using System;
using System.Linq;
using System.Collections.Generic;
using UnityEngine;

namespace UnityEditor.Graphs.Material 
{
	public enum PreviewState
	{
		Full = 0,
		Selected = 1,
		Off = 2
	}

	public class MaterialProperties : ScriptableObject, IGenerateGraphProperties
	{
		private Vector2 m_ScrollPos;

		[SerializeField]
		List<ShaderProperty> m_ShaderProperties = new List<ShaderProperty> ();

		[SerializeField]
		public int previewState;
		
		//static GUIContent[] previewOptions;

		public event EventHandler OnChangePreviewState;

		/*static MaterialProperties ()
		{
			previewOptions = Enum.GetNames (typeof (PreviewState)).Select (x => new GUIContent (x)).ToArray ();
		}*/

		public void OnEnable ()
		{
			if (OnChangePreviewState != null)
				OnChangePreviewState ((PreviewState)previewState, null);
		}

		public void DoGUI (List<Node> nodes)
		{
			//m_ScrollPos1 = BeginArea ("Options", m_ScrollPos1);

			/*GUILayout.BeginHorizontal ();
			GUILayout.Label ("Preview", EditorStyles.largeLabel);
			EditorGUI.BeginChangeCheck ();
			previewState = EditorGUILayout.CycleButton (previewState, previewOptions, EditorStyles.miniButton);
			if (EditorGUI.EndChangeCheck () && OnChangePreviewState != null)
				OnChangePreviewState ((PreviewState)previewState, null);
			GUILayout.EndHorizontal ();*/

			//EndArea ();

			m_ScrollPos = BeginArea ("Exposed Properties", m_ScrollPos);

			if (GUILayout.Button ("Add Property"))
				AddProperty ();

			var propsToRemove = new List<ShaderProperty> ();
			foreach (var property in m_ShaderProperties)
			{
				// property changed
				bool nameChanged;
				bool valuesChanged;
				property.PropertyOnGUI (out nameChanged, out valuesChanged);
				if (nameChanged || valuesChanged)
				{
					foreach (var node in nodes.Where(x => x is PropertyNode).Cast<PropertyNode>())
					{
						node.RefreshBoundProperty (property, nameChanged);
					}
					foreach (var node in nodes.Where(x => x is UVNode).Cast<UVNode>())
					{
						node.RefreshBoundProperty (property, nameChanged);
					}
				}
				if (GUILayout.Button ("Remove"))
				{
					propsToRemove.Add (property);
				}
				EditorGUILayout.Separator ();
			}
			EndArea ();

			foreach (var prop in propsToRemove)
			{
				foreach (var node in nodes.Where(x => x is PropertyNode).Cast<PropertyNode>())
				{
					node.UnbindProperty (prop);
				}
				foreach (var node in nodes.Where(x => x is UVNode).Cast<UVNode>())
				{
					node.UnbindProperty (prop);
				}

				m_ShaderProperties.Remove (prop);
			}
		}

		private void AddProperty()
		{
			var menu = new GenericMenu ();
			menu.AddItem (new GUIContent ("Texture"), false, CreateProperty<TextureProperty>);
			menu.AddItem (new GUIContent ("Color"), false, CreateProperty<ColorProperty>);
			menu.AddItem (new GUIContent ("Vector"), false, CreateProperty<VectorProperty>);
			menu.ShowAsContext ();
		}

		private void CreateProperty <T> () where T : ShaderProperty
		{
			var createdProperty = CreateInstance<T> ();
			createdProperty.name = typeof(T).Name;
			createdProperty.hideFlags = HideFlags.HideInHierarchy;
			m_ShaderProperties.Add (createdProperty);
			AssetDatabase.AddObjectToAsset (createdProperty, this);
		}

		static Vector2 BeginArea (string title, Vector2 scrollPos)
		{
			DoHeader (title);
			scrollPos = GUILayout.BeginScrollView (scrollPos);
			GUILayout.BeginVertical ();
			return scrollPos;
		}

		static void EndArea ()
		{
			GUILayout.EndVertical ();
			GUILayout.EndScrollView();
		}

		static void DoHeader (string title)
		{
			GUILayout.BeginHorizontal (/*EditorStyles.inspectorBig*/);
			GUILayout.BeginVertical ();
			GUILayout.Label (title, EditorStyles.largeLabel);
			GUILayout.EndVertical ();
			GUILayout.EndHorizontal ();
		}

		public IEnumerable<ShaderProperty> GetPropertiesForPropertyType(PropertyType propertyType)
		{
			return m_ShaderProperties.Where(x => x.propertyType == propertyType);
		}

		public void GenerateSharedProperties (PropertyGenerator shaderProperties, ShaderGenerator propertyUsages, GenerationMode generationMode) 
		{
			foreach (var property in m_ShaderProperties)
			{
				property.GeneratePropertyBlock (shaderProperties, generationMode);
				property.GeneratePropertyUsages (propertyUsages, generationMode);
			}
		}
	}
}