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 * IMAPReply 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    private static final String TAGGED_RESPONSE = "^\\w+ (\\S+).*"; // TODO perhaps be less strict on tag match?
066
067    // tag cannot contain: + ( ) { SP CTL % * " \ ]
068    private static final Pattern TAGGED_PATTERN = Pattern.compile(TAGGED_RESPONSE);
069
070    private static final String UNTAGGED_RESPONSE = "^\\* (\\S+).*";
071
072    private static final Pattern UNTAGGED_PATTERN = Pattern.compile(UNTAGGED_RESPONSE);
073    private static final Pattern LITERAL_PATTERN = Pattern.compile("\\{(\\d+)\\}$"); // {dd}
074
075    /**
076     * Interpret the String reply code - OK, NO, BAD - in a tagged response as an integer.
077     *
078     * @param line the tagged line to be checked
079     * @return {@link #OK} or {@link #NO} or {@link #BAD} or {@link #CONT}
080     * @throws IOException if the input has an unexpected format
081     */
082    public static int getReplyCode(final String line) throws IOException {
083        return getReplyCode(line, TAGGED_PATTERN);
084    }
085
086    // Helper method to process both tagged and untagged replies.
087    private static int getReplyCode(final String line, final Pattern pattern) throws IOException {
088        if (isContinuation(line)) {
089            return CONT;
090        }
091        final Matcher m = pattern.matcher(line);
092        if (m.matches()) { // TODO would lookingAt() be more efficient? If so, then drop trailing .* from patterns
093            final String code = m.group(1);
094            if (code.equals(IMAP_OK)) {
095                return OK;
096            }
097            if (code.equals(IMAP_BAD)) {
098                return BAD;
099            }
100            if (code.equals(IMAP_NO)) {
101                return NO;
102            }
103        }
104        throw new MalformedServerReplyException("Received unexpected IMAP protocol response from server: '" + line + "'.");
105    }
106
107    /**
108     * Interpret the String reply code - OK, NO, BAD - in an untagged response as an integer.
109     *
110     * @param line the untagged line to be checked
111     * @return {@link #OK} or {@link #NO} or {@link #BAD} or {@link #CONT}
112     * @throws IOException if the input has an unexpected format
113     */
114    public static int getUntaggedReplyCode(final String line) throws IOException {
115        return getReplyCode(line, UNTAGGED_PATTERN);
116    }
117
118    /**
119     * Checks if the reply line is a continuation, i.e. starts with "+"
120     *
121     * @param replyCode the code to be checked
122     * @return {@code true} if the response was a continuation
123     */
124    public static boolean isContinuation(final int replyCode) {
125        return replyCode == CONT;
126    }
127
128    /**
129     * Checks if the reply line is a continuation, i.e. starts with "+"
130     *
131     * @param line the line to be checked
132     * @return {@code true} if the line is a continuation
133     */
134    public static boolean isContinuation(final String line) {
135        return line.startsWith(IMAP_CONTINUATION_PREFIX);
136    }
137
138    /**
139     * Checks whether the reply code indicates success or not
140     *
141     * @param replyCode the code to check
142     * @return {@code true} if the code equals {@link #OK}
143     */
144    public static boolean isSuccess(final int replyCode) {
145        return replyCode == OK;
146    }
147
148    /**
149     * Checks if the reply line is untagged - e.g. "* OK ..."
150     *
151     * @param line to be checked
152     * @return {@code true} if the line is untagged
153     */
154    public static boolean isUntagged(final String line) {
155        return line.startsWith(IMAP_UNTAGGED_PREFIX);
156    }
157
158    /**
159     * Checks if the line introduces a literal, i.e. ends with {dd}
160     *
161     * @param line the line to check
162     * @return the literal count, or -1 if there was no literal.
163     */
164    public static int literalCount(final String line) {
165        final Matcher m = LITERAL_PATTERN.matcher(line);
166        if (m.find()) {
167            return Integer.parseInt(m.group(1)); // Should always parse because we matched \d+
168        }
169        return -1;
170    }
171
172    /** Cannot be instantiated. */
173    private IMAPReply() {
174    }
175
176}
177
178