using System.Collections.Generic;
using System.Linq;
using System.Runtime.CompilerServices;
using UnityEngine;

namespace DCFApixels.DragonECS
{
    public class EcsEntityConnect : MonoBehaviour
    {
        private sealed class Aspect : EcsAspect
        {
            public EcsPool<UnityGameObject> unityGameObjects;
            protected override void Init(Builder b)
            {
                unityGameObjects = b.Include<UnityGameObject>();
            }
        }

        private entlong _entity;
        private EcsWorld _world;

        [SerializeField]
        private ScriptableEntityTemplate[] _scriptableTemplates;
        [SerializeField]
        private MonoEntityTemplate[] _monoTemplates;

        #region Properties
        public entlong Entity
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get { return _entity; }
        }
        public EcsWorld World
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get => _world;
        }
        public bool IsConected
        {
            [MethodImpl(MethodImplOptions.AggressiveInlining)]
            get => _entity.IsAlive;
        }
        public IEnumerable<ScriptableEntityTemplate> ScriptableTemplates
        {
            get { return _scriptableTemplates; }
        }
        public IEnumerable<MonoEntityTemplate> MonoTemplates
        {
            get { return _monoTemplates; }
        }
        public IEnumerable<ITemplateInternal> AllTemplates
        {
            get { return ((IEnumerable<ITemplateInternal>)_scriptableTemplates).Concat(_monoTemplates); }
        }
        #endregion

        #region Connect
        public void ConnectWith(entlong entity, bool applyTemplates = false)
        {
            if (_entity.TryGetID(out int oldEntityID) && _world != null)
            {
                var a = _world.GetAspect<Aspect>();
                a.unityGameObjects.Del(oldEntityID);
            }
            _world = null;

            if (entity.TryGetID(out int newEntityID))
            {
                _entity = entity;
                _world = _entity.World;
                var a = _world.GetAspect<Aspect>();
                if (!a.unityGameObjects.Has(newEntityID))
                {
                    a.unityGameObjects.Add(newEntityID) = new UnityGameObject(gameObject);
                }
                if (applyTemplates)
                {
                    ApplyTemplates();
                }
            }
            else
            {
                _entity = entlong.NULL;
            }
        }
        #endregion

        #region ApplyTemplates
        public void ApplyTemplates()
        {
            ApplyTemplatesFor(_entity.ID);
        }
        public void ApplyTemplatesFor(int entityID)
        {
            foreach (var template in _scriptableTemplates)
            {
                template.Apply(_world.id, entityID);
            }
            foreach (var template in _monoTemplates)
            {
                template.Apply(_world.id, entityID);
            }
        }
        #endregion

        #region Editor
        internal void SetTemplates_Editor(MonoEntityTemplate[] tempaltes)
        {
            _monoTemplates = tempaltes;
        }
        #endregion
    }
}