/**
 * Repairs missing pb_Object and pb_Entity references.  It is based
 * on this article by Unity Gems: http://unitygems.com/lateral1/
 */

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

/**
 * Extends MonoBehaviour Inspector, automatically fixing missing script
 * references (typically caused by ProBuilder upgrade process).
 */
[CustomEditor(typeof(MonoBehaviour))]
public class pb_MissingScriptEditor : Editor
{
#region Members

	static int index = 0;	///< general idea of where we are in terms of processing this scene.
	static float total;		///< general idea of how many missing script references are in this scene.

	static bool doFix = false;	///< while true, the inspector will attempt to cycle to broken gameobjects until none are found.
	static List<GameObject> unfixable = new List<GameObject>();	///< if a non-pb missing reference is encountered, need to let the iterator know not to bother,

	static MonoScript _mono_pb;	///< MonoScript assets
	static MonoScript _mono_pe;	///< MonoScript assets

	/**
	 * Load the pb_Object and pb_Entity classes to MonoScript assets.  Saves us from having to fall back on Reflection.
	 */
	static void LoadMonoScript()
	{
		GameObject go = new GameObject();

		pb_Object pb = go.AddComponent<pb_Object>();
		pb_Entity pe = go.AddComponent<pb_Entity>();

		_mono_pb = MonoScript.FromMonoBehaviour( pb );
		_mono_pe = MonoScript.FromMonoBehaviour( pe );

		DestroyImmediate(go);
	}

	public MonoScript pb_monoscript
	{
		get
		{
			if(_mono_pb == null) LoadMonoScript();
			return _mono_pb;
		}
	}

	public MonoScript pe_monoscript
	{
		get
		{
			if(_mono_pe == null) LoadMonoScript();
			return _mono_pe;
		}
	}
#endregion

	[MenuItem("Tools/" + pb_Constant.PRODUCT_NAME + "/Repair/Repair Missing Script References")]
	public static void MenuRepairMissingScriptReferences()
	{
		FixAllScriptReferencesInScene();
	}

	static void FixAllScriptReferencesInScene()
	{
		EditorApplication.ExecuteMenuItem("Window/Inspector");

		Object[] all = Resources.FindObjectsOfTypeAll(typeof(GameObject)).Where(x => ((GameObject)x).GetComponents<Component>().Any(n => n == null) ).ToArray();
		total = all.Length;

		unfixable.Clear();

		if(total > 1)
		{
			Undo.RecordObjects(all, "Fix missing script references");

			index = 0;
			doFix = true;

			Next();
		}
		else
		{
			EditorUtility.DisplayDialog("Success", "No missing ProBuilder script references found.", "Okay");
		}
	}

	/**
	 * Advance to the next gameobject with missing components.  If none are found, display dialog and exit.
	 */
	static void Next()
	{
		EditorUtility.DisplayProgressBar("Repair ProBuilder Script References", "Fixing " + (index+1) + " out of " + total + " objects in scene.", ((float)index/total) );

		// Cycle through FindObjectsOfType on every Next() because using a static list didn't work for some reason.
		foreach(GameObject go in Resources.FindObjectsOfTypeAll(typeof(GameObject)))
		{
			if(go.GetComponents<Component>().Any(x => x == null) && !unfixable.Contains(go))
			{
				if( !go.GetComponent<MeshFilter>() || !go.GetComponent<MeshFilter>().sharedMesh) {
					unfixable.Add(go);
					Debug.LogError (go.name + " probably needs deleting." , go);
					continue;
				}
				else if (go.GetComponent<MeshFilter>().sharedMesh.vertices.Length == 0) {
					unfixable.Add(go);
					Debug.LogError (go.name + " probably needs deleting." , go);
					continue;
				}

				if(	(PrefabUtility.GetPrefabType(go) == PrefabType.PrefabInstance ||
					 PrefabUtility.GetPrefabType(go) == PrefabType.Prefab ) )
				{
					GameObject pref = (GameObject)PrefabUtility.GetPrefabParent(go);



					if(pref && (pref.GetComponent<pb_Object>() || pref.GetComponent<pb_Entity>()))
					{
						unfixable.Add(go);
						continue;
					}


				}

				if(go.hideFlags != HideFlags.None)
				{
					unfixable.Add(go);
					continue;
				}

				Selection.activeObject = go;

				return;
			}
		}

		pb_Object[] pbs = (pb_Object[])Resources.FindObjectsOfTypeAll(typeof(pb_Object));

		for(int i = 0; i < pbs.Length; i++)
		{
			EditorUtility.DisplayProgressBar("Force Refresh ProBuilder Objects", "Refresh " + (i+1) + " out of " + total + " objects in scene.", ((float)i/pbs.Length) );

			pbs[i].ToMesh();
			pbs[i].Refresh();
			pbs[i].GenerateUV2();
		}


		EditorUtility.ClearProgressBar();

		EditorUtility.DisplayDialog("Success", "Successfully repaired " + total + " ProBuilder objects.", "Okay");

		if(!EditorApplication.SaveCurrentSceneIfUserWantsTo())
			Debug.LogWarning("Repaired script references will be lost on exit if this scene is not saved!");

		doFix = false;
		skipEvent = true;
	}

	/**
	 * SerializedProperty names found in pb_Entity.
	 */
	List<string> PB_OBJECT_SCRIPT_PROPERTIES = new List<string>()
	{
		"_sharedIndices",
		"_vertices",
		"_uv",
		"_sharedIndicesUV",
		"_quads"
	};

	/**
	 * SerializedProperty names found in pb_Object.
	 */
	List<string> PB_ENTITY_SCRIPT_PROPERTIES = new List<string>()
	{
		"pb",
		"userSetDimensions",
		"_entityType",
		"forceConvex"
	};

	// Prevents ArgumentException after displaying 'Done' dialog.  For some reason the Event loop skips layout phase after DisplayDialog.
	private static bool skipEvent = false;

	public override void OnInspectorGUI()
	{
		if(skipEvent && Event.current.type == EventType.Repaint)
		{
			skipEvent = false;
			return;
		}

		SerializedProperty scriptProperty = this.serializedObject.FindProperty("m_Script");

		if(scriptProperty == null || scriptProperty.objectReferenceValue != null)
		{
			if(doFix)
			{
				if(Event.current.type == EventType.Repaint)
				{
					Next();
				}
			}
			else
			{
				base.OnInspectorGUI();
			}

			return;
		}

		int pbObjectMatches = 0, pbEntityMatches = 0;

		// Shows a detailed tree view of all the properties in this serializedobject.
		// GUILayout.Label( SerializedObjectToString(this.serializedObject) );

		SerializedProperty iterator = this.serializedObject.GetIterator();

		iterator.Next(true);

		while( iterator.Next(true) )
		{
			if( PB_OBJECT_SCRIPT_PROPERTIES.Contains(iterator.name) )
				pbObjectMatches++;

			if( PB_ENTITY_SCRIPT_PROPERTIES.Contains(iterator.name) )
				pbEntityMatches++;
		}

		// If we can fix it, show the help box, otherwise just default inspector it up.
		if(pbObjectMatches >= 3 || pbEntityMatches >= 3)
		{
			EditorGUILayout.HelpBox("Missing Script Reference\n\nProBuilder can automatically fix this missing reference.  To fix all references in the scene, click \"Fix All in Scene\".  To fix just this one, click \"Reconnect\".", MessageType.Warning);
		}
		else
		{
			if(doFix)
			{
				unfixable.Add( ((Component)target).gameObject );
				Next();
				GUIUtility.ExitGUI();
				return;
			}
			else
			{
				base.OnInspectorGUI();
			}

			return;
		}

		GUI.backgroundColor = Color.green;

		if(!doFix)
		{
			if(GUILayout.Button("Fix All in Scene"))
			{
				FixAllScriptReferencesInScene();
				return;
			}
		}

		GUI.backgroundColor = Color.cyan;

		if((doFix && Event.current.type == EventType.Repaint) || GUILayout.Button("Reconnect"))
		{
			if(pbObjectMatches >= 3)	// only increment for pb_Object otherwise the progress bar will fill 2x faster than it should
			{
				index++;
			}
			else
			{
				// Make sure that pb_Object is fixed first if we're automatically cycling objects.
				if(doFix && ((Component)target).gameObject.GetComponent<pb_Object>() == null)
					return;
			}

			if(!doFix)
			{
				Undo.RegisterCompleteObjectUndo(target, "Fix missing reference.");
			}

			// Debug.Log("Fix: " + (pbObjectMatches > 2 ? "pb_Object" : "pb_Entity") + "  " + ((Component)target).gameObject.name);

			scriptProperty.objectReferenceValue = pbObjectMatches >= 3 ? pb_monoscript : pe_monoscript;
			scriptProperty.serializedObject.ApplyModifiedProperties();
			scriptProperty = this.serializedObject.FindProperty("m_Script");
			scriptProperty.serializedObject.Update();

			if(doFix)
				Next();

			GUIUtility.ExitGUI();
		}

		GUI.backgroundColor = Color.white;
	}

	/**
	 * Returns a formatted string with all properties in serialized object.
	 */
	static string SerializedObjectToString(SerializedObject serializedObject)
	{
		System.Text.StringBuilder sb = new System.Text.StringBuilder();

		if(serializedObject == null)
		{
			sb.Append("NULL");
			return sb.ToString();
		}

		SerializedProperty iterator = serializedObject.GetIterator();

		iterator.Next(true);


		while( iterator.Next(true) )
		{
			string tabs = "";
			for(int i = 0; i < iterator.depth; i++) tabs += "\t";

			sb.AppendLine(tabs + iterator.name + (iterator.propertyType == SerializedPropertyType.ObjectReference && iterator.type.Contains("Component") && iterator.objectReferenceValue == null ? " -> NULL" : "") );

			tabs += "  - ";

			sb.AppendLine(tabs + "Type: (" + iterator.type + " / " + iterator.propertyType + " / " + " / " + iterator.name + ")");
			sb.AppendLine(tabs + iterator.propertyPath);
			sb.AppendLine(tabs + "Value: " + SerializedPropertyValue(iterator));
		}

		return sb.ToString();
	}

	/**
	 * Return a string from the value of a SerializedProperty.
	 */
	static string SerializedPropertyValue(SerializedProperty sp)
	{
		switch(sp.propertyType)
		{
			case SerializedPropertyType.Integer:
				return sp.intValue.ToString();

			case SerializedPropertyType.Boolean:
				return sp.boolValue.ToString();

			case SerializedPropertyType.Float:
				return sp.floatValue.ToString();

			case SerializedPropertyType.String:
				return sp.stringValue.ToString();

			case SerializedPropertyType.Color:
				return sp.colorValue.ToString();

			case SerializedPropertyType.ObjectReference:
				return (sp.objectReferenceValue == null ? "null" : sp.objectReferenceValue.name);

			case SerializedPropertyType.LayerMask:
				return sp.intValue.ToString();

			case SerializedPropertyType.Enum:
				return sp.enumValueIndex.ToString();

			case SerializedPropertyType.Vector2:
				return sp.vector2Value.ToString();

			case SerializedPropertyType.Vector3:
				return sp.vector3Value.ToString();

			// Not public api as of 4.3?
			// case SerializedPropertyType.Vector4:
			// 	return sp.vector4Value.ToString();

			case SerializedPropertyType.Rect:
				return sp.rectValue.ToString();

			case SerializedPropertyType.ArraySize:
				return sp.intValue.ToString();

			case SerializedPropertyType.Character:
				return "Character";

			case SerializedPropertyType.AnimationCurve:
				return sp.animationCurveValue.ToString();

			case SerializedPropertyType.Bounds:
				return sp.boundsValue.ToString();

			case SerializedPropertyType.Gradient:
				return "Gradient";

			default:
				return "Unknown type";
		}
	}

}