import type { LlmConfig } from '../config/llmConfig.js';
import type { RenderedPrompt } from './promptTemplate.js';

const OPENROUTER_URL = 'https://openrouter.ai/api/v1/chat/completions';

export interface CompletionRequest extends RenderedPrompt {
  maxTokens?: number;
  temperature?: number;
}

export interface OpenRouterClient {
  complete(request: CompletionRequest): Promise<string | null>;
}

export function createOpenRouterClient(config: LlmConfig): OpenRouterClient {
  return {
    async complete(request: CompletionRequest): Promise<string | null> {
      try {
        const response = await fetch(OPENROUTER_URL, {
          method: 'POST',
          signal: AbortSignal.timeout(config.timeoutMs),
          headers: {
            'Authorization': `Bearer ${config.apiKey}`,
            'Content-Type': 'application/json',
          },
          body: JSON.stringify({
            model: config.model,
            max_tokens: request.maxTokens ?? config.maxTokens,
            temperature: request.temperature ?? config.temperature,
            messages: [
              { role: 'system', content: request.system },
              { role: 'user', content: request.user },
            ],
          }),
        });

        if (!response.ok) {
          console.warn(`OpenRouter API error: ${response.status} ${response.statusText}`);
          return null;
        }

        const data = await response.json();
        const content = data?.choices?.[0]?.message?.content;
        return content ?? null;
      } catch (error) {
        console.warn('OpenRouter request failed:', (error as Error).message);
        return null;
      }
    },
  };
}