Added endpoint to update contact

Controllers/ContactsController.cs

@@ -72,6 +72,73 @@ public class ContactsController : ControllerBase
 
         return Ok(response);
     }
+
+    [HttpPatch("update"), DisableRequestSizeLimit]
+    public IActionResult UpdateContact([FromBody] Contact contact)
+    {
+        var response = new CreateContactResponse();
+        var connString = this._config.GetConnectionString("MongoDBURI");
+        var userRepo = new UsersRepository(connString!);
+        var contactsRepo = new ContactsRepository(connString!);
+
+        try
+        {
+            var contacts = contactsRepo.RetrieveAll();
+            var users = userRepo.RetrieveAllUsers();
+
+            if (users.Count() == 0 || contacts.Count() == 0)
+            {
+                return BadRequest(response);
+            }
+
+            var c = contacts.FirstOrDefault(c => c.Id!.Equals(contact.Id));
+
+            if (c == null ||
+                string.IsNullOrEmpty(contact.UserID))
+            {
+                // The Contact does not exists or no user id provided
+                return BadRequest(response);
+            }
+
+            if (!userRepo.Exists(contact.UserID!).Item1)
+            {
+                return BadRequest(response);
+            }
+
+            if (!c.UserID!.Equals(contact.UserID))
+            {
+                // The provided user id does is not the same that created the contact
+                return BadRequest(response);
+            }
+
+            if (!string.IsNullOrEmpty(contact.Firstname))
+            {
+                c.Firstname = contact.Firstname;
+            }
+
+            if (string.IsNullOrEmpty(contact.Lastname))
+            {
+                c.Lastname = contact.Lastname;
+            }
+
+            if (string.IsNullOrEmpty(contact.PhoneNumber))
+            {
+                if (!contacts.Exists(cc => cc.PhoneNumber!.Equals(contact.PhoneNumber)))
+                {
+                    c.PhoneNumber = contact.PhoneNumber;
+                }
+            }
+
+            contactsRepo.Update(c);
+            response.Data.Add(c);
+        }
+        catch (Exception ex)
+        {
+            this._logger.LogError($"An error occurred: {ex.Message}");
+        }
+
+        return Ok(response);
+    }
     #endregion