"""
Forecast API endpoints.

Responsabilidad: Manejar requests de forecasting y delegar a use cases.
"""

from fastapi import APIRouter, Depends, HTTPException, status
from typing import List

from app.api.dependencies import (
    get_forecast_univariate_use_case,
    get_forecast_multi_series_use_case
)
from app.application.use_cases.forecast_use_case import (
    ForecastUnivariateUseCase,
    ForecastMultiSeriesUseCase
)
from app.application.dtos.forecast_dtos import (
    ForecastUnivariateRequestDTO,
    ForecastUnivariateResponseDTO,
    ForecastMultiSeriesRequestDTO,
    ForecastMultiSeriesResponseDTO
)
from app.utils.logger import setup_logger

logger = setup_logger(__name__)

router = APIRouter(prefix="/forecast", tags=["Forecast"])


@router.post(
    "/univariate",
    response_model=ForecastUnivariateResponseDTO,
    status_code=status.HTTP_200_OK,
    summary="Pronóstico univariado",
    description="Genera pronóstico para una serie temporal sin covariables"
)
async def forecast_univariate(
    request: ForecastUnivariateRequestDTO,
    use_case: ForecastUnivariateUseCase = Depends(get_forecast_univariate_use_case)
):
    """
    Pronóstico univariado.
    
    Genera pronóstico probabilístico para una serie temporal simple,
    sin variables exógenas.
    
    Args:
        request: Datos de la serie y parámetros de predicción
        use_case: Caso de uso inyectado
        
    Returns:
        Pronóstico con mediana y cuantiles
        
    Raises:
        HTTPException: Si hay error en la predicción
        
    Example:
        ```json
        {
            "values": [100, 102, 105, 103, 108, 112],
            "prediction_length": 3,
            "freq": "D",
            "quantile_levels": [0.1, 0.5, 0.9]
        }
        ```
    """
    try:
        logger.info(
            f"Forecast univariate request: {len(request.values)} values, "
            f"{request.prediction_length} steps ahead"
        )
        
        # Ejecutar use case
        response = use_case.execute(request)
        
        logger.info(f"Forecast completed: {len(response.timestamps)} predictions")
        return response
        
    except ValueError as e:
        logger.error(f"Validation error: {e}")
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=str(e)
        )
    except Exception as e:
        logger.error(f"Unexpected error in forecast: {e}", exc_info=True)
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Error interno al generar pronóstico"
        )


@router.post(
    "/multi-series",
    response_model=ForecastMultiSeriesResponseDTO,
    status_code=status.HTTP_200_OK,
    summary="Pronóstico multi-series",
    description="Genera pronósticos para múltiples series simultáneamente"
)
async def forecast_multi_series(
    request: ForecastMultiSeriesRequestDTO,
    use_case: ForecastMultiSeriesUseCase = Depends(get_forecast_multi_series_use_case)
):
    """
    Pronóstico para múltiples series.
    
    Genera pronósticos independientes para varias series temporales
    en una sola llamada.
    
    Args:
        request: Lista de series y parámetros
        use_case: Caso de uso inyectado
        
    Returns:
        Lista de pronósticos, uno por cada serie
        
    Example:
        ```json
        {
            "series_list": [
                {"series_id": "sales", "values": [100, 102, 105]},
                {"series_id": "revenue", "values": [200, 205, 210]}
            ],
            "prediction_length": 3,
            "freq": "D"
        }
        ```
    """
    try:
        logger.info(
            f"Forecast multi-series request: {len(request.series_list)} series"
        )
        
        # Ejecutar use case
        response = use_case.execute(request)
        
        logger.info(
            f"Multi-series forecast completed: "
            f"{len(response.forecasts)} forecasts"
        )
        return response
        
    except ValueError as e:
        logger.error(f"Validation error: {e}")
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=str(e)
        )
    except Exception as e:
        logger.error(
            f"Unexpected error in multi-series forecast: {e}",
            exc_info=True
        )
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Error interno al generar pronósticos"
        )