/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998-2009
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *      Rob McCool  (original author)
 *      Ken Key <key+mozilla@ksquared.net>
 *      Nelson Bolyard <nelson@bolyard.me>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/* *
 *
 * shexp.c: shell-like wildcard match routines
 *
 * See shexp.h for public documentation.
 *
 * Rob McCool
 *
 */

#include "nsWildCard.h"
#include "plstr.h"
#include "prmem.h"

/* ----------------------------- shexp_valid ------------------------------ */

static int
_valid_subexp(const char *expr, char stop1, char stop2)
{
    register int x;
    int nsc = 0;     /* Number of special characters */
    int np;          /* Number of pipe characters in union */
    int tld = 0;     /* Number of tilde characters */

    for (x = 0; expr[x] && (expr[x] != stop1) && (expr[x] != stop2); ++x) {
        switch(expr[x]) {
        case '~':
            if(tld)                 /* at most one exclusion */
                return INVALID_SXP;
            if (stop1)              /* no exclusions within unions */
                return INVALID_SXP;
            if (!expr[x+1])          /* exclusion cannot be last character */
                return INVALID_SXP;
            if (!x)                 /* exclusion cannot be first character */
                return INVALID_SXP;
            ++tld;
            /* fall through */
        case '*':
        case '?':
        case '$':
            ++nsc;
            break;
        case '[':
            ++nsc;
            if((!expr[++x]) || (expr[x] == ']'))
                return INVALID_SXP;
            for(; expr[x] && (expr[x] != ']'); ++x) {
                if(expr[x] == '\\' && !expr[++x])
                    return INVALID_SXP;
            }
            if(!expr[x])
                return INVALID_SXP;
            break;
        case '(':
            ++nsc;
            if (stop1)                  /* no nested unions */
                return INVALID_SXP;
            np = -1;
            do {
                int t = _valid_subexp(&expr[++x], ')', '|');
                if(t == 0 || t == INVALID_SXP)
                    return INVALID_SXP;
                x+=t;
                if(!expr[x])
                    return INVALID_SXP;
                ++np;
            } while (expr[x] == '|' );
            if(np < 1)  /* must be at least one pipe */
                return INVALID_SXP;
            break;
        case ')':
        case ']':
        case '|':
            return INVALID_SXP;
        case '\\':
            ++nsc;
            if(!expr[++x])
                return INVALID_SXP;
            break;
        default:
            break;
        }
    }
    if((!stop1) && (!nsc)) /* must be at least one special character */
        return NON_SXP;
    return ((expr[x] == stop1 || expr[x] == stop2) ? x : INVALID_SXP);
}

int
NS_WildCardValid(const char *expr)
{
    int x;

    x = _valid_subexp(expr, '\0', '\0');
    return (x < 0 ? x : VALID_SXP);
}

/* ----------------------------- shexp_match ----------------------------- */


#define MATCH 0
#define NOMATCH 1
#define ABORTED -1

static int
_shexp_match(const char *str, const char *expr, PRBool case_insensitive,
             unsigned int level);

/* Count characters until we reach a NUL character or either of the
 * two delimiter characters, stop1 or stop2.  If we encounter a bracketed
 * expression, look only for NUL or ']' inside it.  Do not look for stop1
 * or stop2 inside it. Return ABORTED if bracketed expression is unterminated.
 * Handle all escaping.
 * Return index in input string of first stop found, or ABORTED if not found.
 * If "dest" is non-NULL, copy counted characters to it and NUL terminate.
 */
static int
_scan_and_copy(const char *expr, char stop1, char stop2, char *dest)
{
    register int sx;     /* source index */
    register char cc;

    for (sx = 0; (cc = expr[sx]) && cc != stop1 && cc != stop2; sx++) {
        if (cc == '\\') {
            if (!expr[++sx])
                return ABORTED; /* should be impossible */
        }
        else if (cc == '[') {
            while ((cc = expr[++sx]) && cc != ']') {
                if(cc == '\\' && !expr[++sx])
                    return ABORTED;
            }
            if (!cc)
                return ABORTED; /* should be impossible */
        }
    }
    if (dest && sx) {
        /* Copy all but the closing delimiter. */
        memcpy(dest, expr, sx);
        dest[sx] = 0;
    }
    return cc ? sx : ABORTED; /* index of closing delimiter */
}

/* On input, expr[0] is the opening parenthesis of a union.
 * See if any of the alternatives in the union matches as a pattern.
 * The strategy is to take each of the alternatives, in turn, and append
 * the rest of the expression (after the closing ')' that marks the end of
 * this union) to that alternative, and then see if the resultant expression
 * matches the input string.  Repeat this until some alternative matches,
 * or we have an abort.
 */
static int
_handle_union(const char *str, const char *expr, PRBool case_insensitive,
              unsigned int level)
{
    register int sx;     /* source index */
    int cp;              /* source index of closing parenthesis */
    int count;
    int ret   = NOMATCH;
    char *e2;

    /* Find the closing parenthesis that ends this union in the expression */
    cp = _scan_and_copy(expr, ')', '\0', NULL);
    if (cp == ABORTED || cp < 4) /* must be at least "(a|b" before ')' */
        return ABORTED;
    ++cp;                /* now index of char after closing parenthesis */
    e2 = (char *) PR_Malloc(1 + strlen(expr));
    if (!e2)
        return ABORTED;
    for (sx = 1; ; ++sx) {
        /* Here, expr[sx] is one character past the preceeding '(' or '|'. */
        /* Copy everything up to the next delimiter to e2 */
        count = _scan_and_copy(expr + sx, ')', '|', e2);
        if (count == ABORTED || !count) {
            ret = ABORTED;
            break;
        }
        sx += count;
        /* Append everything after closing parenthesis to e2. This is safe. */
        strcpy(e2+count, expr+cp);
        ret = _shexp_match(str, e2, case_insensitive, level + 1);
        if (ret != NOMATCH || !expr[sx] || expr[sx] == ')')
            break;
    }
    PR_Free(e2);
    if (sx < 2)
        ret = ABORTED;
    return ret;
}

/* returns 1 if val is in range from start..end, case insensitive. */
static int
_is_char_in_range(int start, int end, int val)
{
    char map[256];
    memset(map, 0, sizeof map);
    while (start <= end)
        map[tolower(start++)] = 1;
    return map[tolower(val)];
}

static int
_shexp_match(const char *str, const char *expr, PRBool case_insensitive,
             unsigned int level)
{
    register int x;   /* input string index */
    register int y;   /* expression index */
    int ret,neg;

    if (level > 20)      /* Don't let the stack get too deep. */
        return ABORTED;
    for(x = 0, y = 0; expr[y]; ++y, ++x) {
        if((!str[x]) && (expr[y] != '$') && (expr[y] != '*')) {
            return NOMATCH;
        }
        switch(expr[y]) {
        case '$':
            if(str[x])
                return NOMATCH;
            --x;                 /* we don't want loop to increment x */
            break;
        case '*':
            while(expr[++y] == '*'){}
            if(!expr[y])
                return MATCH;
            while(str[x]) {
                ret = _shexp_match(&str[x++], &expr[y], case_insensitive,
                                   level + 1);
                switch(ret) {
                case NOMATCH:
                    continue;
                case ABORTED:
                    return ABORTED;
                default:
                    return MATCH;
                }
            }
            if((expr[y] == '$') && (expr[y+1] == '\0') && (!str[x]))
                return MATCH;
            else
                return NOMATCH;
        case '[': {
            int start, end = 0, i;
            neg = ((expr[++y] == '^') && (expr[y+1] != ']'));
            if (neg)
                ++y;
            i = y;
            start = (unsigned char)(expr[i++]);
            if (start == '\\')
                start = (unsigned char)(expr[i++]);
            if (isalnum(start) && expr[i++] == '-') {
                end = (unsigned char)(expr[i++]);
                if (end == '\\')
                    end = (unsigned char)(expr[i++]);
            }
            if (isalnum(end) && expr[i] == ']') {
                /* This is a range form: a-b */
                int val   = (unsigned char)(str[x]);
                if (end < start) { /* swap them */
                    start ^= end;
                    end ^= start;
                    start ^= end;
                }
                if (case_insensitive && isalpha(val)) {
                    val = _is_char_in_range(start, end, val);
                    if (neg == val)
                        return NOMATCH;
                }
                else if (neg != ((val < start) || (val > end))) {
                    return NOMATCH;
                }
                y = i;
            }
            else {
                /* Not range form */
                int matched = 0;
                for (; expr[y] != ']'; y++) {
                    if (expr[y] == '\\')
                        ++y;
                    if(case_insensitive) {
                        matched |= (toupper(str[x]) == toupper(expr[y]));
                    }
                    else {
                        matched |= (str[x] == expr[y]);
                    }
                }
                if (neg == matched)
                    return NOMATCH;
            }
        }
        break;
        case '(':
            if (!expr[y+1])
                return ABORTED;
            return _handle_union(&str[x], &expr[y], case_insensitive, level);
        case '?':
            break;
        case ')':
        case ']':
        case '|':
            return ABORTED;
        case '\\':
            ++y;
            /* fall through */
        default:
            if(case_insensitive) {
                if(toupper(str[x]) != toupper(expr[y]))
                    return NOMATCH;
            }
            else {
                if(str[x] != expr[y])
                    return NOMATCH;
            }
            break;
        }
    }
    return (str[x] ? NOMATCH : MATCH);
}

static int
ns_WildCardMatch(const char *str, const char *xp, PRBool case_insensitive)
{
    char *expr = 0;
    int x, ret = MATCH;

    if (!strchr(xp, '~'))
        return _shexp_match(str, xp, case_insensitive, 0);

    expr = PL_strdup(xp);
    if(!expr)
        return NOMATCH;

    x = _scan_and_copy(expr, '~', '\0', NULL);
    if (x != ABORTED && expr[x] == '~') {
        expr[x++] = '\0';
        ret = _shexp_match(str, &expr[x], case_insensitive, 0);
        switch (ret) {
        case NOMATCH: ret = MATCH;   break;
        case MATCH:   ret = NOMATCH; break;
        default:                     break;
        }
    }
    if (ret == MATCH)
        ret = _shexp_match(str, expr, case_insensitive, 0);

    PR_Free(expr);
    return ret;
}


int
NS_WildCardMatch(const char *str, const char *expr, PRBool case_insensitive)
{
    int is_valid = NS_WildCardValid(expr);
    switch(is_valid) {
        case INVALID_SXP:
            return -1;
        case NON_SXP:
            if (case_insensitive)
                return (PL_strcasecmp(expr,str) ? NOMATCH : MATCH);
            return (strcmp(expr,str) ? NOMATCH : MATCH);
        default:
            return ns_WildCardMatch(str, expr, case_insensitive);
    }
}