fixing collision with contact change ticket (coscine/issues#1360)

src/Database/Models/ContactChangeModel.cs

-using Coscine.Database.DataModel;
-using Coscine.Database.ReturnObjects;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Linq.Expressions;
-
-namespace Coscine.Database.Models
-{
-    public class ContactChangeModel : DatabaseModel<ContactChange>
-    {
-        public bool UserHasEmailsToConfirm(Guid userId)
-        {
-            IEnumerable<ContactChange> emailData = GetAllWhere((contactChange) => contactChange.UserId == userId);
-            // Return True if entries for a user exist inside the db Table ContactChange. Else return False.
-            if (emailData.Count() > 0)
-                return true;
-            else
-                return false;
-        }
-
-        public ContactChangeObject NewEmailChangeRequest(Guid userId, string email)
-        {
-            if (UserHasEmailsToConfirm(userId))
-                DeleteExpiredEntriesFromDatabase(userId);
-            ContactChangeObject contactChangeObject = AddEntryToDatabase(userId, email);
-            SendConfirmationEmail(contactChangeObject.UserId, contactChangeObject.NewEmail, contactChangeObject.ConfirmationToken);
-            return contactChangeObject;
-        }
-
-        public List<ContactChangeObject> GetUserEmailsForConfirmation(Guid userId)
-        {
-            List<ContactChangeObject> contactChangeObjects = new List<ContactChangeObject>();
-            IEnumerable<ContactChange> emailData = GetAllWhere((contactChange) => contactChange.UserId == userId);
-            foreach (var entry in emailData)
-                contactChangeObjects.Add(ToObject(entry));
-            return contactChangeObjects;
-        }
-
-        public UserObject InitiateEmailConfirmation(Guid userId, Guid token)
-        {
-            ContactChange emailData = GetWhere((contactChange) => contactChange.UserId == userId && contactChange.ConfirmationToken == token);
-            if (emailData != null)
-            {
-                if (emailData.EditDate != null)
-                {
-                    // Add 23 Hours, 59 Minutes and 59 Seconds to EditDate to see when the token has to expire and compare with Now.
-                    DateTime expirationDateTime = emailData.EditDate.Value.AddHours(23).AddMinutes(59).AddSeconds(59);
-                    var compareDateTime = DateTime.Compare(expirationDateTime, DateTime.Now);
-                    // Token EXPIRED when expirationDateTime = -1 (Expiration is BEFORE Now)
-                    // Token VALID when expirationDateTime = 0  OR  = 1 (Expiration IS Now or AFTER Now)
-                    if (compareDateTime >= 0)
-                    {
-                        // VALID
-                        UserModel userModel = new UserModel();
-                        User user = userModel.GetWhere((usr) => usr.Id == userId);
-                        user.EmailAddress = emailData.NewEmail; // Overwrite old Email with New.
-                        userModel.Update(user); // Update Database (User Table).
-                        Delete(emailData); // Delete Entry from Database (ContactChange Table).
-                        UserObject userObject = userModel.CreateReturnObjectFromDatabaseObject(userModel.GetWhere((usr) => usr.Id == userId));
-                        return userObject;
-                    }
-                    else
-                    {
-                        // EXPIRED
-                        throw new Exception("EXPIRED: Token " + token.ToString() + " for User with an ID " + userId.ToString() + " has expired.");
-                    }
-                }
-                else
-                {
-                    // INVALID (null EditDate)
-                    throw new ArgumentNullException("INVALID: Value EditDate is NULL for Token " + token.ToString() + " and User with an ID " + userId.ToString() + ".");
-                }
-
-            }
-            else
-            {
-                // INVALID (token-user combination not in Database)
-                throw new MissingFieldException("INVALID: The Token " + token.ToString() + " and User with an ID " + userId.ToString() + " combination is not valid. No entry inside the Database.");
-            }
-        }
-
-        private ContactChangeObject ToObject(ContactChange contactChange)
-        {
-            return new ContactChangeObject(
-                contactChange.RelationId,
-                contactChange.UserId,
-                contactChange.NewEmail,
-                contactChange.EditDate,
-                contactChange.ConfirmationToken
-                );
-        }
-
-        private void DeleteExpiredEntriesFromDatabase(Guid userId)
-        {
-            IEnumerable<ContactChange> emailData = GetAllWhere((contactChange) => contactChange.UserId == userId);
-            emailData.All((entry) =>
-            {
-                ContactChange contactChange = new ContactChange()
-                {
-                    RelationId = entry.RelationId,
-                    UserId = entry.UserId,
-                    NewEmail = entry.NewEmail,
-                    EditDate = entry.EditDate,
-                    ConfirmationToken = entry.ConfirmationToken
-                };
-                Delete(contactChange);
-                return true;
-            });
-        }
-
-        private ContactChangeObject AddEntryToDatabase(Guid userId, string email)
-        {
-            // Create new entry inside the Database for an Email Change Request for the specific User with an Id.
-            ContactChange contactChange = new ContactChange()
-            {
-                RelationId = Guid.NewGuid(),
-                UserId = userId,
-                NewEmail = email,
-                EditDate = System.DateTime.Now,
-                ConfirmationToken = Guid.NewGuid()
-            };
-            Insert(contactChange);
-
-            // Send a Confirmation Email to User's New Email with a Confirmation Token Link 
-            // TODO
-            return ToObject(contactChange);
-        }
-
-        private void SendConfirmationEmail(Guid userId, string email, Guid confrimationToken)
-        {
-            // TODO: Send an email with a clickable url incl. confirmation token.
-            // Notify old email about the change.
-        }
-
-        public override Expression<Func<ContactChange, Guid>> GetIdFromObject()
-        {
-            return (contactChange) => contactChange.RelationId;
-        }
-
-        public override Microsoft.EntityFrameworkCore.DbSet<ContactChange> GetITableFromDatabase(CoscineDB db)
-        {
-            return db.ContactChanges;
-        }
-
-        public override void SetObjectId(ContactChange databaseObject, Guid id)
-        {
-            databaseObject.RelationId = id;
-        }
-    }
-}

src/Database/ReturnObjects/ContactChangeObject.cs

-using System;
-
-namespace Coscine.Database.ReturnObjects
-{
-    public class ContactChangeObject : IReturnObject
-    {
-        public Guid RelationId { get; set; }
-
-        public Guid UserId { get; set; }
-
-        public string NewEmail { get; set; }
-
-        public DateTime? EditDate { get; set; }
-
-        public Guid ConfirmationToken { get; set; }
-
-
-        public ContactChangeObject(Guid relationId, Guid userId, string newEmail, DateTime? editDate, Guid confirmationToken)
-        {
-            RelationId = relationId;
-            UserId = userId;
-            NewEmail = newEmail;
-            EditDate = editDate;
-            ConfirmationToken = confirmationToken;
-        }
-    }
-}