"""
SLMM API Proxy
Forwards /api/slmm/* requests to the SLMM backend service
"""
import httpx
import logging
from fastapi import APIRouter, Request, Response, WebSocket
from fastapi.responses import StreamingResponse
from app.core.config import SLMM_API_URL

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api/slmm", tags=["slmm-proxy"])


@router.api_route("/{path:path}", methods=["GET", "POST", "PUT", "DELETE", "PATCH"])
async def proxy_slmm_request(path: str, request: Request):
    """Proxy HTTP requests to SLMM backend"""
    # Build target URL - rewrite /api/slmm/* to /api/nl43/*
    target_url = f"{SLMM_API_URL}/api/nl43/{path}"

    # Get query params
    query_string = str(request.url.query)
    if query_string:
        target_url += f"?{query_string}"

    logger.info(f"Proxying {request.method} {target_url}")

    # Read request body
    body = await request.body()

    # Forward headers (exclude host)
    headers = {
        key: value
        for key, value in request.headers.items()
        if key.lower() not in ['host', 'content-length']
    }

    async with httpx.AsyncClient(timeout=30.0) as client:
        try:
            # Make proxied request
            response = await client.request(
                method=request.method,
                url=target_url,
                content=body,
                headers=headers
            )

            # Return response
            return Response(
                content=response.content,
                status_code=response.status_code,
                headers=dict(response.headers)
            )
        except httpx.RequestError as e:
            logger.error(f"Proxy request failed: {e}")
            return Response(
                content=f'{{"detail": "SLMM backend unavailable: {str(e)}"}}',
                status_code=502,
                media_type="application/json"
            )


@router.websocket("/{unit_id}/live")
async def proxy_slmm_websocket(websocket: WebSocket, unit_id: str):
    """Proxy WebSocket connections to SLMM backend for live data streaming"""
    await websocket.accept()

    # Build WebSocket URL
    ws_protocol = "ws" if "localhost" in SLMM_API_URL or "127.0.0.1" in SLMM_API_URL else "wss"
    ws_url = SLMM_API_URL.replace("http://", f"{ws_protocol}://").replace("https://", f"{ws_protocol}://")
    ws_target = f"{ws_url}/api/slmm/{unit_id}/live"

    logger.info(f"Proxying WebSocket to {ws_target}")

    async with httpx.AsyncClient() as client:
        try:
            async with client.stream("GET", ws_target) as response:
                async for chunk in response.aiter_bytes():
                    await websocket.send_bytes(chunk)
        except Exception as e:
            logger.error(f"WebSocket proxy error: {e}")
            await websocket.close(code=1011, reason=f"Backend error: {str(e)}")