1 files changed, 108 insertions, 0 deletions
diff --git a/java/com/google/gerrit/mail/MailHeaderParser.java b/java/com/google/gerrit/mail/MailHeaderParser.java
new file mode 100644
index 0000000000..8eb4d97047
--- /dev/null
+++ b/java/com/google/gerrit/mail/MailHeaderParser.java
@@ -0,0 +1,108 @@
+// 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.mail;
+
+import com.google.common.base.Splitter;
+import com.google.common.base.Strings;
+import com.google.common.flogger.FluentLogger;
+import com.google.common.primitives.Ints;
+import java.sql.Timestamp;
+import java.time.Instant;
+import java.time.format.DateTimeParseException;
+
+/** Parse metadata from inbound email */
+public class MailHeaderParser {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
+  public static MailMetadata parse(MailMessage m) {
+    MailMetadata metadata = new MailMetadata();
+    // Find author
+    metadata.author = m.from().getEmail();
+
+    // Check email headers for X-Gerrit-<Name>
+    for (String header : m.additionalHeaders()) {
+      if (header.startsWith(MailHeader.CHANGE_NUMBER.fieldWithDelimiter())) {
+        String num = header.substring(MailHeader.CHANGE_NUMBER.fieldWithDelimiter().length());
+        metadata.changeNumber = Ints.tryParse(num);
+      } else if (header.startsWith(MailHeader.PATCH_SET.fieldWithDelimiter())) {
+        String ps = header.substring(MailHeader.PATCH_SET.fieldWithDelimiter().length());
+        metadata.patchSet = Ints.tryParse(ps);
+      } else if (header.startsWith(MailHeader.COMMENT_DATE.fieldWithDelimiter())) {
+        String ts = header.substring(MailHeader.COMMENT_DATE.fieldWithDelimiter().length()).trim();
+        try {
+          metadata.timestamp =
+              Timestamp.from(MailProcessingUtil.rfcDateformatter.parse(ts, Instant::from));
+        } catch (DateTimeParseException e) {
+          logger.atSevere().withCause(e).log(
+              "Mail: Error while parsing timestamp from header of message %s", m.id());
+        }
+      } else if (header.startsWith(MailHeader.MESSAGE_TYPE.fieldWithDelimiter())) {
+        metadata.messageType =
+            header.substring(MailHeader.MESSAGE_TYPE.fieldWithDelimiter().length());
+      }
+    }
+    if (metadata.hasRequiredFields()) {
+      return metadata;
+    }
+
+    // If the required fields were not yet found, continue to parse the text
+    if (!Strings.isNullOrEmpty(m.textContent())) {
+      Iterable<String> lines = Splitter.on('\n').split(m.textContent().replace("\r\n", "\n"));
+      extractFooters(lines, metadata, m);
+      if (metadata.hasRequiredFields()) {
+        return metadata;
+      }
+    }
+
+    // If the required fields were not yet found, continue to parse the HTML
+    // HTML footer are contained inside a <div> tag
+    if (!Strings.isNullOrEmpty(m.htmlContent())) {
+      Iterable<String> lines = Splitter.on("</div>").split(m.htmlContent().replace("\r\n", "\n"));
+      extractFooters(lines, metadata, m);
+      if (metadata.hasRequiredFields()) {
+        return metadata;
+      }
+    }
+
+    return metadata;
+  }
+
+  private static void extractFooters(Iterable<String> lines, MailMetadata metadata, MailMessage m) {
+    for (String line : lines) {
+      if (metadata.changeNumber == null && line.contains(MailHeader.CHANGE_NUMBER.getName())) {
+        metadata.changeNumber =
+            Ints.tryParse(extractFooter(MailHeader.CHANGE_NUMBER.withDelimiter(), line));
+      } else if (metadata.patchSet == null && line.contains(MailHeader.PATCH_SET.getName())) {
+        metadata.patchSet =
+            Ints.tryParse(extractFooter(MailHeader.PATCH_SET.withDelimiter(), line));
+      } else if (metadata.timestamp == null && line.contains(MailHeader.COMMENT_DATE.getName())) {
+        String ts = extractFooter(MailHeader.COMMENT_DATE.withDelimiter(), line);
+        try {
+          metadata.timestamp =
+              Timestamp.from(MailProcessingUtil.rfcDateformatter.parse(ts, Instant::from));
+        } catch (DateTimeParseException e) {
+          logger.atSevere().withCause(e).log(
+              "Mail: Error while parsing timestamp from footer of message %s", m.id());
+        }
+      } else if (metadata.messageType == null && line.contains(MailHeader.MESSAGE_TYPE.getName())) {
+        metadata.messageType = extractFooter(MailHeader.MESSAGE_TYPE.withDelimiter(), line);
+      }
+    }
+  }
+
+  private static String extractFooter(String key, String line) {
+    return line.substring(line.indexOf(key) + key.length(), line.length()).trim();
+  }
+}