import json

from fastapi import APIRouter, Request, status
from fastapi.responses import JSONResponse

from core.api.publisher import IngestionQueueFull, KafkaPublishError
from core.domain.errors import CDRProcessingError
from core.domain.validation import parse_raw_cdr


router = APIRouter()


@router.post(
    "/cdr/raw",
    status_code=status.HTTP_202_ACCEPTED,
)
async def ingest_raw_cdr(request: Request) -> JSONResponse:
    try:
        payload = await request.json()

    except (json.JSONDecodeError, UnicodeDecodeError) as exc:
        return JSONResponse(
            status_code=status.HTTP_400_BAD_REQUEST,
            content={
                "error": "invalid_json",
                "detail": str(exc),
            },
        )

    if not isinstance(payload, dict):
        return JSONResponse(
            status_code=status.HTTP_400_BAD_REQUEST,
            content={
                "error": "invalid_payload",
                "detail": "JSON payload must be an object.",
            },
        )

    try:
        raw_cdr = parse_raw_cdr(payload)

    except CDRProcessingError as exc:
        return JSONResponse(
            status_code=status.HTTP_400_BAD_REQUEST,
            content={
                "error": exc.reason.value,
                "detail": exc.detail,
                "failed_field": exc.failed_field,
            },
        )

    try:
        await request.app.state.publisher.publish(
            payload,
            key=raw_cdr.raw_id,
        )

    except IngestionQueueFull:
        return JSONResponse(
            status_code=status.HTTP_429_TOO_MANY_REQUESTS,
            content={
                "error": "backpressure",
                "detail": "Ingestion queue is full.",
            },
        )

    except KafkaPublishError as exc:
        return JSONResponse(
            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
            content={
                "error": "kafka_unavailable",
                "detail": str(exc),
            },
        )

    return JSONResponse(
        status_code=status.HTTP_202_ACCEPTED,
        content={
            "status": "accepted",
            "raw_id": raw_cdr.raw_id,
        },
    )