// Fantasy Adventure Environment
// Copyright Staggart Creations
// staggart.xyz

using UnityEngine;
using System.Collections;
using UnityEditor;
using UnityEditor.Callbacks;
using FAE;
using System;

namespace FAE
{
    [CustomEditor(typeof(PigmentMapGenerator))]
    public class PigmentMapGeneratorInspector : Editor
    {
        PigmentMapGenerator pmg;

        new SerializedObject serializedObject;

        SerializedProperty isMultiTerrain;
        SerializedProperty isMegaSplat;

        SerializedProperty terrainObjects;

        SerializedProperty manualInput;
        SerializedProperty resIdx;
        SerializedProperty useCustomPigmentMap;
        SerializedProperty inputPigmentMap;
        SerializedProperty layerMask;

        public static string[] reslist = new string[] { "64x64", "128x128", "256x256", "512x512", "1024x1024", "2048x2048", "4096x4096" };

        // Use this for initialization
        void OnEnable()
        {
            pmg = (PigmentMapGenerator)target;

            GetProperties();
        }

        private void GetProperties()
        {
            serializedObject = new SerializedObject(pmg);

            isMultiTerrain = serializedObject.FindProperty("isMultiTerrain");
            isMegaSplat = serializedObject.FindProperty("isMegaSplat");
            terrainObjects = serializedObject.FindProperty("terrainObjects");

            manualInput = serializedObject.FindProperty("manualInput");
            resIdx = serializedObject.FindProperty("resIdx");
            useCustomPigmentMap = serializedObject.FindProperty("useCustomPigmentMap");
            inputPigmentMap = serializedObject.FindProperty("customPigmentMap");
            layerMask = serializedObject.FindProperty("layerMask");

        }

        //Meta
        private string terrainInfo;
        private bool showHelp;

        public override void OnInspectorGUI()
        {
            DoHeader();

#if UNITY_2019_3_OR_NEWER
            if (UnityEngine.Rendering.GraphicsSettings.renderPipelineAsset)
            {
                EditorGUILayout.HelpBox("Not available in the Universal Render Pipeline.\n\nThe Stylized Grass Shader package is URP compatible", MessageType.Warning);

                GUILayout.Space(-32);
                using (new EditorGUILayout.HorizontalScope())
                {
                    GUILayout.FlexibleSpace();
                    if (GUILayout.Button("Open Asset Store", GUILayout.Width(120)))
                    {
                        Application.OpenURL("com.unity3d.kharma:content/143830");
                    }
                    GUILayout.Space(8);
                }
                GUILayout.Space(11);
            }
#endif

            EditorGUI.BeginChangeCheck();

            serializedObject.Update();

            DrawTerrainInfo();

            EditorGUILayout.PropertyField(useCustomPigmentMap, new GUIContent("Custom pigment map"));
            if (showHelp) EditorGUILayout.HelpBox("This option allows you to assign a custom pigment map, rather than rendering one.", MessageType.Info);

            EditorGUILayout.Space();

            //Custom pigment map
            if (useCustomPigmentMap.boolValue)
            {
                EditorGUILayout.PropertyField(inputPigmentMap, new GUIContent("Input"));

                if (showHelp) EditorGUILayout.HelpBox("Grass heightmap should be stored in the alpha channel.", MessageType.Info);

                if (pmg.customPigmentMap)
                {
                    //Check if input heightmap is readable
                    try
                    {
                        pmg.customPigmentMap.GetPixel(0, 0);
                    }
                    catch (UnityException e)
                    {
                        if (e.Message.StartsWith("Texture '" + pmg.customPigmentMap.name + "' is not readable"))
                        {

                            EditorGUILayout.HelpBox("Please enable the Read/Write option on texture \"" + pmg.customPigmentMap.name + "\"\n\nIt accessed be read otherwise.", MessageType.Error);
                        }
                    }
                }

                EditorGUILayout.Space();

            }

            //If terrain list is empty, expand it
            if (isMultiTerrain.boolValue && terrainObjects.arraySize == 0 && !manualInput.boolValue)
            {
                terrainObjects.isExpanded = true;
            }

            DoTerrainList();

            EditorGUILayout.Space();

            if (!useCustomPigmentMap.boolValue)
            {
                //Safety check, required for preventing errors when updating from 1.1.2 to 1.2.0
                //if (pmg.terrains == null || pmg.terrains.Length == 0) return;

                //If single terrain without any textures
                if (!isMegaSplat.boolValue)
                {
#if UNITY_2018_3_OR_NEWER
                    if (!isMultiTerrain.boolValue && pmg.workflow == TerrainUVUtil.Workflow.Terrain && pmg.terrains[0].terrainData.terrainLayers.Length == 0)
#else
                    if (!isMultiTerrain.boolValue && pmg.workflow == TerrainUVUtil.Workflow.Terrain && pmg.terrains[0].terrainData.splatPrototypes.Length == 0)
#endif
                    {
                        EditorGUILayout.HelpBox("Assign at least one texture to your terrain", MessageType.Error);
                        return;
                    }
                }

                DoHeightMap();

                DoTexTransforms();

                DoRenderer();
            }

            EditorGUILayout.Space();

            //Button
            //If multi terrain, with no objects assigned, don't show Generate button
            if (isMultiTerrain.boolValue && terrainObjects.arraySize == 0 && !manualInput.boolValue)
            {
                EditorGUILayout.HelpBox("Assign at least one terrain object", MessageType.Error);
            }

            EditorGUI.BeginDisabledGroup(isMultiTerrain.boolValue && terrainObjects.arraySize == 0 && !manualInput.boolValue);
            string buttonLabel = (useCustomPigmentMap.boolValue) ? "Assign" : "Generate";
            if (GUILayout.Button(buttonLabel, GUILayout.Height(40f)))
            {
                pmg.Generate();
            }
            EditorGUI.EndDisabledGroup();
            EditorGUILayout.Space();

            DoPreview();

            //GUIHelper.DrawFooter();

            serializedObject.ApplyModifiedProperties();

            if (GUI.changed || EditorGUI.EndChangeCheck())
            {
                EditorUtility.SetDirty((PigmentMapGenerator)target);
                EditorUtility.SetDirty(this);

            }
        }

        private void DoHeader()
        {

            EditorGUILayout.BeginHorizontal();
            showHelp = GUILayout.Toggle(showHelp, "Toggle help", "Button");
            GUILayout.Label("FAE Pigmentmap Generator", GUIHelper.Header);
            EditorGUILayout.EndHorizontal();
            if (showHelp) EditorGUILayout.HelpBox("This renders a color map from your terrain, which is used by the \"FAE/Grass\" shader to blend the grass color with the terrain.", MessageType.Info);
            if (showHelp) EditorGUILayout.HelpBox("If you'd like some objects to be included, like cliffs, parent them under your terrain object.", MessageType.Info);
            if (showHelp) EditorGUILayout.HelpBox("For a multi-terrain setup, add this script to the parent object of your terrain tiles/chunks.", MessageType.Info);

            EditorGUILayout.Space();
        }

        private void DrawTerrainInfo()
        {
            EditorGUILayout.PropertyField(manualInput, new GUIContent("Manual input"));
            if (showHelp) EditorGUILayout.HelpBox("Allows you to manually set the terrain's size, center and corner values. Particularly useful if your terrain(s) sits in a different scene.", MessageType.Info);

            if (manualInput.boolValue)
            {
                pmg.targetCenterPosition = EditorGUILayout.Vector3Field("Center", pmg.targetCenterPosition);
                pmg.targetSize = EditorGUILayout.Vector3Field("Size", pmg.targetSize);
                pmg.targetOriginPosition = EditorGUILayout.Vector3Field("Corner/Origin", pmg.targetOriginPosition);

                EditorGUILayout.Space();

                using (new EditorGUILayout.HorizontalScope())
                {
                    GUILayout.FlexibleSpace();
                    if (GUILayout.Button("Apply", EditorStyles.miniButton))
                    {
                        Shader.SetGlobalVector("_TerrainUV", new Vector4(pmg.targetSize.x, pmg.targetSize.z, Mathf.Abs(pmg.targetOriginPosition.x), Mathf.Abs(pmg.targetOriginPosition.z)));
                    }
                }

                return;
            }

            terrainInfo = string.Format("Size:           ({0},{1},{2}) \nCenter:       ({3},{4}) \nCorner:       ({5},{6})",
                Mathf.Round(pmg.targetSize.x),
                Mathf.Round(pmg.targetSize.y),
                Mathf.Round(pmg.targetSize.z),
                Mathf.Round(pmg.targetCenterPosition.x),
                Mathf.Round(pmg.targetCenterPosition.z),
                Mathf.Round(pmg.targetOriginPosition.x),
                Mathf.Round(pmg.targetOriginPosition.z)
             );

            EditorGUILayout.HelpBox(terrainInfo, MessageType.Info);

            GUILayout.Space(-32);
            using (new EditorGUILayout.HorizontalScope())
            {
                GUILayout.FlexibleSpace();
                pmg.showArea = GUILayout.Toggle(pmg.showArea, new GUIContent(" Show area", EditorGUIUtility.IconContent("Prefab Icon").image), "Button", GUILayout.MaxHeight(17f));
                GUILayout.Space(8);
            }
            GUILayout.Space(11);

        }

        private void DoTerrainList()
        {
            if (isMultiTerrain.boolValue && !manualInput.boolValue)
            {
                EditorGUILayout.PropertyField(terrainObjects, new GUIContent("Terrain objects"), true);

                if (terrainObjects.isExpanded)
                {
                    EditorGUILayout.HelpBox("The first object in the array must be the corner chunk, where the terrain continues on the postive X and Z axis", MessageType.Warning);

                    using (new EditorGUILayout.HorizontalScope())
                    {
                        if (GUILayout.Button("Assign all child objects"))
                        {
                            pmg.GetChildTerrainObjects(pmg.transform);
                        }
                        if (GUILayout.Button("Add active terrains"))
                        {
                            AssignActiveTerrains();
                        }
                    }
                }
            }
            else
            {
                //Single terrain, don't show array    
            }
        }

        private void DoHeightMap()
        {

            EditorGUILayout.BeginVertical(EditorStyles.helpBox);

            //If is single terrain
            if (!isMultiTerrain.boolValue && pmg.workflow == TerrainUVUtil.Workflow.Terrain && !isMegaSplat.boolValue && !manualInput.boolValue)
            {

                EditorGUILayout.LabelField("Grass heightmap", EditorStyles.boldLabel);
                EditorGUILayout.Space();

                pmg.heightmapChannel = (PigmentMapGenerator.HeightmapChannel)EditorGUILayout.EnumPopup("Height source material", pmg.heightmapChannel);
                if (showHelp) EditorGUILayout.HelpBox("This is the texture whose painted weight will determine the grass height \n\nThe effect can be controlled through the \"Heightmap influence\" parameter on the FAE/Grass shader", MessageType.None);

                /*
                if (pmg.heightmapChannel > 0)
                {
                    using (new EditorGUILayout.HorizontalScope())
                    {
                        GUILayout.FlexibleSpace();
                        EditorGUILayout.LabelField(pmg.terrains[0].terrainData.splatPrototypes[(int)pmg.heightmapChannel - 1].texture.name);
                    }
                }
                */
            }
            //If mesh or multi terrain
            else
            {
                //Field to assign heightmap texture
                EditorGUILayout.LabelField("Input grass heightmap (optional)", EditorStyles.boldLabel);
                EditorGUILayout.Space();

                pmg.inputHeightmap = EditorGUILayout.ObjectField("Heightmap", pmg.inputHeightmap, typeof(Texture2D), false) as Texture2D;

                if (showHelp) EditorGUILayout.HelpBox("This information is used in the \"FAE/Grass\" shader to make the grass shorter where desired", MessageType.Info);

                if (pmg.inputHeightmap)
                {
                    //Check if input heightmap is readable
                    try
                    {
                        pmg.inputHeightmap.GetPixel(0, 0);
                    }
                    catch (UnityException e)
                    {
                        if (e.Message.StartsWith("Texture '" + pmg.inputHeightmap.name + "' is not readable"))
                        {

                            EditorGUILayout.HelpBox("Please enable Read/Write on texture \"" + pmg.inputHeightmap.name + "\"", MessageType.Error);
                        }
                    }
                }

            }

            EditorGUILayout.Space();

            EditorGUILayout.EndVertical();
        }

        private void DoTexTransforms()
        {
            if (pmg.workflow == TerrainUVUtil.Workflow.Terrain) return;

            EditorGUILayout.BeginVertical(EditorStyles.helpBox);

            EditorGUILayout.LabelField("Texture transformation", EditorStyles.boldLabel);
            EditorGUILayout.Space();
            if (showHelp) EditorGUILayout.HelpBox("The UV's of your mesh terrain may differ, so these options allow you to compensate for this.", MessageType.Info);

            pmg.flipHortizontally = EditorGUILayout.Toggle("Flip horizontally", pmg.flipHortizontally);
            pmg.flipVertically = EditorGUILayout.Toggle("Flip vertically", pmg.flipVertically);
            pmg.textureRotation = (PigmentMapGenerator.TextureRotation)EditorGUILayout.EnumPopup("Rotation", pmg.textureRotation);

            EditorGUILayout.Space();
            EditorGUILayout.EndVertical();
        }

        private void DoRenderer()
        {
            EditorGUILayout.BeginVertical(EditorStyles.helpBox);

            EditorGUILayout.LabelField("Renderer", EditorStyles.boldLabel);
            EditorGUILayout.Space();

            if (manualInput.boolValue)
            {
                EditorGUILayout.PropertyField(layerMask, new GUIContent("Layer mask"));
                EditorGUILayout.HelpBox("Manual input mode requires terrains to be on a dedicated layer", MessageType.None);
            }

            resIdx.intValue = EditorGUILayout.Popup("Resolution", resIdx.intValue, reslist, new GUILayoutOption[0]);

            pmg.useAlternativeRenderer = EditorGUILayout.ToggleLeft("Using third-party terrain shader", pmg.useAlternativeRenderer);
            if (showHelp) EditorGUILayout.HelpBox("Some third-party terrain shaders require you to use this, otherwise the result may be black.", MessageType.Info);

            if (pmg.useAlternativeRenderer) pmg.renderLightBrightness = EditorGUILayout.Slider("Brightness adjustment", pmg.renderLightBrightness, 0f, 1f);
            if (pmg.useAlternativeRenderer && showHelp) EditorGUILayout.HelpBox("To compensate for any shader variations on the terrain, you can use this to increase the brightness of the pigment map, in case it turns out too dark/bright.", MessageType.Info);

            EditorGUILayout.Space();
            EditorGUILayout.EndVertical();
        }

        private void DoPreview()
        {
            if (!useCustomPigmentMap.boolValue)
            {
                //Pigment map preview
                if (!pmg.pigmentMap) return;

                EditorGUILayout.BeginHorizontal();
                EditorGUILayout.LabelField(string.Format("Output pigment map ({0}x{0})", pmg.pigmentMap.height), EditorStyles.boldLabel);
                EditorGUILayout.EndHorizontal();

                Rect cRect = EditorGUILayout.GetControlRect();
                using (new EditorGUILayout.HorizontalScope())
                {
                    EditorGUI.DrawPreviewTexture(new Rect(cRect.x, cRect.y, 150f, 150f), pmg.pigmentMap, null, ScaleMode.ScaleAndCrop);
                }
                GUILayout.Space(140f);

                //Single terrain
                if (!isMultiTerrain.boolValue)
                {
                    if (pmg.workflow == TerrainUVUtil.Workflow.Terrain)
                    {
                        if (pmg.hasTerrainData)
                        {
                            EditorGUILayout.LabelField("The output texture file is stored next to the TerrainData asset", EditorStyles.helpBox);
                        }
                        else
                        {
                            EditorGUILayout.LabelField("The output texture file is stored next to the scene file", EditorStyles.helpBox);
                        }
                    }
                    else if (pmg.workflow == TerrainUVUtil.Workflow.Mesh)
                    {
                        EditorGUILayout.LabelField("The output texture file is stored next to the material file", EditorStyles.helpBox);
                    }
                }
                //Multi terrain
                else
                {
                    if (pmg.workflow == TerrainUVUtil.Workflow.Terrain)
                    {
                        EditorGUILayout.LabelField("The output texture file is stored next to the scene file", EditorStyles.helpBox);
                    }
                    else if (pmg.workflow == TerrainUVUtil.Workflow.Mesh)
                    {
                        EditorGUILayout.LabelField("The output texture file is stored next to the material file", EditorStyles.helpBox);
                    }
                }
            }
        }

        private void AssignActiveTerrains()
        {
            Terrain[] terrains = Terrain.activeTerrains;
            pmg.terrainObjects = new GameObject[terrains.Length];

            for (int i = 0; i < terrains.Length; i++)
            {
                pmg.terrainObjects[i] = terrains[i].gameObject;
            }
        }

    }
}