import io
import wave
import struct
from openai import AsyncOpenAI
from app.ai.sarvam_client import SarvamClient
from app.config import OPENAI_API_KEY
from app.voice.audio_manager import AudioManager


class TextToSpeechService:

    def __init__(self):
        self.sarvam = SarvamClient()
        self.openai_key = OPENAI_API_KEY

    async def synthesize(
        self,
        text: str,
        language_code: str = "en-IN",
    ) -> str:
        # Clean any accidental formatting before voice synthesis
        cleaned_text = (
            text.replace("(", "")
            .replace(")", "")
            .replace("*", "")
            .replace("#", "")
            .replace("- ", "")
            .strip()
        )

        # 1. Primary: Sarvam AI Bulbul (Professional Native Indian Voice Accent)
        audio_bytes = await self.sarvam.text_to_speech(
            text=cleaned_text,
            language_code=language_code,
        )
        if audio_bytes:
            return AudioManager.save_audio(audio_bytes, "wav")

        # 2. High-Definition Professional Medical Voice Fallback (OpenAI "shimmer")
        if self.openai_key and self.openai_key != "your_openai_key":
            client = AsyncOpenAI(api_key=self.openai_key, timeout=10.0)
            try:
                resp = await client.audio.speech.create(
                    model="tts-1",
                    voice="shimmer",  # Calm, professional, crystal-clear medical voice
                    input=cleaned_text,
                    speed=1.0,
                )
                return AudioManager.save_audio(resp.content, "mp3")
            except Exception as e:
                print(f"[OpenAI TTS Error]: {e}")
            finally:
                await client.close()

        # 3. Fallback tone
        fallback_data = self._generate_fallback_wav()
        return AudioManager.save_audio(fallback_data, "wav")

    def _generate_fallback_wav(self) -> bytes:
        buf = io.BytesIO()
        with wave.open(buf, "wb") as wf:
            wf.setnchannels(1)
            wf.setsampwidth(2)
            wf.setframerate(16000)
            data = [int(1000 * (i % 32 < 16)) for i in range(4000)]
            wf.writeframes(struct.pack(f"<{len(data)}h", *data))
        return buf.getvalue()