/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "plstr.h"
#include <string.h>

PR_IMPLEMENT(char*)
PL_strstr(const char* big, const char* little)
{
    if (((const char*)0 == big) || ((const char*)0 == little)) {
        return (char*)0;
    }
    if (((char)0 == *big) || ((char)0 == *little)) {
        return (char*)0;
    }

    return strstr(big, little);
}

PR_IMPLEMENT(char*)
PL_strrstr(const char* big, const char* little)
{
    const char* p;
    size_t ll;
    size_t bl;

    if (((const char*)0 == big) || ((const char*)0 == little)) {
        return (char*)0;
    }
    if (((char)0 == *big) || ((char)0 == *little)) {
        return (char*)0;
    }

    ll = strlen(little);
    bl = strlen(big);
    if (bl < ll) {
        return (char*)0;
    }
    p = &big[bl - ll];

    for (; p >= big; p--)
        if (*little == *p)
            if (0 == strncmp(p, little, ll)) {
                return (char*)p;
            }

    return (char*)0;
}

PR_IMPLEMENT(char*)
PL_strnstr(const char* big, const char* little, PRUint32 max)
{
    size_t ll;

    if (((const char*)0 == big) || ((const char*)0 == little)) {
        return (char*)0;
    }
    if (((char)0 == *big) || ((char)0 == *little)) {
        return (char*)0;
    }

    ll = strlen(little);
    if (ll > (size_t)max) {
        return (char*)0;
    }
    max -= (PRUint32)ll;
    max++;

    for (; max && *big; big++, max--)
        if (*little == *big)
            if (0 == strncmp(big, little, ll)) {
                return (char*)big;
            }

    return (char*)0;
}

PR_IMPLEMENT(char*)
PL_strnrstr(const char* big, const char* little, PRUint32 max)
{
    const char* p;
    size_t ll;

    if (((const char*)0 == big) || ((const char*)0 == little)) {
        return (char*)0;
    }
    if (((char)0 == *big) || ((char)0 == *little)) {
        return (char*)0;
    }

    ll = strlen(little);

    for (p = big; max && *p; p++, max--)
        ;

    p -= ll;
    if (p < big) {
        return (char*)0;
    }

    for (; p >= big; p--)
        if (*little == *p)
            if (0 == strncmp(p, little, ll)) {
                return (char*)p;
            }

    return (char*)0;
}