app/services/tts_client.py

import asyncio

import httpx

from app.core.exceptions import GenerationError


class TTSClient:
    def __init__(self, tts_space_url: str, timeout_seconds: float) -> None:
        self._tts_space_url = tts_space_url.rstrip("/")
        self._timeout_seconds = timeout_seconds

    @property
    def is_configured(self) -> bool:
        return bool(self._tts_space_url)

    async def synthesize(self, text: str, voice: str = "am_adam") -> bytes:
        if not self.is_configured:
            raise GenerationError("TTS client is not configured")

        async def _call() -> bytes:
            async with httpx.AsyncClient(timeout=self._timeout_seconds) as client:
                response = await client.post(
                    f"{self._tts_space_url}/synthesize",
                    json={"text": text, "voice": voice},
                    headers={"Content-Type": "application/json"},
                )
                response.raise_for_status()
                audio_bytes = response.content
                if not audio_bytes:
                    raise GenerationError("TTS response was empty")
                return audio_bytes

        try:
            return await asyncio.wait_for(_call(), timeout=self._timeout_seconds)
        except TimeoutError as exc:
            raise GenerationError("TTS request timed out") from exc
        except httpx.HTTPStatusError as exc:
            raise GenerationError(
                "TTS upstream returned an error",
                context={"status_code": exc.response.status_code},
            ) from exc
        except GenerationError:
            raise
        except Exception as exc:
            raise GenerationError("TTS synthesis failed", context={"error": str(exc)}) from exc