using System;
using System.Collections.Generic;
using System.Linq;
using EVLab.Web.Data;
using EVLav.Web.BusinessLogic.Interfaces;
using EVLab.Web.Common;

namespace EVLav.Web.BusinessLogic
{
    public class UsersService : IUsersService
    {
        private readonly IRepository _repository;

        public UsersService(IRepository repository)
        {
            _repository = repository;
        }

        public List<AspNetUser> GetUsers()
        {
            return _repository.SetNoTracking<AspNetUser>().Include(x => x.Company).ToList();
        }

        public AspNetUser GetUser(string email)
        {
            return _repository.SetNoTracking<AspNetUser>().FirstOrDefault(x => x.Email == email);
        }

        public void ManageUserAccess(string id, bool isBlocked)
        {
            var user = _repository.Set<AspNetUser>().FirstOrDefault(x => x.Id == id);

            user.IsActive = !isBlocked;

            _repository.Update(user);
        }

        public RegisterInvitation GetRegisterInvitation(string email)
        {
            return _repository.SetNoTracking<RegisterInvitation>().Where(x => x.Email == email).OrderByDescending(x => x.CreatedOn).FirstOrDefault(); 
        }

        public void Invite(string userId, string email, int companyId)
        {
            var invitation = new RegisterInvitation()
            {
                Email = email,
                CompanyId = companyId,
                RegistrationKey = Guid.NewGuid().ToString().Replace("-", string.Empty),
                CreatedOn = DateTime.UtcNow,
                Expired = false,
                UserRole = companyId == EvConstants.SystemCompanyId ? UserRolesEnum.ADMINISTRATOR : UserRolesEnum.USER,
                InvitedByUserId = userId
            };

            ValidateInvitation(invitation);

            _repository.Add(invitation);

            SendInvitation(invitation);
        }

        void ValidateInvitation(RegisterInvitation invitation)
        {
            if(string.IsNullOrWhiteSpace(invitation.Email))
            {
                throw new Exception("Invitation email cannot be empty.");
            }

            if(_repository.SetNoTracking<AspNetUser>().Any(x => x.Email.ToLower() == invitation.Email.ToLower()))
            {
                throw new Exception($"{ invitation.Email } is an existing user already.");
            }
        }

        void SendInvitation(RegisterInvitation invitation)
        {
            var mailManager = new MailManager();

            try
            {
                var registerUrl = string.Format("{2}/account/register?email={0}&key={1}", invitation.Email, invitation.RegistrationKey, EvConstants.SiteUrl);


                var message = string.Format(@"
                Dear User,<br/>
                <br/>
                You are invited to register to EvLab Web. Please follow this link to complete your registration: <a href='{0}'>Register</a>
                <br/><br/>
                Many Thanks!
                <br/><br/>
                Your EvLab Team", registerUrl);

                mailManager.SendEmail(invitation.Email, message, "EvLab Web Registration");
            }
            catch (Exception ex)
            {
                mailManager.SendEmail("hello@evlab.io", "Register invitation send failed. Message: " + ex.Message);
            }
        }

        public void UpdateRegisterInvitation(RegisterInvitation invitation)
        {
            _repository.Update(invitation);
        }
    }
}