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

namespace UNEC {
    /// <summary> Contains GUI methods </summary>
    public static class NodeEditorGUI {

        public static void BeginZoomed(Rect rect, float zoom) {
            GUI.EndClip();
            
            GUIUtility.ScaleAroundPivot(Vector2.one / zoom, rect.size * 0.5f);
            Vector4 padding = new Vector4(0, 22, 0, 0);
            padding *= zoom;
            GUI.BeginClip(new Rect(
                -((rect.width * zoom) - rect.width) * 0.5f,
                -(((rect.height * zoom) - rect.height) * 0.5f) + (22 * zoom),
                rect.width * zoom,
                rect.height * zoom));
        }

        public static void EndZoomed(Rect rect, float zoom) {
            GUIUtility.ScaleAroundPivot(Vector2.one * zoom, rect.size * 0.5f);
            Vector3 offset = new Vector3(
                (((rect.width * zoom) - rect.width) * 0.5f),
                (((rect.height * zoom) - rect.height) * 0.5f) + (-22 * zoom)+22,
                0);
            GUI.matrix = Matrix4x4.TRS(offset, Quaternion.identity, Vector3.one);
        }

        public static void DrawGrid(Rect rect, float zoom, Vector2 panOffset) {

            rect.position = Vector2.zero;

            Vector2 center = rect.size / 2f;
            Texture2D gridTex = NodeEditorResources.gridTexture;
            Texture2D crossTex = NodeEditorResources.crossTexture;
            
            // Offset from origin in tile units
            float xOffset = -(center.x * zoom + panOffset.x) / gridTex.width;
            float yOffset = ((center.y - rect.size.y) * zoom + panOffset.y) / gridTex.height;

            Vector2 tileOffset = new Vector2(xOffset, yOffset);

            // Amount of tiles
            float tileAmountX = Mathf.Round(rect.size.x * zoom) / gridTex.width;
            float tileAmountY = Mathf.Round(rect.size.y * zoom) / gridTex.height;

            Vector2 tileAmount = new Vector2(tileAmountX, tileAmountY);

            // Draw tiled background
            GUI.DrawTextureWithTexCoords(rect, gridTex, new Rect(tileOffset, tileAmount));
            GUI.DrawTextureWithTexCoords(rect, crossTex, new Rect(tileOffset + new Vector2(0.5f,0.5f), tileAmount));
        }

        public static void DrawToolbar(NodeEditorWindow window) {
            EditorGUILayout.BeginHorizontal("Toolbar");

            if (DropdownButton("File", 50)) FileContextMenu();
            if (DropdownButton("Edit", 50)) EditContextMenu(window);
            if (DropdownButton("View", 50)) { }
            if (DropdownButton("Settings", 70)) { }
            if (DropdownButton("Tools", 50)) { }

            // Make the toolbar extend all throughout the window extension.
            GUILayout.FlexibleSpace();

            EditorGUILayout.EndHorizontal();
        }

        public static bool DropdownButton(string name, float width) {
            return GUILayout.Button(name, EditorStyles.toolbarDropDown, GUILayout.Width(width));
        }

        public static void RightClickContextMenu(NodeEditorWindow window) {
            GenericMenu contextMenu = new GenericMenu();

            if (window.hoveredNode != null) {
                Node node = window.hoveredNode;
                contextMenu.AddItem(new GUIContent("Remove"), false, () => window.graph.RemoveNode(node));
            }
            else {
                Vector2 pos = window.WindowToGridPosition(Event.current.mousePosition);
                for (int i = 0; i < NodeEditorReflection.nodeTypes.Length; i++) {
                    Type type = NodeEditorReflection.nodeTypes[i];
                    contextMenu.AddItem(new GUIContent(NodeEditorReflection.nodeTypes[i].ToString()), false, () => {
                        window.CreateNode(type, pos);
                    });
                }
            }
            contextMenu.DropDown(new Rect(Event.current.mousePosition, Vector2.zero));
        }

        public static void FileContextMenu() {
            GenericMenu contextMenu = new GenericMenu();
            contextMenu.AddItem(new GUIContent("Create New"), false, null);
            contextMenu.AddItem(new GUIContent("Load"), false, null);

            contextMenu.AddSeparator("");
            contextMenu.AddItem(new GUIContent("Save"), false, null);
            contextMenu.AddItem(new GUIContent("Save As"), false, null);

            contextMenu.DropDown(new Rect(5f, 17f, 0f, 0f));
        }

        public static void EditContextMenu(NodeEditorWindow window) {
            GenericMenu contextMenu = new GenericMenu();
            contextMenu.AddItem(new GUIContent("Clear"), false, () => window.graph.Clear());

            contextMenu.DropDown(new Rect(5f, 17f, 0f, 0f));
        }
    }
}