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 */
029
030public final class IMAPReply
031{
032    /** The reply code indicating success of an operation. */
033    public static final int OK = 0;
034
035    /** The reply code indicating failure of an operation. */
036    public static final int NO = 1;
037
038    /** The reply code indicating command rejection. */
039    public static final int BAD = 2;
040
041    /** The reply code indicating command continuation. */
042    public static final int CONT = 3;
043
044    /** The IMAP reply String indicating success of an operation. */
045    private static final String IMAP_OK = "OK";
046
047    /** The IMAP reply String indicating failure of an operation. */
048    private static final String IMAP_NO = "NO";
049
050    /** The IMAP reply String indicating command rejection. */
051    private static final String IMAP_BAD = "BAD";
052
053    // Start of line for untagged replies
054    private static final String IMAP_UNTAGGED_PREFIX = "* ";
055
056    // Start of line for continuation replies
057    private static final String IMAP_CONTINUATION_PREFIX = "+";
058
059    // Cannot be instantiated.
060    private IMAPReply()
061    {}
062
063    /**
064     * Checks if the reply line is untagged - e.g. "* OK ..."
065     * @param line to be checked
066     * @return {@code true} if the line is untagged
067     */
068    public static boolean isUntagged(String line) {
069        return line.startsWith(IMAP_UNTAGGED_PREFIX);
070    }
071
072    /**
073     * Checks if the reply line is a continuation, i.e. starts with "+"
074     * @param line the line to be checked
075     * @return {@code true} if the line is untagged
076     */
077    public static boolean isContinuation(String line) {
078        return line.startsWith(IMAP_CONTINUATION_PREFIX);
079    }
080
081    private static final String TAGGED_RESPONSE = "^\\w+ (\\S+).*"; // TODO perhaps be less strict on tag match?
082    // tag cannot contain: + ( ) { SP CTL % * " \ ]
083    private static final Pattern TAGGED_PATTERN = Pattern.compile(TAGGED_RESPONSE);
084
085    /**
086     * Intepret the String reply code - OK, NO, BAD - in a tagged response as a integer.
087     *
088     * @param line the tagged line to be checked
089     * @return {@link #OK} or {@link #NO} or {@link #BAD} or {@link #CONT}
090     * @throws IOException if the input has an unexpected format
091     */
092    public static int getReplyCode(String line) throws IOException {
093        return getReplyCode(line, TAGGED_PATTERN);
094    }
095
096    private static final String UNTAGGED_RESPONSE = "^\\* (\\S+).*";
097    private static final Pattern UNTAGGED_PATTERN = Pattern.compile(UNTAGGED_RESPONSE);
098
099    private static final Pattern LITERAL_PATTERN = Pattern.compile("\\{(\\d+)\\}$"); // {dd}
100
101    /**
102     * Checks if the line introduces a literal, i.e. ends with {dd}
103     *
104     * @return the literal count, or -1 if there was no literal.
105     */
106    public static int literalCount(String line) {
107        Matcher m = LITERAL_PATTERN.matcher(line);
108        if (m.find()) {
109            return Integer.parseInt(m.group(1)); // Should always parse because we matched \d+
110        }
111        return -1;
112    }
113
114    /**
115     * Intepret the String reply code - OK, NO, BAD - in an untagged response as a integer.
116     *
117     * @param line the untagged line to be checked
118     * @return {@link #OK} or {@link #NO} or {@link #BAD} or {@link #CONT}
119     * @throws IOException if the input has an unexpected format
120     */
121    public static int getUntaggedReplyCode(String line) throws IOException {
122        return getReplyCode(line, UNTAGGED_PATTERN);
123    }
124
125    // Helper method to process both tagged and untagged replies.
126    private static int getReplyCode(String line, Pattern pattern) throws IOException{
127        if (isContinuation(line)) {
128            return CONT;
129        }
130        Matcher m = pattern.matcher(line);
131        if (m.matches()) { // TODO would lookingAt() be more efficient? If so, then drop trailing .* from patterns
132            String code = m.group(1);
133            if (code.equals(IMAP_OK)) {
134                return OK;
135            }
136            if (code.equals(IMAP_BAD)) {
137                return BAD;
138            }
139            if (code.equals(IMAP_NO)) {
140                return NO;
141            }
142        }
143        throw new MalformedServerReplyException(
144            "Received unexpected IMAP protocol response from server: '" + line + "'.");
145    }
146
147    /**
148     * Checks whether the reply code indicates success or not
149     *
150     * @param replyCode the code to check
151     * @return {@code true} if the code equals {@link #OK}
152     */
153    public static boolean isSuccess(int replyCode) {
154        return replyCode == OK;
155    }
156    /**
157     * Checks if the reply line is a continuation, i.e. starts with "+"
158     * @param replyCode the code to be checked
159     * @return {@code true} if the response was a continuation
160     */
161    public static boolean isContinuation(int replyCode) {
162        return replyCode == CONT;
163    }
164
165}
166
167/* kate: indent-width 4; replace-tabs on; */