using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace KodtestDPSenior
{

    /// <summary>
    /// Encapsulates information in the entire collection of instances of 
    /// persistance class KodtestDPSenior.User
    /// </summary>
    public static class Users
    {

        /// <summary>
        /// Returns an authenticated User if a valid combination of LoginName and 
        /// PasswordInPlainLanguage are given. Returns null otherwise.
        /// </summary>
        /// <param name="LoginName"></param>
        /// <param name="PasswordInPlainLanguage"></param>
        /// <returns></returns>
        public static User Authenticated(string LoginName, string PasswordInPlainLanguage)
        {

            if (LoginName == null || PasswordInPlainLanguage == null)
            {
                return null;
            }
                       
            if (LoginName.Trim() == "")
            {
                return null;
            }

            KodtestDPSeniorEntities db = new KodtestDPSeniorEntities();

            // "Where" condition below don't take different shift modes into account 
            var user = db.Users.Where(u => u.LoginName == LoginName.Trim()).FirstOrDefault();

            if (user == null)
            {
                return null;
            }
            else
            {

                if (user.LoginName != LoginName.Trim())
                {
                    // Different shift modes
                    return null;
                }
                
                if (user.LoginPassword == Cryptography.GetHash(PasswordInPlainLanguage.Trim()))
                {
                    return user;
                }
                else
                {
                    return null;
                }

            }

        }
        
    }

}