using Calculator.Domain;
using Calculator.Domain.Extensions;
using Calculator.Test.Extensions;
using MbUnit.Framework;

namespace Calculator.Test.domain {
	[TestFixture]
	public class StandardCalculatorTest {
		[SetUp]
		public void SetUp() {}

		public ICalculator CreateSUT() {
			return new StandardCalculator( );
		}

		[Test]
		public void should_be_able_to_add_2_numbers_together() {
			var ten = Number( 10 );
			var five = Number( 5 );
			var fifteen = Number( 15 );

			var calculator = CreateSUT( );
			var resultOfCalculation = calculator.Number( ten ).Plus( ).Number( five ).ComputesTo( );

			resultOfCalculation.ShouldBeEqualTo( fifteen );
		}

		[Test]
		public void should_be_able_to_subtract_one_number_from_another() {
			var twenty = Number( 20 );
			var three = Number( 3 );
			var seventeen = Number( 17 );

			var calculator = CreateSUT( );
			var resultOfCalculation
				= calculator
					.Number( twenty )
					.Minus( )
					.Number( three )
					.ComputesTo( );

			resultOfCalculation.ShouldBeEqualTo( seventeen );
		}

		[Test]
		public void should_be_able_to_add_two_numbers_together_then_subtract_a_number() {
			var calculator = CreateSUT( );
			var ninetyNine = Number( 99 );
			var one = Number( 1 );
			var sixtyThree = Number( 63 );

			var resultOfCalculation =
				calculator
					.Number( ninetyNine )
					.Plus( )
					.Number( one )
					.Minus( )
					.Number( sixtyThree )
					.ComputesTo( );

			resultOfCalculation.ShouldBeEqualTo( Number( 37 ) );
		}

		private INumber Number( long number ) {
			return new Number( number );
		}
	}
}