From 62d1eca7029627cb1fe24e1a7284d73ac56337b8 Mon Sep 17 00:00:00 2001
From: Dustin Burson <47367432+dustinburson@users.noreply.github.com>
Date: Fri, 22 Apr 2022 16:41:33 -0700
Subject: [PATCH] Revert "Create patient resource using a deterministic id
 (#183)" (#186)

This reverts commit 0600d8044268f4ccc96da6ef9171717b0d1b8a3d.
---
 .../Service/ResourceManagementService.cs      | 27 +------------------
 1 file changed, 1 insertion(+), 26 deletions(-)

diff --git a/src/lib/Microsoft.Health.Extensions.Fhir.R4/Service/ResourceManagementService.cs b/src/lib/Microsoft.Health.Extensions.Fhir.R4/Service/ResourceManagementService.cs
index cec0f4b5..0c0420c6 100644
--- a/src/lib/Microsoft.Health.Extensions.Fhir.R4/Service/ResourceManagementService.cs
+++ b/src/lib/Microsoft.Health.Extensions.Fhir.R4/Service/ResourceManagementService.cs
@@ -4,8 +4,6 @@
 // -------------------------------------------------------------------------------------------------
 
 using System;
-using System.Security.Cryptography;
-using System.Text;
 using System.Threading.Tasks;
 using EnsureThat;
 using Hl7.Fhir.Model;
@@ -71,10 +69,7 @@ protected async Task<TResource> CreateResourceByIdentityAsync<TResource>(Model.I
 
             propertySetter?.Invoke(resource, identifier);
 
-            // Generate id programatically and issue an update to FHIR service
-            // The resource will be created if the resource with the given id does not already exist.
-            resource.Id = ComputeSha256(identifier);
-            return await FhirService.UpdateResourceAsync<TResource>(resource).ConfigureAwait(false);
+            return await FhirService.CreateResourceAsync(resource).ConfigureAwait(false);
         }
 
         private static Model.Identifier BuildIdentifier(string value, string system)
@@ -82,25 +77,5 @@ private static Model.Identifier BuildIdentifier(string value, string system)
             var identifier = new Model.Identifier { Value = value, System = string.IsNullOrWhiteSpace(system) ? null : system };
             return identifier;
         }
-
-        private static string ComputeSha256(Model.Identifier identifier)
-        {
-            EnsureArg.IsNotNullOrWhiteSpace(identifier.Value, nameof(identifier.Value));
-
-            string plainTextSystemAndId = $"{identifier.System}_{identifier.Value}";
-
-            using (SHA256 hashAlgorithm = SHA256.Create())
-            {
-                byte[] bytes = hashAlgorithm.ComputeHash(Encoding.UTF8.GetBytes(plainTextSystemAndId));
-
-                StringBuilder sb = new StringBuilder();
-                for (int i = 0; i < bytes.Length; i++)
-                {
-                    sb.Append(bytes[i].ToString("x2"));
-                }
-
-                return sb.ToString();
-            }
-        }
     }
 }
\ No newline at end of file