using System.Collections.Generic;
using Godot;
using GoDotTest;
using System.Diagnostics;
using Xunit;

public class HexGridTests : TestClass
{
    public HexGridTests(Node testScene) : base(testScene)
    {
    }

    [Test]
    public void TestGetAt()
    {
        HexGrid grid = new HexGrid();
        float w = grid.HexSize.x;
        float h = grid.HexSize.y;

        Debug.Assert(grid.GetHexAt(new Vector2(0, 0)).AxialCoords == new Vector2(0, 0));
        Debug.Assert(grid.GetHexAt(new Vector2(w / 2 - 0.01f, 0)).AxialCoords == new Vector2(0, 0));
        Debug.Assert(grid.GetHexAt(new Vector2(w / 2 - 0.01f, -h / 2)).AxialCoords == new Vector2(1, 0));
        Debug.Assert(grid.GetHexAt(new Vector2(w / 2 - 0.01f, h / 2)).AxialCoords == new Vector2(1, -1));
    }

    [Test]
    public void TestGetCellsForLineSimple()
    {
        HexGrid grid = new HexGrid();

        List<HexCell> lineCells =
            grid.GetCellsForLine(new Vector2(0, 0), grid.GetHexCenterFromOffset(new Vector2(0, 2)));

        Assert.Equal(3, lineCells.Count);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(0, 0)), lineCells[0]);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(0, 1)), lineCells[1]);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(0, 2)), lineCells[2]);

        lineCells =
            grid.GetCellsForLine(grid.GetHexCenterFromOffset(new Vector2(0, 2)), new Vector2(0, 0));

        Assert.Equal(3, lineCells.Count);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(0, 2)), lineCells[0]);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(0, 1)), lineCells[1]);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(0, 0)), lineCells[2]);
    }

    [Test]
    public void TestGetCellsDiagonal()
    {
        HexGrid grid = new HexGrid();

        List<HexCell> lineCells =
            grid.GetCellsForLine(new Vector2(0, 0), grid.GetHexCenterFromOffset(new Vector2(2, 1)));

        Assert.Equal(3, lineCells.Count);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(0, 0)), lineCells[0]);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(1, 0)), lineCells[1]);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(2, 1)), lineCells[2]);

        lineCells =
            grid.GetCellsForLine(grid.GetHexCenterFromOffset(new Vector2(2, 1)), new Vector2(0, 0));

        Assert.Equal(3, lineCells.Count);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(2, 1)), lineCells[0]);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(1, 0)), lineCells[1]);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(0, 0)), lineCells[2]);
    }

    [Test]
    public void TestGetCellsForLineAlongEdge()
    {
        HexGrid grid = new HexGrid();

        List<HexCell> lineCells =
            grid.GetCellsForLine(new Vector2(0, -0.0001f), grid.GetHexCenterFromOffset(new Vector2(2, 0)));

        Assert.Equal(3, lineCells.Count);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(0, 0)), lineCells[0]);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(1, 0)), lineCells[1]);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(2, 0)), lineCells[2]);

        lineCells =
            grid.GetCellsForLine(new Vector2(0, 0.0001f), grid.GetHexCenterFromOffset(new Vector2(2, 0)));

        Assert.Equal(3, lineCells.Count);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(0, 0)), lineCells[0]);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(1, -1)), lineCells[1]);
        Assert.Equal(HexCell.FromOffsetCoords(new Vector2(2, 0)), lineCells[2]);
    }
}