using System;
using System.Collections.Generic;
using System.Linq;
using Babushka.scripts.CSharp.GameEntity.Types;
using Godot;
using Entity = Babushka.scripts.CSharp.GameEntity.Entities.Entity;
using PositionalEntity = Babushka.scripts.CSharp.GameEntity.Entities.PositionalEntity;

namespace Babushka.scripts.CSharp.GameEntity.Management;

public partial class EntityManager : Node
{
    [Export] private EntityNodeCreator _nodeCreator = null!;

    private EntitySceneManager? _currentEntitySceneManager;


    private readonly List<Entity> _allEntities = new();

    public IEnumerable<Entity> AllEntities => _allEntities;

    public IEnumerable<PositionalEntity> AllPositionalEntities => _allEntities.OfType<PositionalEntity>();

    public T NewPositionalEntity<T>(EntityType type, Vector2 position, string? scene = null) where T : PositionalEntity
    {
        if (scene == null)
        {
            if (_currentEntitySceneManager == null)
                throw new Exception("No current scene. Specify scene to spawn an entity");
            
            scene = _currentEntitySceneManager.sceneName;
        }

        var newEntity = _nodeCreator.Create<T>(type);
        newEntity.Position = position;
        newEntity.sceneName = scene;
        _allEntities.Add(newEntity);

        _currentEntitySceneManager.AddIfNeeded(newEntity);

        return newEntity;
    }

    public void UnloadScene()
    {
        if (_currentEntitySceneManager == null) return;
        _currentEntitySceneManager.RemoveAllEntities();
        _currentEntitySceneManager = null;
    }

    public void LoadScene(EntitySceneManager sceneManager)
    {
        _currentEntitySceneManager = sceneManager;
        foreach (var entity in AllPositionalEntities)
        {
            _currentEntitySceneManager.AddIfNeeded(entity);
        }
    }
}