001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.net.imap;
019
020import java.io.IOException;
021import java.util.regex.Matcher;
022import java.util.regex.Pattern;
023
024import org.apache.commons.net.MalformedServerReplyException;
025
026/**
027 * Stores IMAP reply code constants.
028 */
029public final class IMAPReply {
030    /** The reply code indicating success of an operation. */
031    public static final int OK = 0;
032
033    /** The reply code indicating failure of an operation. */
034    public static final int NO = 1;
035
036    /** The reply code indicating command rejection. */
037    public static final int BAD = 2;
038
039    /** The reply code indicating command continuation. */
040    public static final int CONT = 3;
041
042    /**
043     * The reply code indicating a partial response. This is used when a chunk listener is registered and the listener requests that the reply lines are cleared
044     * on return.
045     *
046     * @since 3.4
047     */
048    public static final int PARTIAL = 3;
049
050    /** The IMAP reply String indicating success of an operation. */
051    private static final String IMAP_OK = "OK";
052
053    /** The IMAP reply String indicating failure of an operation. */
054    private static final String IMAP_NO = "NO";
055
056    /** The IMAP reply String indicating command rejection. */
057    private static final String IMAP_BAD = "BAD";
058
059    // Start of line for untagged replies
060    private static final String IMAP_UNTAGGED_PREFIX = "* ";
061
062    // Start of line for continuation replies
063    private static final String IMAP_CONTINUATION_PREFIX = "+";
064
065    /**
066     * Guard against Polynomial regular expression used on uncontrolled data.
067     *
068     * Don't look for more than 80 letters.
069     * Don't look for more than 80 non-whitespace.
070     * Don't look for more than 80 character.
071     */
072    private static final String TAGGED_RESPONSE = "^\\w{1,80} (\\S{1,80}).{0,80}";
073
074    /**
075     * Tag cannot contain: + ( ) { SP CTL % * " \ ]
076     */
077    private static final Pattern TAGGED_PATTERN = Pattern.compile(TAGGED_RESPONSE);
078
079    /**
080     * Guard against Polynomial regular expression used on uncontrolled data.
081     *
082     * Don't look for more than 80 backslashes.
083     * Don't look for more than 80 character.
084     */
085    private static final String UNTAGGED_RESPONSE = "^\\* (\\S{1,80}).{0,160}";
086
087    private static final Pattern UNTAGGED_PATTERN = Pattern.compile(UNTAGGED_RESPONSE);
088    private static final Pattern LITERAL_PATTERN = Pattern.compile("\\{(\\d+)\\}$"); // {dd}
089
090    /**
091     * Interpret the String reply code - OK, NO, BAD - in a tagged response as an integer.
092     *
093     * @param line the tagged line to be checked
094     * @return {@link #OK} or {@link #NO} or {@link #BAD} or {@link #CONT}
095     * @throws IOException if the input has an unexpected format
096     */
097    public static int getReplyCode(final String line) throws IOException {
098        return getReplyCode(line, TAGGED_PATTERN);
099    }
100
101    // Helper method to process both tagged and untagged replies.
102    private static int getReplyCode(final String line, final Pattern pattern) throws IOException {
103        if (isContinuation(line)) {
104            return CONT;
105        }
106        final Matcher m = pattern.matcher(line);
107        if (m.matches()) { // TODO would lookingAt() be more efficient? If so, then drop trailing .* from patterns
108            final String code = m.group(1);
109            if (code.equals(IMAP_OK)) {
110                return OK;
111            }
112            if (code.equals(IMAP_BAD)) {
113                return BAD;
114            }
115            if (code.equals(IMAP_NO)) {
116                return NO;
117            }
118        }
119        throw new MalformedServerReplyException("Received unexpected IMAP protocol response from server: '" + line + "'.");
120    }
121
122    /**
123     * Interpret the String reply code - OK, NO, BAD - in an untagged response as an integer.
124     *
125     * @param line the untagged line to be checked
126     * @return {@link #OK} or {@link #NO} or {@link #BAD} or {@link #CONT}
127     * @throws IOException if the input has an unexpected format
128     */
129    public static int getUntaggedReplyCode(final String line) throws IOException {
130        return getReplyCode(line, UNTAGGED_PATTERN);
131    }
132
133    /**
134     * Tests whether the reply line is a continuation, i.e. starts with "+"
135     *
136     * @param replyCode the code to be checked
137     * @return {@code true} if the response was a continuation
138     */
139    public static boolean isContinuation(final int replyCode) {
140        return replyCode == CONT;
141    }
142
143    /**
144     * Tests whether if the reply line is a continuation, i.e. starts with "+"
145     *
146     * @param line the line to be checked
147     * @return {@code true} if the line is a continuation
148     */
149    public static boolean isContinuation(final String line) {
150        return line.startsWith(IMAP_CONTINUATION_PREFIX);
151    }
152
153    /**
154     * Tests whether whether the reply code indicates success or not
155     *
156     * @param replyCode the code to check
157     * @return {@code true} if the code equals {@link #OK}
158     */
159    public static boolean isSuccess(final int replyCode) {
160        return replyCode == OK;
161    }
162
163    /**
164     * Tests whether if the reply line is untagged - e.g. "* OK ..."
165     *
166     * @param line to be checked
167     * @return {@code true} if the line is untagged
168     */
169    public static boolean isUntagged(final String line) {
170        return line.startsWith(IMAP_UNTAGGED_PREFIX);
171    }
172
173    /**
174     * Checks if the line introduces a literal, i.e. ends with {dd}
175     *
176     * @param line the line to check
177     * @return the literal count, or -1 if there was no literal.
178     */
179    public static int literalCount(final String line) {
180        final Matcher m = LITERAL_PATTERN.matcher(line);
181        if (m.find()) {
182            return Integer.parseInt(m.group(1)); // Should always parse because we matched \d+
183        }
184        return -1;
185    }
186
187    /** Cannot be instantiated. */
188    private IMAPReply() {
189    }
190
191}
192