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

namespace FlowScope.UI
{
    internal sealed class UILayer
    {
        private readonly Stack<UIPanelRecord> _stack = new();
        private readonly Dictionary<Type, UIPanelRecord> _cachedPanels = new();

        public UILayer(string name, Canvas canvas, int sortOrder, PanelStrategy strategy)
        {
            Name = name;
            Canvas = canvas;
            Strategy = strategy;
            Canvas.sortingOrder = sortOrder;
        }

        public string Name { get; }
        public Canvas Canvas { get; }
        public PanelStrategy Strategy { get; }
        public int Count => _stack.Count;

        public void Push(UIPanelRecord record)
        {
            record.IsOpen = true;
            _stack.Push(record);
        }

        public UIPanelRecord Peek()
        {
            return _stack.Peek();
        }

        public UIPanelRecord Pop()
        {
            var record = _stack.Pop();
            record.IsOpen = false;
            return record;
        }

        public bool TryGetCached(Type panelType, out UIPanelRecord record)
        {
            return _cachedPanels.TryGetValue(panelType, out record);
        }

        public void Cache(UIPanelRecord record)
        {
            _cachedPanels[record.PanelType] = record;
        }

        public void RemoveCached(Type panelType)
        {
            _cachedPanels.Remove(panelType);
        }

        public bool ContainsOpen(Type panelType, out UIPanelRecord record)
        {
            foreach (var current in _stack)
            {
                if (current.PanelType == panelType)
                {
                    record = current;
                    return true;
                }
            }

            record = null;
            return false;
        }
    }
}