src/Database/Database.csproj

@@ -4,7 +4,7 @@
 		<RootNamespace>Coscine.Database</RootNamespace>
 		<AssemblyName>Coscine.Database</AssemblyName>
 		<TargetFrameworks>net5.0;net461</TargetFrameworks>
-		<Version>2.0.1</Version>
+		<Version>2.1.0</Version>
 	</PropertyGroup>
 	<PropertyGroup>
 		<Authors>RWTH Aachen University</Authors>

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
+{
+    // ------------------------------------------------------------------------------------
+    // This Class makes use of "GetAllWhere(...Id)" method rather than "GetById(...Id)" 
+    // to make it future proof in case on a later stage more than a single entry 
+    // is allowed inside the ContactChange table (e.g. history of contact change requests).
+    // To achieve that, remove usage of "DeleteAllDbEntries(...Id)" method.
+    // The line in quesiton is marked with an appropiate comment.
+    // ------------------------------------------------------------------------------------
+
+    public class ContactChangeModel : DatabaseModel<ContactChange>
+    {
+        public bool UserHasEmailsToConfirm(Guid userId)
+        {
+            // Perform deletion of all expired entries (older than 24 Hours).
+            DeleteExpiredDbEntries(userId);
+            IEnumerable<ContactChange> emailData = GetAllWhere((contactChange) => contactChange.UserId == userId);
+            // Return True if entries for a user exist inside the database table ContactChange. Else return False.
+            if (emailData.Count() > 0)
+            {
+                return true;
+            }
+            else
+            {
+                return false;
+            }
+        }
+
+        public ContactChangeObject NewEmailChangeRequest(Guid userId, string email)
+        {
+            if (UserHasEmailsToConfirm(userId))
+            {
+                DeleteAllDbEntries(userId); // <--- REMOVE THIS LINE IF YOU WANT TO KEEP HISTORY OF EMAIL CHANGES.
+            }
+            ContactChangeObject contactChangeObject = AddDbEntry(userId, email);
+            // Sending a confirmation email after an addition to the database is handled by the Controller.
+            return contactChangeObject;
+        }
+
+        public List<ContactChangeObject> GetEmailsForConfirmation(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 ExecuteConfirmation(Guid token)
+        {
+            ContactChange emailData = GetWhere((contactChange) => contactChange.ConfirmationToken == token);
+            if (emailData != null)
+            {
+                if (emailData.EditDate != null)
+                {
+                    // Add 23 Hours, 59 Minutes and 59 Seconds to EditDate, 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.GetById(emailData.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 == emailData.UserId));
+                        return userObject;
+                    }
+                    else
+                    {
+                        throw new Exception("EXPIRED: Token " + token.ToString() + " has expired.");
+                    }
+                }
+                else
+                {
+                    throw new ArgumentNullException("INVALID: Value EditDate is NULL for Token " + token.ToString() + ".");
+                }
+
+            }
+            else
+            {
+                throw new MissingFieldException("INVALID: The Token " + token.ToString() + " is not valid. No entry inside the Database.");
+            }
+        }
+        
+        private void DeleteExpiredDbEntries(Guid userId)
+        {
+            IEnumerable<ContactChange> emailData = GetAllWhere((contactChange) => contactChange.UserId == userId);
+            foreach (var entry in emailData)
+            {
+                // Add 23 Hours, 59 Minutes and 59 Seconds to EditDate, see when the token has to expire and compare with Now.
+                DateTime expirationDateTime = entry.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)
+                {
+                    Delete(entry);
+                }
+            }
+        }
+
+        private void DeleteAllDbEntries(Guid userId)
+        {
+            IEnumerable<ContactChange> emailData = GetAllWhere((contactChange) => contactChange.UserId == userId);
+            foreach (var entry in emailData)
+            {
+                Delete(entry);
+            }
+        }
+
+        private ContactChangeObject AddDbEntry(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 = DateTime.Now,
+                ConfirmationToken = Guid.NewGuid()
+            };
+            Insert(contactChange);
+            return ToObject(contactChange);
+        }
+
+        public static ContactChangeObject ToObject(ContactChange contactChange)
+        {
+            return new ContactChangeObject(
+                contactChange.RelationId,
+                contactChange.UserId,
+                contactChange.NewEmail,
+                contactChange.EditDate,
+                contactChange.ConfirmationToken
+                );
+        }
+
+        public static ContactChange FromObject(ContactChangeObject contactChangeObject)
+        {
+            return new ContactChange() 
+            {
+                RelationId = contactChangeObject.RelationId,
+                UserId = contactChangeObject.UserId,
+                NewEmail = contactChangeObject.NewEmail,
+                EditDate = contactChangeObject.EditDate,
+                ConfirmationToken = contactChangeObject.ConfirmationToken
+            };
+        }
+
+        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;
+        }
+    }
+}

src/Scaffolding/DataModel/Model.cs

@@ -21,6 +21,7 @@ namespace Coscine.Database.DataModel
 
         public virtual DbSet<ActivatedFeature> ActivatedFeatures { get; set; }
         public virtual DbSet<ApiToken> ApiTokens { get; set; }
+        public virtual DbSet<ContactChange> ContactChanges { get; set; }
         public virtual DbSet<Discipline> Disciplines { get; set; }
         public virtual DbSet<ExternalAuthenticator> ExternalAuthenticators { get; set; }
         public virtual DbSet<ExternalId> ExternalIds { get; set; }
@@ -98,6 +99,29 @@ namespace Coscine.Database.DataModel
                     .HasConstraintName("FK_ApiTokens_UserId_Users_Id");
             });
 
+            modelBuilder.Entity<ContactChange>(entity =>
+            {
+                entity.HasKey(e => e.RelationId);
+
+                entity.ToTable("ContactChange");
+
+                entity.Property(e => e.RelationId).HasDefaultValueSql("(newid())");
+
+                entity.Property(e => e.ConfirmationToken).HasDefaultValueSql("(newid())");
+
+                entity.Property(e => e.EditDate).HasColumnType("datetime");
+
+                entity.Property(e => e.NewEmail)
+                    .IsRequired()
+                    .HasMaxLength(200);
+
+                entity.HasOne(d => d.User)
+                    .WithMany(p => p.ContactChanges)
+                    .HasForeignKey(d => d.UserId)
+                    .OnDelete(DeleteBehavior.ClientSetNull)
+                    .HasConstraintName("FK_ContactChange_UserId_Users_Id");
+            });
+
             modelBuilder.Entity<Discipline>(entity =>
             {
                 entity.Property(e => e.Id).HasDefaultValueSql("(newid())");

src/Scaffolding/DataModel/User.cs

@@ -12,6 +12,7 @@ namespace Coscine.Database.DataModel
         public User()
         {
             ApiTokens = new HashSet<ApiToken>();
+            ContactChanges = new HashSet<ContactChange>();
             ExternalIds = new HashSet<ExternalId>();
             GroupMemberships = new HashSet<GroupMembership>();
             ProjectRoles = new HashSet<ProjectRole>();
@@ -33,6 +34,7 @@ namespace Coscine.Database.DataModel
         public virtual Language Language { get; set; }
         public virtual Title Title { get; set; }
         public virtual ICollection<ApiToken> ApiTokens { get; set; }
+        public virtual ICollection<ContactChange> ContactChanges { get; set; }
         public virtual ICollection<ExternalId> ExternalIds { get; set; }
         public virtual ICollection<GroupMembership> GroupMemberships { get; set; }
         public virtual ICollection<ProjectRole> ProjectRoles { get; set; }