using Game.NavigationTool.Editor.Toolbar;
using UnityEditor;
using UnityEngine;

namespace Game.NavigationTool.Editor
{
    [InitializeOnLoad]
    internal static class ToolbarDrawer
    {
        private static bool IS_INITIALIZED;
        private static IToolbarDrawer[] DRAWERS;
        private static Styles styles;
        
        static ToolbarDrawer()
        {
            EditorApplication.update -= OnEditorUpdate;
            EditorApplication.update += OnEditorUpdate;
        }
        
        private static void OnEditorUpdate()
        {
            if (!IS_INITIALIZED)
            {
                styles = new Styles();
                DRAWERS = ToolbarUtility.GetAllDrawers();
                ToolbarUtility.AddGuiListener(OnGUI);
                IS_INITIALIZED = true;
            }

            for (var i = 0; i < DRAWERS.Length; i++)
            {
                DRAWERS[i].Update();
            }
        }

        private static void OnGUI()
        {
            const float Y = 5.0f;
            const float SPACING = 4.0f;
            const float HEIGHT = 22.0f;
            const float PLAY_BUTTON_EXTENT = 75.0f;
            const float PLAY_BUTTON_OFFSET = -23.0f;

            if (DRAWERS == null)
                return;
            
            styles.Initialize(GUI.skin);
            float xLeft = EditorGUIUtility.currentViewWidth * 0.5f + PLAY_BUTTON_OFFSET - PLAY_BUTTON_EXTENT;
            float xRight = EditorGUIUtility.currentViewWidth * 0.5f + PLAY_BUTTON_OFFSET + PLAY_BUTTON_EXTENT;

            for (var i = 0; i < DRAWERS.Length; i++)
            {
                IToolbarDrawer drawer = DRAWERS[i];
                
                if (!drawer.Visible)
                    continue;

                GUI.enabled = drawer.Enabled;
                float width = drawer.CalculateWidth();
                Rect rect;

                if (drawer.Placement == EToolbarPlacement.Left)
                {
                    rect = new Rect(xLeft - width, Y, width, HEIGHT);
                    xLeft -= width + SPACING;
                }
                else
                {
                    rect = new Rect(xRight, Y, width, HEIGHT);
                    xRight += width + SPACING;
                }

                drawer.Draw(rect, styles);
            }
            
            GUI.enabled = true;
        }
    }
}