using System;
using System.Collections.Generic;
using System.Linq;
using MongoDB.Bson;

namespace Model
{
    public class GameObjectManager
    {
        private readonly Dictionary<ObjectId, GameObject> gameObjects =
                new Dictionary<ObjectId, GameObject>();

        private readonly Dictionary<GameObjectType, Dictionary<ObjectId, GameObject>> typeGameObjects =
                new Dictionary<GameObjectType, Dictionary<ObjectId, GameObject>>();

        public void Add(GameObject gameObject)
        {
            this.gameObjects.Add(gameObject.Id, gameObject);
            if (!this.typeGameObjects.ContainsKey(gameObject.Type))
            {
                this.typeGameObjects.Add(gameObject.Type, new Dictionary<ObjectId, GameObject>());
            }
            this.typeGameObjects[gameObject.Type].Add(gameObject.Id, gameObject);
        }

        public GameObject Get(ObjectId id)
        {
            GameObject gameObject = null;
            this.gameObjects.TryGetValue(id, out gameObject);
            return gameObject;
        }

        public GameObject[] GetOneType(GameObjectType type)
        {
            Dictionary<ObjectId, GameObject> oneTypeGameObjects = null;
            if (!this.typeGameObjects.TryGetValue(type, out oneTypeGameObjects))
            {
                return new GameObject[0];
            }
            return oneTypeGameObjects.Values.ToArray();
        }

        public bool Remove(GameObject gameObject)
        {
            if (gameObject == null)
            {
                throw new ArgumentNullException("gameObject");
            }
            if (!this.gameObjects.Remove(gameObject.Id))
            {
                return false;
            }
            if (!this.typeGameObjects[gameObject.Type].Remove(gameObject.Id))
            {
                return false;
            }
            return true;
        }

        public bool Remove(ObjectId id)
        {
            GameObject gameObject = this.Get(id);
            if (gameObject == null)
            {
                return false;
            }
            return this.Remove(gameObject);
        }
    }
}