Monogame-Extended/tests/MonoGame.Extended.Tests/Tilemaps/TilemapTileTests.cs

using System;
using Microsoft.Xna.Framework.Graphics;
using MonoGame.Extended.Tilemaps;

namespace MonoGame.Extended.Tests;

public sealed class TilemapTileTests
{
    private Texture2D CreateDummyTexture()
    {
        // TODO: setup with xvfb later
        return null;
    }

    private TilemapTilesetCollection CreateTestTilesets()
    {
        var collection = new TilemapTilesetCollection();

        var tileset1 = new TilemapTileset("Tileset1", CreateDummyTexture(), 32, 32, 100, 10);
        tileset1.FirstGlobalId = 1;

        var tileset2 = new TilemapTileset("Tileset2", CreateDummyTexture(), 32, 32, 50, 5);
        tileset2.FirstGlobalId = 101;

        collection.Add(tileset1);
        collection.Add(tileset2);

        return collection;
    }

    [Fact]
    public void Constructor_SetsProperties()
    {
        var tile = new TilemapTile(42, TilemapTileFlipFlags.FlipHorizontally);
        Assert.Equal(42, tile.GlobalId);
        Assert.Equal(TilemapTileFlipFlags.FlipHorizontally, tile.FlipFlags);
    }

    [Fact]
    public void Constructor_DefaultFlipFlags_SetsToNone()
    {
        var tile = new TilemapTile(42);
        Assert.Equal(42, tile.GlobalId);
        Assert.Equal(TilemapTileFlipFlags.None, tile.FlipFlags);
    }

    [Fact]
    public void GetTileset_WithValidGid_ReturnsTileset()
    {
        var tilesets = CreateTestTilesets();
        var tile = new TilemapTile(50);

        var tileset = tile.GetTileset(tilesets);

        Assert.NotNull(tileset);
        Assert.Equal("Tileset1", tileset.Name);
    }

    [Fact]
    public void GetTileset_WithGidInSecondTileset_ReturnsSecondTileset()
    {
        var tilesets = CreateTestTilesets();
        var tile = new TilemapTile(125);

        var tileset = tile.GetTileset(tilesets);

        Assert.NotNull(tileset);
        Assert.Equal("Tileset2", tileset.Name);
    }

    [Fact]
    public void GetTileset_WithInvalidGid_ReturnsNull()
    {
        var tilesets = CreateTestTilesets();

        // Beyond any tileset
        var tile = new TilemapTile(999);

        var tileset = tile.GetTileset(tilesets);

        Assert.Null(tileset);
    }

    [Fact]
    public void GetLocalId_WithValidGid_ReturnsCorrectLocalId()
    {
        var tilesets = CreateTestTilesets();
        var tile = new TilemapTile(50);

        var localId = tile.GetLocalId(tilesets);

        // Assert
        // 50 - 1 = 49
        Assert.Equal(49, localId);
    }

    [Fact]
    public void GetLocalId_WithFirstGid_ReturnsZero()
    {
        var tilesets = CreateTestTilesets();
        var tile = new TilemapTile(1);

        var localId = tile.GetLocalId(tilesets);

        // Assert
        // 1 - 1  = 0
        Assert.Equal(0, localId);
    }

    [Fact]
    public void GetLocalId_WithGidInSecondTileset_ReturnsCorrectLocalId()
    {
        var tilesets = CreateTestTilesets();
        var tile = new TilemapTile(125);

        var localId = tile.GetLocalId(tilesets);

        // 125 - 101 = 24
        Assert.Equal(24, localId);
    }

    [Fact]
    public void GetLocalId_WithInvalidGid_ThrowsInvalidOperationException()
    {
        var tilesets = CreateTestTilesets();
        var tile = new TilemapTile(999);
        Assert.Throws<InvalidOperationException>(() => tile.GetLocalId(tilesets));
    }

    [Fact]
    public void GetLocalId_WithOutParameter_ReturnsTilesetAndLocalId()
    {
        var tilesets = CreateTestTilesets();
        var tile = new TilemapTile(125);

        var localId = tile.GetLocalId(tilesets, out var tileset);

        Assert.Equal(24, localId);
        Assert.NotNull(tileset);
        Assert.Equal("Tileset2", tileset.Name);
    }

    [Fact]
    public void GetLocalId_WithOutParameter_AndInvalidGid_ThrowsException()
    {
        var tilesets = CreateTestTilesets();
        var tile = new TilemapTile(999);
        Assert.Throws<InvalidOperationException>(() => tile.GetLocalId(tilesets, out _));
    }

    [Fact]
    public void GetTileData_WithValidGid_ReturnsTileData()
    {
        var tilesets = CreateTestTilesets();
        var tileData = new TilemapTileData(49) { Class = "Water" };
        tilesets[0].AddTileData(tileData);

        var tile = new TilemapTile(50); // Tileset1 FirstGlobalId=1, so localId=49

        var retrieved = tile.GetTileData(tilesets);

        Assert.NotNull(retrieved);
        Assert.Equal("Water", retrieved.Class);
    }

    [Fact]
    public void GetTileData_WithNoTileData_ReturnsNull()
    {
        var tilesets = CreateTestTilesets();
        var tile = new TilemapTile(50);

        var retrieved = tile.GetTileData(tilesets);

        Assert.Null(retrieved);
    }

    [Fact]
    public void GetTileData_WithInvalidGid_ReturnsNull()
    {
        var tilesets = CreateTestTilesets();
        var tile = new TilemapTile(999);

        var retrieved = tile.GetTileData(tilesets);

        Assert.Null(retrieved);
    }

    [Theory]
    [InlineData(TilemapTileFlipFlags.None)]
    [InlineData(TilemapTileFlipFlags.FlipHorizontally)]
    [InlineData(TilemapTileFlipFlags.FlipVertically)]
    [InlineData(TilemapTileFlipFlags.FlipDiagonally)]
    [InlineData(TilemapTileFlipFlags.FlipHorizontally | TilemapTileFlipFlags.FlipVertically)]
    public void FlipFlags_PreservesValue(TilemapTileFlipFlags flags)
    {
        var tile = new TilemapTile(42, flags);
        Assert.Equal(flags, tile.FlipFlags);
    }
}