1 files changed, 116 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/group/GroupResolver.java b/java/com/google/gerrit/server/group/GroupResolver.java
new file mode 100644
index 0000000000..5fe3e8ea36
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+++ b/java/com/google/gerrit/server/group/GroupResolver.java
@@ -0,0 +1,116 @@
+// Copyright (C) 2018 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.server.group;
+
+import com.google.gerrit.common.data.GroupDescription;
+import com.google.gerrit.common.data.GroupReference;
+import com.google.gerrit.extensions.restapi.UnprocessableEntityException;
+import com.google.gerrit.reviewdb.client.AccountGroup;
+import com.google.gerrit.server.account.GroupBackend;
+import com.google.gerrit.server.account.GroupBackends;
+import com.google.gerrit.server.account.GroupCache;
+import com.google.gerrit.server.account.GroupControl;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+import java.util.Optional;
+
+@Singleton
+public class GroupResolver {
+  private final GroupBackend groupBackend;
+  private final GroupCache groupCache;
+  private final GroupControl.Factory groupControlFactory;
+
+  @Inject
+  GroupResolver(
+      GroupBackend groupBackend, GroupCache groupCache, GroupControl.Factory groupControlFactory) {
+    this.groupBackend = groupBackend;
+    this.groupCache = groupCache;
+    this.groupControlFactory = groupControlFactory;
+  }
+
+  /**
+   * Parses a group ID from a request body and returns the group.
+   *
+   * @param id ID of the group, can be a group UUID, a group name or a legacy group ID
+   * @return the group
+   * @throws UnprocessableEntityException thrown if the group ID cannot be resolved or if the group
+   *     is not visible to the calling user
+   */
+  public GroupDescription.Basic parse(String id) throws UnprocessableEntityException {
+    GroupDescription.Basic group = parseId(id);
+    if (group == null || !groupControlFactory.controlFor(group).isVisible()) {
+      throw new UnprocessableEntityException(String.format("Group Not Found: %s", id));
+    }
+    return group;
+  }
+
+  /**
+   * Parses a group ID from a request body and returns the group if it is a Gerrit internal group.
+   *
+   * @param id ID of the group, can be a group UUID, a group name or a legacy group ID
+   * @return the group
+   * @throws UnprocessableEntityException thrown if the group ID cannot be resolved, if the group is
+   *     not visible to the calling user or if it's an external group
+   */
+  public GroupDescription.Internal parseInternal(String id) throws UnprocessableEntityException {
+    GroupDescription.Basic group = parse(id);
+    if (group instanceof GroupDescription.Internal) {
+      return (GroupDescription.Internal) group;
+    }
+
+    throw new UnprocessableEntityException(String.format("External Group Not Allowed: %s", id));
+  }
+
+  /**
+   * Parses a group ID and returns the group without making any permission check whether the current
+   * user can see the group.
+   *
+   * @param id ID of the group, can be a group UUID, a group name or a legacy group ID
+   * @return the group, null if no group is found for the given group ID
+   */
+  public GroupDescription.Basic parseId(String id) {
+    AccountGroup.UUID uuid = new AccountGroup.UUID(id);
+    if (groupBackend.handles(uuid)) {
+      GroupDescription.Basic d = groupBackend.get(uuid);
+      if (d != null) {
+        return d;
+      }
+    }
+
+    // Might be a numeric AccountGroup.Id. -> Internal group.
+    if (id.matches("^[1-9][0-9]*$")) {
+      try {
+        AccountGroup.Id groupId = AccountGroup.Id.parse(id);
+        Optional<InternalGroup> group = groupCache.get(groupId);
+        if (group.isPresent()) {
+          return new InternalGroupDescription(group.get());
+        }
+      } catch (IllegalArgumentException e) {
+        // Ignored
+      }
+    }
+
+    // Might be a group name, be nice and accept unique names.
+    GroupReference ref = GroupBackends.findExactSuggestion(groupBackend, id);
+    if (ref != null) {
+      GroupDescription.Basic d = groupBackend.get(ref.getUUID());
+      if (d != null) {
+        return d;
+      }
+    }
+
+    return null;
+  }
+}