using System;

using System.Collections.Generic;

using System.Linq;

using Microsoft.EntityFrameworkCore;

​

// Models

public class TeslaCar

{

    public int Id { get; set; }

    public string Model { get; set; } = string.Empty;

    public decimal HourlyRate { get; set; }

    public decimal PerKmRate { get; set; }

}

​

public class Customer

{

    public int Id { get; set; }

    public string FullName { get; set; } = string.Empty;

    public string Email { get; set; } = string.Empty;

}

​

public class Rental

{

    public int Id { get; set; }

    public int CustomerId { get; set; }

    public int TeslaCarId { get; set; }

    public DateTime RentalStart { get; set; }

    public DateTime? RentalEnd { get; set; }

    public int? KilometersDriven { get; set; }

    public decimal? TotalPayment { get; set; }

​

    public Customer? Customer { get; set; }

    public TeslaCar? TeslaCar { get; set; }

}

​

// Database Context

public class RentalDbContext : DbContext

{

    public DbSet<TeslaCar> TeslaCars { get; set; }

    public DbSet<Customer> Customers { get; set; }

    public DbSet<Rental> Rentals { get; set; }

​

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)

    {

        optionsBuilder.UseSqlite("Data Source=tesla_rental.db");

    }

​

    protected override void OnModelCreating(ModelBuilder modelBuilder)

    {

        base.OnModelCreating(modelBuilder);

​

        modelBuilder.Entity<TeslaCar>().HasData(

            new TeslaCar { Id = 1, Model = "Model 3", HourlyRate = 15, PerKmRate = 0.5M },

            new TeslaCar { Id = 2, Model = "Model Y", HourlyRate = 20, PerKmRate = 0.7M }

        );

    }

}

​

// Services

public class CustomerService

{

    public Customer RegisterCustomer(string fullName, string email)

    {

        using var context = new RentalDbContext();

        var customer = new Customer { FullName = fullName, Email = email };

        context.Customers.Add(customer);

        context.SaveChanges();

        return customer;

    }

}

​

public class RentalService

{

    public List<TeslaCar> GetAvailableCars()

    {

        using var context = new RentalDbContext();

        return context.TeslaCars.ToList();

    }

​

    public Rental StartRental(int customerId, int carId)

    {

        using var context = new RentalDbContext();

        var rental = new Rental

        {

            CustomerId = customerId,

            TeslaCarId = carId,

            RentalStart = DateTime.Now

        };

        context.Rentals.Add(rental);

        context.SaveChanges();

        return rental;

    }

​

    public Rental EndRental(int rentalId, int kilometersDriven)

    {

        using var context = new RentalDbContext();

        var rental = context.Rentals

            .Include(r => r.TeslaCar)

            .FirstOrDefault(r => r.Id == rentalId);

​

        if (rental == null || rental.RentalEnd != null)

            throw new Exception("Rental not found or already ended!");

​

        rental.RentalEnd = DateTime.Now;

        rental.KilometersDriven = kilometersDriven;

​

        var hours = (rental.RentalEnd.Value - rental.RentalStart).TotalHours;

        rental.TotalPayment = (decimal)hours * rental.TeslaCar!.HourlyRate +

                              kilometersDriven * rental.TeslaCar.PerKmRate;

​

        context.SaveChanges();

        return rental;

    }

}

​

// Main Program

class Program

{

    static void Main(string[] args)

    {

        using var context = new RentalDbContext();

        context.Database.EnsureCreated();

​

        var customerService = new CustomerService();

        var rentalService = new RentalService();

​

        // Register a new customer

        var customer = customerService.RegisterCustomer("John Doe", "john.doe@example.com");

        Console.WriteLine($"Customer registered: {customer.FullName} ({customer.Email})");

​

        // List available Tesla cars

        var cars = rentalService.GetAvailableCars();

        Console.WriteLine("Available Tesla cars:");

        foreach (var car in cars)

        {

            Console.WriteLine($"- {car.Model}: {car.HourlyRate} EUR/h, {car.PerKmRate} EUR/km");

        }

​

        // Start a rental

        var rental = rentalService.StartRental(customer.Id, cars.First().Id);

        Console.WriteLine($"Rental started for customer {customer.FullName} with car {cars.First().Model} at {rental.RentalStart}");

​

        // Simulate rental ending

        var endedRental = rentalService.EndRental(rental.Id, 100);

        Console.WriteLine($"Rental ended. Total payment: {endedRental.TotalPayment} EUR");

    }

}

​