// Exercise 2: abstract classes, interfaces, and default interface methods
//
// Implement:
//   - abstract class Employee with abstract MonthlyPay() and a concrete
//     AnnualPay() that's computed FROM MonthlyPay() (polymorphically).
//   - interface IBenefits with a default-implemented Describe() method,
//     and one abstract member HasHealthInsurance.
//   - Manager : Employee, IBenefits

using System;

interface IBenefits
{
    bool HasHealthInsurance { get; }
    string Describe() => HasHealthInsurance ? "has health insurance" : "no health insurance";
}

abstract class Employee
{
    public abstract decimal MonthlyPay();

    public decimal AnnualPay()
    {
        // TODO: return MonthlyPay() * 12. Must call the polymorphic
        // MonthlyPay() so subclass overrides are respected.
        throw new NotImplementedException();
    }
}

class Manager : Employee, IBenefits
{
    public decimal BaseSalary { get; init; }
    public bool HasHealthInsurance => true;

    public override decimal MonthlyPay()
    {
        // TODO: return BaseSalary
        throw new NotImplementedException();
    }
}

class Program
{
    static void Main()
    {
        int pass = 0, total = 0;

        Employee mgr = new Manager { BaseSalary = 5000m };
        total++;
        if (mgr.AnnualPay() == 60000m) { Console.WriteLine("PASS: AnnualPay uses overridden MonthlyPay"); pass++; }
        else Console.WriteLine("FAIL: AnnualPay uses overridden MonthlyPay, got " + mgr.AnnualPay());

        IBenefits benefits = new Manager { BaseSalary = 5000m };
        total++;
        if (benefits.Describe() == "has health insurance") { Console.WriteLine("PASS: default interface method works"); pass++; }
        else Console.WriteLine("FAIL: default interface method works, got " + benefits.Describe());

        Console.WriteLine($"--- {pass}/{total} checks passed ---");
    }
}