sql-utilities/tests/Strata.SqlTools.Markdown.Tests/LinqToSql/QueryBreakdownGeneratorTests.cs

using Strata.SqlTools.Breakdowns.LinqToSql;
using Strata.SqlTools.Markdown.LinqToSql;

namespace Strata.SqlTools.Markdown.Tests.LinqToSql;

[TestFixture]
public class QueryBreakdownGeneratorTests
{
    private QueryBreakdownGenerator _generator = null!;
    private TestDataContext _context = null!;

    [SetUp]
    public void Setup()
    {
        _generator = new QueryBreakdownGenerator();
        _context = new TestDataContext();
    }

    [Test]
    public void GenerateMermaidDiagram_SimpleLinqQuery_GeneratesValidMermaid()
    {
        // Arrange
        var query = TestDataContext.Users.Where(u => u.Age > 21);
        var breakdown = LinqQueryBreakdown.Analyze(query);

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(breakdown, "Simple User Query");

        // Assert
        Assert.That(result, Does.Contain("```mermaid"));
        Assert.That(result, Does.Contain("flowchart TD"));
        Assert.That(result, Does.Contain("### Simple User Query"));
        Assert.That(result, Does.Contain("SELECT"));
        Assert.That(result, Does.Contain("WHERE"));
        Assert.That(result, Does.Contain("```"));
    }

    [Test]
    public void GenerateMethodChainDiagram_WithMethodCalls_ShowsChain()
    {
        // Arrange
        var query = TestDataContext.Users
            .Where(u => u.Age > 18)
            .OrderBy(u => u.Name)
            .Select(u => new { u.Id, u.Name });
        var breakdown = LinqQueryBreakdown.Analyze(query);

        // Act
        var result = QueryBreakdownGenerator.GenerateMethodChainDiagram(breakdown, "Method Chain");

        // Assert
        Assert.That(result, Does.Contain("```mermaid"));
        Assert.That(result, Does.Contain("flowchart LR"));
        Assert.That(result, Does.Contain("### Method Chain"));
        Assert.That(result, Does.Contain("Where"));
        Assert.That(result, Does.Contain("OrderBy"));
        Assert.That(result, Does.Contain("Select"));
        Assert.That(result, Does.Contain("IQueryable"));
        Assert.That(result, Does.Contain("Result"));
    }

    [Test]
    public void GenerateMethodChainDiagram_EmptyChain_ShowsBasicFlow()
    {
        // Arrange
        var breakdown = new LinqQueryBreakdown("*", "Users");

        // Act
        var result = QueryBreakdownGenerator.GenerateMethodChainDiagram(breakdown);

        // Assert
        Assert.That(result, Does.Contain("IQueryable"));
        Assert.That(result, Does.Contain("Result"));
    }

    [Test]
    public void GenerateCombinedDiagram_IncludesBothDiagrams()
    {
        // Arrange
        var query = TestDataContext.Users.Where(u => u.Age > 21).OrderBy(u => u.Name);
        var breakdown = LinqQueryBreakdown.Analyze(query);

        // Act
        var result = QueryBreakdownGenerator.GenerateCombinedDiagram(breakdown, "User Query Analysis");

        // Assert
        Assert.That(result, Does.Contain("## User Query Analysis"));
        Assert.That(result, Does.Contain("### LINQ Method Chain"));
        Assert.That(result, Does.Contain("### SQL Query Structure"));
        Assert.That(result, Does.Contain("flowchart LR"));
        Assert.That(result, Does.Contain("flowchart TD"));
    }

    [Test]
    public void GenerateMermaidDiagram_WithProjection_ShowsSelectedFields()
    {
        // Arrange
        var query = TestDataContext.Users.Select(u => new { u.Id, u.Name, u.Email });
        var breakdown = LinqQueryBreakdown.Analyze(query);

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(breakdown);

        // Assert
        Assert.That(result, Does.Contain("SELECT"));
        Assert.That(result, Does.Contain("```mermaid"));
    }

    [Test]
    public void GenerateMermaidDiagram_NullTitle_GeneratesWithoutTitle()
    {
        // Arrange
        var query = TestDataContext.Users;
        var breakdown = LinqQueryBreakdown.Analyze(query);

        // Act
        var result = QueryBreakdownGenerator.GenerateMermaidDiagram(breakdown, null);

        // Assert
        Assert.That(result, Does.Not.Contain("###"));
        Assert.That(result, Does.Contain("```mermaid"));
    }
}

// Test data context
public class TestDataContext
{
    public static IQueryable<User> Users => new List<User>().AsQueryable();
}

public class User
{
    public int Id { get; set; }
    public string Name { get; set; } = string.Empty;
    public string Email { get; set; } = string.Empty;
    public int Age { get; set; }
}