using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections.Concurrent;

namespace VideoStore.Infrastructure
{
    public abstract class InMemoryRepository<T> : ICommands<T>, IQueries<T> where T : IEntity
    {
        protected static ConcurrentDictionary<int, T> items;

        public IQueryable<T> All()
        {
            return items.Values.AsQueryable();
        }

        public T ById(int id)
        {
            if (items.ContainsKey(id))
                return items[id];
            return default(T);
        }

        private object lockObj = new Object();
        public T Add(T entity)
        {
            lock (lockObj)
            {
                var newId = items.Keys.Max() + 1;
                entity.Id = newId;
                items.TryAdd(newId, entity);
            }
            return entity;
        }

        public T Update(T entity)
        {
            items[entity.Id] = entity;
            return entity;
        }

        public void Remove(int id)
        {
            T x;
            items.TryRemove(id, out x);
        }
    }
}