using System;
using Unity.Mathematics;
using UnityEngine;

namespace GamecraftModdingAPI.Interface.IMGUI
{
    /// <summary>
    /// A clickable button.
    /// This wraps Unity's IMGUI Button.
    /// </summary>
    public class Button : UIElement
    {
        private bool automaticLayout = false;

        private string text;
        
        /// <summary>
        /// The rectangular area that the button can use.
        /// </summary>
        public Rect Box { get; set; } = Rect.zero;

        /// <summary>
        /// An event that fires when the button is clicked.
        /// </summary>
        public event EventHandler<bool> OnClick;
        
        public void OnGUI()
        {
            if (automaticLayout)
            {
                if (GUILayout.Button(text, Constants.Default.button))
                {
                    OnClick?.Invoke(this, true);
                }
            }
            else
            {
                if (GUI.Button(Box, text, Constants.Default.button))
                {
                    OnClick?.Invoke(this, true);
                }
            }
        }

        /// <summary>
        /// The button's unique name.
        /// </summary>
        public string Name { get; private set; }

        /// <summary>
        /// Whether to display the button.
        /// </summary>
        public bool Enabled { get; set; } = true;

        /// <summary>
        /// Initialize a new button with automatic layout.
        /// </summary>
        /// <param name="text">The text to display on the button.</param>
        /// <param name="name">The button's name.</param>
        public Button(string text, string name = null)
        {
            automaticLayout = true;
            this.text = text;
            if (name == null)
            {
                this.Name = typeof(Button).FullName + "::" + text;
            }
            else
            {
                this.Name = name;
            }
            IMGUIManager.AddElement(this);
        }

        /// <summary>
        /// Initialize a new button.
        /// </summary>
        /// <param name="text">The text to display on the button.</param>
        /// <param name="box">Rectangular area for the button to use.</param>
        /// <param name="name">The button's name.</param>
        public Button(string text, Rect box, string name = null) : this(text, name)
        {
            automaticLayout = false;
            this.Box = box;
        }
        
        ~Button()
        {
            IMGUIManager.RemoveElement(this);
        }
    }
}