my_voice_assistant_v3_jamulix/app/api/chat.py

from io import BytesIO

from fastapi import APIRouter, Depends, HTTPException, Query
from fastapi.responses import JSONResponse, StreamingResponse

from app.config import settings
from app.errors import RoutingError
from app.auth import require_user
from app.store import User, SessionOwnershipError
from app.dependencies import (
    resolve_route,
    build_orchestrator,
    resolve_output_endpoint,
)
from app.schemas import ChatRequest

router = APIRouter()


def _route_headers(route) -> dict:
    return {
        "X-Input-Endpoint": route.input_endpoint,
        "X-Output-Endpoint": route.output_endpoint,
        "X-STT-Provider": route.stt_provider,
        "X-LLM-Provider": route.llm_provider,
        "X-TTS-Provider": route.tts_provider,
    }


@router.post("/chat")
async def chat(
    payload: ChatRequest,
    debug: bool = Query(
        default=False,
        description="Return JSON trace instead of audio response",
    ),
    session_id: str | None = Query(
        default=None,
        description="Optional session id to apply a stored route",
    ),
    user: User = Depends(require_user),
):
    overrides = {
        "input_endpoint": payload.input_endpoint,
        "output_endpoint": payload.output_endpoint,
        "language": payload.language,
        "stt_provider": payload.stt_provider,
        "llm_provider": payload.llm_provider,
        "tts_provider": payload.tts_provider,
    }
    voice = payload.voice or settings.openrouter_tts_voice

    try:
        route = resolve_route(user, session_id, overrides)
        orchestrator = build_orchestrator(route)
        output = await resolve_output_endpoint(route)
    except SessionOwnershipError as exc:
        raise HTTPException(status_code=403, detail=str(exc))
    except RoutingError as exc:
        raise HTTPException(status_code=422, detail=str(exc))

    try:
        trace, audio = await orchestrator.chat_text(
            payload.text,
            language=route.language,
            voice=voice,
            output=output,
        )

        if debug:
            return JSONResponse(
                content={
                    "ok": True,
                    "voice": voice,
                    "route": route.as_dict(),
                    "trace": {
                        "raw_transcript": trace.raw_transcript,
                        "cleaned_transcript": trace.cleaned_transcript,
                        "semantic_response": trace.semantic_response,
                        "spoken_response": trace.spoken_response,
                        "tts_ready_text": trace.tts_ready_text,
                    },
                }
            )

        headers = {
            "Content-Language": route.language,
            "X-Audio-Format": "pcm",
            "X-Audio-Sample-Rate": "24000",
            "X-Audio-Channels": "1",
            "X-Audio-Sample-Width": "16",
            **_route_headers(route),
        }
        return StreamingResponse(BytesIO(audio), media_type="audio/pcm", headers=headers)

    except Exception as exc:
        raise HTTPException(status_code=502, detail=str(exc))