import { useState, useCallback, useRef } from 'react'
import { ReviewCardData, AnswerFeedback, ConfidenceLevel, ReviewResult } from '@/types/review'

interface UseReviewLogicProps {
  cardData: ReviewCardData
  testType: string
}

export const useReviewLogic = ({ cardData, testType }: UseReviewLogicProps) => {
  // 共用狀態
  const [userAnswer, setUserAnswer] = useState<string>('')
  const [feedback, setFeedback] = useState<AnswerFeedback | null>(null)
  const [isSubmitted, setIsSubmitted] = useState(false)
  const [confidence, setConfidence] = useState<ConfidenceLevel | undefined>(undefined)
  const [startTime] = useState(Date.now())

  // 答案驗證邏輯
  const validateAnswer = useCallback((answer: string): AnswerFeedback => {
    const correctAnswer = cardData.word.toLowerCase()
    const normalizedAnswer = answer.toLowerCase().trim()

    // 檢查是否為正確答案或同義詞
    const isCorrect = normalizedAnswer === correctAnswer ||
                     cardData.synonyms.some(synonym =>
                       synonym.toLowerCase() === normalizedAnswer)

    return {
      isCorrect,
      userAnswer: answer,
      correctAnswer: cardData.word,
      explanation: isCorrect ?
        '答案正確！' :
        `正確答案是 "${cardData.word}"${cardData.synonyms.length > 0 ?
          `，同義詞包括：${cardData.synonyms.join(', ')}` : ''}`
    }
  }, [cardData])

  // 提交答案
  const submitAnswer = useCallback((answer: string) => {
    if (isSubmitted) return

    const result = validateAnswer(answer)
    setUserAnswer(answer)
    setFeedback(result)
    setIsSubmitted(true)

    return result
  }, [validateAnswer, isSubmitted])

  // 提交信心度
  const submitConfidence = useCallback((level: ConfidenceLevel) => {
    setConfidence(level)
  }, [])

  // 生成測試結果
  const generateResult = useCallback((): ReviewResult => {
    return {
      cardId: cardData.id,
      testType,
      isCorrect: feedback?.isCorrect ?? false,
      confidence,
      timeSpent: Math.round((Date.now() - startTime) / 1000),
      userAnswer
    }
  }, [cardData.id, testType, feedback, confidence, startTime, userAnswer])

  // 重置狀態
  const reset = useCallback(() => {
    setUserAnswer('')
    setFeedback(null)
    setIsSubmitted(false)
    setConfidence(undefined)
  }, [])

  return {
    // 狀態
    userAnswer,
    feedback,
    isSubmitted,
    confidence,

    // 方法
    setUserAnswer,
    submitAnswer,
    submitConfidence,
    generateResult,
    reset,

    // 輔助方法
    validateAnswer
  }
}