// 模擬真實API數據結構
import apiSeeds from './api_seeds.json'

// API響應接口 (匹配真實API結構 + 同義詞擴展)
export interface ApiFlashcard {
  id: string
  word: string
  translation: string
  definition: string
  partOfSpeech: string
  pronunciation: string
  example: string
  exampleTranslation: string
  isFavorite: boolean
  difficultyLevelNumeric: number
  cefr: string
  createdAt: string
  updatedAt: string
  hasExampleImage: boolean
  primaryImageUrl: string | null
  // 添加同義詞支持
  synonyms?: string[]
}

// 前端狀態擴展接口 (延遲計數系統)
export interface CardState extends ApiFlashcard {
  // 延遲計數欄位
  skipCount: number        // 跳過次數
  wrongCount: number       // 答錯次數
  isCompleted: boolean     // 是否已完成
  originalOrder: number    // 原始順序
}

// 測驗項目接口 (線性流程核心)
export interface QuizItem {
  id: string                    // 測驗項目ID
  cardId: string               // 所屬詞卡ID
  quizType: 'flip-card' | 'vocab-choice'  // 測驗類型
  isCompleted: boolean         // 個別測驗完成狀態
  skipCount: number            // 跳過次數
  wrongCount: number           // 答錯次數
  order: number               // 序列順序
  cardData: CardState         // 詞卡數據引用
}


// 為詞卡添加延遲計數狀態
const addStateFields = (flashcard: ApiFlashcard, index: number): CardState => ({
  ...flashcard,
  skipCount: 0,
  wrongCount: 0,
  isCompleted: false,
  originalOrder: index
})

// 提取詞卡數據 (方便組件使用)
export const SIMPLE_CARDS = (apiSeeds as any).data.flashcards.map(addStateFields)

// 生成線性測驗項目序列
export const generateQuizItems = (cards: CardState[]): QuizItem[] => {
  const quizItems: QuizItem[] = []
  let order = 0

  cards.forEach((card) => {
    // 為每張詞卡生成兩個測驗項目：先翻卡記憶，再詞彙選擇
    const flipCardQuiz: QuizItem = {
      id: `${card.id}-flip-card`,
      cardId: card.id,
      quizType: 'flip-card',
      isCompleted: false,
      skipCount: 0,
      wrongCount: 0,
      order: order++,
      cardData: card
    }

    const vocabChoiceQuiz: QuizItem = {
      id: `${card.id}-vocab-choice`,
      cardId: card.id,
      quizType: 'vocab-choice',
      isCompleted: false,
      skipCount: 0,
      wrongCount: 0,
      order: order++,
      cardData: card
    }

    quizItems.push(flipCardQuiz, vocabChoiceQuiz)
  })

  return quizItems
}

// 測驗項目優先級排序 (修正後的延遲計數系統)
export const sortQuizItemsByPriority = (quizItems: QuizItem[]): QuizItem[] => {
  return quizItems.sort((a, b) => {
    // 1. 已完成的測驗項目排到最後
    if (a.isCompleted && !b.isCompleted) return 1
    if (!a.isCompleted && b.isCompleted) return -1

    // 2. 未完成項目按延遲分數排序 (修正：延遲分數低的排前面)
    const aDelayScore = a.skipCount + a.wrongCount
    const bDelayScore = b.skipCount + b.wrongCount

    if (aDelayScore !== bDelayScore) {
      return aDelayScore - bDelayScore  // 修正：延遲分數低的排前面，保持線性順序
    }

    // 3. 延遲分數相同時按原始順序
    return a.order - b.order
  })
}


// 生成詞彙選擇測驗選項
export const generateVocabOptions = (correctWord: string, allCards: CardState[]): string[] => {
  const allWords = allCards.map(card => card.word).filter(word => word !== correctWord)
  const shuffledWords = allWords.sort(() => Math.random() - 0.5)
  const distractors = shuffledWords.slice(0, 3)
  const options = [correctWord, ...distractors]
  return options.sort(() => Math.random() - 0.5)
}

// 初始化測驗項目列表
export const INITIAL_TEST_ITEMS = generateQuizItems(SIMPLE_CARDS)