using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using Iesi.Collections.Generic;
using JetBrains.Annotations;
using Portoa.Persistence;

namespace VideoGameQuotes.Api {
	public class Game : Entity<int>, IDtoMappable<GameDto> {
		private readonly Iesi.Collections.Generic.ISet<GamingSystem> systems = new HashedSet<GamingSystem>();
		private readonly Iesi.Collections.Generic.ISet<Publisher> publishers = new HashedSet<Publisher>();

		public Game() {
			Created = DateTime.UtcNow;
		}

		[CanBeNull]
		public virtual string Website { get; set; }
		public virtual User Creator { get; set; }
		public virtual DateTime Created { get; set; }
		public virtual IEnumerable<GamingSystem> Systems { get { return systems; } }
		[Required]
		public virtual string Name { get; set; }
		public virtual IEnumerable<Publisher> Publishers { get { return publishers; } }
		[CanBeNull, StringLength(1024)]
		public virtual byte[] Icon { get; set; }
		public virtual Region Region { get; set; }

		#region adding and removing stuff
		public virtual Game AddSystem(GamingSystem system) {
			systems.Add(system);
			return this;
		}

		public virtual void ClearSystems() {
			systems.Clear();
		}

		public virtual Game AddPublisher(Publisher publisher) {
			publishers.Add(publisher);
			return this;
		}

		public virtual void ClearPublishers() {
			publishers.Clear();
		}
		#endregion

		public virtual GameDto ToDto() {
			return new GameDto {
				Id = Id,
				Website = Website,
				Created = Created,
				Systems = Systems.Select(system => system.ToDto()),
				Name = Name,
				Regions = Region.ToString().Split(',').Select(region => region.Trim()),
				Publishers = Publishers.Select(publisher => publisher.ToDto()),
				Icon = Icon != null ? Convert.ToBase64String(Icon) : null
			};
		}

		#region criterion handlers
		public sealed class SystemCriterionHandler : CriterionHandler<Game> {
			protected override Func<Game, bool> HandleInteger(int value) {
				return game => game.Systems.Any(system => system.Id == value);
			}

			protected override Func<Game, bool> HandleString(string value) {
				return game => game.Systems.Any(system => system.Name == value);
			}
		}

		public sealed class PublisherCriterionHandler : CriterionHandler<Game> {
			protected override Func<Game, bool> HandleInteger(int value) {
				return game => game.Publishers.Any(publisher => publisher.Id == value);
			}

			protected override Func<Game, bool> HandleString(string value) {
				return game => game.Publishers.Any(publisher => publisher.Name == value);
			}
		}
		#endregion
	}

	public class GameDto {
		public int Id { get; set; }
		[CanBeNull]
		public string Website { get; set; }
		[CanBeNull]
		public string Icon { get; set; }
		public DateTime Created { get; set; }
		public IEnumerable<SystemDto> Systems { get; set; }
		public string Name { get; set; }
		public IEnumerable<PublisherDto> Publishers { get; set; }
		public IEnumerable<string> Regions { get; set; }
	}

	public static class GameExtensions {
		public static string GetBase64EncodedIcon(this Game game) {
			if (game.Icon == null || game.Icon.Length == 0) {
				return null;
			}

			return Convert.ToBase64String(game.Icon);
		}
	}
}