feat(auth): add IGroupRoleMapper<string> seam (Task 1.1)

src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardAuthenticator.cs

@@ -142,56 +142,20 @@ public sealed class DashboardAuthenticator(
     /// Maps the user's LDAP groups to dashboard roles. A user can pick up
     /// multiple roles; Admin and Viewer are the only legal values. Returns
     /// an empty list when no group matches (caller rejects the login).
+    /// Delegates to <see cref="DashboardGroupRoleMapping"/>, the single source
+    /// of truth shared with <see cref="DashboardGroupRoleMapper"/>.
     /// </summary>
     /// <param name="groups">The collection of LDAP groups the user belongs to.</param>
     /// <param name="groupToRole">The mapping from group names to dashboard role names.</param>
     internal static IReadOnlyList<string> MapGroupsToRoles(
         IEnumerable<string> groups,
         IReadOnlyDictionary<string, string> groupToRole)
-    {
-        if (groupToRole.Count == 0)
-        {
-            return [];
-        }
-
-        HashSet<string> roles = new(StringComparer.Ordinal);
-        foreach (string group in groups)
-        {
-            string normalizedGroup = group.Trim();
-
-            // Lookup precedence (Server-040): the full literal group string is
-            // tried first; only if that misses do we fall back to the leading
-            // RDN value (e.g. "GwAdmin" extracted from
-            // "ou=GwAdmin,ou=groups,..."). The map's comparer is
-            // OrdinalIgnoreCase (see DashboardOptions.GroupToRole), so e.g.
-            // "GwAdmin" and "gwadmin" both match.
-            if (groupToRole.TryGetValue(normalizedGroup, out string? mapped)
-                || groupToRole.TryGetValue(ExtractFirstRdnValue(normalizedGroup), out mapped))
-            {
-                roles.Add(mapped);
-            }
-        }
-
-        return [.. roles];
-    }
+        => DashboardGroupRoleMapping.MapGroupsToRoles(groups, groupToRole);
 
     /// <summary>Extracts the first RDN value from a distinguished name.</summary>
     /// <param name="distinguishedName">The LDAP distinguished name.</param>
     internal static string ExtractFirstRdnValue(string distinguishedName)
-    {
-        int equalsIndex = distinguishedName.IndexOf('=');
-        if (equalsIndex < 0)
-        {
-            return distinguishedName;
-        }
-
-        int valueStart = equalsIndex + 1;
-        int commaIndex = distinguishedName.IndexOf(',', valueStart);
-
-        return commaIndex > valueStart
-            ? distinguishedName[valueStart..commaIndex]
-            : distinguishedName[valueStart..];
-    }
+        => DashboardGroupRoleMapping.ExtractFirstRdnValue(distinguishedName);
 
     private static Task BindServiceAccountAsync(
         LdapConnection connection,

src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardGroupRoleMapper.cs

@@ -0,0 +1,31 @@
+using Microsoft.Extensions.Options;
+using ZB.MOM.WW.Auth.Abstractions.Roles;
+using ZB.MOM.WW.MxGateway.Server.Configuration;
+
+namespace ZB.MOM.WW.MxGateway.Server.Dashboard;
+
+/// <summary>
+/// Shared-Auth <see cref="IGroupRoleMapper{TRole}"/> seam over the dashboard's
+/// LDAP-group → role mapping. Roles are plain strings
+/// (<see cref="DashboardRoles.Admin"/> / <see cref="DashboardRoles.Viewer"/>),
+/// so <c>TRole</c> is <see cref="string"/>. The mapping rules (full-DN first,
+/// leading-RDN fallback, case-insensitive) live in
+/// <see cref="DashboardGroupRoleMapping"/>, shared with
+/// <see cref="DashboardAuthenticator"/> so behaviour stays identical.
+/// </summary>
+/// <param name="options">Gateway options supplying the dashboard GroupToRole map.</param>
+public sealed class DashboardGroupRoleMapper(IOptions<GatewayOptions> options)
+    : IGroupRoleMapper<string>
+{
+    /// <inheritdoc />
+    public Task<GroupRoleMapping<string>> MapAsync(
+        IReadOnlyList<string> groups,
+        CancellationToken ct)
+    {
+        IReadOnlyList<string> roles = DashboardGroupRoleMapping.MapGroupsToRoles(
+            groups,
+            options.Value.Dashboard.GroupToRole);
+
+        return Task.FromResult(new GroupRoleMapping<string>(roles, Scope: null));
+    }
+}

src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardGroupRoleMapping.cs

@@ -0,0 +1,66 @@
+namespace ZB.MOM.WW.MxGateway.Server.Dashboard;
+
+/// <summary>
+/// Single source of truth for mapping a user's LDAP groups to dashboard roles.
+/// Both <see cref="DashboardAuthenticator"/> (the existing login flow) and
+/// <see cref="DashboardGroupRoleMapper"/> (the shared-Auth
+/// <see cref="ZB.MOM.WW.Auth.Abstractions.Roles.IGroupRoleMapper{TRole}"/> seam)
+/// delegate here so the precedence and case rules stay identical.
+/// </summary>
+internal static class DashboardGroupRoleMapping
+{
+    /// <summary>
+    /// Maps the user's LDAP groups to dashboard roles. A user can pick up
+    /// multiple roles; Admin and Viewer are the only legal values. Returns
+    /// an empty list when no group matches (caller rejects the login).
+    /// </summary>
+    /// <param name="groups">The collection of LDAP groups the user belongs to.</param>
+    /// <param name="groupToRole">The mapping from group names to dashboard role names.</param>
+    internal static IReadOnlyList<string> MapGroupsToRoles(
+        IEnumerable<string> groups,
+        IReadOnlyDictionary<string, string> groupToRole)
+    {
+        if (groupToRole.Count == 0)
+        {
+            return [];
+        }
+
+        HashSet<string> roles = new(StringComparer.Ordinal);
+        foreach (string group in groups)
+        {
+            string normalizedGroup = group.Trim();
+
+            // Lookup precedence (Server-040): the full literal group string is
+            // tried first; only if that misses do we fall back to the leading
+            // RDN value (e.g. "GwAdmin" extracted from
+            // "ou=GwAdmin,ou=groups,..."). The map's comparer is
+            // OrdinalIgnoreCase (see DashboardOptions.GroupToRole), so e.g.
+            // "GwAdmin" and "gwadmin" both match.
+            if (groupToRole.TryGetValue(normalizedGroup, out string? mapped)
+                || groupToRole.TryGetValue(ExtractFirstRdnValue(normalizedGroup), out mapped))
+            {
+                roles.Add(mapped);
+            }
+        }
+
+        return [.. roles];
+    }
+
+    /// <summary>Extracts the first RDN value from a distinguished name.</summary>
+    /// <param name="distinguishedName">The LDAP distinguished name.</param>
+    internal static string ExtractFirstRdnValue(string distinguishedName)
+    {
+        int equalsIndex = distinguishedName.IndexOf('=');
+        if (equalsIndex < 0)
+        {
+            return distinguishedName;
+        }
+
+        int valueStart = equalsIndex + 1;
+        int commaIndex = distinguishedName.IndexOf(',', valueStart);
+
+        return commaIndex > valueStart
+            ? distinguishedName[valueStart..commaIndex]
+            : distinguishedName[valueStart..];
+    }
+}

src/ZB.MOM.WW.MxGateway.Server/Dashboard/DashboardServiceCollectionExtensions.cs

@@ -2,6 +2,7 @@ using Microsoft.AspNetCore.Authentication;
 using Microsoft.AspNetCore.Authentication.Cookies;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.Extensions.Options;
+using ZB.MOM.WW.Auth.Abstractions.Roles;
 using ZB.MOM.WW.MxGateway.Server.Configuration;
 
 namespace ZB.MOM.WW.MxGateway.Server.Dashboard;
@@ -20,6 +21,7 @@ public static class DashboardServiceCollectionExtensions
         services.AddSingleton<IDashboardSnapshotService, DashboardSnapshotService>();
         services.AddSingleton<IDashboardLiveDataService, DashboardLiveDataService>();
         services.AddSingleton<IDashboardAuthenticator, DashboardAuthenticator>();
+        services.AddSingleton<IGroupRoleMapper<string>, DashboardGroupRoleMapper>();
         services.AddSingleton<DashboardApiKeyAuthorization>();
         services.AddSingleton<IDashboardApiKeyManagementService, DashboardApiKeyManagementService>();
         services.AddSingleton<IDashboardSessionAdminService, DashboardSessionAdminService>();

src/ZB.MOM.WW.MxGateway.Server/ZB.MOM.WW.MxGateway.Server.csproj

@@ -6,6 +6,7 @@
 
   <ItemGroup>
     <PackageReference Include="Grpc.AspNetCore" Version="2.76.0" />
+    <PackageReference Include="ZB.MOM.WW.Auth.Abstractions" Version="0.1.0" />
     <PackageReference Include="ZB.MOM.WW.Configuration" Version="0.1.0" />
     <PackageReference Include="ZB.MOM.WW.Health" Version="0.1.0" />
     <PackageReference Include="ZB.MOM.WW.Telemetry" Version="0.1.0" />