'C1': 'C2', 'C2': 'C2'
  }
  return ranges[userLevel] || 'B1-B2'
}

interface GrammarCorrection {
  hasErrors: boolean;
  originalText: string;
  correctedText: string | null;
  corrections: Array<{
    position: { start: number; end: number };
    error: string;
    correction: string;
    type: string;
    explanation: string;
    severity: 'high' | 'medium' | 'low';
  }>;
  confidenceScore: number;
}

interface IdiomPopup {
  idiom: string;
  analysis: any;
  position: { x: number; y: number };
}

function GenerateContent() {
  const [textInput, setTextInput] = useState('')
  const [isAnalyzing, setIsAnalyzing] = useState(false)
  const [showAnalysisView, setShowAnalysisView] = useState(false)
  const [sentenceAnalysis, setSentenceAnalysis] = useState<Record<string, any> | null>(null)
  const [sentenceMeaning, setSentenceMeaning] = useState('')
  const [grammarCorrection, setGrammarCorrection] = useState<GrammarCorrection | null>(null)
  const [idiomPopup, setIdiomPopup] = useState<IdiomPopup | null>(null)


  // 處理句子分析 - 使用真實API
  const handleAnalyzeSentence = async () => {
    console.log('🚀 handleAnalyzeSentence 被調用 (真實API模式)')

    setIsAnalyzing(true)

    try {
      const response = await fetch('http://localhost:5008/api/ai/analyze-sentence', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json'
        },
        body: JSON.stringify({
          inputText: textInput,
          analysisMode: 'full',
          options: {
            includeGrammarCheck: true,
            includeVocabularyAnalysis: true,
            includeTranslation: true,
            includeIdiomDetection: true,
            includeExamples: true
          }
        })
      })

      if (!response.ok) {
        let errorMessage = `API請求失敗: ${response.status}`
        try {
          const errorData = await response.json()
          errorMessage = errorData.error?.message || errorData.message || errorMessage
        } catch (e) {
          console.warn('無法解析錯誤回應:', e)
        }
        throw new Error(errorMessage)
      }

      const result = await response.json()

      if (!result.success || !result.data) {
        throw new Error('API回應格式錯誤')
      }

      // 處理API回應 - 適配新的後端格式
      const apiData = result.data

      // 設定完整的分析結果（包含vocabularyAnalysis和其他數據）
      const analysisData = {
        originalText: apiData.originalText,
        sentenceMeaning: apiData.sentenceMeaning,
        grammarCorrection: apiData.grammarCorrection,
        vocabularyAnalysis: apiData.vocabularyAnalysis,
        idioms: apiData.idioms || [],
        processingTime: result.processingTime
      }

      setSentenceAnalysis(analysisData)
      setSentenceMeaning(apiData.sentenceMeaning || '')

      // 處理語法修正
      if (apiData.grammarCorrection) {
        setGrammarCorrection({
          hasErrors: apiData.grammarCorrection.hasErrors,
          originalText: textInput,
          correctedText: apiData.grammarCorrection.correctedText || textInput,
          corrections: apiData.grammarCorrection.corrections || [],
          confidenceScore: apiData.grammarCorrection.confidenceScore || 0.9
        })
      } else {
        setGrammarCorrection({
          hasErrors: false,
          originalText: textInput,
          correctedText: textInput,
          corrections: [],
          confidenceScore: 1.0
        })
      }

      setShowAnalysisView(true)
      console.log('✅ API分析完成', apiData)
    } catch (error) {
      console.error('Error in sentence analysis:', error)
      setGrammarCorrection({
        hasErrors: true,
        originalText: textInput,
        correctedText: textInput,
        corrections: [],
        confidenceScore: 0.0
      })
      setSentenceMeaning('分析過程中發生錯誤，請稍後再試。')
      // 錯誤時也不設置finalText，使用原始輸入
      setShowAnalysisView(true)
    } finally {
      setIsAnalyzing(false)
    }
  }






  const handleAcceptCorrection = useCallback(() => {
    if (grammarCorrection?.correctedText) {
      // 更新用戶輸入為修正後的版本
      setTextInput(grammarCorrection.correctedText)
      console.log('✅ 已採用修正版本，文本已更新為正確版本！')
    }
  }, [grammarCorrection?.correctedText])

  const handleRejectCorrection = useCallback(() => {
    // 保持原始輸入不變，只是隱藏語法修正面板
    setGrammarCorrection(null)
    console.log('📝 已保持原始版本，繼續使用您的原始輸入。')
  }, [])

  // 詞彙統計計算 - 適配新的後端API格式
  const vocabularyStats = useMemo(() => {
    if (!sentenceAnalysis?.vocabularyAnalysis) {
      return { simpleCount: 0, moderateCount: 0, difficultCount: 0, idiomCount: 0 }
    }

    const userLevel = localStorage.getItem('userEnglishLevel') || 'A2'
    let simpleCount = 0
    let moderateCount = 0
    let difficultCount = 0

    // 處理vocabularyAnalysis物件
    Object.values(sentenceAnalysis.vocabularyAnalysis).forEach((wordData: any) => {
      const difficultyLevel = wordData?.difficultyLevel || 'A1'
      const userIndex = getLevelIndex(userLevel)
      const wordIndex = getLevelIndex(difficultyLevel)

      if (userIndex > wordIndex) {
        simpleCount++
      } else if (userIndex === wordIndex) {
        moderateCount++
      } else {
        difficultCount++
      }
    })

    // 處理慣用語統計
    const idiomCount = sentenceAnalysis.idioms?.length || 0

    return { simpleCount, moderateCount, difficultCount, idiomCount }
  }, [sentenceAnalysis])

  // 保存單個詞彙
  const handleSaveWord = useCallback(async (word: string, analysis: any) => {
    try {
      const cardData = {
        word: word,
        translation: analysis.translation || analysis.Translation || '',
        definition: analysis.definition || analysis.Definition || '',
        pronunciation: analysis.pronunciation || analysis.Pronunciation || `/${word}/`,
        partOfSpeech: analysis.partOfSpeech || analysis.PartOfSpeech || 'unknown',
        example: `Example sentence with ${word}.` // 提供預設例句
      }

      const response = await flashcardsService.createFlashcard(cardData)

      if (response.success) {
        // 顯示成功提示
        const successMessage = `✅ 已成功將「${word}」保存到詞卡庫！`
        alert(successMessage)
        console.log(successMessage)
        return { success: true }
      } else if (response.error && response.error.includes('已存在')) {
        // 顯示重複提示
        const duplicateMessage = `⚠️ 詞卡「${word}」已經存在於詞卡庫中`
        alert(duplicateMessage)
        console.log(duplicateMessage)
        return { success: false, error: 'duplicate', message: duplicateMessage }
      } else {
        throw new Error(response.error || '保存失敗')
      }
    } catch (error) {
      console.error('Save word error:', error)
      const errorMessage = error instanceof Error ? error.message : '保存失敗'
      alert(`❌ 保存詞卡失敗: ${errorMessage}`)
      return { success: false, error: errorMessage }
    }
  }, [])

  return (
    <div className="min-h-screen bg-gray-50">
      <Navigation />

      <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-8">
        {!showAnalysisView ? (
          <div className="max-w-4xl mx-auto">
            <h1 className="text-3xl font-bold mb-4">AI 智能生成詞卡</h1>

            {/* 星星標記說明 */}
            <div className="bg-blue-50 border border-blue-200 rounded-lg p-4 mb-6">
              <div className="flex items-center gap-2 text-sm text-blue-800">
                <span className="text-yellow-500 text-lg">⭐</span>
                <span className="font-medium">星星標記說明：</span>
                標有星星的詞彙和慣用語代表
                <strong className="text-blue-900">常用、高頻詞彙</strong>
                ，建議優先學習！
              </div>
            </div>

            {/* Content Input */}
            <div className="bg-white rounded-xl shadow-sm p-4 sm:p-6 mb-6">
              <h2 className="text-lg font-semibold mb-4">輸入英文文本</h2>
              <textarea
                value={textInput}
                onChange={(e) => {
                  const value = e.target.value
                  if (value.length > MAX_MANUAL_INPUT_LENGTH) {
                    return
                  }
                  setTextInput(value)
                }}
                placeholder={`輸入英文句子（最多${MAX_MANUAL_INPUT_LENGTH}字）...`}
                className={`w-full h-32 sm:h-40 px-3 sm:px-4 py-2 sm:py-3 text-sm sm:text-base border rounded-lg focus:ring-2 focus:ring-primary focus:border-transparent outline-none resize-none ${
                  textInput.length >= MAX_MANUAL_INPUT_LENGTH - 20 ? 'border-yellow-400' :
                  textInput.length >= MAX_MANUAL_INPUT_LENGTH ? 'border-red-400' : 'border-gray-300'
                }`}
              />
              <div className="mt-2 flex justify-between text-sm">
                <span className={`${
                  textInput.length >= MAX_MANUAL_INPUT_LENGTH - 20 ? 'text-yellow-600' :
                  textInput.length >= MAX_MANUAL_INPUT_LENGTH ? 'text-red-600' : 'text-gray-600'
                }`}>
                  最多 {MAX_MANUAL_INPUT_LENGTH} 字元 • 目前：{textInput.length} 字元
                </span>
                {textInput.length > MAX_MANUAL_INPUT_LENGTH - 50 && (
                  <span className={textInput.length >= MAX_MANUAL_INPUT_LENGTH ? 'text-red-600' : 'text-yellow-600'}>
                    {textInput.length >= MAX_MANUAL_INPUT_LENGTH ? '已達上限！' : `還可輸入 ${MAX_MANUAL_INPUT_LENGTH - textInput.length} 字元`}
                  </span>
                )}
              </div>
            </div>


            {/* Action Buttons */}
            <div className="space-y-4">
              {/* 句子分析按鈕 */}
              <button
                onClick={handleAnalyzeSentence}
                disabled={isAnalyzing || !textInput || textInput.length > MAX_MANUAL_INPUT_LENGTH}
                className="w-full bg-blue-600 text-white py-4 rounded-lg font-semibold hover:bg-blue-700 transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
              >
                {isAnalyzing ? (
                  <span className="flex items-center justify-center">
                    <svg className="animate-spin -ml-1 mr-3 h-5 w-5 text-white" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24">
                      <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4"></circle>
                      <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"></path>
                    </svg>
                    正在分析句子... (AI 分析約需 3-5 秒)
                  </span>
                ) : (
                  '🔍 分析句子'
                )}
              </button>


              {/* 個人化程度指示器 */}
              <div className="text-center text-sm text-gray-600 mt-2">
                {(() => {
                  const userLevel = localStorage.getItem('userEnglishLevel') || 'A2'
                  return (
                    <div className="flex items-center justify-center gap-2">
                      <span>🎯 您的程度: {userLevel}</span>
                      <span className="text-gray-400">|</span>
                      <span>📈 重點學習範圍: {getTargetLearningRange(userLevel)}</span>
                      <Link
                        href="/settings"
                        className="text-blue-500 hover:text-blue-700 ml-2"
                      >
                        調整 ⚙️
                      </Link>
                    </div>
                  )
                })()}
              </div>
            </div>
          </div>
        ) : (
          /* 重新設計的句子分析視圖 - 簡潔流暢 */
          <div className="max-w-4xl mx-auto">
            {/* 移除冗餘標題，直接進入內容 */}

            {/* 語法修正面板 - 如果需要的話 */}
            {grammarCorrection && grammarCorrection.hasErrors && (
              <div className="bg-yellow-50 border border-yellow-200 rounded-xl p-6 mb-6">
                <div className="flex items-start gap-3">
                  <div className="text-yellow-600 text-2xl">⚠️</div>
                  <div className="flex-1">
                    <h3 className="text-lg font-semibold text-yellow-800 mb-2">發現語法問題</h3>
                    <p className="text-yellow-700 mb-4">AI建議修正以下內容，這將提高學習效果：</p>

                    <div className="space-y-3 mb-4">
                      <div>
                        <span className="text-sm font-medium text-yellow-700">原始輸入：</span>
                        <div className="bg-white p-3 rounded border border-yellow-300 mt-1">
                          {textInput}
                        </div>
                      </div>
                      <div>
                        <span className="text-sm font-medium text-yellow-700">建議修正：</span>
                        <div className="bg-yellow-100 p-3 rounded border border-yellow-300 mt-1 font-medium">
                          {grammarCorrection.correctedText || textInput}
                        </div>
                      </div>
                    </div>

                    <div className="flex gap-3">
                      <button
                        onClick={handleAcceptCorrection}
                        className="px-4 py-2 bg-green-600 text-white rounded-lg hover:bg-green-700 transition-colors"
                      >
                        ✅ 採用修正
                      </button>
                      <button
                        onClick={handleRejectCorrection}
                        className="px-4 py-2 bg-gray-500 text-white rounded-lg hover:bg-gray-600 transition-colors"
                      >
                        📝 保持原樣
                      </button>
                    </div>
                  </div>
                </div>
              </div>
            )}

            {/* 主句子展示 - 最重要的內容 */}
            <div className="bg-white rounded-xl shadow-lg p-8 mb-6">
              {/* 詞彙統計卡片區 */}
              {vocabularyStats && (
                <div className="grid grid-cols-2 sm:grid-cols-4 gap-3 sm:gap-4 mb-6">
                  {/* 簡單詞彙卡片 */}
                  <div className="bg-gray-50 border border-dashed border-gray-300 rounded-lg p-3 sm:p-4 text-center">
                    <div className="text-xl sm:text-2xl font-bold text-gray-600 mb-1">{vocabularyStats.simpleCount}</div>
                    <div className="text-gray-600 text-sm sm:text-base font-medium">太簡單啦</div>
                  </div>

                  {/* 適中詞彙卡片 */}
                  <div className="bg-green-50 border border-green-200 rounded-lg p-3 sm:p-4 text-center">
                    <div className="text-xl sm:text-2xl font-bold text-green-700 mb-1">{vocabularyStats.moderateCount}</div>
                    <div className="text-green-700 text-sm sm:text-base font-medium">重點學習</div>
                  </div>

                  {/* 艱難詞彙卡片 */}
                  <div className="bg-orange-50 border border-orange-200 rounded-lg p-3 sm:p-4 text-center">
                    <div className="text-xl sm:text-2xl font-bold text-orange-700 mb-1">{vocabularyStats.difficultCount}</div>
                    <div className="text-orange-700 text-sm sm:text-base font-medium">有點挑戰</div>
                  </div>

                  {/* 片語與俚語卡片 */}
                  <div className="bg-blue-50 border border-blue-200 rounded-lg p-3 sm:p-4 text-center">
                    <div className="text-xl sm:text-2xl font-bold text-blue-700 mb-1">{vocabularyStats.idiomCount}</div>
                    <div className="text-blue-700 text-sm sm:text-base font-medium">慣用語</div>
                  </div>
                </div>
              )}

              {/* 句子主體展示 */}
              <div className="text-left mb-8">
                <div className="text-xl sm:text-2xl lg:text-3xl font-medium text-gray-900 mb-6" >
                  <ClickableTextV2
                    text={textInput}
                    analysis={sentenceAnalysis?.vocabularyAnalysis || undefined}
                    showIdiomsInline={false}
                    onWordClick={(word, analysis) => {
                      console.log('Clicked word:', word, analysis)
                    }}
                    onSaveWord={handleSaveWord}
                  />
                </div>

                {/* 翻譯 - 參考翻卡背面設計 */}
                <div className="bg-gray-50 rounded-lg p-4">
                  <h3 className="font-semibold text-gray-900 mb-2 text-left">中文翻譯</h3>
                  <p className="text-gray-700 text-left">{sentenceMeaning}</p>
                </div>

                {/* 片語和慣用語展示區 */}
                {(() => {
                  if (!sentenceAnalysis?.idioms || sentenceAnalysis.idioms.length === 0) return null

                  // 使用新的API格式中的idioms陣列
                  const idioms = sentenceAnalysis.idioms


                  return (
                    <div className="bg-gray-50 rounded-lg p-4 mt-4">
                      <h3 className="font-semibold text-gray-900 mb-2 text-left">慣用語</h3>
                      <div className="flex flex-wrap gap-2">
                        {idioms.map((idiom: any, index: number) => (
                          <span
                            key={index}
                            className="cursor-pointer transition-all duration-200 rounded-lg relative mx-0.5 px-1 py-0.5 inline-flex items-center gap-1 bg-blue-50 border border-blue-200 hover:bg-blue-100 hover:shadow-lg transform hover:-translate-y-0.5 text-blue-700 font-medium"
                            onClick={(e) => {
                              // 使用新的API格式，直接使用idiom物件
                              setIdiomPopup({
                                idiom: idiom.idiom,
                                analysis: idiom,
                                position: {
                                  x: e.currentTarget.getBoundingClientRect().left + e.currentTarget.getBoundingClientRect().width / 2,
                                  y: e.currentTarget.getBoundingClientRect().bottom + 10
                                }
                              })
                            }}
                            title={`${idiom.idiom}: ${idiom.translation}`}
                          >
                            {idiom.idiom}
                            {idiom?.frequency === 'high' && (
                              <span
                                className="absolute -top-1 -right-1 text-xs pointer-events-none z-10"
                                style={{ fontSize: '8px', lineHeight: 1 }}
                              >
                                ⭐
                              </span>
                            )}
                          </span>
                        ))}
                      </div>
                    </div>
                  )
                })()}
              </div>

            </div>

            {/* 下方操作區 - 簡化 */}
            <div className="flex justify-center px-4">
              <button
                onClick={() => setShowAnalysisView(false)}
                className="w-full sm:w-auto px-6 sm:px-8 py-3 bg-primary text-white rounded-lg font-medium hover:bg-primary-hover transition-colors flex items-center justify-center gap-2"
              >
                <span>分析新句子</span>
              </button>
            </div>
          </div>
        )}

        {/* 片語彈窗 */}
        {idiomPopup && (
          <>
            <div
              className="fixed inset-0 bg-black bg-opacity-50 z-40"
              onClick={() => setIdiomPopup(null)}
            />
            <div
              className="fixed z-50 bg-white rounded-xl shadow-lg w-96 max-w-md overflow-hidden"
              style={{
                left: `${idiomPopup.position.x}px`,
                top: `${idiomPopup.position.y}px`,
                transform: 'translate(-50%, 8px)',
                maxHeight: '85vh',
                overflowY: 'auto'
              }}
            >
              <div className="bg-gradient-to-br from-blue-50 to-indigo-50 p-5 border-b border-blue-200">
                <div className="flex justify-end mb-3">
                  <button
                    onClick={() => setIdiomPopup(null)}
                    className="text-gray-400 hover:text-gray-600 w-6 h-6 rounded-full bg-white bg-opacity-80 hover:bg-opacity-100 transition-all flex items-center justify-center"
                  >
                    ✕
                  </button>
                </div>

                <div className="mb-3">
                  <h3 className="text-2xl font-bold text-gray-900">{idiomPopup.analysis.idiom}</h3>
                </div>

                <div className="flex items-center justify-between">
                  <div className="flex items-center gap-3">
                    <div className="flex items-center gap-2">
                      <span className="text-base text-gray-600">{idiomPopup.analysis.pronunciation}</span>
                      <button
                        onClick={() => {
                          const utterance = new SpeechSynthesisUtterance(idiomPopup.analysis.idiom);
                          utterance.lang = 'en-US';
                          utterance.rate = 0.8;
                          speechSynthesis.speak(utterance);
                        }}
                        className="flex items-center justify-center w-8 h-8 rounded-full bg-blue-600 hover:bg-blue-700 text-white transition-colors"
                        title="播放發音"
                      >
                        <Play size={16} />
                      </button>
                    </div>
                  </div>

                  <span className="px-3 py-1 rounded-full text-sm font-medium border bg-blue-100 text-blue-700 border-blue-200">
                    {idiomPopup.analysis.difficultyLevel}
                  </span>
                </div>
              </div>

              <div className="p-4 space-y-4">
                <div className="bg-green-50 rounded-lg p-3 border border-green-200">
                  <h4 className="font-semibold text-green-900 mb-2 text-left text-sm">中文翻譯</h4>
                  <p className="text-green-800 font-medium text-left">{idiomPopup.analysis.translation}</p>
                </div>

                <div className="bg-gray-50 rounded-lg p-3 border border-gray-200">
                  <h4 className="font-semibold text-gray-900 mb-2 text-left text-sm">英文定義</h4>
                  <p className="text-gray-700 text-left text-sm leading-relaxed">{idiomPopup.analysis.definition}</p>
                </div>

                {idiomPopup.analysis.example && (
                  <div className="bg-blue-50 rounded-lg p-3 border border-blue-200">
                    <h4 className="font-semibold text-blue-900 mb-2 text-left text-sm">例句</h4>
                    <div className="space-y-2">
                      <p className="text-blue-800 text-left text-sm italic">
                        "{idiomPopup.analysis.example}"
                      </p>
                      <p className="text-blue-700 text-left text-sm">
                        {idiomPopup.analysis.exampleTranslation}
                      </p>
                    </div>
                  </div>
                )}

                {idiomPopup.analysis.synonyms && Array.isArray(idiomPopup.analysis.synonyms) && idiomPopup.analysis.synonyms.length > 0 && (
                  <div className="bg-purple-50 rounded-lg p-3 border border-purple-200">
                    <h4 className="font-semibold text-purple-900 mb-2 text-left text-sm">同義詞</h4>
                    <div className="flex flex-wrap gap-2">
                      {idiomPopup.analysis.synonyms.map((synonym: string, index: number) => (
                        <span
                          key={index}
                          className="bg-purple-100 text-purple-700 px-2 py-1 rounded-full text-xs font-medium"
                        >
                          {synonym}
                        </span>
                      ))}
                    </div>
                  </div>
                )}
              </div>

              <div className="p-4 pt-2">
                <button
                  onClick={async () => {
                    const result = await handleSaveWord(idiomPopup.idiom, idiomPopup.analysis)
                    if (result.success) {
                      setIdiomPopup(null)
                    } else {
                      console.error('Save idiom error:', result.error)
                    }
                  }}
                  className="w-full bg-primary text-white py-3 rounded-lg font-medium hover:bg-primary-hover transition-colors flex items-center justify-center gap-2"
                >
                  <span className="font-medium">保存到詞卡</span>
                </button>
              </div>
            </div>
          </>
        )}
      </div>
    </div>
  )
}

export default function GeneratePage() {
  return (
    <ProtectedRoute>
      <GenerateContent />
    </ProtectedRoute>
  )
}