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

namespace XNodeEditor {
    public static class NodeEditorPreferences {
        public enum NoodleType { Curve, Line, Angled }

        /// <summary> The last editor we checked. This should be the one we modify </summary>
        private static XNodeEditor.NodeGraphEditor lastEditor;
        /// <summary> The last key we checked. This should be the one we modify </summary>
        private static string lastKey = "xNode.Settings";

        private static Dictionary<string, Color> typeColors = new Dictionary<string, Color>();
        private static Dictionary<string, Settings> settings = new Dictionary<string, Settings>();

        [System.Serializable]
        public class Settings : ISerializationCallbackReceiver {
            [SerializeField] private Color32 _gridLineColor = new Color(0.45f, 0.45f, 0.45f);
            public Color32 gridLineColor { get { return _gridLineColor; } set { _gridLineColor = value; _gridTexture = null; _crossTexture = null; } }

            [SerializeField] private Color32 _gridBgColor = new Color(0.18f, 0.18f, 0.18f);
            public Color32 gridBgColor { get { return _gridBgColor; } set { _gridBgColor = value; _gridTexture = null; } }

            public Color32 highlightColor = new Color32(255, 255, 255, 255);
            public bool gridSnap = true;
            [SerializeField] private string typeColorsData = "";
            [NonSerialized] public Dictionary<string, Color> typeColors = new Dictionary<string, Color>();
            public NoodleType noodleType = NoodleType.Curve;

            private Texture2D _gridTexture;
            public Texture2D gridTexture {
                get {
                    if (_gridTexture == null) _gridTexture = NodeEditorResources.GenerateGridTexture(gridLineColor, gridBgColor);
                    return _gridTexture;
                }
            }
            private Texture2D _crossTexture;
            public Texture2D crossTexture {
                get {
                    if (_crossTexture == null) _crossTexture = NodeEditorResources.GenerateCrossTexture(gridLineColor);
                    return _crossTexture;
                }
            }

            public void OnAfterDeserialize() {
                // Deserialize typeColorsData
                typeColors = new Dictionary<string, Color>();
                string[] data = typeColorsData.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
                for (int i = 0; i < data.Length; i += 2) {
                    Color col;
                    if (ColorUtility.TryParseHtmlString("#" + data[i + 1], out col)) {
                        typeColors.Add(data[i], col);
                    }
                }
            }

            public void OnBeforeSerialize() {
                // Serialize typeColors
                typeColorsData = "";
                foreach (var item in typeColors) {
                    typeColorsData += item.Key + "," + ColorUtility.ToHtmlStringRGB(item.Value) + ",";
                }
            }
        }

        /// <summary> Get settings of current active editor </summary>
        public static Settings GetSettings() {
            if (lastEditor != XNodeEditor.NodeEditorWindow.current.graphEditor) {
                object[] attribs = XNodeEditor.NodeEditorWindow.current.graphEditor.GetType().GetCustomAttributes(typeof(XNodeEditor.NodeGraphEditor.CustomNodeGraphEditorAttribute), true);
                if (attribs.Length == 1) {
                    XNodeEditor.NodeGraphEditor.CustomNodeGraphEditorAttribute attrib = attribs[0] as XNodeEditor.NodeGraphEditor.CustomNodeGraphEditorAttribute;
                    lastEditor = XNodeEditor.NodeEditorWindow.current.graphEditor;
                    lastKey = attrib.editorPrefsKey;
                    VerifyLoaded();
                } else return null;
            }
            return settings[lastKey];
        }

        [PreferenceItem("Node Editor")]
        private static void PreferencesGUI() {
            VerifyLoaded();
            Settings settings = NodeEditorPreferences.settings[lastKey];

            NodeSettingsGUI(lastKey, settings);
            GridSettingsGUI(lastKey, settings);
            TypeColorsGUI(lastKey, settings);
            if (GUILayout.Button(new GUIContent("Set Default", "Reset all values to default"), GUILayout.Width(120))) {
                ResetPrefs();
            }
        }

        private static void GridSettingsGUI(string key, Settings settings) {
            //Label
            EditorGUILayout.LabelField("Grid", EditorStyles.boldLabel);
            settings.gridSnap = EditorGUILayout.Toggle("Snap", settings.gridSnap);

            settings.gridLineColor = EditorGUILayout.ColorField("Color", settings.gridLineColor);
            settings.gridBgColor = EditorGUILayout.ColorField(" ", settings.gridBgColor);
            if (GUI.changed) {
                SavePrefs(key, settings);

                NodeEditorWindow.RepaintAll();
            }
            EditorGUILayout.Space();
        }

        private static void NodeSettingsGUI(string key, Settings settings) {
            //Label
            EditorGUILayout.LabelField("Node", EditorStyles.boldLabel);
            settings.highlightColor = EditorGUILayout.ColorField("Selection", settings.highlightColor);
            settings.noodleType = (NoodleType) EditorGUILayout.EnumPopup("Noodle type", (Enum) settings.noodleType);
            if (GUI.changed) {
                SavePrefs(key, settings);
                NodeEditorWindow.RepaintAll();
            }
            EditorGUILayout.Space();
        }

        private static void TypeColorsGUI(string key, Settings settings) {
            //Label
            EditorGUILayout.LabelField("Types", EditorStyles.boldLabel);

            //Display type colors. Save them if they are edited by the user
            List<string> typeColorKeys = new List<string>(typeColors.Keys);
            foreach (string typeColorKey in typeColorKeys) {
                Color col = typeColors[typeColorKey];
                EditorGUI.BeginChangeCheck();
                EditorGUILayout.BeginHorizontal();
                col = EditorGUILayout.ColorField(typeColorKey, col);
                EditorGUILayout.EndHorizontal();
                if (EditorGUI.EndChangeCheck()) {
                    typeColors[typeColorKey] = col;
                    if (settings.typeColors.ContainsKey(typeColorKey)) settings.typeColors[typeColorKey] = col;
                    else settings.typeColors.Add(typeColorKey, col);
                    SavePrefs(typeColorKey, settings);
                    NodeEditorWindow.RepaintAll();
                }
            }
        }

        /// <summary> Load prefs if they exist. Create if they don't </summary>
        private static Settings LoadPrefs() {
            // Create settings if it doesn't exist
            if (!EditorPrefs.HasKey(lastKey)) {
                if (lastEditor != null) EditorPrefs.SetString(lastKey, JsonUtility.ToJson(lastEditor.GetDefaultPreferences()));
                else EditorPrefs.SetString(lastKey, JsonUtility.ToJson(new Settings()));
            }
            return JsonUtility.FromJson<Settings>(EditorPrefs.GetString(lastKey));
        }

        /// <summary> Delete all prefs </summary>
        public static void ResetPrefs() {
            if (EditorPrefs.HasKey(lastKey)) EditorPrefs.DeleteKey(lastKey);
            if (settings.ContainsKey(lastKey)) settings.Remove(lastKey);
            typeColors = new Dictionary<string, Color>();
            VerifyLoaded();
            NodeEditorWindow.RepaintAll();
        }

        /// <summary> Save preferences in EditorPrefs </summary>
        private static void SavePrefs(string key, Settings settings) {
            EditorPrefs.SetString(key, JsonUtility.ToJson(settings));
        }

        /// <summary> Check if we have loaded settings for given key. If not, load them </summary>
        private static void VerifyLoaded() {
            if (!settings.ContainsKey(lastKey)) settings.Add(lastKey, LoadPrefs());
        }

        /// <summary> Return color based on type </summary>
        public static Color GetTypeColor(System.Type type) {
            VerifyLoaded();
            if (type == null) return Color.gray;
            string typeName = type.PrettyName();
            if (!typeColors.ContainsKey(typeName)) {
                if (settings[lastKey].typeColors.ContainsKey(typeName)) typeColors.Add(typeName, settings[lastKey].typeColors[typeName]);
                else {
#if UNITY_5_4_OR_NEWER
                    UnityEngine.Random.InitState(typeName.GetHashCode());
#else
                    UnityEngine.Random.seed = typeName.GetHashCode();
#endif
                    typeColors.Add(typeName, new Color(UnityEngine.Random.value, UnityEngine.Random.value, UnityEngine.Random.value));
                }
            }
            return typeColors[typeName];
        }
    }
}