sql-utilities/tests/Strata.SqlTools.Rules.Tests/MarkdownParserTests.cs

using Strata.SqlTools.Rules.Rule.Expression;

namespace Strata.SqlTools.Rules.Tests;

[TestFixture]
public class MarkdownParserTests
{
    #region Basic Literals

    [Test]
    public void Parse_IntegerLiteral_ReturnsNumberLiteral()
    {
        var result = Markdown.Parse("42");

        Assert.Multiple(() =>
        {
            Assert.That(result, Is.InstanceOf<NumberLiteral>());
            Assert.That(((NumberLiteral)result).Value, Is.EqualTo(42m));
        });
    }

    [Test]
    public void Parse_DecimalLiteral_ReturnsNumberLiteral()
    {
        var result = Markdown.Parse("3.14");

        Assert.Multiple(() =>
        {
            Assert.That(result, Is.InstanceOf<NumberLiteral>());
            Assert.That(((NumberLiteral)result).Value, Is.EqualTo(3.14m));
        });
    }

    [Test]
    public void Parse_StringLiteral_DoubleQuotes_ReturnsStringLiteral()
    {
        var result = Markdown.Parse("\"hello world\"");

        Assert.Multiple(() =>
        {
            Assert.That(result, Is.InstanceOf<StringLiteral>());
            Assert.That(((StringLiteral)result).Value, Is.EqualTo("hello world"));
        });
    }

    [Test]
    public void Parse_StringLiteral_SingleQuotes_ReturnsStringLiteral()
    {
        var result = Markdown.Parse("'test string'");

        Assert.Multiple(() =>
        {
            Assert.That(result, Is.InstanceOf<StringLiteral>());
            Assert.That(((StringLiteral)result).Value, Is.EqualTo("test string"));
        });
    }

    [Test]
    public void Parse_BooleanLiteral_True_ReturnsLiteral()
    {
        var result = Markdown.Parse("true");

        Assert.Multiple(() =>
        {
            Assert.That(result, Is.InstanceOf<Literal>());
            Assert.That(((Literal)result).Value, Is.EqualTo(true));
        });
    }

    [Test]
    public void Parse_BooleanLiteral_False_ReturnsLiteral()
    {
        var result = Markdown.Parse("false");

        Assert.Multiple(() =>
        {
            Assert.That(result, Is.InstanceOf<Literal>());
            Assert.That(((Literal)result).Value, Is.EqualTo(false));
        });
    }

    #endregion

    #region Property Access

    [Test]
    public void Parse_SimpleProperty_ReturnsProperty()
    {
        var result = Markdown.Parse("PropertyName");

        Assert.That(result, Is.InstanceOf<Property>());
        var prop = (Property)result;
        Assert.Multiple(() =>
        {
            Assert.That(prop.PropertyName, Is.EqualTo("PropertyName"));
            Assert.That(prop.Expression, Is.Null);
        });
    }

    [Test]
    public void Parse_PropertyWithParameter_ReturnsProperty()
    {
        var result = Markdown.Parse("x.Age");

        Assert.That(result, Is.InstanceOf<Property>());
        var prop = (Property)result;
        Assert.Multiple(() =>
        {
            Assert.That(prop.PropertyName, Is.EqualTo("Age"));
            Assert.That(prop.Expression, Is.InstanceOf<Parameter>());
        });
    }

    [Test]
    public void Parse_LatexTextProperty_ReturnsProperty()
    {
        var result = Markdown.Parse("\\text{input.Department}");

        Assert.That(result, Is.InstanceOf<Property>());
        var prop = (Property)result;
        Assert.Multiple(() =>
        {
            Assert.That(prop.PropertyName, Is.EqualTo("Department"));
            Assert.That(prop.Expression, Is.InstanceOf<Parameter>());
        });
    }

    [Test]
    public void Parse_LatexTextString_ReturnsStringLiteral()
    {
        var result = Markdown.Parse("\\text{some text}");

        Assert.Multiple(() =>
        {
            Assert.That(result, Is.InstanceOf<StringLiteral>());
            Assert.That(((StringLiteral)result).Value, Is.EqualTo("some text"));
        });
    }

    #endregion

    #region Comparisons

    [Test]
    public void Parse_Equality_ReturnsEqual()
    {
        var result = Markdown.Parse("x.Age = 25");

        Assert.That(result, Is.InstanceOf<Equal>());
        var equal = (Equal)result;
        Assert.Multiple(() =>
        {
            Assert.That(equal.Left, Is.InstanceOf<Property>());
            Assert.That(equal.Right, Is.InstanceOf<NumberLiteral>());
        });
    }

    [Test]
    public void Parse_NotEqual_ReturnsNotEqual()
    {
        var result = Markdown.Parse("x.Status != 'active'");

        Assert.That(result, Is.InstanceOf<NotEqual>());
        var notEqual = (NotEqual)result;
        Assert.Multiple(() =>
        {
            Assert.That(notEqual.Left, Is.InstanceOf<Property>());
            Assert.That(notEqual.Right, Is.InstanceOf<StringLiteral>());
        });
    }

    [Test]
    public void Parse_LatexNotEqual_ReturnsNotEqual()
    {
        var result = Markdown.Parse("x.Value \\neq 100");

        Assert.That(result, Is.InstanceOf<NotEqual>());
        var notEqual = (NotEqual)result;
        Assert.Multiple(() =>
        {
            Assert.That(notEqual.Left, Is.InstanceOf<Property>());
            Assert.That(notEqual.Right, Is.InstanceOf<NumberLiteral>());
        });
    }

    [Test]
    public void Parse_GreaterThan_ReturnsGreaterThan()
    {
        var result = Markdown.Parse("x.Score > 100");

        Assert.That(result, Is.InstanceOf<GreaterThan>());
        var greaterThan = (GreaterThan)result;
        Assert.Multiple(() =>
        {
            Assert.That(greaterThan.Left, Is.InstanceOf<Property>());
            Assert.That(greaterThan.Right, Is.InstanceOf<NumberLiteral>());
        });
    }

    [Test]
    public void Parse_LatexGreaterThan_ReturnsGreaterThan()
    {
        var result = Markdown.Parse("x.Total \\gt 500");

        Assert.That(result, Is.InstanceOf<GreaterThan>());
        var greaterThan = (GreaterThan)result;
        Assert.Multiple(() =>
        {
            Assert.That(greaterThan.Left, Is.InstanceOf<Property>());
            Assert.That(greaterThan.Right, Is.InstanceOf<NumberLiteral>());
        });
    }

    #endregion

    #region Logical Operations

    [Test]
    public void Parse_And_ReturnsAnd()
    {
        var result = Markdown.Parse("x.Age > 18 AND y.Active = true");

        Assert.That(result, Is.InstanceOf<And>());
        var and = (And)result;
        Assert.Multiple(() =>
        {
            Assert.That(and.Left, Is.InstanceOf<GreaterThan>());
            Assert.That(and.Right, Is.InstanceOf<Equal>());
        });
    }

    [Test]
    public void Parse_Or_ReturnsOr()
    {
        var result = Markdown.Parse("x.Status = 'pending' OR x.Status = 'active'");

        Assert.That(result, Is.InstanceOf<Or>());
        var or = (Or)result;
        Assert.Multiple(() =>
        {
            Assert.That(or.Left, Is.InstanceOf<Equal>());
            Assert.That(or.Right, Is.InstanceOf<Equal>());
        });
    }

    [Test]
    public void Parse_LatexLand_ReturnsAnd()
    {
        var result = Markdown.Parse("x.Valid = true \\land y.Count > 0");

        Assert.That(result, Is.InstanceOf<And>());
        var and = (And)result;
        Assert.Multiple(() =>
        {
            Assert.That(and.Left, Is.InstanceOf<Equal>());
            Assert.That(and.Right, Is.InstanceOf<GreaterThan>());
        });
    }

    [Test]
    public void Parse_LatexLor_ReturnsOr()
    {
        var result = Markdown.Parse("a.Type = 1 \\lor b.Type = 2");

        Assert.That(result, Is.InstanceOf<Or>());
        var or = (Or)result;
        Assert.Multiple(() =>
        {
            Assert.That(or.Left, Is.InstanceOf<Equal>());
            Assert.That(or.Right, Is.InstanceOf<Equal>());
        });
    }

    [Test]
    public void Parse_LatexWedge_ReturnsAnd()
    {
        var result = Markdown.Parse("x.Active = true \\wedge x.Verified = true");

        Assert.That(result, Is.InstanceOf<And>());
    }

    [Test]
    public void Parse_LatexVee_ReturnsOr()
    {
        var result = Markdown.Parse("x.Status = 'A' \\vee x.Status = 'B'");

        Assert.That(result, Is.InstanceOf<Or>());
    }

    #endregion

    #region Complex Expressions

    [Test]
    public void Parse_NestedParentheses_ReturnsCorrectStructure()
    {
        var result = Markdown.Parse("(x.Age > 18 AND x.Active = true) OR y.Override = true");

        Assert.That(result, Is.InstanceOf<Or>());
        var or = (Or)result;
        Assert.Multiple(() =>
        {
            Assert.That(or.Left, Is.InstanceOf<And>());
            Assert.That(or.Right, Is.InstanceOf<Equal>());
        });
    }

    [Test]
    public void Parse_LatexParentheses_ReturnsCorrectStructure()
    {
        var result = Markdown.Parse("\\left(x.Value = 10\\right) \\land y.Value = 20");

        Assert.That(result, Is.InstanceOf<And>());
        var and = (And)result;
        Assert.Multiple(() =>
        {
            Assert.That(and.Left, Is.InstanceOf<Equal>());
            Assert.That(and.Right, Is.InstanceOf<Equal>());
        });
    }

    [Test]
    public void Parse_ComplexExpression_ReturnsCorrectStructure()
    {
        var result = Markdown.Parse("x.Age > 18 AND (y.Status = 'active' OR y.Status = 'pending')");

        Assert.That(result, Is.InstanceOf<And>());
        var and = (And)result;
        Assert.Multiple(() =>
        {
            Assert.That(and.Left, Is.InstanceOf<GreaterThan>());
            Assert.That(and.Right, Is.InstanceOf<Or>());
        });

        var or = (Or)and.Right;
        Assert.Multiple(() =>
        {
            Assert.That(or.Left, Is.InstanceOf<Equal>());
            Assert.That(or.Right, Is.InstanceOf<Equal>());
        });
    }

    #endregion

    #region Markdown Delimiters

    [Test]
    public void Parse_InlineMath_RemovesDelimiters()
    {
        var result = Markdown.Parse("$x.Age = 25$");

        Assert.That(result, Is.InstanceOf<Equal>());
    }

    [Test]
    public void Parse_BlockMath_RemovesDelimiters()
    {
        var result = Markdown.Parse("$$\nx.Age > 18\n$$");

        Assert.That(result, Is.InstanceOf<GreaterThan>());
    }

    [Test]
    public void Parse_MathCodeFence_RemovesDelimiters()
    {
        var result = Markdown.Parse("```math\nx.Active = true\n```");

        Assert.That(result, Is.InstanceOf<Equal>());
    }

    #endregion

    #region Error Handling

    [Test]
    public void Parse_NullString_ThrowsArgumentException()
    {
        Assert.Throws<ArgumentException>(() => Markdown.Parse(null!));
    }

    [Test]
    public void Parse_EmptyString_ThrowsArgumentException()
    {
        Assert.Throws<ArgumentException>(() => Markdown.Parse(""));
    }

    [Test]
    public void Parse_WhitespaceOnly_ThrowsArgumentException()
    {
        Assert.Throws<ArgumentException>(() => Markdown.Parse("   "));
    }

    [Test]
    public void Parse_InvalidExpression_ThrowsArgumentException()
    {
        Assert.Throws<ArgumentException>(() => Markdown.Parse("@#$%"));
    }

    [Test]
    public void TryParse_ValidExpression_ReturnsTrue()
    {
        var success = Markdown.TryParse("x.Age = 25", out var expression);

        Assert.Multiple(() =>
        {
            Assert.That(success, Is.True);
            Assert.That(expression, Is.Not.Null);
        });
        Assert.That(expression, Is.InstanceOf<Equal>());
    }

    [Test]
    public void TryParse_InvalidExpression_ReturnsFalse()
    {
        var success = Markdown.TryParse("@#$%", out var expression);

        Assert.Multiple(() =>
        {
            Assert.That(success, Is.False);
            Assert.That(expression, Is.Null);
        });
    }

    #endregion

    #region Integration Tests

    [Test]
    public void Parse_RealWorldExample_UserAgeAndStatus()
    {
        var markdown = "$$\\text{user.Age} > 18 \\land \\text{user.Status} = \\text{active}$$";
        var result = Markdown.Parse(markdown);

        Assert.That(result, Is.InstanceOf<And>());
        var and = (And)result;

        // Left side: user.Age > 18
        Assert.That(and.Left, Is.InstanceOf<GreaterThan>());
        var greaterThan = (GreaterThan)and.Left;
        Assert.That(greaterThan.Left, Is.InstanceOf<Property>());
        var userAge = (Property)greaterThan.Left;
        Assert.Multiple(() =>
        {
            Assert.That(userAge.PropertyName, Is.EqualTo("Age"));

            // Right side: user.Status = "active"
            Assert.That(and.Right, Is.InstanceOf<Equal>());
        });
        var equal = (Equal)and.Right;
        Assert.That(equal.Left, Is.InstanceOf<Property>());
        var userStatus = (Property)equal.Left;
        Assert.That(userStatus.PropertyName, Is.EqualTo("Status"));
    }

    [Test]
    public void Parse_RealWorldExample_ComplexBusinessRule()
    {
        var markdown = @"$
            (invoice.TotalCharges > 1000 AND invoice.Status = 'pending')
            OR
            (invoice.Priority = 'urgent' AND invoice.ApprovedBy != '')
        $";

        var result = Markdown.Parse(markdown);

        Assert.That(result, Is.InstanceOf<Or>());
        var or = (Or)result;
        Assert.Multiple(() =>
        {
            Assert.That(or.Left, Is.InstanceOf<And>());
            Assert.That(or.Right, Is.InstanceOf<And>());
        });

        // Left AND: TotalCharges > 1000 AND Status = 'pending'
        var leftAnd = (And)or.Left;
        Assert.Multiple(() =>
        {
            Assert.That(leftAnd.Left, Is.InstanceOf<GreaterThan>());
            Assert.That(leftAnd.Right, Is.InstanceOf<Equal>());
        });

        // Right AND: Priority = 'urgent' AND ApprovedBy != ''
        var rightAnd = (And)or.Right;
        Assert.Multiple(() =>
        {
            Assert.That(rightAnd.Left, Is.InstanceOf<Equal>());
            Assert.That(rightAnd.Right, Is.InstanceOf<NotEqual>());
        });
    }

    #endregion
}