export enum Role {
  USER = 'user',
  MODEL = 'model',
}

export enum MessageType {
  TEXT = 'text',
  AUDIO = 'audio',
  IMAGE = 'image',
  VIDEO = 'video',
}

export interface ChatMessage {
  id: string;
  role: Role;
  type: MessageType;
  content: string; // Text content or base64/url for media
  model?: string; // Model used for generation
  metadata?: {
    isThinking?: boolean;
    audioUrl?: string; // For TTS playback or User recording
    imageUrl?: string;
    videoUrl?: string;
    transcription?: string; // For audio inputs
  };
  timestamp: number;
}

// New Interface for Chat Sessions
export interface ChatSession {
  id: string;
  title: string;
  messages: ChatMessage[];
  createdAt: number;
  updatedAt: number;
}

export enum AppMode {
  CHAT = 'chat',
  READING = 'reading',
  LISTENING = 'listening', // New Listening Mode
  SPEAKING = 'speaking',
  CREATIVE = 'creative', 
  TRANSLATION = 'translation', 
  OCR = 'ocr', 
}

export type Language = 'en' | 'ja' | 'zh';

// Specific Gemini Models
export enum ModelNames {
  TEXT_FAST = 'gemini-2.5-flash',
  TEXT_REASONING = 'gemini-3-pro-preview',
  TTS = 'gemini-2.5-flash-preview-tts',
  IMAGE_GEN = 'imagen-4.0-generate-001',
  IMAGE_EDIT = 'gemini-2.5-flash-image', // Nano Banana
  VIDEO_GEN = 'veo-3.1-fast-generate-preview',
  TRANSCRIPTION = 'gemini-2.5-flash',
}

export const AVAILABLE_CHAT_MODELS = [
  { id: 'gemini-3-pro-preview', name: 'Gemini 3 Pro (Default - Best Reasoning)' },
  { id: 'gemini-2.5-flash', name: 'Gemini 2.5 Flash (Fast & Balanced)' }
];

// Speaking Mode Types
export interface PronunciationFeedback {
  score: number; // 0-100
  transcription: string;
  response: string; // AI Reply in Japanese
  translation: string; // AI Reply in English/Native Lang
  pronunciationIssues: string[]; // List of specific phoneme/pitch errors
  advice: string; // General advice
}

export interface Scenario {
  id: string;
  title: string;
  icon: string;
  description: string;
  initialMessage: string; // What AI says first
  initialTranslation?: string; // Translation of initial message
  role: string; // Who the AI is
}

// Reading Mode Types
export enum ReadingDifficulty {
  BEGINNER = 'beginner', // N5/N4
  INTERMEDIATE = 'intermediate', // N3/N2
  ADVANCED = 'advanced', // N1+
}

export interface ReadingLesson {
  title: string;
  japaneseContent: string;
  translation: string;
  vocabulary: { word: string; reading: string; meaning: string }[];
  grammarPoints?: { point: string; explanation: string }[];
}

export interface ReadingLessonRecord extends ReadingLesson {
  id: string;
  topic: string;
  difficulty: ReadingDifficulty;
  timestamp: number;
  chatHistory?: ChatMessage[]; // Persist tutor chat
}

// Listening Mode Types
export interface QuizQuestion {
  id: string;
  question: string;
  options: string[];
  correctIndex: number;
  explanation: string;
}

export interface ListeningLesson {
  title: string;
  script: string; // The full Japanese text (initially hidden)
  translation: string;
  vocabulary: { word: string; reading: string; meaning: string }[];
  questions: QuizQuestion[];
  grammarPoints?: { point: string; explanation: string }[];
}

export interface ListeningLessonRecord extends ListeningLesson {
  id: string;
  topic: string;
  difficulty: ReadingDifficulty;
  timestamp: number;
  chatHistory?: ChatMessage[];
}

// OCR Mode Types
export interface OCRAnalysis {
  extractedText: string;
  detectedLanguage: string;
  summary: string;
  vocabulary: { word: string; reading: string; meaning: string }[];
  grammarPoints: { point: string; explanation: string }[];
}

export interface OCRRecord {
  id: string;
  timestamp: number;
  imagePreview: string;
  analysis: OCRAnalysis;
}

// Translation Mode Types
export interface TranslationRecord {
  id: string;
  sourceText: string;
  targetText: string;
  sourceLang: string; // e.g. 'Detected Language' or 'English'
  targetLang: string; // e.g. 'Japanese'
  timestamp: number;
}

// Backup Data Type
export interface AppDataBackup {
  version: number;
  createdAt: number;
  language: Language;
  chatSessions: ChatSession[]; 
  translationHistory: TranslationRecord[];
  readingHistory?: ReadingLessonRecord[];
  ocrHistory?: OCRRecord[];
  listeningHistory?: ListeningLessonRecord[];
}