from fastapi import APIRouter, Depends, HTTPException, Query, BackgroundTasks
from typing import List, Optional, Dict, Any
from datetime import datetime, date
import structlog

from app.schemas.forecast import (
    ForecastRequest,
    ForecastResponse,
    BatchForecastRequest,
    ForecastPerformanceResponse
)
from app.services.forecast_service import ForecastService
from app.services.messaging import publish_forecast_generated

# Import unified authentication
from shared.auth.decorators import (
    get_current_user_dep,
    get_current_tenant_id_dep
)

router = APIRouter(prefix="/forecasts", tags=["forecasting"])
logger = structlog.get_logger()

@router.post("/generate", response_model=ForecastResponse)
async def generate_forecast(
    request: ForecastRequest,
    background_tasks: BackgroundTasks,
    tenant_id: str = Depends(get_current_tenant_id_dep),
    current_user: Dict[str, Any] = Depends(get_current_user_dep),
):
    """Generate forecast for products"""
    try:
        logger.info("Generating forecast",
                   tenant_id=tenant_id,
                   user_id=current_user["user_id"],
                   products=len(request.products) if request.products else "all")
        
        forecast_service = ForecastService()
        
        # Ensure products belong to tenant
        if request.products:
            valid_products = await forecast_service.validate_products(
                tenant_id, request.products
            )
            if len(valid_products) != len(request.products):
                raise HTTPException(
                    status_code=400,
                    detail="Some products not found or not accessible"
                )
        
        # Generate forecast
        forecast = await forecast_service.generate_forecast(
            tenant_id=tenant_id,
            request=request,
            user_id=current_user["user_id"]
        )
        
        # Publish event
        background_tasks.add_task(
            publish_forecast_generated,
            forecast_id=forecast.id,
            tenant_id=tenant_id,
            user_id=current_user["user_id"]
        )
        
        return forecast
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error("Failed to generate forecast", error=str(e))
        raise HTTPException(status_code=500, detail=str(e))