const { test } = require('node:test');
const assert = require('node:assert/strict');

const ENV_KEYS = ['TTS_PROVIDER', 'LITELLM_API_BASE', 'LITELLM_API_KEY', 'ELEVENLABS_API_KEY', 'GOOGLE_VERTEX_PROJECT'];

function withEnv(overrides, fn) {
  const previous = {};
  ENV_KEYS.forEach((key) => { previous[key] = process.env[key]; delete process.env[key]; });
  Object.entries(overrides).forEach(([key, value]) => { process.env[key] = value; });
  try {
    return fn();
  } finally {
    ENV_KEYS.forEach((key) => {
      if (previous[key] === undefined) delete process.env[key];
      else process.env[key] = previous[key];
    });
  }
}

test('TTS provider defaults to LiteLLM when gateway is configured', () => {
  const ttsProvider = require('../src/utils/ttsProvider');
  withEnv({ LITELLM_API_BASE: 'https://llm.example.com' }, () => {
    assert.equal(ttsProvider.getTTSEnvProvider(), 'auto');
    assert.equal(ttsProvider.getTTSProvider(), 'litellm');
  });
});

test('TTS provider respects explicit provider override', () => {
  const ttsProvider = require('../src/utils/ttsProvider');
  withEnv({ TTS_PROVIDER: 'elevenlabs', LITELLM_API_BASE: 'https://llm.example.com' }, () => {
    assert.equal(ttsProvider.getTTSEnvProvider(), 'elevenlabs');
    assert.equal(ttsProvider.getTTSProvider(), 'elevenlabs');
  });
});

test('LiteLLM TTS voice list stays OpenAI-compatible', () => {
  const ttsProvider = require('../src/utils/ttsProvider');
  assert.deepEqual(ttsProvider.getTTSVoiceLists().litellm, [
    'alloy',
    'echo',
    'fable',
    'onyx',
    'nova',
    'shimmer',
    'ash',
    'sage',
    'coral'
  ]);
});

test('TTS model discovery keeps OpenAI speech models only', () => {
  const ttsProvider = require('../src/utils/ttsProvider');
  assert.equal(ttsProvider.isOpenAITTSModel('openai/tts-1'), true);
  assert.equal(ttsProvider.isOpenAITTSModel('openai-tts-1-hd'), true);
  assert.equal(ttsProvider.isOpenAITTSModel('openai-gpt-4o-mini-tts'), true);
  assert.equal(ttsProvider.isOpenAITTSModel('mistral-voxtral-mini-tts'), false);
  assert.equal(ttsProvider.isOpenAITTSModel('vertex-gemini-2.5-flash-tts'), false);
});

test('LiteLLM TTS model extraction filters gateway model objects', () => {
  const ttsProvider = require('../src/utils/ttsProvider');
  assert.deepEqual(ttsProvider.getLiteLLMTTSModels([
    { id: 'openai-tts-1' },
    { id: 'mistral-voxtral-mini-tts' },
    { id: 'openai-gpt-4o-mini-tts' },
    { id: 'vertex-gemini-2.5-flash-tts' },
    { id: 'gpt-4.1' }
  ]), ['openai-tts-1', 'openai-gpt-4o-mini-tts']);
});

test('LiteLLM headers include optional content type without exposing key value', () => {
  const ttsProvider = require('../src/utils/ttsProvider');
  withEnv({ LITELLM_API_KEY: 'secret-token' }, () => {
    assert.deepEqual(ttsProvider.getLiteLLMHeaders('application/json'), {
      'Content-Type': 'application/json',
      Authorization: 'Bearer secret-token'
    });
  });
});