using System;

using System.Reflection;

using System.Collections.Generic;

using UnityEngine;



namespace Leap.Unity.DevGui {

  using Query;



  public class Dev : MonoBehaviour {

    private static bool _enabled = false;

    private static Vector2 _scroll;



    private static Dictionary<object, List<DevElement>> _registered;



    private static HashSet<string> _expandedCategories;

    private static List<CategoryInfo> _categories;



    private class CategoryInfo {

      public string name;

      public List<DevElementInfo> elementInfo = new List<DevElementInfo>();



      public CategoryInfo(string name) {

        this.name = name;

      }

    }



    private class DevElementInfo {

      public List<object> targets;

      public DevElement element;

    }



    static Dev() {

      _registered = new Dictionary<object, List<DevElement>>();

      _expandedCategories = new HashSet<string>();

      _categories = new List<CategoryInfo>();

    }



    private static Dev _devInstance;



    [RuntimeInitializeOnLoadMethod]

    private static void ensureInstanceExists() {

      if (_devInstance == null) {

        _devInstance = FindObjectOfType<Dev>();

        if (_devInstance == null) {

          _devInstance = new GameObject("__Dev").AddComponent<Dev>();

          DontDestroyOnLoad(_devInstance.gameObject);

        }

      }

    }



    private static void onOpenGui() {

      _registered.Clear();



      var objs = FindObjectsOfType<MonoBehaviour>();

      foreach (var obj in objs) {

        List<DevElement> elements;

        if (DevElementBuilder.TryBuildElements(obj, out elements)) {

          _registered.Add(obj, elements);

        }

      }



      rebuildCategoryMap();

    }



    private static void rebuildCategoryMap() {

      _categories.Clear();

      var typeMap = new Dictionary<Type, KeyValuePair<List<object>, List<DevElement>>>();



      foreach (var reg in _registered) {

        var obj = reg.Key;

        var elements = reg.Value;



        KeyValuePair<List<object>, List<DevElement>> pair;

        if (!typeMap.TryGetValue(obj.GetType(), out pair)) {

          pair = new KeyValuePair<List<object>, List<DevElement>>(new List<object>(), elements);

          typeMap[obj.GetType()] = pair;

        }

        pair.Key.Add(obj);

      }



      foreach (var pair in typeMap) {

        var objs = pair.Value.Key;

        var elements = pair.Value.Value;



        foreach (var element in elements) {

          CategoryInfo categoryInfo = _categories.Query().FirstOrDefault(t => t.name == element.category);

          if (categoryInfo == null) {

            categoryInfo = new CategoryInfo(element.category);

            _categories.Add(categoryInfo);

          }



          categoryInfo.elementInfo.Add(new DevElementInfo() {

            targets = new List<object>(objs),

            element = element.Clone()

          });

        }

      }



      _categories.Sort((a, b) => a.name.CompareTo(b.name));

    }



    private void Update() {

      if (Input.GetKeyDown(KeyCode.F12)) {

        _enabled = !_enabled;

        if (_enabled) {

          onOpenGui();

        }

      }

    }



    private void OnGUI() {

      if (!Application.isPlaying) {

        return;

      }



      if (_enabled) {

        GUIStyle boxStyle = new GUIStyle();

        boxStyle.normal.background = Resources.Load<Texture2D>("ImageBackground");

        boxStyle.border = new RectOffset(4, 4, 4, 4);



        GUIStyle overlayStyle = new GUIStyle();

        overlayStyle.normal.background = Resources.Load<Texture2D>("ImageOverlay");

        overlayStyle.border = new RectOffset(4, 4, 4, 4);



        GUIStyle overlayFooterStyle = new GUIStyle();

        overlayFooterStyle.normal.background = Resources.Load<Texture2D>("ImageOverlayFooter");

        overlayFooterStyle.border = new RectOffset(4, 4, 4, 4);



        GUIStyle foldoutStyle = new GUIStyle();

        foldoutStyle.normal.background = Resources.Load<Texture2D>("ImageFoldout");

        foldoutStyle.border = new RectOffset(4, 4, 4, 4);



        GUIStyle blackStyle = new GUIStyle(GUIStyle.none);

        blackStyle.normal.background = Resources.Load<Texture2D>("ImageBlack");

        blackStyle.border = new RectOffset(4, 4, 4, 4);



        GUIStyle barStyle = new GUIStyle(GUIStyle.none);

        barStyle.normal.background = Resources.Load<Texture2D>("ImageBar");

        barStyle.border = new RectOffset(4, 4, 0, 0);



        _scroll = GUILayout.BeginScrollView(_scroll, GUIStyle.none, GUIStyle.none);

        GUILayout.BeginVertical(boxStyle);

        GUILayout.Label("-- Leap Motion Dev Window --");



        for (int i = 0; i < _categories.Count; i++) {

          var category = _categories[i];

          bool isExpanded = _expandedCategories.Contains(category.name);



          if (i == _categories.Count - 1 && !isExpanded) {

            GUILayout.BeginVertical(overlayFooterStyle);

          } else {

            GUILayout.BeginVertical(overlayStyle);

          }



          bool shouldBeExpanded = GUILayout.Toggle(isExpanded, category.name);

          GUILayout.EndVertical();



          if (shouldBeExpanded) {

            _expandedCategories.Add(category.name);

          } else {

            _expandedCategories.Remove(category.name);

          }



          if (shouldBeExpanded) {

            GUILayout.BeginHorizontal();

            GUILayout.Box("", blackStyle, GUILayout.Width(4), GUILayout.ExpandHeight(true));

            GUILayout.BeginVertical(foldoutStyle);



            for (int j = 0; j < category.elementInfo.Count; j++) {

              if (j != 0) {

                GUILayout.Box("", barStyle, GUILayout.Height(1), GUILayout.ExpandWidth(true));

              }



              category.elementInfo[j].element.Draw(category.elementInfo[j].targets);

            }



            GUILayout.EndVertical();

            GUILayout.EndHorizontal();

          }

        }



        GUILayout.EndVertical();

        GUILayout.EndScrollView();

      }

    }

  }

}