using System;

public class Program

{

    public static void Main()

    {

        var car = new Car()

        {

            Make = "Ford",

            AgeInMonths = 36,

            PurchaseValue = 35000m,

            NumberOfMiles = 50000,

            NumberOfCollisions = 1,

            NumberOfPreviousOwners = 1,

        };

        var expectedCorrectEstimate = 24813.4m;

        var calculatedEstValue = new PriceDeterminator().DetermineCarPrice(car);

        if (expectedCorrectEstimate == calculatedEstValue)

        {

            Console.WriteLine($"Calculated value was correct: {calculatedEstValue}");

        }

        else

        {

            Console.WriteLine($"Calculated value should have been: {expectedCorrectEstimate} but returned: {calculatedEstValue}");

        }       

    }

}

​

public class Car

{

    public decimal PurchaseValue { get; set; }

    public int AgeInMonths { get; set; }

    public int NumberOfMiles { get; set; }

    public int NumberOfPreviousOwners { get; set; }

    public int NumberOfCollisions { get; set; }

    public string Make { get; set; }

}

​

/*

 Write A PriceDeterminator for a used car given the following rules that reduce a car's Purchase value, in this order:

 1) Age: Given the number of months of age, reduce its value one-half (0.5) percent.

         After 10 years, it's value cannot be reduced further by age. This is not cumulative.

2) Miles: For every 1,000 miles on the car, reduce its value by one-fifth of a percent (0.2). Do not consider remaining miles.

            After 150,000 miles, it's value cannot be reduced further by miles.

​

3) Number of Owners: If the car has had more than 2 previous owners, reduce its value by twenty-five (25) percent.

                     If the car has had no previous owners, add ten (10) percent of the FINAL car value at the end (after #5 below).

4) Accidents: Remove two (2) percent of it's the value for every accident/collision, up to five (5) accidents.

​

5) Resell Value: If the Make is Toyota, add 5%.  If the Make is Ford, subtract $500.

​

6) Min. Profit: The final calculated price cannot exceed 90% of the purchase price.

​

*/

public class PriceDeterminator

{

    protected decimal CurrentEstimate { get; set; } = 0.0M;

​

    public decimal DetermineCarPrice(Car car)

    {

        CurrentEstimate = car.PurchaseValue;

​

        PriceAge(car);

​

        PriceMiles(car);

​

        var noPrevOwnerAdd10 = PriceOwners(car);

​

        PriceAccidents(car);

​

        Resell(car);

​

        if (noPrevOwnerAdd10)

        {

            CurrentEstimate *= 1.1M;

        }

​

        PriceProfit(car);

​

        return CurrentEstimate;

    }

​

    private void PriceAccidents(Car car)

    {

        if (car.NumberOfCollisions > 4)

        {

            CurrentEstimate *= (decimal)Math.Pow(0.98, 5.0);

            return;

        }

​

        CurrentEstimate *= (decimal)Math.Pow(0.98, car.NumberOfCollisions);

    }

​

    private void PriceProfit(Car car)

    {

        var maxEst = (car.PurchaseValue * 0.90M);

        if (CurrentEstimate > maxEst)

        {

            // instructions don't quite say what to do here...

            // if estimate cannot exceed 90% of purchase price is that a MAX estimate we can give?

            // Or does that mean Pricer shouldn't even return an estimate?

            // Assuming the former...

​

            // throw out previous estimate and just return 90% of purchase, our top/cannot_exceed value

            CurrentEstimate = maxEst;

        }

    }

​

    private void Resell(Car car)

    {

        // if Toyo add 5%, if Ford reduce by $500... lol

        switch (car.Make.ToUpperInvariant())

        {

            case "TOYOTA":

                CurrentEstimate = 1.05M * CurrentEstimate;

                break;

            case "FORD":

                CurrentEstimate -= 500M;

                break;

            default:

                break;

        }

    }

​

    private bool PriceOwners(Car car)

    {

        // "if more than 2", reduce value by 25% .. this really should have been worded "If 2 or more owners..."

        // if no prev owners, add 10% AT THE END after final value

        if (car.NumberOfPreviousOwners > 2)

        {

            CurrentEstimate *= 0.75M;

            return false;

        }

​

        if (car.NumberOfPreviousOwners < 1)

        {

            return true;

        }

​

        //between 1-2 owners there's no penalty

        return false;

    }

​

    private void PriceMiles(Car car)

    {

        // reduce value by .002 for every 1000 in mileage, up until 150k miles.

        // "After 150,000 miles" ... is that including 150K ?

​

        if (car.NumberOfMiles >= 150000)

        {

            CurrentEstimate *= (decimal)Math.Pow(.998, 150);

            return;

        }

​

        var k = (int)Math.Floor((double)car.NumberOfMiles / 1000);

        CurrentEstimate *= (decimal)Math.Pow(.998, k);

    }

​

    private void PriceAge(Car car)

    {

        // if < 10 yrs reduce purchase value by .005 (i.e .995 x value) for each month of age (?) ...

        // instructions are a bit badly worded on this criteria.

        if (car.AgeInMonths > 120)

        {

            this.CurrentEstimate *= (decimal)(Math.Pow(0.995, 120));

            return;

        }

​

        this.CurrentEstimate *= (decimal)(Math.Pow(0.995, car.AgeInMonths));

    }

}