import mongoose, { Document, Schema } from 'mongoose';

// 单词接口
export interface IWord extends Document {
  word: string;
  translation: string;
  pronunciation?: string;
  example?: string;
  wordSet: mongoose.Types.ObjectId;
  createdAt: Date;
  updatedAt: Date;
}

// 单词集接口
export interface IWordSet extends Document {
  name: string;
  description?: string;
  owner: mongoose.Types.ObjectId;
  totalWords: number;
  createdAt: Date;
  updatedAt: Date;
}

// 单词学习记录接口
export interface IWordRecord extends Document {
  user: mongoose.Types.ObjectId;
  word: mongoose.Types.ObjectId;
  mode: 'chinese-to-english' | 'audio-to-english' | 'multiple-choice';
  streak: number;
  totalCorrect: number;
  totalWrong: number;
  mastered: boolean;
  inWrongBook: boolean;
  lastTestedAt: Date;
  lastMasteredAt: Date;
  createdAt: Date;
}

// 单词测试记录接口
export interface IVocabularyTestRecord extends Document {
  user: mongoose.Types.ObjectId;
  wordSet: mongoose.Types.ObjectId;
  testType: 'chinese-to-english' | 'audio-to-english' | 'multiple-choice';
  attempt?: mongoose.Types.ObjectId;
  stats: {
    totalWords: number;
    correctWords: number;
    accuracy: number;
    startTime: Date;
    endTime: Date;
    duration: number;
  };
  results?: Array<{
    word: mongoose.Types.ObjectId;
    userAnswer: string;
    correctAnswer: string;
    isCorrect: boolean;
  }>;
  createdAt: Date;
}

export interface IVocabularyTestAttempt extends Document {
  user: mongoose.Types.ObjectId;
  wordSet: mongoose.Types.ObjectId;
  testType: 'chinese-to-english' | 'audio-to-english' | 'multiple-choice';
  questionWordIds: mongoose.Types.ObjectId[];
  questionTokens: string[];
  issuedAt: Date;
  expiresAt: Date;
  submittedAt?: Date;
  status: 'active' | 'submitted' | 'expired';
  createdAt: Date;
  updatedAt: Date;
}

// 单词模式
const WordSchema = new Schema<IWord>({
  word: { type: String, required: true, trim: true },
  translation: { type: String, required: true, trim: true },
  pronunciation: { type: String, trim: true },
  example: { type: String, trim: true },
  wordSet: { type: Schema.Types.ObjectId, ref: 'WordSet', required: true },
}, { timestamps: true });

// 为单词模型添加索引
WordSchema.index({ word: 1, wordSet: 1 }, { unique: true });
WordSchema.index({ translation: 'text', word: 'text' });

// 单词集模式
const WordSetSchema = new Schema<IWordSet>({
  name: { type: String, required: true, trim: true },
  description: { type: String, trim: true },
  owner: { type: Schema.Types.ObjectId, ref: 'User', required: true },
  totalWords: { type: Number, default: 0 },
}, { timestamps: true });

// 为单词集模型添加索引
WordSetSchema.index({ name: 1, owner: 1 }, { unique: true });

// 简化的嵌套模式统计
const ModeStatsSchema = new Schema({
  streak: { type: Number, default: 0 },
  totalCorrect: { type: Number, default: 0 },
  totalWrong: { type: Number, default: 0 },
  mastered: { type: Boolean, default: false },
  inWrongBook: { type: Boolean, default: false },
  lastTestedAt: Date,
  lastMasteredAt: Date
}, { _id: false });

// 简化后的主记录模式
const WordRecordSchema = new Schema({
  user: { type: Schema.Types.ObjectId, ref: 'User', required: true },
  word: { type: Schema.Types.ObjectId, ref: 'Word', required: true },
  
  // 各模式的基础统计数据
  multipleChoice: { type: ModeStatsSchema, default: () => ({}) },
  audioToEnglish: { type: ModeStatsSchema, default: () => ({}) },
  chineseToEnglish: { type: ModeStatsSchema, default: () => ({}) },
  
  // 只在顶层保留整体掌握状态
  isFullyMastered: { type: Boolean, default: false },
  lastFullyMasteredAt: Date,
  
  createdAt: { type: Date, default: Date.now }
});

// 单词测试记录模式
const VocabularyTestRecordSchema = new Schema<IVocabularyTestRecord>({
  user: { type: Schema.Types.ObjectId, ref: 'User', required: true },
  wordSet: { type: Schema.Types.ObjectId, ref: 'WordSet', required: true },
  attempt: { type: Schema.Types.ObjectId, ref: 'VocabularyTestAttempt' },
  testType: { 
    type: String, 
    enum: ['chinese-to-english', 'audio-to-english', 'multiple-choice'],
    required: true 
  },
  stats: {
    totalWords: { type: Number, required: true },
    correctWords: { type: Number, required: true },
    accuracy: { type: Number, required: true },
    startTime: { type: Date, required: true },
    endTime: { type: Date, required: true },
    duration: { type: Number, required: true }
  },
  results: [{
    word: { type: Schema.Types.ObjectId, ref: 'Word', required: true },
    userAnswer: { type: String, default: '' },
    correctAnswer: { type: String, required: true },
    isCorrect: { type: Boolean, required: true }
  }],
  createdAt: { type: Date, default: Date.now }
});

// 单词测试会话模式，用于防止直接伪造测试提交
const VocabularyTestAttemptSchema = new Schema<IVocabularyTestAttempt>({
  user: { type: Schema.Types.ObjectId, ref: 'User', required: true },
  wordSet: { type: Schema.Types.ObjectId, ref: 'WordSet', required: true },
  testType: {
    type: String,
    enum: ['chinese-to-english', 'audio-to-english', 'multiple-choice'],
    required: true
  },
  questionWordIds: [{ type: Schema.Types.ObjectId, ref: 'Word', required: true }],
  questionTokens: [{ type: String, required: true }],
  issuedAt: { type: Date, required: true },
  expiresAt: { type: Date, required: true },
  submittedAt: Date,
  status: {
    type: String,
    enum: ['active', 'submitted', 'expired'],
    default: 'active',
    required: true
  }
}, { timestamps: true });

VocabularyTestAttemptSchema.index({ user: 1, status: 1, expiresAt: 1 });
VocabularyTestAttemptSchema.index({ expiresAt: 1 });

// 创建和导出模型
export const Word = mongoose.model<IWord>('Word', WordSchema);
export const WordSet = mongoose.model<IWordSet>('WordSet', WordSetSchema);
export const WordRecord = mongoose.model('WordRecord', WordRecordSchema);
export const VocabularyTestRecord = mongoose.model<IVocabularyTestRecord>('VocabularyTestRecord', VocabularyTestRecordSchema);
export const VocabularyTestAttempt = mongoose.model<IVocabularyTestAttempt>('VocabularyTestAttempt', VocabularyTestAttemptSchema);

export default {
  Word,
  WordSet,
  WordRecord,
  VocabularyTestRecord,
  VocabularyTestAttempt
};