type Message = {
  role: "system" | "user" | "assistant";
  content: string;
};

type OpenRouterConfig = {
  baseURL?: string;
  defaultModel?: string;
};

export class OpenRouterClient {
  private apiKey: string;
  private baseURL: string;
  private defaultModel: string;
  private freeModels = [
    "google/gemini-2.0-flash-exp:free",
    "deepseek/deepseek-chat:free",
    "meta/llama-3.3-70b-instruct:free",
  ];
  private providers = ["openai", "google", "anthropic", "deepseek", "meta", "xai"];

  constructor(apiKey: string, config?: OpenRouterConfig) {
    this.apiKey = apiKey;
    this.baseURL = config?.baseURL ?? "https://openrouter.ai/api/v1";
    this.defaultModel = config?.defaultModel ?? "google/gemini-2.0-flash-exp:free";
  }

  getFreeModels(): string[] {
    return [...this.freeModels];
  }

  getProviders(): string[] {
    return [...this.providers];
  }

  async createChatCompletion(
    messages: Message[],
    model?: string
  ): Promise<unknown> {
    const response = await fetch(`${this.baseURL}/chat/completions`, {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        Authorization: `Bearer ${this.apiKey}`,
        "HTTP-Referer": "https://aitrader.local",
        "X-Title": "AITrader",
      },
      body: JSON.stringify({
        model: model ?? this.defaultModel,
        messages,
      }),
    });

    if (!response.ok) {
      throw new Error(`OpenRouter API error: ${response.status}`);
    }

    return response.json();
  }
}