/************************************************************************************
Copyright : Copyright (c) Facebook Technologies, LLC and its affiliates. All rights reserved.

Licensed under the Oculus Utilities SDK License Version 1.31 (the "License"); you may not use
the Utilities SDK except in compliance with the License, which is provided at the time of installation
or download, or which otherwise accompanies this software in either electronic or hard copy form.

You may obtain a copy of the License at
https://developer.oculus.com/licenses/utilities-1.31

Unless required by applicable law or agreed to in writing, the Utilities SDK distributed
under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
ANY KIND, either express or implied. See the License for the specific language governing
permissions and limitations under the License.
************************************************************************************/
using UnityEngine;
using UnityEditor;

[CustomEditor(typeof(OVROverlayCanvas))]
public class OVROverlayCanvasEditor : Editor {

	public override void OnInspectorGUI()
	{
		OVROverlayCanvas canvas = target as OVROverlayCanvas;

		EditorGUI.BeginChangeCheck();

		float lastTextureSize = canvas.MaxTextureSize;
		canvas.MaxTextureSize = EditorGUILayout.IntField(new GUIContent("Max Texture Size", "Limits the maximum size of the texture used for this canvas"), canvas.MaxTextureSize);
		canvas.MinTextureSize = EditorGUILayout.IntField(new GUIContent("Min Texture Size", "Limits the minimum size this texture will be displayed at"), canvas.MinTextureSize);

		// Automatically adjust pixels per unit when texture size is adjusted to maintain the same density
		canvas.PixelsPerUnit *= lastTextureSize / (float)canvas.MaxTextureSize;
		canvas.PixelsPerUnit = EditorGUILayout.FloatField(new GUIContent("Pixels Per Unit", "Controls the density of the texture"), canvas.PixelsPerUnit);

		canvas.DrawRate = EditorGUILayout.IntField(new GUIContent("Draw Rate", "Controls how frequently this canvas updates. A value of 1 means every frame, 2 means every other, etc."), canvas.DrawRate);
		if (canvas.DrawRate > 1)
		{
			canvas.DrawFrameOffset = EditorGUILayout.IntField(new GUIContent("Draw Frame Offset", "Allows you to alternate which frame each canvas will draw on by specifying a frame offset."), canvas.DrawFrameOffset);
		}

		canvas.Expensive = EditorGUILayout.Toggle(new GUIContent("Expensive", "Improve the visual appearance at the cost of additional GPU time"), canvas.Expensive);
		canvas.Opacity = (OVROverlayCanvas.DrawMode)EditorGUILayout.EnumPopup(new GUIContent("Opacity", "Treat this canvas as opaque, which is a big performance improvement"), canvas.Opacity);

		if (canvas.Opacity == OVROverlayCanvas.DrawMode.TransparentDefaultAlpha)
		{
			var prevColor = GUI.contentColor;
			GUI.contentColor = Color.yellow;
			EditorGUILayout.LabelField("Transparent Default Alpha is not recommended with overlapping semitransparent graphics.");
			GUI.contentColor = prevColor;
		}

		if (canvas.Opacity == OVROverlayCanvas.DrawMode.TransparentCorrectAlpha)
		{
			var graphics = canvas.GetComponentsInChildren<UnityEngine.UI.Graphic>();
			bool usingDefaultMaterial = false;
			foreach(var graphic in graphics)
			{
				if (graphic.material == null || graphic.material == graphic.defaultMaterial)
				{
					usingDefaultMaterial = true;
					break;
				}
			}

			if (usingDefaultMaterial)
			{
				var prevColor = GUI.contentColor;
				GUI.contentColor = Color.yellow;
				EditorGUILayout.LabelField("Some graphics in this canvas are using the default UI material.");
				EditorGUILayout.LabelField("Would you like to replace all of them with the corrected UI Material?");
				GUI.contentColor = prevColor;

				if (GUILayout.Button("Replace Materials"))
				{
					var matList = AssetDatabase.FindAssets("t:Material UI Default Correct");
					if (matList.Length > 0)
					{
						var mat = AssetDatabase.LoadAssetAtPath<Material>(AssetDatabase.GUIDToAssetPath(matList[0]));

						foreach(var graphic in graphics)
						{
							if (graphic.material == null || graphic.material == graphic.defaultMaterial)
							{
								graphic.material = mat;
							}
						}
					}
				}
			}
		}
		if (canvas.Opacity == OVROverlayCanvas.DrawMode.TransparentCorrectAlpha ||
			canvas.Opacity == OVROverlayCanvas.DrawMode.TransparentDefaultAlpha)
		{
			if (PlayerSettings.colorSpace == ColorSpace.Gamma)
			{
				var prevColor = GUI.contentColor;
				GUI.contentColor = Color.yellow;
				EditorGUILayout.LabelField("Alpha blending may not be correct with Gamma Color Space");
				GUI.contentColor = prevColor;
			}
		}


		canvas.Layer = EditorGUILayout.LayerField(new GUIContent("Layer", "The layer this overlay should be drawn on"), canvas.Layer);

		if (Camera.main != null)
		{
			if ((Camera.main.cullingMask & (1 << canvas.gameObject.layer)) != 0)
			{
				var prevColor = GUI.contentColor;
				GUI.contentColor = Color.red;
				EditorGUILayout.LabelField("Main Camera does not cull " + LayerMask.LayerToName(canvas.gameObject.layer)+". Make sure the layer of this object is not drawn by the main camera");
				GUI.contentColor = prevColor;
			}
			if ((Camera.main.cullingMask & (1 << canvas.Layer)) == 0)
			{
				var prevColor = GUI.contentColor;
				GUI.contentColor = Color.red;
				EditorGUILayout.LabelField("Layer should be assigned to a layer visible to your main camera.");
				GUI.contentColor = prevColor;
			}
		}
		else
		{
			var prevColor = GUI.contentColor;
			GUI.contentColor = Color.yellow;
			EditorGUILayout.LabelField("No Main Camera found. Make sure you camera does not draw layer "+LayerMask.LayerToName(canvas.gameObject.layer));
			GUI.contentColor = prevColor;
		}

		if (canvas.Layer == canvas.gameObject.layer)
		{
			var prevColor = GUI.contentColor;
			GUI.contentColor = Color.red;
			EditorGUILayout.LabelField("Layer is set to the same layer as this object (" + LayerMask.LayerToName(canvas.gameObject.layer) + ").");
			GUI.contentColor = prevColor;
		}

		if (Application.isPlaying)
		{
			EditorGUILayout.Space();
			EditorGUILayout.LabelField("Editor Debug", EditorStyles.boldLabel);
			canvas.overlayEnabled = EditorGUILayout.Toggle("Overlay Enabled", canvas.overlayEnabled);			
		}
	}
}