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

namespace UIWidgets
{
	public class Templates<T> where T : MonoBehaviour, ITemplatable
	{
		private Dictionary<string, T> templates = new Dictionary<string, T>();

		private Dictionary<string, Stack<T>> cache = new Dictionary<string, Stack<T>>();

		private bool findTemplatesCalled;

		private Action<T> onCreateCallback;

		public Templates(Action<T> onCreateCallback = null)
		{
			this.onCreateCallback = onCreateCallback;
		}

		public void FindTemplates()
		{
			findTemplatesCalled = true;
			Resources.FindObjectsOfTypeAll<T>().ForEach(AddTemplate);
		}

		private void AddTemplate(T template)
		{
			Add(template.name, template);
			template.gameObject.SetActive(false);
		}

		public void ClearCache()
		{
			cache.Keys.ForEach(ClearCache);
		}

		public void ClearCache(string name)
		{
			if (cache.ContainsKey(name))
			{
				cache[name].ForEach(DestroyCached);
				cache[name].Clear();
				cache[name].TrimExcess();
			}
		}

		private void DestroyCached(T cached)
		{
			if (cached != null && cached.gameObject != null)
			{
				UnityEngine.Object.Destroy(cached.gameObject);
			}
		}

		public bool Exists(string name)
		{
			return templates.ContainsKey(name);
		}

		public T Get(string name)
		{
			if (!Exists(name))
			{
				throw new ArgumentException("Not found template with name '" + name + "'");
			}
			return templates[name];
		}

		public void Delete(string name)
		{
			if (Exists(name))
			{
				templates.Remove(name);
				ClearCache(name);
			}
		}

		public void Add(string name, T template, bool replace = true)
		{
			if (Exists(name))
			{
				if (!replace)
				{
					throw new ArgumentException("Template with name '" + name + "' already exists.");
				}
				ClearCache(name);
				templates[name] = template;
			}
			else
			{
				templates.Add(name, template);
			}
			template.IsTemplate = true;
			template.TemplateName = name;
		}

		public T Instance(string name)
		{
			if (!findTemplatesCalled)
			{
				FindTemplates();
			}
			if (!Exists(name))
			{
				throw new ArgumentException("Not found template with name '" + name + "'");
			}
			if (templates[name] == null)
			{
				templates.Clear();
				FindTemplates();
			}
			T val;
			if (cache.ContainsKey(name) && cache[name].Count > 0)
			{
				val = cache[name].Pop();
			}
			else
			{
				val = UnityEngine.Object.Instantiate(templates[name]);
				val.TemplateName = name;
				val.IsTemplate = false;
				if (onCreateCallback != null)
				{
					onCreateCallback(val);
				}
			}
			Transform transform = val.transform;
			T val2 = templates[name];
			transform.SetParent(val2.transform.parent, false);
			return val;
		}

		public void ToCache(T instance)
		{
			instance.gameObject.SetActive(false);
			if (!cache.ContainsKey(instance.TemplateName))
			{
				cache[instance.TemplateName] = new Stack<T>();
			}
			cache[instance.TemplateName].Push(instance);
		}
	}
}