# ================================================================
# gateway/app/routes/data.py
# ================================================================
"""Data service routes for API Gateway"""

from fastapi import APIRouter, Request, Depends, HTTPException
from fastapi.responses import StreamingResponse
import httpx
import structlog

from app.core.config import settings
from app.core.auth import verify_token

logger = structlog.get_logger()
router = APIRouter()

@router.api_route("/sales/{path:path}", methods=["GET", "POST", "PUT", "DELETE"])
async def proxy_sales(request: Request, path: str, current_user: dict = Depends(verify_token)):
    """Proxy sales data requests to data service"""
    return await _proxy_request(request, f"/api/v1/sales/{path}")

@router.api_route("/weather/{path:path}", methods=["GET", "POST"])
async def proxy_weather(request: Request, path: str, current_user: dict = Depends(verify_token)):
    """Proxy weather requests to data service"""
    return await _proxy_request(request, f"/api/v1/weather/{path}")

@router.api_route("/traffic/{path:path}", methods=["GET", "POST"])
async def proxy_traffic(request: Request, path: str, current_user: dict = Depends(verify_token)):
    """Proxy traffic requests to data service"""
    return await _proxy_request(request, f"/api/v1/traffic/{path}")

async def _proxy_request(request: Request, target_path: str):
    """Proxy request to data service"""
    try:
        url = f"{settings.DATA_SERVICE_URL}{target_path}"
        
        # Forward headers (including auth)
        headers = dict(request.headers)
        headers.pop("host", None)  # Remove host header
        
        # Get request body if present
        body = None
        if request.method in ["POST", "PUT", "PATCH"]:
            body = await request.body()
        
        async with httpx.AsyncClient(timeout=30.0) as client:
            response = await client.request(
                method=request.method,
                url=url,
                params=request.query_params,
                headers=headers,
                content=body
            )
            
            # Return streaming response for large payloads
            if int(response.headers.get("content-length", 0)) > 1024:
                return StreamingResponse(
                    iter([response.content]),
                    status_code=response.status_code,
                    headers=dict(response.headers),
                    media_type=response.headers.get("content-type")
                )
            else:
                return response.json() if response.headers.get("content-type", "").startswith("application/json") else response.content
                
    except httpx.RequestError as e:
        logger.error("Data service request failed", error=str(e))
        raise HTTPException(status_code=503, detail="Data service unavailable")
    except Exception as e:
        logger.error("Unexpected error in data proxy", error=str(e))
        raise HTTPException(status_code=500, detail="Internal server error")