using NUnit.Framework;

namespace InverseOfLife.Test;

[TestFixture]
public class CellTracerTests
{
    private Board board;

    [SetUp]
    public void Setup()
    {
        board = new Board(5, 5, useTracer: true);
    }

    [Test]
    public void InitializeBoard_WithTracer_ShouldHaveNoCellsOrContributions()
    {
        var initialState = board.ToString();
        
        Assert.IsNotNull(board.Tracer);
        Assert.That(board.Tracer!.Contribution, Is.Empty);
    }

    [Test]
    public void Toggle_ShouldNotAffectTracer()
    {
        board.Toggle(1, 1);
        board.Toggle(2, 2);
        
        Assert.That(board.Lives, Is.EquivalentTo(new[] { (1, 1), (2, 2) }));
        Assert.That(board.Tracer!.Contribution, Is.Empty); // Tracer not affected by Toggle
    }

    [Test]
    public void Evaluate_WithTracer_ShouldTrackNewCellContributions()
    {
        board.Toggle(1, 2, initialConfig: true);
        board.Toggle(2, 2, initialConfig: true);
        board.Toggle(3, 2, initialConfig: true);

        board.Evaluate();

        Assert.That(board.Lives, Is.EquivalentTo(new[] { (2, 1), (2, 2), (2, 3) }));

        var tracer = board.Tracer!;
        Assert.That(tracer.Contribution.ContainsKey((2, 1)), Is.True);
        Assert.That(tracer.Contribution.ContainsKey((2, 3)), Is.True);

        var contributions = tracer.Contribution[(2, 1)];
        Assert.That(contributions.Keys, Is.EquivalentTo(new[] { (1, 2), (2, 2), (3, 2) }));
        Assert.That(contributions[(1, 2)], Is.EqualTo(1.0 / 3.0));
        Assert.That(contributions[(2, 2)], Is.EqualTo(1.0 / 3.0));
        Assert.That(contributions[(3, 2)], Is.EqualTo(1.0 / 3.0));
    }

    [Test]
    public void Evaluate_WithTracer_ShouldRemoveDeadCellContributions()
    {
        board.Toggle(1, 2, initialConfig: true);
        board.Toggle(2, 2, initialConfig: true);
        board.Toggle(3, 2, initialConfig: true);

        board.Evaluate();

        board.Evaluate();

        Assert.That(board.Lives, Is.EquivalentTo(new[] { (2, 2), (1, 2), (3, 2) }));

        var tracer = board.Tracer!;
        Assert.That(tracer.Contribution.ContainsKey((2, 2)), Is.True);
        Assert.That(tracer.Contribution.ContainsKey((2, 1)), Is.False);
        Assert.That(tracer.Contribution.ContainsKey((2, 3)), Is.False);
    }
    
    [Test]
    public void BatchProcess_ShouldApplyDeferredAddAndRemoveCorrectly()
    {
        board.Toggle(1, 2, initialConfig: true);
        board.Toggle(2, 2, initialConfig: true);
        board.Toggle(3, 2, initialConfig: true);
        board.Evaluate();
        
        Assert.That(board.Lives, Does.Contain((2, 1)));
        Assert.That(board.Lives, Does.Not.Contain((1, 2)));

        Assert.That(board.Tracer!.Contribution.ContainsKey((1, 2)), Is.False);
        Assert.That(board.Tracer!.Contribution.ContainsKey((2, 1)), Is.True);
    }

    [Test]
    public void Play_ShouldRunGenerationsAndUpdateTracer()
    {
        board.Toggle(1, 2, initialConfig: true);
        board.Toggle(2, 2, initialConfig: true);
        board.Toggle(3, 2, initialConfig: true);

        board.Play(3, delay: 0);

        Assert.That(board.Lives, Is.EquivalentTo(new[] { (2, 1), (2, 2), (2, 3) }));

        var tracer = board.Tracer!;
        Assert.That(tracer.Contribution.ContainsKey((2, 2)), Is.True);
    }
}