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

namespace FolderIcons
    {
    [InitializeOnLoad]
    internal static class FolderIconsReplacer
        {
        // References
        private static Object[] allFolderIcons;
        private static FolderIconSettings folderIcons;

        public static bool showFolder;
        public static bool showOverlay;

        private static readonly Color selectedColor = new Color (60f/255f, 92f/255f, 148f/255f);

        static FolderIconsReplacer()
            {
            CheckPreferences ();
               
            EditorApplication.projectWindowItemOnGUI -= ReplaceFolders;
            EditorApplication.projectWindowItemOnGUI += ReplaceFolders;
            }

        private static void ReplaceFolders(string guid, Rect selectionRect)
            {
            // Does the folder asset exist at all?
            if (allFolderIcons == null)
                allFolderIcons = GetAllInstances<FolderIconSettings> ();

            if (folderIcons == null)
                {
                if (allFolderIcons.Length > 0)
                    folderIcons = allFolderIcons[0] as FolderIconSettings;
                }

            if (folderIcons == null)
                return;

            if (!folderIcons.showCustomFolder && !folderIcons.showOverlay)
                return;

            string path = AssetDatabase.GUIDToAssetPath (guid);
            Object folderAsset = AssetDatabase.LoadAssetAtPath (path, typeof (DefaultAsset));

            if (folderAsset == null)
                return;
        
            for (int i = 0; i < folderIcons.icons.Length; i++)
                {
                var icon = folderIcons.icons[i];

                if (icon.folder != folderAsset)
                    continue;

                DrawTextures (selectionRect, icon, folderAsset, guid);
                }
            }

        private static void DrawTextures(Rect rect, FolderIconSettings.FolderIcon icon, Object folderAsset, string guid)
            {
            bool isTreeView = rect.width > rect.height;
            bool isSideView = FolderIconGUI.IsSideView (rect);

            // Vertical Folder View
            if (isTreeView)
                {
                rect.width = rect.height = FolderIconConstants.MAX_TREE_HEIGHT;

                //Add small offset for correct placement
                if (!isSideView)
                    rect.x += 3f;
                }
            else
                {
                rect.height -= 14f;
                }

            if (showFolder && icon.folderIcon)
                FolderIconGUI.DrawFolderTexture (rect, icon.folderIcon, guid);

            if (showOverlay && icon.overlayIcon)
                FolderIconGUI.DrawOverlayTexture (rect, icon.overlayIcon);
            }

        #region Initialize 

        private static void CheckPreferences()
            {
            string prefFolder = FolderIconConstants.FOLDER_TEXTURE_PATH;
            string prefIcon = FolderIconConstants.ICONS_TEXTURE_PATH;

            if (!EditorPrefs.HasKey (prefFolder))
                EditorPrefs.SetBool (prefFolder, true);

            if (!EditorPrefs.HasKey (prefIcon))
                EditorPrefs.SetBool (prefIcon, true);

            showFolder = EditorPrefs.GetBool (prefFolder);
            showOverlay = EditorPrefs.GetBool (prefIcon);
            }

        private static bool FindOrCreateFolder(string path, string folderCreateName)
            {
            if (AssetDatabase.IsValidFolder (path))
                return true;

            string parentFolder = path.Substring (0, path.LastIndexOf ('/'));
            return AssetDatabase.CreateFolder(parentFolder, folderCreateName) != "";
            }

        private static T[] GetAllInstances<T>() where T : Object
            {
            string[] guids = AssetDatabase.FindAssets ("t:" + typeof (T).Name); 

            T[] instances = new T[guids.Length];

            //probably could get optimized 
            for (int i = 0; i < guids.Length; i++)
                {
                string path = AssetDatabase.GUIDToAssetPath (guids[i]);
                instances[i] = AssetDatabase.LoadAssetAtPath<T> (path);
                }


            return instances;

            }

        #endregion

        }


    }