Make calculation of mail recipients for new changes/patchsets reusable

The code to calculate the recipients for notification mails on upload
of a new change and patch set was very similar. Move the code into a
util class so that the same code can be reused from both places. Having
it in a util class allows further reuse from other places and also
makes the ReceiveCommits class a little leaner.

Change-Id: I20cb011b7b1f8a7194a362464426eb577a524bff
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

gerrit-server/src/main/java/com/google/gerrit/server/mail/MailUtil.java

@@ -0,0 +1,131 @@
+// 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.mail;
+
+import com.google.gerrit.common.errors.NoSuchAccountException;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.reviewdb.client.PatchSetApproval;
+import com.google.gerrit.server.account.AccountResolver;
+import com.google.gwtorm.server.OrmException;
+
+import org.eclipse.jgit.revwalk.FooterKey;
+import org.eclipse.jgit.revwalk.FooterLine;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+public class MailUtil {
+  private static final FooterKey REVIEWED_BY = new FooterKey("Reviewed-by");
+  private static final FooterKey TESTED_BY = new FooterKey("Tested-by");
+
+  public static MailRecipients getRecipientsFromFooters(
+      final AccountResolver accountResolver, final PatchSet ps,
+      final List<FooterLine> footerLines) throws OrmException {
+    final MailRecipients recipients = new MailRecipients();
+    if (!ps.isDraft()) {
+      for (final FooterLine footerLine : footerLines) {
+        try {
+          if (isReviewer(footerLine)) {
+            recipients.reviewers.add(toAccountId(accountResolver, footerLine
+                .getValue().trim()));
+          } else if (footerLine.matches(FooterKey.CC)) {
+            recipients.cc.add(toAccountId(accountResolver, footerLine
+                .getValue().trim()));
+          }
+        } catch (NoSuchAccountException e) {
+          continue;
+        }
+      }
+    }
+    return recipients;
+  }
+
+  public static MailRecipients getRecipientsFromApprovals(
+      final List<PatchSetApproval> approvals) {
+    final MailRecipients recipients = new MailRecipients();
+    for (PatchSetApproval a : approvals) {
+      if (a.getValue() != 0) {
+        recipients.reviewers.add(a.getAccountId());
+      } else {
+        recipients.cc.add(a.getAccountId());
+      }
+    }
+    return recipients;
+  }
+
+  private static Account.Id toAccountId(final AccountResolver accountResolver,
+      final String nameOrEmail) throws OrmException, NoSuchAccountException {
+    final Account a = accountResolver.findByNameOrEmail(nameOrEmail);
+    if (a == null) {
+      throw new NoSuchAccountException("\"" + nameOrEmail
+          + "\" is not registered");
+    }
+    return a.getId();
+  }
+
+  private static boolean isReviewer(final FooterLine candidateFooterLine) {
+    return candidateFooterLine.matches(FooterKey.SIGNED_OFF_BY)
+        || candidateFooterLine.matches(FooterKey.ACKED_BY)
+        || candidateFooterLine.matches(REVIEWED_BY)
+        || candidateFooterLine.matches(TESTED_BY);
+  }
+
+  public static class MailRecipients {
+    private final Set<Account.Id> reviewers;
+    private final Set<Account.Id> cc;
+
+    public MailRecipients() {
+      this.reviewers = new HashSet<Account.Id>();
+      this.cc = new HashSet<Account.Id>();
+    }
+
+    public MailRecipients(final Set<Account.Id> reviewers,
+        final Set<Account.Id> cc) {
+      this.reviewers = new HashSet<Account.Id>(reviewers);
+      this.cc = new HashSet<Account.Id>(cc);
+    }
+
+    public void add(final MailRecipients recipients) {
+      reviewers.addAll(recipients.reviewers);
+      cc.addAll(recipients.cc);
+    }
+
+    public void remove(final Account.Id toRemove) {
+      reviewers.remove(toRemove);
+      cc.remove(toRemove);
+    }
+
+    public Set<Account.Id> getReviewers() {
+      return Collections.unmodifiableSet(reviewers);
+    }
+
+    public Set<Account.Id> getCcOnly() {
+      final Set<Account.Id> cc = new HashSet<Account.Id>(this.cc);
+      cc.removeAll(reviewers);
+      return Collections.unmodifiableSet(cc);
+    }
+
+    public Set<Account.Id> getAll() {
+      final Set<Account.Id> all =
+          new HashSet<Account.Id>(reviewers.size() + cc.size());
+      all.addAll(reviewers);
+      all.addAll(cc);
+      return Collections.unmodifiableSet(all);
+    }
+  }
+}