const express = require('express');
const router = express.Router();
const axios = require('axios');
const { litellmClient } = require('../utils/ai');
const { authMiddleware } = require('../middleware/auth');

// TTS_PROVIDER=litellm  → LiteLLM proxy (routes to any OpenAI-compatible TTS)
// TTS_PROVIDER=elevenlabs → ElevenLabs (not HIPAA)
// (auto) LITELLM_API_BASE set → litellm
// (auto) ELEVENLABS_API_KEY set → elevenlabs
function getTTSProvider() {
  var env = process.env.TTS_PROVIDER;
  if (env === 'litellm')   return 'litellm';
  if (env === 'elevenlabs') return 'elevenlabs';
  if (process.env.LITELLM_API_BASE && litellmClient) return 'litellm';
  if (process.env.ELEVENLABS_API_KEY) return 'elevenlabs';
  return 'none';
}

var ttsProvider = getTTSProvider();
console.log('🔊 TTS provider:', ttsProvider);

router.post('/text-to-speech', authMiddleware, async (req, res) => {
  try {
    var text = (req.body.text || '').substring(0, 5000);
    if (!text) return res.status(400).json({ error: 'No text provided' });

    if (ttsProvider === 'litellm') {
      if (!litellmClient) return res.status(400).json({ error: 'LiteLLM not configured. Set LITELLM_API_BASE.' });
      var ttsModel = process.env.LITELLM_TTS_MODEL || 'tts-1';
      var ttsVoice = process.env.LITELLM_TTS_VOICE || 'alloy';
      var mp3 = await litellmClient.audio.speech.create({
        model: ttsModel,
        voice: ttsVoice,
        input: text,
        response_format: 'mp3'
      });
      var buffer = Buffer.from(await mp3.arrayBuffer());
      res.set('Content-Type', 'audio/mpeg');
      return res.send(buffer);
    }

    if (ttsProvider === 'elevenlabs') {
      if (!process.env.ELEVENLABS_API_KEY) return res.status(400).json({ error: 'ElevenLabs not configured' });
      const response = await axios({
        method: 'POST',
        url: 'https://api.elevenlabs.io/v1/text-to-speech/pNInz6obpgDQGcFmaJgB',
        headers: { 'xi-api-key': process.env.ELEVENLABS_API_KEY, 'Content-Type': 'application/json' },
        data: { text: text, model_id: 'eleven_turbo_v2_5', voice_settings: { stability: 0.5, similarity_boost: 0.75 } },
        responseType: 'arraybuffer'
      });
      res.set('Content-Type', 'audio/mpeg');
      return res.send(Buffer.from(response.data));
    }

    res.status(400).json({ error: 'TTS not configured. Set LITELLM_API_BASE or ELEVENLABS_API_KEY.' });
  } catch (err) {
    res.status(500).json({ error: 'TTS failed: ' + err.message });
  }
});

module.exports = router;