/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

/* Derived from PCRE's pcreposix.h.

            Copyright (c) 1997-2004 University of Cambridge

-----------------------------------------------------------------------------
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modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
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    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
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    * Neither the name of the University of Cambridge nor the names of its
      contributors may be used to endorse or promote products derived from
      this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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-----------------------------------------------------------------------------
*/

/**
 * @file ap_regex.h
 * @brief Apache Regex defines
 */

#ifndef AP_REGEX_H
#define AP_REGEX_H

#include "apr.h"

/* Allow for C++ users */

#ifdef __cplusplus
extern "C" {
#endif

/* Options for ap_regexec: */

#define AP_REG_ICASE    0x01 /** use a case-insensitive match */
#define AP_REG_NEWLINE  0x02 /** don't match newlines against '.' etc */
#define AP_REG_NOTBOL   0x04 /** ^ will not match against start-of-string */
#define AP_REG_NOTEOL   0x08 /** $ will not match against end-of-string */

#define AP_REG_EXTENDED (0)  /** unused */
#define AP_REG_NOSUB    (0)  /** unused */

/* Error values: */
enum {
  AP_REG_ASSERT = 1,  /** internal error ? */
  AP_REG_ESPACE,      /** failed to get memory */
  AP_REG_INVARG,      /** invalid argument */
  AP_REG_NOMATCH      /** match failed */
};

/* The structure representing a compiled regular expression. */
typedef struct {
    void *re_pcre;
    apr_size_t re_nsub;
    apr_size_t re_erroffset;
} ap_regex_t;

/* The structure in which a captured offset is returned. */
typedef struct {
    int rm_so;
    int rm_eo;
} ap_regmatch_t;

/* The functions */

/**
 * Compile a regular expression.
 * @param preg Returned compiled regex
 * @param regex The regular expression string
 * @param cflags Must be zero (currently).
 * @return Zero on success or non-zero on error
 */
int ap_regcomp(ap_regex_t *preg, const char *regex, int cflags);

/**
 * Match a NUL-terminated string against a pre-compiled regex.
 * @param preg The pre-compiled regex
 * @param string The string to match
 * @param nmatch Provide information regarding the location of any matches
 * @param pmatch Provide information regarding the location of any matches
 * @param eflags Bitwise OR of any of AP_REG_* flags
 * @return 0 for successful match, #REG_NOMATCH otherwise
 */
int ap_regexec(const ap_regex_t *preg, const char *string,
                           apr_size_t nmatch, ap_regmatch_t *pmatch, int eflags);

/**
 * Return the error code returned by regcomp or regexec into error messages
 * @param errcode the error code returned by regexec or regcomp
 * @param preg The precompiled regex
 * @param errbuf A buffer to store the error in
 * @param errbuf_size The size of the buffer
 */
apr_size_t ap_regerror(int errcode, const ap_regex_t *preg,
                                   char *errbuf, apr_size_t errbuf_size);

/** Destroy a pre-compiled regex.
 * @param preg The pre-compiled regex to free.
 */
void ap_regfree(ap_regex_t *preg);

/**
 * Compile a regular expression to be used later
 * @param p The pool to allocate from
 * @param pattern the regular expression to compile
 * @param cflags The bitwise or of one or more of the following:
 *   @li REG_EXTENDED - Use POSIX extended Regular Expressions
 *   @li REG_ICASE    - Ignore case
 *   @li REG_NOSUB    - Support for substring addressing of matches
 *       not required
 *   @li REG_NEWLINE  - Match-any-character operators don't match new-line
 * @return The compiled regular expression
 */
ap_regex_t * ap_pregcomp(apr_pool_t *p, const char *pattern,
                                     int cflags);

/**
 * Free the memory associated with a compiled regular expression
 * @param p The pool the regex was allocated from
 * @param reg The regular expression to free
 */
void ap_pregfree(apr_pool_t *p, ap_regex_t *reg);

/**
 * After performing a successful regex match, you may use this function to
 * perform a series of string substitutions based on subexpressions that were
 * matched during the call to ap_regexec
 * @param p The pool to allocate from
 * @param input An arbitrary string containing $1 through $9.  These are
 *              replaced with the corresponding matched sub-expressions
 * @param source The string that was originally matched to the regex
 * @param nmatch the nmatch returned from ap_pregex
 * @param pmatch the pmatch array returned from ap_pregex
 */
char * ap_pregsub(apr_pool_t *p, const char *input, const char *source,
                              size_t nmatch, ap_regmatch_t pmatch[]);

#ifdef __cplusplus
}   /* extern "C" */
#endif

#endif /* AP_REGEX_T */