vegasco/src/Vegasco.Server.Api/Consumptions/GetConsumptions.cs

using Microsoft.AspNetCore.Http.HttpResults;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using Vegasco.Server.Api.Cars;
using Vegasco.Server.Api.Persistence;

namespace Vegasco.Server.Api.Consumptions;

public static class GetConsumptions
{
	public class ApiResponse
	{
		public IEnumerable<ResponseDto> Consumptions { get; set; } = [];
	}

	public record ResponseDto(
		Guid Id,
		DateTimeOffset DateTime,
		double Distance,
		double Amount,
		CarDto Car,
		double? LiterPer100Km);

	public record CarDto(
		Guid Id,
		string Name)
	{
		public static CarDto FromCar(Car car)
		{
			return new CarDto(car.Id.Value, car.Name);
		}
	}

	public class Request
	{
		[FromQuery(Name = "page")] public int? Page { get; set; }
		[FromQuery(Name = "pageSize")] public int? PageSize { get; set; }
	}

	public static RouteHandlerBuilder MapEndpoint(IEndpointRouteBuilder builder)
	{
		return builder
			.MapGet("consumptions", Endpoint)
			.WithDescription("Returns all consumption entries")
			.WithTags("Consumptions")
			.Produces<ApiResponse>();
	}

	private static async Task<Ok<ApiResponse>> Endpoint(
		[AsParameters] Request request,
		ApplicationDbContext dbContext,
		CancellationToken cancellationToken)
	{
		List<Consumption> consumptions = await dbContext.Consumptions
			.OrderByDescending(x => x.DateTime)
			.Include(x => x.Car)
			.ToListAsync(cancellationToken);

		List<ResponseDto> responses = [];

		for (int i = 0; i < consumptions.Count; i++)
		{
			Consumption consumption = consumptions[i];

			double? literPer100Km = null;

			bool isLast = i == consumptions.Count - 1;
			if (!isLast)
			{
				Consumption previousConsumption = consumptions[i + 1];
				double distanceDiff = consumption.Distance - previousConsumption.Distance;
				literPer100Km = consumption.Amount / (distanceDiff / 100);
			}

			responses.Add(new ResponseDto(
				consumption.Id.Value,
				consumption.DateTime,
				consumption.Distance,
				consumption.Amount,
				CarDto.FromCar(consumption.Car),
				literPer100Km));
		}

		ApiResponse apiResponse = new() { Consumptions = responses };
		return TypedResults.Ok(apiResponse);
	}
}