/*

 * Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

#include <ctype.h>

#include <stdlib.h>

#include <string.h>

#include <sys/types.h>

#include "jni.h"

#include "jli_util.h"

#include "version_comp.h"

/*

 *      A collection of useful strings. One should think of these as #define

 *      entries, but actual strings can be more efficient (with many compilers).

 */

static const char *separators   = ".-_";

static const char *zero_string  = "0";

/*

 *      Validate a string as parsable as a "Java int". If so parsable,

 *      return true (non-zero) and store the numeric value at the address

 *      passed in as "value"; otherwise return false (zero).

 *

 *      Note that the maximum allowable value is 2147483647 as defined by

 *      the "Java Language Specification" which precludes the use of native

 *      conversion routines which may have other limits.

 *

 *      Also note that we don't have to worry about the alternate maximum

 *      allowable value of 2147483648 because it is only allowed after

 *      the unary negation operator and this grammar doesn't have one

 *      of those.

 *

 *      Finally, note that a value which exceeds the maximum jint value will

 *      return false (zero). This results in the otherwise purely numeric

 *      string being compared as a string of characters (as per the spec.)

 */

static int

isjavaint(const char *s, jint *value)

{

    jlong sum = 0;

    jint digit;

    while (*s != '\0')

        if (isdigit(*s)) {

            digit = (jint)((int)(*s++) - (int)('0'));

            sum = (sum * 10) + digit;

            if (sum > 2147483647)

                return (0);     /* Overflows jint (but not jlong) */

        } else

            return (0);

    *value = (jint)sum;

    return (1);

}

/*

 *      Modeled after strcmp(), compare two strings (as in the grammar defined

 *      in Appendix A of JSR 56).  If both strings can be interpreted as

 *      Java ints, do a numeric comparison, else it is strcmp().

 */

static int

comp_string(const char *s1, const char *s2)

{

    jint v1, v2;

    if (isjavaint(s1, &v1) && isjavaint(s2, &v2))

        return ((int)(v1 - v2));

    else

        return (JLI_StrCmp(s1, s2));

}

/*

 *      Modeled after strcmp(), compare two version-ids for a Prefix

 *      Match as defined in JSR 56.

 */

int

JLI_PrefixVersionId(const char *id1, char *id2)

{

    char        *s1 = JLI_StringDup(id1);

    char        *s2 = JLI_StringDup(id2);

    char        *m1 = s1;

    char        *m2 = s2;

    char        *end1 = NULL;

    char        *end2 = NULL;

    int res = 0;

    do {

        if ((s1 != NULL) && ((end1 = JLI_StrPBrk(s1, ".-_")) != NULL))

            *end1 = '\0';

        if ((s2 != NULL) && ((end2 = JLI_StrPBrk(s2, ".-_")) != NULL))

            *end2 = '\0';

        res = comp_string(s1, s2);

        if (end1 != NULL)

            s1 = end1 + 1;

        else

            s1 = NULL;

        if (end2 != NULL)

            s2 = end2 + 1;

        else

            s2 = NULL;

    } while (res == 0 && ((s1 != NULL) && (s2 != NULL)));

    JLI_MemFree(m1);

    JLI_MemFree(m2);

    return (res);

}

/*

 *      Modeled after strcmp(), compare two version-ids for an Exact

 *      Match as defined in JSR 56.

 */

int

JLI_ExactVersionId(const char *id1, char *id2)

{

    char        *s1 = JLI_StringDup(id1);

    char        *s2 = JLI_StringDup(id2);

    char        *m1 = s1;

    char        *m2 = s2;

    char        *end1 = NULL;

    char        *end2 = NULL;

    int res = 0;

    do {

        if ((s1 != NULL) && ((end1 = JLI_StrPBrk(s1, separators)) != NULL))

            *end1 = '\0';

        if ((s2 != NULL) && ((end2 = JLI_StrPBrk(s2, separators)) != NULL))

            *end2 = '\0';

        if ((s1 != NULL) && (s2 == NULL))

            res = comp_string(s1, zero_string);

        else if ((s1 == NULL) && (s2 != NULL))

            res = comp_string(zero_string, s2);

        else

            res = comp_string(s1, s2);

        if (end1 != NULL)

            s1 = end1 + 1;

        else

            s1 = NULL;

        if (end2 != NULL)

            s2 = end2 + 1;

        else

            s2 = NULL;

    } while (res == 0 && ((s1 != NULL) || (s2 != NULL)));

    JLI_MemFree(m1);

    JLI_MemFree(m2);

    return (res);

}

/*

 *      Return true if this simple-element (as defined in JSR 56) forms

 *      an acceptable match.

 *

 *      JSR 56 is modified by the Java Web Start <rel> Developer Guide

 *      where it is stated "... Java Web Start will not consider an installed

 *      non-FCS (i.e., milestone) JRE as a match. ... a JRE from Sun

 *      Microsystems, Inc., is by convention a non-FCS (milestone) JRE

 *      if there is a dash (-) in the version string."

 *

 *      An undocumented caveat to the above is that an exact match with a

 *      hyphen is accepted as a development extension.

 *

 *      These modifications are addressed by the specific comparisons

 *      for releases with hyphens.

 */

static int

acceptable_simple_element(const char *release, char *simple_element)

{

    char        *modifier;

    modifier = simple_element + JLI_StrLen(simple_element) - 1;

    if (*modifier == '*') {

        *modifier = '\0';

        if (JLI_StrChr(release, '-'))

            return ((JLI_StrCmp(release, simple_element) == 0)?1:0);

        return ((JLI_PrefixVersionId(release, simple_element) == 0)?1:0);

    } else if (*modifier == '+') {

        *modifier = '\0';

        if (JLI_StrChr(release, '-'))

            return ((JLI_StrCmp(release, simple_element) == 0)?1:0);

        return ((JLI_ExactVersionId(release, simple_element) >= 0)?1:0);

    } else {

        return ((JLI_ExactVersionId(release, simple_element) == 0)?1:0);

    }

}

/*

 *      Return true if this element (as defined in JSR 56) forms

 *      an acceptable match. An element is the intersection (and)

 *      of multiple simple-elements.

 */

static int

acceptable_element(const char *release, char *element)

{

    char        *end;

    do {

        if ((end = JLI_StrChr(element, '&')) != NULL)

            *end = '\0';

        if (!acceptable_simple_element(release, element))

            return (0);

        if (end != NULL)

            element = end + 1;

    } while (end != NULL);

    return (1);

}

/*

 *      Checks if release is acceptable by the specification version-string.

 *      Return true if this version-string (as defined in JSR 56) forms

 *      an acceptable match. A version-string is the union (or) of multiple

 *      elements.

 */

int

JLI_AcceptableRelease(const char *release, char *version_string)

{

    char        *vs;

    char        *m1;

    char        *end;

    m1 = vs = JLI_StringDup(version_string);

    do {

        if ((end = JLI_StrChr(vs, ' ')) != NULL)

            *end = '\0';

        if (acceptable_element(release, vs)) {

            JLI_MemFree(m1);

            return (1);

        }

        if (end != NULL)

            vs = end + 1;

    } while (end != NULL);

    JLI_MemFree(m1);

    return (0);

}

/*

 *      Return true if this is a valid simple-element (as defined in JSR 56).

 *

 *      The official grammar for a simple-element is:

 *

 *              simple-element  ::= version-id | version-id modifier

 *              modifier        ::= '+' | '*'

 *              version-id      ::= string ( separator  string )*

 *              string          ::= char ( char )*

 *              char            ::= Any ASCII character except a space, an

 *                                  ampersand, a separator or a modifier

 *              separator       ::= '.' | '-' | '_'

 *

 *      However, for efficiency, it is time to abandon the top down parser

 *      implementation.  After deleting the potential trailing modifier, we

 *      are left with a version-id.

 *

 *      Note that a valid version-id has three simple properties:

 *

 *      1) Doesn't contain a space, an ampersand or a modifier.

 *

 *      2) Doesn't begin or end with a separator.

 *

 *      3) Doesn't contain two adjacent separators.

 *

 *      Any other line noise constitutes a valid version-id.

 */

static int

valid_simple_element(char *simple_element)

{

    char        *last;

    size_t      len;

    if ((simple_element == NULL) || ((len = JLI_StrLen(simple_element)) == 0))

        return (0);

    last = simple_element + len - 1;

    if (*last == '*' || *last == '+') {

        if (--len == 0)

            return (0);

        *last-- = '\0';

    }

    if (JLI_StrPBrk(simple_element, " &+*") != NULL)    /* Property #1 */

        return (0);

    if ((JLI_StrChr(".-_", *simple_element) != NULL) || /* Property #2 */

      (JLI_StrChr(".-_", *last) != NULL))

        return (0);

    for (; simple_element != last; simple_element++)    /* Property #3 */

        if ((JLI_StrChr(".-_", *simple_element) != NULL) &&

          (JLI_StrChr(".-_", *(simple_element + 1)) != NULL))

            return (0);

    return (1);

}

/*

 *      Return true if this is a valid element (as defined in JSR 56).

 *      An element is the intersection (and) of multiple simple-elements.

 */

static int

valid_element(char *element)

{

    char        *end;

    if ((element == NULL) || (JLI_StrLen(element) == 0))

        return (0);

    do {

        if ((end = JLI_StrChr(element, '&')) != NULL)

            *end = '\0';

        if (!valid_simple_element(element))

            return (0);

        if (end != NULL)

            element = end + 1;

    } while (end != NULL);

    return (1);

}

/*

 *      Validates a version string by the extended JSR 56 grammar.

 */

int

JLI_ValidVersionString(char *version_string)

{

    char        *vs;

    char        *m1;

    char        *end;

    if ((version_string == NULL) || (JLI_StrLen(version_string) == 0))

        return (0);

    m1 = vs = JLI_StringDup(version_string);

    do {

        if ((end = JLI_StrChr(vs, ' ')) != NULL)

            *end = '\0';

        if (!valid_element(vs)) {

            JLI_MemFree(m1);

            return (0);

        }

        if (end != NULL)

            vs = end + 1;

    } while (end != NULL);

    JLI_MemFree(m1);

    return (1);

}