using MathEngine.Parser.Tokeniser;
using MathEngine.Parser.Parser;
namespace EngineTests
{
    /// <summary>
    /// Class for testing the Parser
    /// </summary>
    [TestClass]
    public class ParserTests
    {

        /// <summary>
        /// Test the Parser on a basic List of tokens
        /// </summary>
        [TestMethod]
        public void TestParserBasicExpression()
        {
            //Arrange
            string testString = "3+4";
            List<Token> testList = Tokeniser.Tokenise(testString);
            Token three = new("3", Token.Type.Numeric, Token.NumericType.Decimal, 0);
            Token four = new("4", Token.Type.Numeric, Token.NumericType.Decimal, 0);
            Assert.IsNotNull(testList);
            Stack<Token> expectedStack = new();
            expectedStack.Push(Token.Plus);
            expectedStack.Push(four);
            expectedStack.Push(three);
            //Act
            Stack<Token> returnedStack = Parser.Parse(testList);
            //Assert
            if (returnedStack.Count != expectedStack.Count)
            {
                Assert.Fail();
            }
            else
            {
                while (returnedStack.Count > 0)
                {
                    if (!returnedStack.Pop().Equals(expectedStack.Pop()))
                    {
                        Assert.Fail();
                    }
                }
            }
        }

        /// <summary>
        /// Test the Parser on a more compilicated basic expression to see if operator precedence is respected
        /// </summary>
        [TestMethod]
        public void TestParserBasicExpressionAllOperators()
        {
            //Arrange
            string testString = "3+4*8-47.2/9";
            List<Token> testList = Tokeniser.Tokenise(testString);
            Token three = new("3", Token.Type.Numeric, Token.NumericType.Decimal, 0);
            Token four = new("4", Token.Type.Numeric, Token.NumericType.Decimal, 0);
            Token eight = new("8", Token.Type.Numeric, Token.NumericType.Decimal, 0);
            Token nine = new("9", Token.Type.Numeric, Token.NumericType.Decimal, 0);
            Token fourSevenPoint2 = new("47.2", Token.Type.Numeric, Token.NumericType.Decimal, 0);
            Assert.IsNotNull(testList);
            Stack<Token> expectedStack = new();
            expectedStack.Push(Token.Minus);
            expectedStack.Push(Token.Divide);
            expectedStack.Push(nine);
            expectedStack.Push(fourSevenPoint2);
            expectedStack.Push(Token.Plus);
            expectedStack.Push(Token.Multiply);
            expectedStack.Push(eight);
            expectedStack.Push(four);
            expectedStack.Push(three);
            //Act
            Stack<Token> returnedStack = Parser.Parse(testList);
            //Assert
            if (returnedStack.Count != expectedStack.Count)
            {
                Assert.Fail();
            }
            else
            {
                while (returnedStack.Count > 0)
                {
                    if (!returnedStack.Pop().Equals(expectedStack.Pop()))
                    {
                        Assert.Fail();
                    }
                }
            }
        }


    }
}