Add REST endpoint to suggest reviewers

Change-Id: I28eedd3dbde5750dffa1482f19da5cd7cb3310f1

Documentation/rest-api-changes.txt

@@ -1020,6 +1020,48 @@ As result a list of link:#reviewer-info[ReviewerInfo] entries is returned.
   ]
 ----
 
+[[suggest-reviewers]]
+Suggest Reviewers
+~~~~~~~~~~~~~~~~~
+[verse]
+'GET /changes/link:#change-id[\{change-id\}]/suggest_reviewers?q=J&n=5'
+
+Suggest the reviewers for a given query `q` and result limit `n`. If result
+limit is not passed, then the default 10 is used.
+
+As result a list of link:#suggested-reviewer-info[SuggestedReviewerInfo] entries is returned.
+
+.Request
+----
+  GET /changes/myProject~master~I8473b95934b5732ac55d26311a706c9c2bde9940/suggest_reviewers?q=J HTTP/1.0
+----
+
+.Response
+----
+  HTTP/1.1 200 OK
+  Content-Disposition: attachment
+  Content-Type: application/json;charset=UTF-8
+
+  )]}'
+  [
+    {
+      "kind": "gerritcodereview#suggestedreviewer",
+      "account": {
+        "_account_id": 1000097,
+        "name": "Jane Roe",
+        "email": "jane.roe@example.com"
+      }
+    },
+    {
+      "kind": "gerritcodereview#suggestedreviewer",
+      "group": {
+        "id": "4fd581c0657268f2bdcc26699fbf9ddb76e3a279",
+        "name": "Joiner"
+      }
+    }
+  ]
+----
+
 [[get-reviewer]]
 Get Reviewer
 ~~~~~~~~~~~~
@@ -2540,6 +2582,18 @@ permitted to vote on that label.
 The time and date describing when the approval was made.
 |===========================
 
+[[group-base-info]]
+GroupBaseInfo
+~~~~~~~~~~~~~
+The `GroupBaseInfo` entity contains base information about the group.
+
+[options="header",width="50%",cols="1,6"]
+|==========================
+|Field Name    |Description
+|`id`          |The id of the group.
+|`name`        |The name of the group.
+|==========================
+
 [[change-info]]
 ChangeInfo
 ~~~~~~~~~~
@@ -3118,6 +3172,17 @@ If `SKIP` the parent filters are not called, allowing the test
 to return results from the input rule.
 |===========================
 
+[[suggested-reviewer-info]]
+SuggestedReviewerInfo
+~~~~~~~~~~~~~~~~~~~~~
+The `SuggestedReviewerInfo` entity contains information about a reviewer
+that can be added to a change (an account or a group).
+
+`SuggestedReviewerInfo` has either the `account` field that contains
+the link:rest-api-accounts.html#account-info[AccountInfo] entity, or
+the `group` field that contains the
+link:rest-api-changes.html#group-base-info[GroupBaseInfo] entity.
+
 [[submit-info]]
 SubmitInfo
 ~~~~~~~~~~

gerrit-gwtui/src/main/java/com/google/gerrit/client/groups/GroupBaseInfo.java

@@ -0,0 +1,31 @@
+// Copyright (C) 2013 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.client.groups;
+
+import com.google.gerrit.reviewdb.client.AccountGroup;
+import com.google.gwt.core.client.JavaScriptObject;
+import com.google.gwt.http.client.URL;
+
+public class GroupBaseInfo extends JavaScriptObject {
+  public final AccountGroup.UUID getGroupUUID() {
+    return new AccountGroup.UUID(URL.decodeQueryString(id()));
+  }
+
+  public final native String id() /*-{ return this.id; }-*/;
+  public final native String name() /*-{ return this.name; }-*/;
+
+  protected GroupBaseInfo() {
+  }
+}

gerrit-gwtui/src/main/java/com/google/gerrit/client/groups/GroupInfo.java

@@ -20,17 +20,11 @@ import com.google.gwt.core.client.JavaScriptObject;
 import com.google.gwt.core.client.JsArray;
 import com.google.gwt.http.client.URL;
 
-public class GroupInfo extends JavaScriptObject {
+public class GroupInfo extends GroupBaseInfo {
   public final AccountGroup.Id getGroupId() {
     return new AccountGroup.Id(group_id());
   }
 
-  public final AccountGroup.UUID getGroupUUID() {
-    return new AccountGroup.UUID(URL.decodeQueryString(id()));
-  }
-
-  public final native String id() /*-{ return this.id; }-*/;
-  public final native String name() /*-{ return this.name; }-*/;
   public final native GroupOptionsInfo options() /*-{ return this.options; }-*/;
   public final native String description() /*-{ return this.description; }-*/;
   public final native String url() /*-{ return this.url; }-*/;

gerrit-server/src/main/java/com/google/gerrit/server/change/Module.java

@@ -59,6 +59,7 @@ 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);
     child(CHANGE_KIND, "reviewers").to(Reviewers.class);
     get(REVIEWER_KIND).to(GetReviewer.class);
     delete(REVIEWER_KIND).to(DeleteReviewer.class);

gerrit-server/src/main/java/com/google/gerrit/server/change/SuggestReviewers.java

@@ -0,0 +1,296 @@
+// Copyright (C) 2013 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.common.base.Objects;
+import com.google.common.base.Strings;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.gerrit.common.data.GroupReference;
+import com.google.gerrit.common.errors.NoSuchGroupException;
+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.AccountInfo;
+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.group.GroupJson.GroupBaseInfo;
+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.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+class SuggestReviewers implements RestReadView<ChangeResource> {
+
+  private static final String MAX_SUFFIX = "\u9fa5";
+  private static final int MAX = 10;
+
+  private final AccountInfo.Loader.Factory accountLoaderFactory;
+  private final AccountControl.Factory accountControlFactory;
+  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;
+  private final boolean suggestAccounts;
+  private final int suggestFrom;
+  private final int maxAllowed;
+  private int limit;
+  private String query;
+
+  @Option(name = "--limit", aliases = {"-n"}, metaVar = "CNT",
+      usage = "maximum number of reviewers to list")
+  public void setLimit(int l) {
+    this.limit = l <= 0 ? MAX : Math.min(l, MAX);
+  }
+
+  @Option(name = "--query", aliases = {"-q"}, metaVar = "QUERY",
+      usage = "match reviewers query")
+  public void setQuery(String q) {
+    this.query = q;
+  }
+
+  @Inject
+  SuggestReviewers(AccountVisibility av,
+      AccountInfo.Loader.Factory accountLoaderFactory,
+      AccountControl.Factory accountControlFactory,
+      AccountCache accountCache,
+      GroupMembers.Factory groupMembersFactory,
+      IdentifiedUser.GenericFactory identifiedUserFactory,
+      Provider<CurrentUser> currentUser,
+      Provider<ReviewDb> dbProvider,
+      @GerritServerConfig Config cfg,
+      GroupBackend groupBackend) {
+    this.accountLoaderFactory = accountLoaderFactory;
+    this.accountControlFactory = accountControlFactory;
+    this.accountCache = accountCache;
+    this.groupMembersFactory = groupMembersFactory;
+    this.dbProvider = dbProvider;
+    this.identifiedUserFactory = identifiedUserFactory;
+    this.currentUser = currentUser;
+    this.groupBackend = groupBackend;
+
+    String suggest = cfg.getString("suggest", null, "accounts");
+    if ("OFF".equalsIgnoreCase(suggest)
+        || "false".equalsIgnoreCase(suggest)) {
+      this.suggestAccounts = false;
+    } else {
+      this.suggestAccounts = (av != AccountVisibility.NONE);
+    }
+
+    this.suggestFrom = cfg.getInt("suggest", null, "from", 0);
+    this.maxAllowed = cfg.getInt("addreviewer", "maxAllowed",
+        PostReviewers.DEFAULT_MAX_REVIEWERS);
+  }
+
+  private interface VisibilityControl {
+    boolean isVisibleTo(Account 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 = suggestAccount(visibilityControl);
+    accountLoaderFactory.create(true).fill(suggestedAccounts);
+
+    List<SuggestedReviewerInfo> reviewer = Lists.newArrayList();
+    for (AccountInfo a : suggestedAccounts) {
+      reviewer.add(new SuggestedReviewerInfo(a));
+    }
+
+    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();
+        reviewer.add(new SuggestedReviewerInfo(info));
+      }
+    }
+
+    Collections.sort(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 account) throws OrmException {
+          return true;
+        }
+      };
+    } else {
+      return new VisibilityControl() {
+        @Override
+        public boolean isVisibleTo(Account account) throws OrmException {
+          IdentifiedUser who =
+              identifiedUserFactory.create(dbProvider, account.getId());
+          // 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;
+
+    LinkedHashMap<Account.Id, AccountInfo> r = Maps.newLinkedHashMap();
+    for (Account p : dbProvider.get().accounts()
+        .suggestByFullName(a, b, limit)) {
+      addSuggestion(r, p, new AccountInfo(p.getId()), visibilityControl);
+    }
+
+    if (r.size() < limit) {
+      for (Account p : dbProvider.get().accounts()
+          .suggestByPreferredEmail(a, b, limit - r.size())) {
+        addSuggestion(r, p, new AccountInfo(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();
+          AccountInfo info = new AccountInfo(p.getId());
+          addSuggestion(r, p, info, visibilityControl);
+        }
+      }
+    }
+
+    return Lists.newArrayList(r.values());
+  }
+
+  private void addSuggestion(Map<Account.Id, AccountInfo> map, Account account,
+      AccountInfo info, VisibilityControl visibilityControl)
+      throws OrmException {
+    if (!map.containsKey(account.getId())
+        && account.isActive()
+        // Can the suggestion see the change?
+        && visibilityControl.isVisibleTo(account)
+        // Can the account see the current user?
+        && accountControlFactory.get().canSee(account)) {
+      map.put(account.getId(), info);
+    }
+  }
+
+  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)) {
+          return true;
+        }
+      }
+    } catch (NoSuchGroupException e) {
+      return false;
+    } catch (NoSuchProjectException e) {
+      return false;
+    }
+
+    return false;
+  }
+
+  static class SuggestedReviewerInfo implements Comparable<SuggestedReviewerInfo> {
+    String kind = "gerritcodereview#suggestedreviewer";
+    AccountInfo account;
+    GroupBaseInfo group;
+
+    SuggestedReviewerInfo(AccountInfo a) {
+      this.account = a;
+    }
+
+    SuggestedReviewerInfo(GroupBaseInfo g) {
+      this.group = g;
+    }
+
+    @Override
+    public int compareTo(SuggestedReviewerInfo o) {
+      return getSortValue().compareTo(o.getSortValue());
+    }
+
+    private String getSortValue() {
+      return account != null
+          ? Objects.firstNonNull(account.email,
+              Strings.nullToEmpty(account.name))
+          : Strings.nullToEmpty(group.name);
+    }
+  }
+}

gerrit-server/src/main/java/com/google/gerrit/server/group/GroupJson.java

@@ -126,10 +126,8 @@ public class GroupJson {
     }
   }
 
-  public static class GroupInfo {
+  public static class GroupInfo extends GroupBaseInfo {
     final String kind = "gerritcodereview#group";
-    public String id;
-    public String name;
     public String url;
     public GroupOptionsInfo options;
 
@@ -143,4 +141,9 @@ public class GroupJson {
     public List<AccountInfo> members;
     public List<GroupInfo> includes;
   }
+
+  public static class GroupBaseInfo {
+    public String id;
+    public String name;
+  }
 }