/*
* Copyright (C) 2009 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.android.email.mail.transport;
import com.android.email.mail.Address;
import com.android.email.mail.MessagingException;
import com.android.email.mail.internet.MimeUtility;
import com.android.email.provider.EmailContent.Attachment;
import com.android.email.provider.EmailContent.Body;
import com.android.email.provider.EmailContent.Message;
import org.apache.commons.io.IOUtils;
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.util.Base64;
import android.util.Base64OutputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Utility class to output RFC 822 messages from provider email messages
*/
public class Rfc822Output {
private static final Pattern PATTERN_START_OF_LINE = Pattern.compile("(?m)^");
private static final Pattern PATTERN_ENDLINE_CRLF = Pattern.compile("\r\n");
// In MIME, en_US-like date format should be used. In other words "MMM" should be encoded to
// "Jan", not the other localized format like "Ene" (meaning January in locale es).
static final SimpleDateFormat mDateFormat =
new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss Z", Locale.US);
/*package*/ static String buildBodyText(Context context, Message message,
boolean appendQuotedText) {
Body body = Body.restoreBodyWithMessageId(context, message.mId);
if (body == null) {
return null;
}
String text = body.mTextContent;
int flags = message.mFlags;
boolean isReply = (flags & Message.FLAG_TYPE_REPLY) != 0;
boolean isForward = (flags & Message.FLAG_TYPE_FORWARD) != 0;
String intro = body.mIntroText == null ? "" : body.mIntroText;
if (!appendQuotedText) {
// appendQuotedText is set to false for use by SmartReply/SmartForward in EAS.
// SmartReply doesn't appear to work properly, so we will still add the header into
// the original message.
// SmartForward doesn't put any kind of break between the original and the new text,
// so we add a CRLF
if (isReply) {
text += intro;
} else if (isForward) {
text += "\r\n";
}
return text;
}
String quotedText = body.mTextReply;
if (quotedText != null) {
// fix CR-LF line endings to LF-only needed by EditText.
Matcher matcher = PATTERN_ENDLINE_CRLF.matcher(quotedText);
quotedText = matcher.replaceAll("\n");
}
if (isReply) {
text += intro;
if (quotedText != null) {
Matcher matcher = PATTERN_START_OF_LINE.matcher(quotedText);
text += matcher.replaceAll(">");
}
} else if (isForward) {
text += intro;
if (quotedText != null) {
text += quotedText;
}
}
return text;
}
/**
* Write the entire message to an output stream. This method provides buffering, so it is
* not necessary to pass in a buffered output stream here.
*
* @param context system context for accessing the provider
* @param messageId the message to write out
* @param out the output stream to write the message to
* @param appendQuotedText whether or not to append quoted text if this is a reply/forward
*
* TODO alternative parts (e.g. text+html) are not supported here.
*/
public static void writeTo(Context context, long messageId, OutputStream out,
boolean appendQuotedText, boolean sendBcc) throws IOException, MessagingException {
Message message = Message.restoreMessageWithId(context, messageId);
if (message == null) {
// throw something?
return;
}
OutputStream stream = new BufferedOutputStream(out, 1024);
Writer writer = new OutputStreamWriter(stream);
// Write the fixed headers. Ordering is arbitrary (the legacy code iterated through a
// hashmap here).
String date = mDateFormat.format(new Date(message.mTimeStamp));
writeHeader(writer, "Date", date);
writeEncodedHeader(writer, "Subject", message.mSubject);
writeHeader(writer, "Message-ID", message.mMessageId);
writeAddressHeader(writer, "From", message.mFrom);
writeAddressHeader(writer, "To", message.mTo);
writeAddressHeader(writer, "Cc", message.mCc);
// Address fields. Note that we skip bcc unless the sendBcc argument is true
// SMTP should NOT send bcc headers, but EAS must send it!
if (sendBcc) {
writeAddressHeader(writer, "Bcc", message.mBcc);
}
writeAddressHeader(writer, "Reply-To", message.mReplyTo);
writeHeader(writer, "MIME-Version", "1.0");
// Analyze message and determine if we have multiparts
String text = buildBodyText(context, message, appendQuotedText);
Uri uri = ContentUris.withAppendedId(Attachment.MESSAGE_ID_URI, messageId);
Cursor attachmentsCursor = context.getContentResolver().query(uri,
Attachment.CONTENT_PROJECTION, null, null, null);
try {
int attachmentCount = attachmentsCursor.getCount();
boolean multipart = attachmentCount > 0;
String multipartBoundary = null;
String multipartType = "mixed";
// Simplified case for no multipart - just emit text and be done.
if (!multipart) {
if (text != null) {
writeTextWithHeaders(writer, stream, text);
} else {
writer.write("\r\n"); // a truly empty message
}
} else {
// continue with multipart headers, then into multipart body
multipartBoundary = "--_com.android.email_" + System.nanoTime();
// Move to the first attachment; this must succeed because multipart is true
attachmentsCursor.moveToFirst();
if (attachmentCount == 1) {
// If we've got one attachment and it's an ics "attachment", we want to send
// this as multipart/alternative instead of multipart/mixed
int flags = attachmentsCursor.getInt(Attachment.CONTENT_FLAGS_COLUMN);
if ((flags & Attachment.FLAG_ICS_ALTERNATIVE_PART) != 0) {
multipartType = "alternative";
}
}
writeHeader(writer, "Content-Type",
"multipart/" + multipartType + "; boundary=\"" + multipartBoundary + "\"");
// Finish headers and prepare for body section(s)
writer.write("\r\n");
// first multipart element is the body
if (text != null) {
writeBoundary(writer, multipartBoundary, false);
writeTextWithHeaders(writer, stream, text);
}
// Write out the attachments until we run out
do {
writeBoundary(writer, multipartBoundary, false);
Attachment attachment =
Attachment.getContent(attachmentsCursor, Attachment.class);
writeOneAttachment(context, writer, stream, attachment);
writer.write("\r\n");
} while (attachmentsCursor.moveToNext());
// end of multipart section
writeBoundary(writer, multipartBoundary, true);
}
} finally {
attachmentsCursor.close();
}
writer.flush();
out.flush();
}
/**
* Write a single attachment and its payload
*/
private static void writeOneAttachment(Context context, Writer writer, OutputStream out,
Attachment attachment) throws IOException, MessagingException {
writeHeader(writer, "Content-Type",
attachment.mMimeType + ";\n name=\"" + attachment.mFileName + "\"");
writeHeader(writer, "Content-Transfer-Encoding", "base64");
// Most attachments (real files) will send Content-Disposition. The suppression option
// is used when sending calendar invites.
if ((attachment.mFlags & Attachment.FLAG_ICS_ALTERNATIVE_PART) == 0) {
writeHeader(writer, "Content-Disposition",
"attachment;"
+ "\n filename=\"" + attachment.mFileName + "\";"
+ "\n size=" + Long.toString(attachment.mSize));
}
writeHeader(writer, "Content-ID", attachment.mContentId);
writer.append("\r\n");
// Set up input stream and write it out via base64
InputStream inStream = null;
try {
// Use content, if provided; otherwise, use the contentUri
if (attachment.mContentBytes != null) {
inStream = new ByteArrayInputStream(attachment.mContentBytes);
} else {
// try to open the file
Uri fileUri = Uri.parse(attachment.mContentUri);
inStream = context.getContentResolver().openInputStream(fileUri);
}
// switch to output stream for base64 text output
writer.flush();
Base64OutputStream base64Out = new Base64OutputStream(
out, Base64.CRLF | Base64.NO_CLOSE);
// copy base64 data and close up
IOUtils.copy(inStream, base64Out);
base64Out.close();
// The old Base64OutputStream wrote an extra CRLF after
// the output. It's not required by the base-64 spec; not
// sure if it's required by RFC 822 or not.
out.write('\r');
out.write('\n');
out.flush();
}
catch (FileNotFoundException fnfe) {
// Ignore this - empty file is OK
}
catch (IOException ioe) {
throw new MessagingException("Invalid attachment.", ioe);
}
}
/**
* Write a single header with no wrapping or encoding
*
* @param writer the output writer
* @param name the header name
* @param value the header value
*/
private static void writeHeader(Writer writer, String name, String value) throws IOException {
if (value != null && value.length() > 0) {
writer.append(name);
writer.append(": ");
writer.append(value);
writer.append("\r\n");
}
}
/**
* Write a single header using appropriate folding & encoding
*
* @param writer the output writer
* @param name the header name
* @param value the header value
*/
private static void writeEncodedHeader(Writer writer, String name, String value)
throws IOException {
if (value != null && value.length() > 0) {
writer.append(name);
writer.append(": ");
writer.append(MimeUtility.foldAndEncode2(value, name.length() + 2));
writer.append("\r\n");
}
}
/**
* Unpack, encode, and fold address(es) into a header
*
* @param writer the output writer
* @param name the header name
* @param value the header value (a packed list of addresses)
*/
private static void writeAddressHeader(Writer writer, String name, String value)
throws IOException {
if (value != null && value.length() > 0) {
writer.append(name);
writer.append(": ");
writer.append(MimeUtility.fold(Address.packedToHeader(value), name.length() + 2));
writer.append("\r\n");
}
}
/**
* Write a multipart boundary
*
* @param writer the output writer
* @param boundary the boundary string
* @param end false if inner boundary, true if final boundary
*/
private static void writeBoundary(Writer writer, String boundary, boolean end)
throws IOException {
writer.append("--");
writer.append(boundary);
if (end) {
writer.append("--");
}
writer.append("\r\n");
}
/**
* Write text (either as main body or inside a multipart), preceded by appropriate headers.
*
* Note this always uses base64, even when not required. Slightly less efficient for
* US-ASCII text, but handles all formats even when non-ascii chars are involved. A small
* optimization might be to prescan the string for safety and send raw if possible.
*
* @param writer the output writer
* @param out the output stream inside the writer (used for byte[] access)
* @param text The original text of the message
*/
private static void writeTextWithHeaders(Writer writer, OutputStream out, String text)
throws IOException {
writeHeader(writer, "Content-Type", "text/plain; charset=utf-8");
writeHeader(writer, "Content-Transfer-Encoding", "base64");
writer.write("\r\n");
byte[] bytes = text.getBytes("UTF-8");
writer.flush();
out.write(Base64.encode(bytes, Base64.CRLF));
}
}