using NUnit.Framework;
namespace InverseOfLife.Test;

[TestFixture]
public class GeneTests
{
    [Test]
    public void Gene_Constructor_FromBoard_CorrectEncoding()
    {
        int resolution = 4;
        var board = new Board(8, 8);
        board.Toggle(1, 1);
        board.Toggle(5, 5);
        
        var gene = new Gene(resolution, board);
        
        int encodedBits = gene.RiboseSequence.Sum(b => CountSetBits(b));
        Assert.That(encodedBits, Is.EqualTo(2), "Encoded bits should match the number of live cells.");
    }

    [Test]
    public void Gene_Constructor_FromSequence_CorrectRestoration()
    {
        int resolution = 4;
        var expectedBoard = new Board(8, 8);
        expectedBoard.Toggle(1, 1);
        expectedBoard.Toggle(5, 5);
        var gene = new Gene(resolution, expectedBoard);

        var restoredBoard = gene.Restore(8,8);
        
        Assert.That(restoredBoard.Lives, Is.EquivalentTo(expectedBoard.Lives), "Restored board should match the original board.");
    }

    [Test]
    public void Gene_Constructor_EmptyBoard_RestoreEmptyBoard()
    {
        int resolution = 4;
        var board = new Board(8, 8);

        var gene = new Gene(resolution, board);
        var restoredBoard = gene.Restore(8,8);

        Assert.IsEmpty(restoredBoard.Lives, "Restored board should be empty for an empty input board.");
    }

    [Test]
    public void Gene_Restore_LargerBoard()
    {
        int resolution = 4;
        var board = new Board(16, 16);
        board.Toggle(2, 2);
        board.Toggle(10, 10);

        var gene = new Gene(resolution, board);
        var restoredBoard = gene.Restore(16,16);

        Assert.IsTrue(restoredBoard.Lives.Contains((2, 2)), "Cell (2, 2) should be alive.");
        Assert.IsTrue(restoredBoard.Lives.Contains((10, 10)), "Cell (10, 10) should be alive.");
        Assert.That(restoredBoard.Lives, Is.EquivalentTo(board.Lives), "Restored board should match the original board.");
    }

    [Test]
    public void Gene_Restore_BoundaryCells()
    {

        int resolution = 4;
        var board = new Board(8, 8);
        board.Toggle(0, 0);
        board.Toggle(7, 7);

        var gene = new Gene(resolution, board);
        var restoredBoard = gene.Restore(8,8);

        Assert.IsTrue(restoredBoard.Lives.Contains((0, 0)), "Top-left corner cell should be alive.");
        Assert.IsTrue(restoredBoard.Lives.Contains((7, 7)), "Bottom-right corner cell should be alive.");
        Assert.That(restoredBoard.Lives, Is.EquivalentTo(board.Lives), "Restored board should match the original board.");
    }
    
    [Test]
    public void Gene_Restore_NonMultipleWidth()
    {
        int resolution = 4;
        int width = 10;
        int height = 8;
        var board = new Board(width, height);
        board.Toggle(9, 1);
        board.Toggle(1, 7);

        var gene = new Gene(resolution, board);
        var restoredBoard = gene.Restore(width, height);

        Assert.IsTrue(restoredBoard.Lives.Contains((9, 1)));
        Assert.IsTrue(restoredBoard.Lives.Contains((1, 7)));
    }
    
    [Test]
    public void Gene_Restore_NonMultipleHeight()
    {
        int resolution = 4;
        int width = 8;
        int height = 9;
        var board = new Board(width, height);
        board.Toggle(7, 8);
        board.Toggle(0, 0);

        var gene = new Gene(resolution, board);
        var restoredBoard = gene.Restore(width, height);

        Assert.IsTrue(restoredBoard.Lives.Contains((7, 8)));
        Assert.IsTrue(restoredBoard.Lives.Contains((0, 0)));
    }
    [Test]
    public void Gene_Restore_NonMultipleWidthAndHeight()
    {
        int resolution = 4;
        int width = 10;
        int height = 9;
        var board = new Board(width, height);
        board.Toggle(9, 8);
        board.Toggle(0, 0);

        var gene = new Gene(resolution, board);
        var restoredBoard = gene.Restore(width, height);

        Assert.IsTrue(restoredBoard.Lives.Contains((9, 8)));
        Assert.IsTrue(restoredBoard.Lives.Contains((0, 0)));
    }
    
    private int CountSetBits(byte b)
    {
        int count = 0;
        while (b > 0)
        {
            count += b & 1;
            b >>= 1;
        }
        return count;
    }
}