import { loadConfig, type Config } from '../config.js';

const TIMEOUT_MS = 10_000;

export async function taskModelCompletion(opts: {
  system: string;
  user: string;
  maxTokens?: number;
  temperature?: number;
  fallbackModel?: string;
}): Promise<string> {
  const config = loadConfig();
  const maxTokens = opts.maxTokens ?? 30;
  const temperature = opts.temperature ?? 0.3;

  const { url, model } = resolveEndpoint(config, opts.fallbackModel);

  try {
    const res = await fetch(`${url}/v1/chat/completions`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({
        model,
        messages: [
          { role: 'system', content: opts.system },
          { role: 'user', content: opts.user },
        ],
        max_tokens: maxTokens,
        temperature,
        stream: false,
        chat_template_kwargs: { enable_thinking: false },
      }),
      signal: AbortSignal.timeout(TIMEOUT_MS),
    });
    if (!res.ok) {
      const text = await res.text().catch(() => '');
      console.warn(`task-model: ${res.status} ${text.slice(0, 200)}`);
      return '';
    }
    const data = (await res.json()) as {
      choices?: Array<{
        message?: { content?: string; reasoning_content?: string };
      }>;
    };
    const choice = data.choices?.[0]?.message;
    if (!choice) return '';
    const content = (choice.content ?? '').trim();
    if (content.length > 0) return content;
    const reasoning = choice.reasoning_content ?? '';
    if (reasoning.length === 0) return '';
    const lines = reasoning.split('\n').map((l) => l.trim()).filter((l) => l.length > 0);
    return lines[lines.length - 1] ?? '';
  } catch (err) {
    console.warn('task-model: request failed', err);
    return '';
  }
}

function resolveEndpoint(
  config: Config,
  fallbackModel?: string,
): { url: string; model: string } {
  if (config.TASK_MODEL_URL) {
    return { url: config.TASK_MODEL_URL, model: 'gemma-3-270m-it' };
  }
  const model = config.FAST_MODEL ?? fallbackModel ?? config.DEFAULT_MODEL;
  return { url: config.LLAMA_SWAP_URL, model };
}