roads and bridges fixes

Directory.Build.props

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
     <PropertyGroup>
-        <Version>0.7.0</Version>
+        <Version>0.7.1</Version>
         <Authors>Anton Makarevich</Authors>
         <Company>Anton Makarevich</Company>
         <PackageLicenseExpression>GPL-3.0-only</PackageLicenseExpression>

src/MakaMek.MapEditor/ViewModels/EditMapViewModel.cs

@@ -422,14 +422,15 @@ private void LoadTools()
     }
 
     private static bool IsGroundTerrain(MakaMekTerrains id) =>
-        id is MakaMekTerrains.LightWoods
-            or MakaMekTerrains.HeavyWoods or MakaMekTerrains.Rough
-            or MakaMekTerrains.Pavement or MakaMekTerrains.Rubble;
+        id is MakaMekTerrains.Clear
+            or MakaMekTerrains.LightWoods or MakaMekTerrains.HeavyWoods
+            or MakaMekTerrains.Rough or MakaMekTerrains.Pavement
+            or MakaMekTerrains.Rubble;
 
     /// <summary>
     /// Applies a terrain to a hex with correct layering:
     /// - Ground terrains (Clear/Woods/Rough/Pavement/Rubble) are mutually exclusive with each other
-    /// - Water coexists with ground and road layers; adding Water over Road converts Road to Bridge
+    /// - Water replaces any ground terrain and coexists with road layers; adding Water over Road converts Road to Bridge
     /// - Road/Bridge sits on top and coexists with ground + water layers
     /// </summary>
     private static Hex ApplyTerrainToHex(Hex hex, Terrain terrain)
@@ -457,6 +458,8 @@ private static Hex ApplyTerrainToHex(Hex hex, Terrain terrain)
         if (newId == MakaMekTerrains.Water)
         {
             hex.RemoveTerrain(MakaMekTerrains.Water);
+            foreach (var t in hex.GetTerrains().Where(t => IsGroundTerrain(t.Id)).ToList())
+                hex.RemoveTerrain(t.Id);
             if (hex.HasTerrain(MakaMekTerrains.Road))
             {
                 hex.RemoveTerrain(MakaMekTerrains.Road);

tests/MakaMek.MapEditor.Test/ViewModels/EditMapViewModelTests.cs

@@ -1715,6 +1715,107 @@ public void HandleHexSelection_TerrainMode_WaterOnBridge_ShouldPreserveBridge()
         result.HasTerrain(MakaMekTerrains.Bridge).ShouldBeTrue();
     }
 
+    [Fact]
+    public void HandleHexSelection_TerrainMode_WaterOnClear_ShouldRemoveClear()
+    {
+        var hex = new Hex(new HexCoordinates(0, 0));
+        hex.AddTerrain(new ClearTerrain());
+        _sut.SelectedTerrain = new WaterTerrain(-1);
+
+        var result = _sut.HandleHexSelection(hex);
+
+        result.ShouldNotBeNull();
+        result.HasTerrain(MakaMekTerrains.Water).ShouldBeTrue();
+        result.HasTerrain(MakaMekTerrains.Clear).ShouldBeFalse();
+    }
+
+    [Fact]
+    public void HandleHexSelection_TerrainMode_WaterOnLightWoods_ShouldRemoveLightWoods()
+    {
+        var hex = new Hex(new HexCoordinates(0, 0));
+        hex.AddTerrain(new LightWoodsTerrain());
+        _sut.SelectedTerrain = new WaterTerrain(-1);
+
+        var result = _sut.HandleHexSelection(hex);
+
+        result.ShouldNotBeNull();
+        result.HasTerrain(MakaMekTerrains.Water).ShouldBeTrue();
+        result.HasTerrain(MakaMekTerrains.LightWoods).ShouldBeFalse();
+    }
+
+    [Fact]
+    public void HandleHexSelection_TerrainMode_WaterOnHeavyWoods_ShouldRemoveHeavyWoods()
+    {
+        var hex = new Hex(new HexCoordinates(0, 0));
+        hex.AddTerrain(new HeavyWoodsTerrain());
+        _sut.SelectedTerrain = new WaterTerrain(-1);
+
+        var result = _sut.HandleHexSelection(hex);
+
+        result.ShouldNotBeNull();
+        result.HasTerrain(MakaMekTerrains.Water).ShouldBeTrue();
+        result.HasTerrain(MakaMekTerrains.HeavyWoods).ShouldBeFalse();
+    }
+
+    [Fact]
+    public void HandleHexSelection_TerrainMode_WaterOnRough_ShouldRemoveRough()
+    {
+        var hex = new Hex(new HexCoordinates(0, 0));
+        hex.AddTerrain(new RoughTerrain());
+        _sut.SelectedTerrain = new WaterTerrain(-1);
+
+        var result = _sut.HandleHexSelection(hex);
+
+        result.ShouldNotBeNull();
+        result.HasTerrain(MakaMekTerrains.Water).ShouldBeTrue();
+        result.HasTerrain(MakaMekTerrains.Rough).ShouldBeFalse();
+    }
+
+    [Fact]
+    public void HandleHexSelection_TerrainMode_WaterOnGroundWithRoad_ShouldRemoveGroundAndConvertRoadToBridge()
+    {
+        var hex = new Hex(new HexCoordinates(0, 0));
+        hex.AddTerrain(new LightWoodsTerrain());
+        hex.AddTerrain(new RoadTerrain());
+        _sut.SelectedTerrain = new WaterTerrain(-1);
+
+        var result = _sut.HandleHexSelection(hex);
+
+        result.ShouldNotBeNull();
+        result.HasTerrain(MakaMekTerrains.Water).ShouldBeTrue();
+        result.HasTerrain(MakaMekTerrains.LightWoods).ShouldBeFalse();
+        result.HasTerrain(MakaMekTerrains.Bridge).ShouldBeTrue();
+        result.HasTerrain(MakaMekTerrains.Road).ShouldBeFalse();
+    }
+
+    [Fact]
+    public void HandleHexSelection_TerrainMode_LightWoodsOnClear_ShouldRemoveClear()
+    {
+        var hex = new Hex(new HexCoordinates(0, 0));
+        hex.AddTerrain(new ClearTerrain());
+        _sut.SelectedTerrain = new LightWoodsTerrain();
+
+        var result = _sut.HandleHexSelection(hex);
+
+        result.ShouldNotBeNull();
+        result.HasTerrain(MakaMekTerrains.LightWoods).ShouldBeTrue();
+        result.HasTerrain(MakaMekTerrains.Clear).ShouldBeFalse();
+    }
+
+    [Fact]
+    public void HandleHexSelection_TerrainMode_RoughOnClear_ShouldRemoveClear()
+    {
+        var hex = new Hex(new HexCoordinates(0, 0));
+        hex.AddTerrain(new ClearTerrain());
+        _sut.SelectedTerrain = new RoughTerrain();
+
+        var result = _sut.HandleHexSelection(hex);
+
+        result.ShouldNotBeNull();
+        result.HasTerrain(MakaMekTerrains.Rough).ShouldBeTrue();
+        result.HasTerrain(MakaMekTerrains.Clear).ShouldBeFalse();
+    }
+
     // --- Bridge Command Tests ---
     [Fact]
     public async Task RaiseBridgeLevelCommand_ConvertsRoadToBridge()