From 03526d9a6f6336597f0fd4d9a0506fa3aaad5228 Mon Sep 17 00:00:00 2001
From: Colin Surprenant <colin.surprenant@gmail.com>
Date: Fri, 14 Mar 2014 21:34:57 -0400
Subject: [PATCH] main message codec support and headers transcoding

---
 lib/logstash/inputs/imap.rb | 72 +++++++++++++++++++++----------------
 1 file changed, 42 insertions(+), 30 deletions(-)

diff --git a/lib/logstash/inputs/imap.rb b/lib/logstash/inputs/imap.rb
index 5e5837660..c3fb794e6 100644
--- a/lib/logstash/inputs/imap.rb
+++ b/lib/logstash/inputs/imap.rb
@@ -13,6 +13,8 @@ class LogStash::Inputs::IMAP < LogStash::Inputs::Base
   milestone 1
   ISO8601_STRFTIME = "%04d-%02d-%02dT%02d:%02d:%02d.%06d%+03d:00".freeze
 
+  default :codec, "plain"
+
   config :host, :validate => :string, :required => true
   config :port, :validate => :number
 
@@ -91,41 +93,42 @@ class LogStash::Inputs::IMAP < LogStash::Inputs::Base
       message = part.decoded
     end
 
-    event = LogStash::Event.new("message" => message)
+    @codec.decode(message) do |event|
+      # event = LogStash::Event.new("message" => message)
 
-    # Use the 'Date' field as the timestamp
-    event["@timestamp"] = mail.date.to_time.gmtime
+      # Use the 'Date' field as the timestamp
+      event["@timestamp"] = mail.date.to_time.gmtime
 
-    # Add fields: Add message.header_fields { |h| h.name=> h.value }
-    mail.header_fields.each do |header|
-      if @lowercase_headers
-        # 'header.name' can sometimes be a Mail::Multibyte::Chars, get it in
-        # String form
-        name = header.name.to_s.downcase
-      else
-        name = header.name.to_s
-      end
-      # Call .decoded on the header in case it's in encoded-word form.
-      # Details at:
-      #   https://github.com/mikel/mail/blob/master/README.md#encodings
-      #   http://tools.ietf.org/html/rfc2047#section-2
-      value = header.decoded
+      # Add fields: Add message.header_fields { |h| h.name=> h.value }
+      mail.header_fields.each do |header|
+        if @lowercase_headers
+          # 'header.name' can sometimes be a Mail::Multibyte::Chars, get it in
+          # String form
+          name = header.name.to_s.downcase
+        else
+          name = header.name.to_s
+        end
+        # Call .decoded on the header in case it's in encoded-word form.
+        # Details at:
+        #   https://github.com/mikel/mail/blob/master/README.md#encodings
+        #   http://tools.ietf.org/html/rfc2047#section-2
+        value = transcode_to_utf8(header.decoded)
 
-      # Assume we already processed the 'date' above.
-      next if name == "Date"
+        # Assume we already processed the 'date' above.
+        next if name == "Date"
 
-      case event[name]
-        # promote string to array if a header appears multiple times
-        # (like 'received')
-        when String; event[name] = [event[name], value]
-        when Array; event[name].is_a?(Array)
-        when nil; event[name] = value
-      end
-    end # mail.header_fields.each
+        case event[name]
+          # promote string to array if a header appears multiple times
+          # (like 'received')
+          when String; event[name] = [event[name], value]
+          when Array; event[name].is_a?(Array)
+          when nil; event[name] = value
+        end
+      end # mail.header_fields.each
 
-    decorate(event)
-
-    return event
+      decorate(event)
+      event
+    end
   end # def handle
 
   public
@@ -133,4 +136,13 @@ class LogStash::Inputs::IMAP < LogStash::Inputs::Base
     $stdin.close
     finished
   end # def teardown
+
+  private
+
+  # transcode_to_utf8 is meant for headers transcoding.
+  # the mail gem will set the correct encoding on header strings decoding
+  # and we want to transcode it to utf8
+  def transcode_to_utf8(s)
+    s.encode(Encoding::UTF_8, :invalid => :replace, :undef => :replace)
+  end
 end # class LogStash::Inputs::IMAP