namespace Mapbox.Editor
{
	using UnityEngine;
	using UnityEditor;
	using System;
	using System.Collections.Generic;
	using System.Linq;
	using System.Reflection;
	using Mapbox.Unity.Map;
	using Mapbox.Unity.MeshGeneration.Data;

	/// <summary>
	/// EditorHelper class provides methods for working with serialzed properties.
	/// Methods in this class are based on the spacepuppy-unity-framework, available at the url below.
	/// https://github.com/lordofduct/spacepuppy-unity-framework/tree/d8d592e212b26cad53264421d22c3d26c6799923/SpacepuppyBaseEditor.
	/// </summary>
	public static class EditorHelper
	{

		[UnityEditor.Callbacks.DidReloadScripts]
		private static void OnScriptsReloaded()
		{
			if (Application.isEditor)
			{
				AbstractMap abstractMap = UnityEngine.Object.FindFirstObjectByType<AbstractMap>();

				if (abstractMap == null)
				{
					return;
				}

				UnityTile[] unityTiles = abstractMap.GetComponentsInChildren<UnityTile>();

				for (int i = 0; i < unityTiles.Length; i++)
				{
					UnityEngine.Object.DestroyImmediate(unityTiles[i].gameObject);
				}

				abstractMap.DestroyChildObjects();
				if (EditorApplication.isPlaying)
				{
					abstractMap.ResetMap();
					return;
				}
				if (abstractMap.IsEditorPreviewEnabled == true)
				{
					if (EditorApplication.isPlayingOrWillChangePlaymode)
					{
						return;
					}
					else
					{
						abstractMap.DisableEditorPreview();
						abstractMap.EnableEditorPreview();
					}
				}
			}
		}


		public static void CheckForModifiedProperty<T>(SerializedProperty property, T targetObject, bool forceHasChanged = false)
		{
			MapboxDataProperty targetObjectAsDataProperty = GetMapboxDataPropertyObject(targetObject);
			if (targetObjectAsDataProperty != null)
			{
				targetObjectAsDataProperty.HasChanged = forceHasChanged || property.serializedObject.ApplyModifiedProperties();
			}
		}

		public static void CheckForModifiedProperty(SerializedProperty property, bool forceHasChanged = false)
		{
			CheckForModifiedProperty(property, GetTargetObjectOfProperty(property), forceHasChanged);
		}

		public static MapboxDataProperty GetMapboxDataPropertyObject<T>(T targetObject)
		{
			return targetObject as MapboxDataProperty;
		}

		public static bool DidModifyProperty<T>(SerializedProperty property, T targetObject)
		{
			MapboxDataProperty targetObjectAsDataProperty = targetObject as MapboxDataProperty;
			return (property.serializedObject.ApplyModifiedProperties() && targetObjectAsDataProperty != null);
		}

		public static bool DidModifyProperty(SerializedProperty property)
		{
			return DidModifyProperty(property, GetTargetObjectOfProperty(property));
		}

		public static IEnumerable<SerializedProperty> GetChildren(this SerializedProperty property)
		{
			property = property.Copy();
			var nextElement = property.Copy();
			bool hasNextElement = nextElement.NextVisible(false);
			if (!hasNextElement)
			{
				nextElement = null;
			}

			property.NextVisible(true);
			while (true)
			{
				if ((SerializedProperty.EqualContents(property, nextElement)))
				{
					yield break;
				}

				yield return property;

				bool hasNext = property.NextVisible(false);
				if (!hasNext)
				{
					break;
				}
			}
		}

		public static System.Type GetTargetType(this SerializedObject obj)
		{
			if (obj == null) return null;

			if (obj.isEditingMultipleObjects)
			{
				var c = obj.targetObjects[0];
				return c.GetType();
			}
			else
			{
				return obj.targetObject.GetType();
			}
		}


		/// <summary>
		/// Gets the object the property represents.
		/// </summary>
		/// <param name="prop"></param>
		/// <returns></returns>
		public static object GetTargetObjectOfProperty(SerializedProperty prop)
		{
			var path = prop.propertyPath.Replace(".Array.data[", "[");
			object obj = prop.serializedObject.targetObject;
			var elements = path.Split('.');
			foreach (var element in elements)
			{
				if (element.Contains("["))
				{
					var elementName = element.Substring(0, element.IndexOf("[", StringComparison.CurrentCulture));
					var index = System.Convert.ToInt32(element.Substring(element.IndexOf("[", StringComparison.CurrentCulture)).Replace("[", "").Replace("]", ""));
					obj = GetValue_Imp(obj, elementName, index);
				}
				else
				{
					obj = GetValue_Imp(obj, element);
				}
			}
			return obj;
		}

		public static void SetTargetObjectOfProperty(SerializedProperty prop, object value)
		{
			var path = prop.propertyPath.Replace(".Array.data[", "[");
			object obj = prop.serializedObject.targetObject;
			var elements = path.Split('.');
			foreach (var element in elements.Take(elements.Length - 1))
			{
				if (element.Contains("["))
				{
					var elementName = element.Substring(0, element.IndexOf("[", StringComparison.CurrentCulture));
					var index = System.Convert.ToInt32(element.Substring(element.IndexOf("[", StringComparison.CurrentCulture)).Replace("[", "").Replace("]", ""));
					obj = GetValue_Imp(obj, elementName, index);
				}
				else
				{
					obj = GetValue_Imp(obj, element);
				}
			}

			if (System.Object.ReferenceEquals(obj, null)) return;

			try
			{
				var element = elements.Last();

				if (element.Contains("["))
				{
					var tp = obj.GetType();
					var elementName = element.Substring(0, element.IndexOf("[", StringComparison.CurrentCulture));
					var index = System.Convert.ToInt32(element.Substring(element.IndexOf("[", StringComparison.CurrentCulture)).Replace("[", "").Replace("]", ""));
					var field = tp.GetField(elementName, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
					var arr = field.GetValue(obj) as System.Collections.IList;
					arr[index] = value;
				}
				else
				{
					var tp = obj.GetType();
					var field = tp.GetField(element, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
					if (field != null)
					{
						field.SetValue(obj, value);
					}
				}

			}
			catch
			{
				return;
			}
		}


		/// <summary>
		/// Gets the object that the property is a member of
		/// </summary>
		/// <param name="prop"></param>
		/// <returns></returns>
		public static object GetTargetObjectWithProperty(SerializedProperty prop)
		{
			var path = prop.propertyPath.Replace(".Array.data[", "[");
			object obj = prop.serializedObject.targetObject;
			var elements = path.Split('.');
			foreach (var element in elements.Take(elements.Length - 1))
			{
				if (element.Contains("["))
				{
					var elementName = element.Substring(0, element.IndexOf("[", StringComparison.CurrentCulture));
					var index = System.Convert.ToInt32(element.Substring(element.IndexOf("[", StringComparison.CurrentCulture)).Replace("[", "").Replace("]", ""));
					obj = GetValue_Imp(obj, elementName, index);
				}
				else
				{
					obj = GetValue_Imp(obj, element);
				}
			}
			return obj;
		}

		private static object GetValue_Imp(object source, string name)
		{
			if (source == null)
				return null;
			var type = source.GetType();

			while (type != null)
			{
				var f = type.GetField(name, BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance);
				if (f != null)
					return f.GetValue(source);

				var p = type.GetProperty(name, BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);
				if (p != null)
					return p.GetValue(source, null);

				type = type.BaseType;
			}
			return null;
		}

		private static object GetValue_Imp(object source, string name, int index)
		{
			var enumerable = GetValue_Imp(source, name) as System.Collections.IEnumerable;
			if (enumerable == null) return null;
			var enm = enumerable.GetEnumerator();

			for (int i = 0; i <= index; i++)
			{
				if (!enm.MoveNext()) return null;
			}
			return enm.Current;
		}

		public static int GetChildPropertyCount(SerializedProperty property, bool includeGrandChildren = false)
		{
			var pstart = property.Copy();
			var pend = property.GetEndProperty();
			int cnt = 0;

			pstart.Next(true);
			while (!SerializedProperty.EqualContents(pstart, pend))
			{
				cnt++;
				pstart.Next(includeGrandChildren);
			}

			return cnt;
		}
	}
}