import express from 'express';
import cors from 'cors';
import fetch from 'node-fetch';

const app = express();

// CORS
app.use(cors({
  origin: '*',
  methods: ['GET', 'POST', 'OPTIONS'],
  allowedHeaders: ['Content-Type', 'Authorization']
}));
app.use(express.json());
app.options('*', (req, res) => res.sendStatus(204));

// Список моделей
app.get(['/models', '/v1/models'], (req, res) => {
  res.json({
    object: 'list',
    data: [
      // OpenAI — GPT‑4.1 / 4.5
      { id: 'gpt-4.1',                    object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4.1-2025-04-14',         object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4.1-mini',               object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4.1-mini-2025-04-14',    object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4.1-nano',               object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4.1-nano-2025-04-14',    object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4.5-preview',            object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4.5-preview-2025-02-27', object: 'model', created: 0, owned_by: 'helix' },

      // OpenAI — GPT‑4o
      { id: 'gpt-4o',                           object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4o-2024-05-13',                object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4o-2024-08-06',                object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4o-2024-11-20',                object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4o-mini',                      object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4o-mini-2024-07-18',           object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4o-search-preview',            object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4o-search-preview-2025-03-11', object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4o-mini-search-preview',       object: 'model', created: 0, owned_by: 'helix' },
      { id: 'gpt-4o-mini-search-preview-2025-03-11', object: 'model', created: 0, owned_by: 'helix' },

      // Helix — GPT‑3.5 Turbo
      { id: 'gpt-3.5-turbo', object: 'model', created: 0, owned_by: 'helix' }
    ]
  });
});

// Прокси для чата
app.post(['/chat/completions', '/v1/chat/completions'], async (req, res) => {
  const {
    model,
    messages = [],
    stream = false,
    temperature,
    top_p,
    presence_penalty,
    frequency_penalty,
    ...rest
  } = req.body;

  // Заменили префиксы "用户：" и "AI：" на английские
  const historyText = messages
    .map(m => (m.role === 'user' ? 'User: ' : 'Assistant: ') + m.content)
    .join('\n');

  const helixPayload = {
    type: 'text',
    stream,
    provider: getProvider(model),
    model,
    messages: [
      {
        role: 'user',
        content: { content_type: 'text', parts: [historyText] }
      }
    ],
    temperature,
    top_p,
    presence_penalty,
    frequency_penalty,
    ...rest
  };

  // Отправляем в Helix
  const helixRes = await fetch('https://app.tryhelix.ai/api/v1/sessions/chat', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      Authorization: req.header('authorization') || ''
    },
    body: JSON.stringify(helixPayload)
  });

  if (!stream) {
    const data = await helixRes.json();
    const reply = data?.choices?.[0]?.message?.content ?? '';
    return res.status(helixRes.status).json({
      id: `chatcmpl-proxy-${data.id ?? Date.now()}`,
      object: 'chat.completion',
      created: Math.floor(Date.now() / 1000),
      model,
      choices: [
        {
          index: 0,
          message: { role: 'assistant', content: reply },
          finish_reason: 'stop'
        }
      ]
    });
  }

  // Если нужен стрим — прокидываем SSE напрямую
  res.status(helixRes.status);
  res.set('Content-Type', 'text/event-stream');
  helixRes.body.pipe(res);
});

function getProvider(m) {
  if (/^gpt-[34]|^gpt-3\.5/.test(m)) return 'openai';
  if (/^(llama|phi|aya|gemma|deepseek|qwen)/.test(m)) return 'helix';
  return 'togetherai';
}

const PORT = process.env.PORT || 7860;
app.listen(PORT, () => {
  console.log(`🚀 Server listening on port ${PORT}`);
});