from fastapi import APIRouter, HTTPException
from typing import Optional
from decimal import Decimal

from database import get_session
from models import Vehicle, FuelRecord
from schemas import (
    VehicleCreate,
    VehicleUpdate,
    VehicleDelete,
    VehicleResponse,
    VehicleStats,
)


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


@router.get("/list", response_model=list[VehicleResponse])
def get_vehicles():
    """获取所有车辆列表（排除已删除）"""
    with get_session() as session:
        vehicles = (
            session.query(Vehicle)
            .filter(Vehicle.is_deleted == False)
            .order_by(Vehicle.created_at.desc())
            .all()
        )
        return vehicles


@router.post("/create", response_model=VehicleResponse)
def create_vehicle(vehicle: VehicleCreate):
    """添加新车辆"""
    with get_session() as session:
        db_vehicle = Vehicle(
            name=vehicle.name,
            purchase_date=vehicle.purchase_date,
            initial_mileage=vehicle.initial_mileage,
        )
        session.add(db_vehicle)
        session.commit()
        session.refresh(db_vehicle)
        return db_vehicle


@router.post("/update", response_model=VehicleResponse)
def update_vehicle(vehicle: VehicleUpdate):
    """更新车辆信息"""
    with get_session() as session:
        db_vehicle = session.query(Vehicle).filter(Vehicle.id == vehicle.id).first()
        if not db_vehicle:
            raise HTTPException(status_code=404, detail="Vehicle not found")

        if vehicle.name is not None:
            db_vehicle.name = vehicle.name
        if vehicle.purchase_date is not None:
            db_vehicle.purchase_date = vehicle.purchase_date
        if vehicle.initial_mileage is not None:
            db_vehicle.initial_mileage = vehicle.initial_mileage

        session.commit()
        session.refresh(db_vehicle)
        return db_vehicle


@router.post("/delete")
def delete_vehicle(vehicle: VehicleDelete):
    """软删除车辆"""
    with get_session() as session:
        db_vehicle = (
            session.query(Vehicle)
            .filter(Vehicle.id == vehicle.id, Vehicle.is_deleted == False)
            .first()
        )
        if not db_vehicle:
            raise HTTPException(status_code=404, detail="Vehicle not found")

        db_vehicle.is_deleted = True
        session.commit()
        return {"message": "Vehicle deleted successfully"}


@router.get("/stats", response_model=VehicleStats)
def get_vehicle_stats(vehicle_id: int):
    """获取车辆统计信息"""
    with get_session() as session:
        vehicle = (
            session.query(Vehicle)
            .filter(Vehicle.id == vehicle_id, Vehicle.is_deleted == False)
            .first()
        )
        if not vehicle:
            raise HTTPException(status_code=404, detail="Vehicle not found")

        # 获取所有未删除的加油记录
        fuel_records = (
            session.query(FuelRecord)
            .filter(FuelRecord.vehicle_id == vehicle_id, FuelRecord.is_deleted == False)
            .order_by(FuelRecord.date.asc())
            .all()
        )

        # 计算总里程
        if fuel_records:
            latest_mileage = max(r.mileage for r in fuel_records)
            total_mileage = latest_mileage - vehicle.initial_mileage
        else:
            total_mileage = 0

        # 计算总油费和总加油量（只算加满的记录）
        total_fuel_cost = sum(float(r.total_cost) for r in fuel_records)
        total_fuel_amount = sum(
            float(r.fuel_amount) for r in fuel_records if r.is_full_tank
        )

        # 计算平均油耗
        avg_fuel_consumption = None
        if total_mileage > 0 and total_fuel_amount > 0:
            avg_fuel_consumption = round((total_fuel_amount / total_mileage) * 100, 2)

        return VehicleStats(
            total_mileage=total_mileage,
            total_fuel_cost=round(total_fuel_cost, 2),
            total_fuel_amount=round(total_fuel_amount, 2),
            avg_fuel_consumption=avg_fuel_consumption,
        )