from fastapi import APIRouter
from typing import Optional, List, Dict, Any
from pydantic import BaseModel, Field

from common.log.module_logger import ModuleLogger
from backend.services.prometheus_metrics_service import PrometheusMetricsService


class MetricDataPoint(BaseModel):
    """Single data point in a time series."""
    date: str = Field(..., description="Timestamp in ISO format")
    value: Optional[float] = Field(None, description="Metric value")
    labels: Optional[Dict[str, str]] = Field(None, description="Metric labels")


class MetricTimeSeriesResponse(BaseModel):
    """Response model for metric time series data."""
    metric_name: str = Field(..., description="Name of the queried metric")
    data_points: List[MetricDataPoint] = Field(..., description="List of data points")
    total_points: int = Field(..., description="Total number of data points")
    time_range: Dict[str, str] = Field(..., description="Start and end time of the query")
    step: str = Field("1h", description="Query resolution step")


class MetricQueryRequest(BaseModel):
    """Request model for metric query."""
    product_id: str = Field(..., description="Product ID to identify which product's metrics to query")
    metric_name: str = Field(..., description="Name of the metric to query")
    start_time: str = Field(..., description="Start time in ISO format or RFC3339")
    end_time: str = Field(..., description="End time in ISO format or RFC3339")
    step: str = Field("1h", description="Query resolution step (e.g., 1m, 5m, 1h)")


router = APIRouter()

# Initialize service and logger
prometheus_service = PrometheusMetricsService()
module_logger = ModuleLogger(__file__)


@router.post("/prometheus/metrics_query", response_model=MetricTimeSeriesResponse)
async def metrics_query(
        request: MetricQueryRequest
):
    """
    Query metrics time series data.
    
    Returns XY curve data (time series) for the specified metric within the given time range.
    """
    await module_logger.log_info(
        f"Querying metric '{request.metric_name}' from product '{request.product_id}' from {request.start_time} to {request.end_time}")

    # Query the metric data
    data_points = await prometheus_service.query_metric_by_time_range(
        product_id=request.product_id,
        metric_name=request.metric_name,
        start_time=request.start_time,
        end_time=request.end_time,
        step=request.step
    )

    # Format response
    response = MetricTimeSeriesResponse(
        metric_name=request.metric_name,
        data_points=[
            MetricDataPoint(
                date=point["date"],
                value=point["value"],
                labels=point["labels"]
            )
            for point in data_points
        ],
        total_points=len(data_points),
        time_range={
            "start": request.start_time,
            "end": request.end_time
        },
        step=request.step
    )

    await module_logger.log_info(
        f"Successfully queried metric '{request.metric_name}' with {len(data_points)} data points")
    return response