using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using DevHive.Data.Interfaces.Repositories;
using DevHive.Data.Models;
using Microsoft.EntityFrameworkCore;

namespace DevHive.Data.Repositories
{
	public class UserRepository : BaseRepository<User>, IUserRepository
	{
		private readonly DevHiveContext _context;

		public UserRepository(DevHiveContext context)
			: base(context)
		{
			this._context = context;
		}

		#region Read
		public IEnumerable<User> QueryAll()
		{
			return this._context.Users
				.Include(x => x.Roles)
				.AsNoTracking()
				.AsEnumerable();
		}

		public override async Task<User> GetByIdAsync(Guid id)
		{
			return await this._context.Users
				.Include(x => x.Friends)
				.Include(x => x.Roles)
				.Include(x => x.Languages)
				.Include(x => x.Technologies)
				.FirstOrDefaultAsync(x => x.Id == id);
		}

		public async Task<User> GetByUsernameAsync(string username)
		{
			return await this._context.Users
				.AsNoTracking()
				.Include(x => x.Friends)
				.Include(x => x.Roles)
				.Include(x => x.Languages)
				.Include(x => x.Technologies)
				.FirstOrDefaultAsync(x => x.UserName == username);
		}

		public HashSet<Language> GetUserLanguages(User user)
		{
			return user.Languages;
		}

		public Language GetUserLanguage(User user, Language language)
		{
			return user.Languages
				.FirstOrDefault(x => x.Id == language.Id);
		}

		public HashSet<Technology> GetUserTechnologies(User user)
		{
			return user.Technologies;
		}

		public Technology GetUserTechnology(User user, Technology technology)
		{
			return user.Technologies
				.FirstOrDefault(x => x.Id == technology.Id);
		}
		#endregion

		#region Validations
		public async Task<bool> DoesUserExistAsync(Guid id)
		{
			return await this._context.Users
				.AsNoTracking()
				.AnyAsync(x => x.Id == id);
		}

		public async Task<bool> DoesUsernameExistAsync(string username)
		{
			return await this._context.Users
				.AsNoTracking()
				.AnyAsync(u => u.UserName == username);
		}

		public async Task<bool> DoesEmailExistAsync(string email)
		{
			return await this._context.Users
				.AsNoTracking()
				.AnyAsync(u => u.Email == email);
		}

		public async Task<bool> DoesUserHaveThisFriendAsync(Guid userId, Guid friendId)
		{
			User user = await this._context.Users
				.FirstOrDefaultAsync(x => x.Id == userId);

			User friend = await this._context.Users
				.FirstOrDefaultAsync(x => x.Id == friendId);

			return user.Friends.Contains(friend);
		}

		public bool DoesUserHaveThisUsername(Guid id, string username)
		{
			return this._context.Users
				.AsNoTracking()
				.Any(x => x.Id == id &&
					x.UserName == username);
		}

		public bool DoesUserHaveFriends(User user)
		{
			return user.Friends.Count >= 1;
		}

		public bool DoesUserHaveThisLanguage(User user, Language language)
		{
			return user.Languages.Contains(language);
		}

		public bool DoesUserHaveThisTechnology(User user, Technology technology)
		{
			return user.Technologies.Contains(technology);
		}
		#endregion
	}
}