Move the logic out of SuggestReviewers and make super class

The logic was moved into a class called ReviewersUtil so that it can be
reused by multiple implementations using different resources (i.e:
ChangeResource and ProjectResource).

This refactor is made to enable a bug fix[1] in the reviewers plugin.

[1] https://gerrit-review.googlesource.com/#/c/75307

Bug: Issue 3892
Change-Id: I7c48463f44c64e35a5be7b83f524bd4c616c32da

6 files changed, 409 insertions, 278 deletions

diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/ReviewersUtil.java b/gerrit-server/src/main/java/com/google/gerrit/server/ReviewersUtil.java
new file mode 100644
index 0000000000..e38f88c731
--- /dev/null
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/ReviewersUtil.java
@@ -0,0 +1,286 @@
+// Copyright (C) 2016 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;
+
+import com.google.common.base.Function;
+import com.google.common.base.MoreObjects;
+import com.google.common.base.Strings;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Ordering;
+import com.google.gerrit.common.Nullable;
+import com.google.gerrit.common.data.GroupReference;
+import com.google.gerrit.common.errors.NoSuchGroupException;
+import com.google.gerrit.extensions.common.AccountInfo;
+import com.google.gerrit.extensions.common.GroupBaseInfo;
+import com.google.gerrit.extensions.common.SuggestedReviewerInfo;
+import com.google.gerrit.extensions.restapi.BadRequestException;
+import com.google.gerrit.extensions.restapi.Url;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.AccountExternalId;
+import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.account.AccountCache;
+import com.google.gerrit.server.account.AccountControl;
+import com.google.gerrit.server.account.AccountLoader;
+import com.google.gerrit.server.account.GroupBackend;
+import com.google.gerrit.server.account.GroupMembers;
+import com.google.gerrit.server.change.PostReviewers;
+import com.google.gerrit.server.change.ReviewerSuggestionCache;
+import com.google.gerrit.server.change.SuggestReviewers;
+import com.google.gerrit.server.project.NoSuchProjectException;
+import com.google.gerrit.server.project.ProjectControl;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public class ReviewersUtil {
+  private static final String MAX_SUFFIX = "\u9fa5";
+  private static final Ordering<SuggestedReviewerInfo> ORDERING =
+      Ordering.natural().onResultOf(new Function<SuggestedReviewerInfo, String>() {
+        @Nullable
+        @Override
+        public String apply(@Nullable SuggestedReviewerInfo suggestedReviewerInfo) {
+          if (suggestedReviewerInfo == null) {
+            return null;
+          }
+          return suggestedReviewerInfo.account != null
+              ? MoreObjects.firstNonNull(suggestedReviewerInfo.account.email,
+              Strings.nullToEmpty(suggestedReviewerInfo.account.name))
+              : Strings.nullToEmpty(suggestedReviewerInfo.group.name);
+        }
+      });
+  private final AccountLoader accountLoader;
+  private final AccountCache accountCache;
+  private final ReviewerSuggestionCache reviewerSuggestionCache;
+  private final AccountControl accountControl;
+  private final Provider<ReviewDb> dbProvider;
+  private final GroupBackend groupBackend;
+  private final GroupMembers.Factory groupMembersFactory;
+  private final Provider<CurrentUser> currentUser;
+
+  @Inject
+  ReviewersUtil(AccountLoader.Factory accountLoaderFactory,
+      AccountCache accountCache,
+      ReviewerSuggestionCache reviewerSuggestionCache,
+      AccountControl.Factory accountControlFactory,
+      Provider<ReviewDb> dbProvider,
+      GroupBackend groupBackend,
+      GroupMembers.Factory groupMembersFactory,
+      Provider<CurrentUser> currentUser) {
+    this.accountLoader = accountLoaderFactory.create(true);
+    this.accountCache = accountCache;
+    this.reviewerSuggestionCache = reviewerSuggestionCache;
+    this.accountControl = accountControlFactory.get();
+    this.dbProvider = dbProvider;
+    this.groupBackend = groupBackend;
+    this.groupMembersFactory = groupMembersFactory;
+    this.currentUser = currentUser;
+  }
+
+  public interface VisibilityControl {
+    boolean isVisibleTo(Account.Id account) throws OrmException;
+  }
+
+  public List<SuggestedReviewerInfo> suggestReviewers(
+      SuggestReviewers suggestReviewers, ProjectControl projectControl,
+      VisibilityControl visibilityControl)
+      throws IOException, OrmException, BadRequestException {
+    String query = suggestReviewers.getQuery();
+    boolean suggestAccounts = suggestReviewers.getSuggestAccounts();
+    int suggestFrom = suggestReviewers.getSuggestFrom();
+    boolean useFullTextSearch = suggestReviewers.getUseFullTextSearch();
+    int limit = suggestReviewers.getLimit();
+
+    if (Strings.isNullOrEmpty(query)) {
+      throw new BadRequestException("missing query field");
+    }
+
+    if (!suggestAccounts || query.length() < suggestFrom) {
+      return Collections.emptyList();
+    }
+
+    List<AccountInfo> suggestedAccounts;
+    if (useFullTextSearch) {
+      suggestedAccounts = suggestAccountFullTextSearch(suggestReviewers, visibilityControl);
+    } else {
+      suggestedAccounts = suggestAccount(suggestReviewers, visibilityControl);
+    }
+
+    List<SuggestedReviewerInfo> reviewer = Lists.newArrayList();
+    for (AccountInfo a : suggestedAccounts) {
+      SuggestedReviewerInfo info = new SuggestedReviewerInfo();
+      info.account = a;
+      reviewer.add(info);
+    }
+
+    for (GroupReference g : suggestAccountGroup(suggestReviewers, projectControl)) {
+      if (suggestGroupAsReviewer(suggestReviewers, projectControl.getProject(),
+          g, visibilityControl)) {
+        GroupBaseInfo info = new GroupBaseInfo();
+        info.id = Url.encode(g.getUUID().get());
+        info.name = g.getName();
+        SuggestedReviewerInfo suggestedReviewerInfo = new SuggestedReviewerInfo();
+        suggestedReviewerInfo.group = info;
+        reviewer.add(suggestedReviewerInfo);
+      }
+    }
+
+    reviewer = ORDERING.immutableSortedCopy(reviewer);
+    if (reviewer.size() <= limit) {
+      return reviewer;
+    } else {
+      return reviewer.subList(0, limit);
+    }
+  }
+
+  private List<AccountInfo> suggestAccountFullTextSearch(
+      SuggestReviewers suggestReviewers, VisibilityControl visibilityControl)
+          throws IOException, OrmException {
+    List<AccountInfo> results = reviewerSuggestionCache.search(
+        suggestReviewers.getQuery(), suggestReviewers.getFullTextMaxMatches());
+
+    Iterator<AccountInfo> it = results.iterator();
+    while (it.hasNext()) {
+      Account.Id accountId = new Account.Id(it.next()._accountId);
+      if (!(visibilityControl.isVisibleTo(accountId)
+          && accountControl.canSee(accountId))) {
+        it.remove();
+      }
+    }
+
+    return results;
+  }
+
+  private List<AccountInfo> suggestAccount(SuggestReviewers suggestReviewers,
+      VisibilityControl visibilityControl)
+      throws OrmException {
+    String query = suggestReviewers.getQuery();
+    int limit = suggestReviewers.getLimit();
+
+    String a = query;
+    String b = a + MAX_SUFFIX;
+
+    Map<Account.Id, AccountInfo> r = new LinkedHashMap<>();
+    Map<Account.Id, String> queryEmail = new HashMap<>();
+
+    for (Account p : dbProvider.get().accounts()
+        .suggestByFullName(a, b, limit)) {
+      if (p.isActive()) {
+        addSuggestion(r, p.getId(), visibilityControl);
+      }
+    }
+
+    if (r.size() < limit) {
+      for (Account p : dbProvider.get().accounts()
+          .suggestByPreferredEmail(a, b, limit - r.size())) {
+        if (p.isActive()) {
+          addSuggestion(r, p.getId(), visibilityControl);
+        }
+      }
+    }
+
+    if (r.size() < limit) {
+      for (AccountExternalId e : dbProvider.get().accountExternalIds()
+          .suggestByEmailAddress(a, b, limit - r.size())) {
+        if (!r.containsKey(e.getAccountId())) {
+          Account p = accountCache.get(e.getAccountId()).getAccount();
+          if (p.isActive()) {
+            if (addSuggestion(r, p.getId(), visibilityControl)) {
+              queryEmail.put(e.getAccountId(), e.getEmailAddress());
+            }
+          }
+        }
+      }
+    }
+
+    accountLoader.fill();
+    for (Map.Entry<Account.Id, String> p : queryEmail.entrySet()) {
+      AccountInfo info = r.get(p.getKey());
+      if (info != null) {
+        info.email = p.getValue();
+      }
+    }
+    return new ArrayList<>(r.values());
+  }
+
+  private boolean addSuggestion(Map<Account.Id, AccountInfo> map,
+      Account.Id account, VisibilityControl visibilityControl)
+      throws OrmException {
+    if (!map.containsKey(account)
+        // Can the suggestion see the change?
+        && visibilityControl.isVisibleTo(account)
+        // Can the account see the current user?
+        && accountControl.canSee(account)) {
+      map.put(account, accountLoader.get(account));
+      return true;
+    }
+    return false;
+  }
+
+  private List<GroupReference> suggestAccountGroup(
+      SuggestReviewers suggestReviewers, ProjectControl ctl) {
+    return Lists.newArrayList(
+        Iterables.limit(groupBackend.suggest(suggestReviewers.getQuery(), ctl),
+            suggestReviewers.getLimit()));
+  }
+
+  private boolean suggestGroupAsReviewer(SuggestReviewers suggestReviewers,
+      Project project, GroupReference group,
+      VisibilityControl visibilityControl) throws OrmException, IOException {
+    int maxAllowed = suggestReviewers.getMaxAllowed();
+
+    if (!PostReviewers.isLegalReviewerGroup(group.getUUID())) {
+      return false;
+    }
+
+    try {
+      Set<Account> members = groupMembersFactory
+          .create(currentUser.get())
+          .listAccounts(group.getUUID(), project.getNameKey());
+
+      if (members.isEmpty()) {
+        return false;
+      }
+
+      if (maxAllowed > 0 && members.size() > maxAllowed) {
+        return false;
+      }
+
+      // require that at least one member in the group can see the change
+      for (Account account : members) {
+        if (visibilityControl.isVisibleTo(account.getId())) {
+          return true;
+        }
+      }
+    } catch (NoSuchGroupException e) {
+      return false;
+    } catch (NoSuchProjectException e) {
+      return false;
+    }
+
+    return false;
+  }
+}
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/api/changes/ChangeApiImpl.java b/gerrit-server/src/main/java/com/google/gerrit/server/api/changes/ChangeApiImpl.java
index b55642cccc..d4f685108b 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/api/changes/ChangeApiImpl.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/api/changes/ChangeApiImpl.java
@@ -48,7 +48,7 @@ import com.google.gerrit.server.change.Restore;
 import com.google.gerrit.server.change.Revert;
 import com.google.gerrit.server.change.Revisions;
 import com.google.gerrit.server.change.SubmittedTogether;
-import com.google.gerrit.server.change.SuggestReviewers;
+import com.google.gerrit.server.change.SuggestChangeReviewers;
 import com.google.gerrit.server.git.UpdateException;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
@@ -70,7 +70,7 @@ class ChangeApiImpl implements ChangeApi {
   private final Changes changeApi;
   private final Revisions revisions;
   private final RevisionApiImpl.Factory revisionApi;
-  private final Provider<SuggestReviewers> suggestReviewers;
+  private final Provider<SuggestChangeReviewers> suggestReviewers;
   private final ChangeResource change;
   private final Abandon abandon;
   private final Revert revert;
@@ -92,7 +92,7 @@ class ChangeApiImpl implements ChangeApi {
       Changes changeApi,
       Revisions revisions,
       RevisionApiImpl.Factory revisionApi,
-      Provider<SuggestReviewers> suggestReviewers,
+      Provider<SuggestChangeReviewers> suggestReviewers,
       Abandon abandon,
       Revert revert,
       Restore restore,
@@ -257,7 +257,7 @@ class ChangeApiImpl implements ChangeApi {
   private List<SuggestedReviewerInfo> suggestReviewers(SuggestedReviewersRequest r)
       throws RestApiException {
     try {
-      SuggestReviewers mySuggestReviewers = suggestReviewers.get();
+      SuggestChangeReviewers mySuggestReviewers = suggestReviewers.get();
       mySuggestReviewers.setQuery(r.getQuery());
       mySuggestReviewers.setLimit(r.getLimit());
       return mySuggestReviewers.apply(change);
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/Module.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/Module.java
index 9c588ed769..55c65e7744 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/Module.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/Module.java
@@ -25,6 +25,7 @@ import static com.google.gerrit.server.change.RevisionResource.REVISION_KIND;
 import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.extensions.restapi.RestApiModule;
 import com.google.gerrit.server.account.AccountLoader;
+import com.google.gerrit.server.change.SuggestChangeReviewers;
 import com.google.gerrit.server.change.Reviewed.DeleteReviewed;
 import com.google.gerrit.server.change.Reviewed.PutReviewed;
 
@@ -69,7 +70,7 @@ public class Module extends RestApiModule {
     post(CHANGE_KIND, "index").to(Index.class);
 
     post(CHANGE_KIND, "reviewers").to(PostReviewers.class);
-    get(CHANGE_KIND, "suggest_reviewers").to(SuggestReviewers.class);
+    get(CHANGE_KIND, "suggest_reviewers").to(SuggestChangeReviewers.class);
     child(CHANGE_KIND, "reviewers").to(Reviewers.class);
     get(REVIEWER_KIND).to(GetReviewer.class);
     delete(REVIEWER_KIND).to(DeleteReviewer.class);
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/ReviewerSuggestionCache.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/ReviewerSuggestionCache.java
index ffb63f626c..20078cca1b 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/ReviewerSuggestionCache.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/ReviewerSuggestionCache.java
@@ -102,7 +102,7 @@ public class ReviewerSuggestionCache {
             });
   }
 
-  List<AccountInfo> search(String query, int n) throws IOException {
+  public List<AccountInfo> search(String query, int n) throws IOException {
     IndexSearcher searcher = get();
     if (searcher == null) {
       return Collections.emptyList();
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/SuggestChangeReviewers.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/SuggestChangeReviewers.java
new file mode 100644
index 0000000000..1596e316fc
--- /dev/null
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/SuggestChangeReviewers.java
@@ -0,0 +1,76 @@
+// Copyright (C) 2016 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.change;
+
+import com.google.gerrit.extensions.common.SuggestedReviewerInfo;
+import com.google.gerrit.extensions.restapi.BadRequestException;
+import com.google.gerrit.extensions.restapi.RestReadView;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.ReviewersUtil;
+import com.google.gerrit.server.IdentifiedUser.GenericFactory;
+import com.google.gerrit.server.ReviewersUtil.VisibilityControl;
+import com.google.gerrit.server.account.AccountVisibility;
+import com.google.gerrit.server.config.GerritServerConfig;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+
+import org.eclipse.jgit.lib.Config;
+
+import java.io.IOException;
+import java.util.List;
+
+public class SuggestChangeReviewers extends SuggestReviewers
+    implements RestReadView<ChangeResource> {
+  @Inject
+  SuggestChangeReviewers(AccountVisibility av,
+      GenericFactory identifiedUserFactory,
+      Provider<ReviewDb> dbProvider,
+      @GerritServerConfig Config cfg,
+      ReviewersUtil reviewersUtil) {
+    super(av, identifiedUserFactory, dbProvider, cfg, reviewersUtil);
+  }
+
+  @Override
+  public List<SuggestedReviewerInfo> apply(ChangeResource rsrc)
+      throws BadRequestException, OrmException, IOException {
+    return reviewersUtil.suggestReviewers(this,
+        rsrc.getControl().getProjectControl(), getVisibility(rsrc));
+  }
+
+  private VisibilityControl getVisibility(final ChangeResource rsrc) {
+    if (rsrc.getControl().getRefControl().isVisibleByRegisteredUsers()) {
+      return new VisibilityControl() {
+        @Override
+        public boolean isVisibleTo(Account.Id account) throws OrmException {
+          return true;
+        }
+      };
+    } else {
+      return new VisibilityControl() {
+        @Override
+        public boolean isVisibleTo(Account.Id account) throws OrmException {
+          IdentifiedUser who =
+              identifiedUserFactory.create(dbProvider, account);
+          // we can't use changeControl directly as it won't suggest reviewers
+          // to drafts
+          return rsrc.getControl().forUser(who).isRefVisible();
+        }
+      };
+    }
+  }
+}
\ No newline at end of file
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/SuggestReviewers.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/SuggestReviewers.java
index 4561ae45bc..3b610336e2 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/SuggestReviewers.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/SuggestReviewers.java
@@ -14,89 +14,33 @@
 
 package com.google.gerrit.server.change;
 
-import com.google.common.base.Function;
-import com.google.common.base.MoreObjects;
-import com.google.common.base.Strings;
-import com.google.common.collect.Iterables;
-import com.google.common.collect.Lists;
-import com.google.common.collect.Ordering;
-import com.google.gerrit.common.Nullable;
-import com.google.gerrit.common.data.GroupReference;
-import com.google.gerrit.common.errors.NoSuchGroupException;
-import com.google.gerrit.extensions.common.AccountInfo;
-import com.google.gerrit.extensions.common.GroupBaseInfo;
-import com.google.gerrit.extensions.common.SuggestedReviewerInfo;
-import com.google.gerrit.extensions.restapi.BadRequestException;
-import com.google.gerrit.extensions.restapi.RestReadView;
-import com.google.gerrit.extensions.restapi.Url;
-import com.google.gerrit.reviewdb.client.Account;
-import com.google.gerrit.reviewdb.client.AccountExternalId;
-import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.server.ReviewDb;
-import com.google.gerrit.server.CurrentUser;
 import com.google.gerrit.server.IdentifiedUser;
-import com.google.gerrit.server.account.AccountCache;
-import com.google.gerrit.server.account.AccountControl;
-import com.google.gerrit.server.account.AccountLoader;
+import com.google.gerrit.server.ReviewersUtil;
 import com.google.gerrit.server.account.AccountVisibility;
-import com.google.gerrit.server.account.GroupBackend;
-import com.google.gerrit.server.account.GroupMembers;
 import com.google.gerrit.server.config.GerritServerConfig;
-import com.google.gerrit.server.project.NoSuchProjectException;
-import com.google.gerrit.server.project.ProjectControl;
-import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 
 import org.eclipse.jgit.lib.Config;
 import org.kohsuke.args4j.Option;
 
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.LinkedHashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-public class SuggestReviewers implements RestReadView<ChangeResource> {
-  private static final String MAX_SUFFIX = "\u9fa5";
+public class SuggestReviewers {
   private static final int DEFAULT_MAX_SUGGESTED = 10;
   private static final int DEFAULT_MAX_MATCHES = 100;
-  private static final Ordering<SuggestedReviewerInfo> ORDERING =
-      Ordering.natural().onResultOf(new Function<SuggestedReviewerInfo, String>() {
-        @Nullable
-        @Override
-        public String apply(@Nullable SuggestedReviewerInfo suggestedReviewerInfo) {
-          if (suggestedReviewerInfo == null) {
-            return null;
-          }
-          return suggestedReviewerInfo.account != null
-              ? MoreObjects.firstNonNull(suggestedReviewerInfo.account.email,
-              Strings.nullToEmpty(suggestedReviewerInfo.account.name))
-              : Strings.nullToEmpty(suggestedReviewerInfo.group.name);
-        }
-      });
 
-  private final AccountLoader accountLoader;
-  private final AccountControl accountControl;
-  private final GroupMembers.Factory groupMembersFactory;
-  private final AccountCache accountCache;
-  private final Provider<ReviewDb> dbProvider;
-  private final Provider<CurrentUser> currentUser;
-  private final IdentifiedUser.GenericFactory identifiedUserFactory;
-  private final GroupBackend groupBackend;
+  protected final Provider<ReviewDb> dbProvider;
+  protected final IdentifiedUser.GenericFactory identifiedUserFactory;
+  protected final ReviewersUtil reviewersUtil;
+
   private final boolean suggestAccounts;
   private final int suggestFrom;
   private final int maxAllowed;
-  private int limit;
-  private String query;
+  protected int limit;
+  protected String query;
   private boolean useFullTextSearch;
   private final int fullTextMaxMatches;
-  private final int maxSuggestedReviewers;
-  private final ReviewerSuggestionCache reviewerSuggestionCache;
+  protected final int maxSuggestedReviewers;
 
   @Option(name = "--limit", aliases = {"-n"}, metaVar = "CNT",
       usage = "maximum number of reviewers to list")
@@ -112,27 +56,43 @@ public class SuggestReviewers implements RestReadView<ChangeResource> {
     this.query = q;
   }
 
+  public String getQuery() {
+    return query;
+  }
+
+  public boolean getSuggestAccounts() {
+    return suggestAccounts;
+  }
+
+  public int getSuggestFrom() {
+    return suggestFrom;
+  }
+
+  public boolean getUseFullTextSearch() {
+    return useFullTextSearch;
+  }
+
+  public int getFullTextMaxMatches() {
+    return fullTextMaxMatches;
+  }
+
+  public int getLimit() {
+    return limit;
+  }
+
+  public int getMaxAllowed() {
+    return maxAllowed;
+  }
+
   @Inject
-  SuggestReviewers(AccountVisibility av,
-      AccountLoader.Factory accountLoaderFactory,
-      AccountControl.Factory accountControlFactory,
-      AccountCache accountCache,
-      GroupMembers.Factory groupMembersFactory,
+  public SuggestReviewers(AccountVisibility av,
       IdentifiedUser.GenericFactory identifiedUserFactory,
-      Provider<CurrentUser> currentUser,
       Provider<ReviewDb> dbProvider,
       @GerritServerConfig Config cfg,
-      GroupBackend groupBackend,
-      ReviewerSuggestionCache reviewerSuggestionCache) {
-    this.accountLoader = accountLoaderFactory.create(true);
-    this.accountControl = accountControlFactory.get();
-    this.accountCache = accountCache;
-    this.groupMembersFactory = groupMembersFactory;
+      ReviewersUtil reviewersUtil) {
     this.dbProvider = dbProvider;
     this.identifiedUserFactory = identifiedUserFactory;
-    this.currentUser = currentUser;
-    this.groupBackend = groupBackend;
-    this.reviewerSuggestionCache = reviewerSuggestionCache;
+    this.reviewersUtil = reviewersUtil;
     this.maxSuggestedReviewers =
         cfg.getInt("suggest", "maxSuggestedReviewers", DEFAULT_MAX_SUGGESTED);
     this.limit = this.maxSuggestedReviewers;
@@ -152,196 +112,4 @@ public class SuggestReviewers implements RestReadView<ChangeResource> {
     this.maxAllowed = cfg.getInt("addreviewer", "maxAllowed",
         PostReviewers.DEFAULT_MAX_REVIEWERS);
   }
-
-  private interface VisibilityControl {
-    boolean isVisibleTo(Account.Id account) throws OrmException;
-  }
-
-  @Override
-  public List<SuggestedReviewerInfo> apply(ChangeResource rsrc)
-      throws BadRequestException, OrmException, IOException {
-    if (Strings.isNullOrEmpty(query)) {
-      throw new BadRequestException("missing query field");
-    }
-
-    if (!suggestAccounts || query.length() < suggestFrom) {
-      return Collections.emptyList();
-    }
-
-    VisibilityControl visibilityControl = getVisibility(rsrc);
-    List<AccountInfo> suggestedAccounts;
-    if (useFullTextSearch) {
-      suggestedAccounts = suggestAccountFullTextSearch(visibilityControl);
-    } else {
-      suggestedAccounts = suggestAccount(visibilityControl);
-    }
-
-    List<SuggestedReviewerInfo> reviewer = Lists.newArrayList();
-    for (AccountInfo a : suggestedAccounts) {
-      SuggestedReviewerInfo info = new SuggestedReviewerInfo();
-      info.account = a;
-      reviewer.add(info);
-    }
-
-    Project p = rsrc.getControl().getProject();
-    for (GroupReference g : suggestAccountGroup(
-        rsrc.getControl().getProjectControl())) {
-      if (suggestGroupAsReviewer(p, g, visibilityControl)) {
-        GroupBaseInfo info = new GroupBaseInfo();
-        info.id = Url.encode(g.getUUID().get());
-        info.name = g.getName();
-        SuggestedReviewerInfo suggestedReviewerInfo = new SuggestedReviewerInfo();
-        suggestedReviewerInfo.group = info;
-        reviewer.add(suggestedReviewerInfo);
-      }
-    }
-
-    reviewer = ORDERING.immutableSortedCopy(reviewer);
-    if (reviewer.size() <= limit) {
-      return reviewer;
-    } else {
-      return reviewer.subList(0, limit);
-    }
-  }
-
-  private VisibilityControl getVisibility(final ChangeResource rsrc) {
-    if (rsrc.getControl().getRefControl().isVisibleByRegisteredUsers()) {
-      return new VisibilityControl() {
-        @Override
-        public boolean isVisibleTo(Account.Id account) throws OrmException {
-          return true;
-        }
-      };
-    } else {
-      return new VisibilityControl() {
-        @Override
-        public boolean isVisibleTo(Account.Id account) throws OrmException {
-          IdentifiedUser who =
-              identifiedUserFactory.create(dbProvider, account);
-          // we can't use changeControl directly as it won't suggest reviewers
-          // to drafts
-          return rsrc.getControl().forUser(who).isRefVisible();
-        }
-      };
-    }
-  }
-
-  private List<GroupReference> suggestAccountGroup(ProjectControl ctl) {
-    return Lists.newArrayList(
-        Iterables.limit(groupBackend.suggest(query, ctl), limit));
-  }
-
-  private List<AccountInfo> suggestAccount(VisibilityControl visibilityControl)
-      throws OrmException {
-    String a = query;
-    String b = a + MAX_SUFFIX;
-
-    Map<Account.Id, AccountInfo> r = new LinkedHashMap<>();
-    Map<Account.Id, String> queryEmail = new HashMap<>();
-
-    for (Account p : dbProvider.get().accounts()
-        .suggestByFullName(a, b, limit)) {
-      if (p.isActive()) {
-        addSuggestion(r, p.getId(), visibilityControl);
-      }
-    }
-
-    if (r.size() < limit) {
-      for (Account p : dbProvider.get().accounts()
-          .suggestByPreferredEmail(a, b, limit - r.size())) {
-        if (p.isActive()) {
-          addSuggestion(r, p.getId(), visibilityControl);
-        }
-      }
-    }
-
-    if (r.size() < limit) {
-      for (AccountExternalId e : dbProvider.get().accountExternalIds()
-          .suggestByEmailAddress(a, b, limit - r.size())) {
-        if (!r.containsKey(e.getAccountId())) {
-          Account p = accountCache.get(e.getAccountId()).getAccount();
-          if (p.isActive()) {
-            if (addSuggestion(r, p.getId(), visibilityControl)) {
-              queryEmail.put(e.getAccountId(), e.getEmailAddress());
-            }
-          }
-        }
-      }
-    }
-
-    accountLoader.fill();
-    for (Map.Entry<Account.Id, String> p : queryEmail.entrySet()) {
-      AccountInfo info = r.get(p.getKey());
-      if (info != null) {
-        info.email = p.getValue();
-      }
-    }
-    return new ArrayList<>(r.values());
-  }
-
-  private List<AccountInfo> suggestAccountFullTextSearch(
-      VisibilityControl visibilityControl) throws IOException, OrmException {
-    List<AccountInfo> results = reviewerSuggestionCache.search(
-        query, fullTextMaxMatches);
-
-    Iterator<AccountInfo> it = results.iterator();
-    while (it.hasNext()) {
-      Account.Id accountId = new Account.Id(it.next()._accountId);
-      if (!(visibilityControl.isVisibleTo(accountId)
-          && accountControl.canSee(accountId))) {
-        it.remove();
-      }
-    }
-
-    return results;
-  }
-
-  private boolean addSuggestion(Map<Account.Id, AccountInfo> map,
-      Account.Id account, VisibilityControl visibilityControl)
-      throws OrmException {
-    if (!map.containsKey(account)
-        // Can the suggestion see the change?
-        && visibilityControl.isVisibleTo(account)
-        // Can the account see the current user?
-        && accountControl.canSee(account)) {
-      map.put(account, accountLoader.get(account));
-      return true;
-    }
-    return false;
-  }
-
-  private boolean suggestGroupAsReviewer(Project project,
-      GroupReference group, VisibilityControl visibilityControl)
-      throws OrmException, IOException {
-    if (!PostReviewers.isLegalReviewerGroup(group.getUUID())) {
-      return false;
-    }
-
-    try {
-      Set<Account> members = groupMembersFactory
-          .create(currentUser.get())
-          .listAccounts(group.getUUID(), project.getNameKey());
-
-      if (members.isEmpty()) {
-        return false;
-      }
-
-      if (maxAllowed > 0 && members.size() > maxAllowed) {
-        return false;
-      }
-
-      // require that at least one member in the group can see the change
-      for (Account account : members) {
-        if (visibilityControl.isVisibleTo(account.getId())) {
-          return true;
-        }
-      }
-    } catch (NoSuchGroupException e) {
-      return false;
-    } catch (NoSuchProjectException e) {
-      return false;
-    }
-
-    return false;
-  }
 }