/*
 * Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 */

#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円')
 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円';
 if ((s2 != NULL) && ((end2 = JLI_StrPBrk(s2, ".-_")) != NULL))
 *end2 = '0円';

 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円';
 if ((s2 != NULL) && ((end2 = JLI_StrPBrk(s2, separators)) != NULL))
 *end2 = '0円';

 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円';
 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円';
 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円';
 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円';
 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円';
 }
 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円';
 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円';
 if (!valid_element(vs)) {
 JLI_MemFree(m1);
 return (0);
 }
 if (end != NULL)
 vs = end + 1;
 } while (end != NULL);
 JLI_MemFree(m1);
 return (1);
}