// Exercise 1: custom exception + Withdraw validation (easy)
//
// Implement:
//   - InsufficientFundsException: derives from Exception, constructor takes
//     (decimal requested, decimal available), calls base(message) with
//     "requested {requested}, only {available} available", and stores both
//     values as public get-only properties Requested/Available.
//   - Withdraw(balance, amount): returns balance - amount if amount <= balance
//     and amount > 0; throws InsufficientFundsException if amount > balance;
//     throws ArgumentOutOfRangeException if amount <= 0.
//
// Run with: dotnet run (inside a console project) or paste into a Main method.

using System;

class InsufficientFundsException : Exception
{
    public decimal Requested { get; }
    public decimal Available { get; }

    public InsufficientFundsException(decimal requested, decimal available)
        // TODO: call base(...) with the formatted message, then set
        // Requested and Available.
        : base("")
    {
    }
}

class Program
{
#pragma warning disable IDE0060
    static decimal Withdraw(decimal balance, decimal amount)
    {
        // TODO: validate amount > 0 (else ArgumentOutOfRangeException),
        // validate amount <= balance (else InsufficientFundsException),
        // otherwise return balance - amount.
        return 0m;
    }
#pragma warning restore IDE0060

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

        total++;
        if (Withdraw(100m, 40m) == 60m) { Console.WriteLine("PASS: normal withdrawal"); pass++; }
        else Console.WriteLine("FAIL: normal withdrawal");

        total++;
        try
        {
            Withdraw(100m, 200m);
            Console.WriteLine("FAIL: expected InsufficientFundsException");
        }
        catch (InsufficientFundsException e)
        {
            if (e.Requested == 200m && e.Available == 100m &&
                e.Message == "requested 200, only 100 available")
            { Console.WriteLine("PASS: InsufficientFundsException thrown with correct data"); pass++; }
            else Console.WriteLine("FAIL: InsufficientFundsException data wrong, got " + e.Message);
        }

        total++;
        try
        {
            Withdraw(100m, -5m);
            Console.WriteLine("FAIL: expected ArgumentOutOfRangeException");
        }
        catch (ArgumentOutOfRangeException)
        {
            Console.WriteLine("PASS: ArgumentOutOfRangeException thrown for non-positive amount");
            pass++;
        }
        catch (InsufficientFundsException)
        {
            Console.WriteLine("FAIL: wrong exception type for non-positive amount");
        }

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