const OPENAI_MODELS_BY_QUALITY = {
  easy: 'whisper-1',
  medium: 'gpt-4o-mini-transcribe',
  hard: 'gpt-4o-transcribe',
};

const PIPER_LENGTH_SCALE_BY_QUALITY = {
  easy: '1.15',
  medium: '1.0',
  hard: '0.9',
};

function normalizeOpenAiBaseUrl(url) {
  const value = String(url || '').trim();
  if (!value) return 'https://api.openai.com/v1';
  return value.replace(/\/+$/, '');
}

function resolveSttModel(config) {
  const quality = String(config?.quality || 'medium').toLowerCase();
  const customModel = String(config?.model || '').trim();
  return customModel || OPENAI_MODELS_BY_QUALITY[quality] || OPENAI_MODELS_BY_QUALITY.medium;
}

export function isSpeechToTextConfigured(entrySettings) {
  const cfg = entrySettings?.tools?.speechToText || {};
  if (String(cfg.provider || 'openai') !== 'openai') return false;
  return !!String(cfg.apiKey || '').trim();
}

export function isTextToSpeechConfigured(entrySettings) {
  const cfg = entrySettings?.tools?.textToSpeech || {};
  const provider = String(cfg.provider || 'browser');
  if (provider === 'browser') return true;
  if (provider === 'piper-http') return !!String(cfg.piperBaseUrl || '').trim();
  if (provider === 'openai') return !!String(cfg.apiKey || '').trim();
  return false;
}

export async function transcribeAudioBySettings(audioBlob, entrySettings) {
  const cfg = entrySettings?.tools?.speechToText || {};
  const provider = String(cfg.provider || 'openai');
  if (provider !== 'openai') {
    throw new Error('Поддерживается только провайдер OpenAI для распознавания.');
  }

  const apiKey = String(cfg.apiKey || '').trim();
  if (!apiKey) throw new Error('Не заполнен OpenAI API key.');

  const model = resolveSttModel(cfg);
  const baseUrl = normalizeOpenAiBaseUrl(cfg.baseUrl);

  const form = new FormData();
  form.append('model', model);
  form.append('language', 'ru');
  form.append('response_format', 'json');
  form.append('file', audioBlob, 'voice-input.webm');

  const response = await fetch(`${baseUrl}/audio/transcriptions`, {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${apiKey}`,
    },
    body: form,
  });

  if (!response.ok) {
    const body = await response.text().catch(() => '');
    throw new Error(`Ошибка STT API (${response.status}): ${body || 'unknown error'}`);
  }

  const payload = await response.json();
  const text = String(payload?.text || '').trim();
  if (!text) throw new Error('Пустой ответ распознавания.');
  return text;
}

export function createMicrophoneRecorder() {
  const Ctx = window.AudioContext || window.webkitAudioContext;
  let stream = null;
  let recorder = null;
  let startedAtMs = 0;
  let chunks = [];
  let timerId = 0;
  let level = 0;
  let analyser = null;
  let rafId = 0;

  async function start(onTick) {
    stream = await navigator.mediaDevices.getUserMedia({ audio: true, video: false });
    recorder = new MediaRecorder(stream, { mimeType: 'audio/webm' });
    startedAtMs = Date.now();
    chunks = [];

    recorder.ondataavailable = (event) => {
      if (event?.data?.size > 0) chunks.push(event.data);
    };
    recorder.start(250);

    timerId = window.setInterval(() => {
      if (typeof onTick === 'function') {
        onTick({
          elapsedMs: Date.now() - startedAtMs,
          level,
        });
      }
    }, 120);

    if (Ctx) {
      const audioCtx = new Ctx();
      const source = audioCtx.createMediaStreamSource(stream);
      analyser = audioCtx.createAnalyser();
      analyser.fftSize = 256;
      source.connect(analyser);
      const data = new Uint8Array(analyser.frequencyBinCount);
      const read = () => {
        if (!analyser) return;
        analyser.getByteFrequencyData(data);
        let sum = 0;
        for (let i = 0; i < data.length; i += 1) sum += data[i];
        level = data.length > 0 ? Math.max(0, Math.min(1, (sum / data.length) / 255)) : 0;
        rafId = window.requestAnimationFrame(read);
      };
      read();
    }
  }

  async function stop() {
    if (!recorder) return null;
    const blob = await new Promise((resolve) => {
      recorder.onstop = () => resolve(new Blob(chunks, { type: 'audio/webm' }));
      recorder.stop();
    });
    cleanup();
    return blob;
  }

  function cancel() {
    try {
      recorder?.stop();
    } catch {
      // ignore
    }
    cleanup();
  }

  function cleanup() {
    if (timerId) window.clearInterval(timerId);
    if (rafId) window.cancelAnimationFrame(rafId);
    timerId = 0;
    rafId = 0;
    analyser = null;
    if (stream) {
      stream.getTracks().forEach((track) => {
        try {
          track.stop();
        } catch {
          // ignore
        }
      });
    }
    stream = null;
    recorder = null;
  }

  return { start, stop, cancel };
}

export async function speakTextBySettings(text, entrySettings) {
  const value = String(text || '').trim();
  if (!value) return;

  const cfg = entrySettings?.tools?.textToSpeech || {};
  const provider = String(cfg.provider || 'browser');

  if (provider === 'browser') {
    const utt = new SpeechSynthesisUtterance(value);
    utt.lang = 'ru-RU';
    const selected = String(cfg.voice || '').trim();
    if (selected) {
      const voice = window.speechSynthesis.getVoices().find((v) => v.name === selected);
      if (voice) utt.voice = voice;
    }
    window.speechSynthesis.speak(utt);
    return;
  }

  if (provider === 'piper-http') {
    const baseUrl = String(cfg.piperBaseUrl || '').trim().replace(/\/+$/, '');
    if (!baseUrl) throw new Error('Не указан адрес Piper HTTP.');
    const quality = String(cfg.quality || 'medium').toLowerCase();
    const voice = String(cfg.voice || '').trim();
    const lengthScale = PIPER_LENGTH_SCALE_BY_QUALITY[quality] || PIPER_LENGTH_SCALE_BY_QUALITY.medium;
    const resp = await fetch(`${baseUrl}/api/tts`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({
        text: value,
        voice,
        quality,
        length_scale: lengthScale,
      }),
    });
    if (!resp.ok) throw new Error(`Piper HTTP недоступен (${resp.status}).`);
    const blob = await resp.blob();
    const audioUrl = URL.createObjectURL(blob);
    const audio = new Audio(audioUrl);
    await audio.play();
    window.setTimeout(() => URL.revokeObjectURL(audioUrl), 30000);
    return;
  }

  if (provider === 'openai') {
    const apiKey = String(cfg.apiKey || '').trim();
    if (!apiKey) throw new Error('Не заполнен API key для OpenAI TTS.');
    const model = String(cfg.model || '').trim() || 'gpt-4o-mini-tts';
    const baseUrl = normalizeOpenAiBaseUrl(cfg.externalBaseUrl || cfg.baseUrl || 'https://api.openai.com/v1');
    const voice = String(cfg.voice || '').trim() || 'alloy';
    const resp = await fetch(`${baseUrl}/audio/speech`, {
      method: 'POST',
      headers: {
        Authorization: `Bearer ${apiKey}`,
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        model,
        voice,
        input: value,
        format: 'mp3',
      }),
    });
    if (!resp.ok) throw new Error(`OpenAI TTS недоступен (${resp.status}).`);
    const blob = await resp.blob();
    const audioUrl = URL.createObjectURL(blob);
    const audio = new Audio(audioUrl);
    await audio.play();
    window.setTimeout(() => URL.revokeObjectURL(audioUrl), 30000);
    return;
  }

  throw new Error('Неизвестный провайдер озвучки.');
}