/**
 * LLM API Configuration
 * 支援 Gemini, DeepSeek, OpenAI 三種 LLM 服務
 */

require('dotenv').config();

const llmConfig = {
  // Gemini Configuration
  gemini: {
    apiKey: process.env.GEMINI_API_KEY,
    model: process.env.GEMINI_MODEL || 'gemini-pro',
    apiUrl: 'https://generativelanguage.googleapis.com/v1beta',
    enabled: !!process.env.GEMINI_API_KEY,
    timeout: 30000, // 30 seconds
  },

  // DeepSeek Configuration
  deepseek: {
    apiKey: process.env.DEEPSEEK_API_KEY,
    apiUrl: process.env.DEEPSEEK_API_URL || 'https://api.deepseek.com/v1',
    model: process.env.DEEPSEEK_MODEL || 'deepseek-chat',
    enabled: !!process.env.DEEPSEEK_API_KEY,
    timeout: 30000,
  },

  // OpenAI Configuration
  openai: {
    apiKey: process.env.OPENAI_API_KEY,
    apiUrl: process.env.OPENAI_API_URL || 'https://api.openai.com/v1',
    model: process.env.OPENAI_MODEL || 'gpt-4',
    enabled: !!process.env.OPENAI_API_KEY,
    timeout: 30000,
  },

  // Default LLM Provider
  defaultProvider: 'gemini',

  // Common Settings
  maxTokens: 2000,
  temperature: 0.7,
};

/**
 * 取得啟用的 LLM 服務清單
 */
function getEnabledProviders() {
  const enabled = [];
  if (llmConfig.gemini.enabled) enabled.push('gemini');
  if (llmConfig.deepseek.enabled) enabled.push('deepseek');
  if (llmConfig.openai.enabled) enabled.push('openai');
  return enabled;
}

/**
 * 取得指定 LLM 服務的設定
 */
function getProviderConfig(provider) {
  if (!llmConfig[provider]) {
    throw new Error(`Unknown LLM provider: ${provider}`);
  }
  return llmConfig[provider];
}

/**
 * 檢查 LLM 服務是否可用
 */
function isProviderEnabled(provider) {
  return llmConfig[provider]?.enabled || false;
}

module.exports = {
  llmConfig,
  getEnabledProviders,
  getProviderConfig,
  isProviderEnabled,
};