#include "util.h"
#include "linux/string.h"

#define K 1024LL
/*
 * perf_atoll()
 * Parse (\d+)(b|B|kb|KB|mb|MB|gb|GB|tb|TB) (e.g. "256MB")
 * and return its numeric value
 */
s64 perf_atoll(const char *str)
{
        s64 length;
        char *p;
        char c;

        if (!isdigit(str[0]))
                goto out_err;

        length = strtoll(str, &p, 10);
        switch (c = *p++) {
                case 'b': case 'B':
                        if (*p)
                                goto out_err;
                case '\0':
                        return length;
                default:
                        goto out_err;
                /* two-letter suffices */
                case 'k': case 'K':
                        length <<= 10;
                        break;
                case 'm': case 'M':
                        length <<= 20;
                        break;
                case 'g': case 'G':
                        length <<= 30;
                        break;
                case 't': case 'T':
                        length <<= 40;
                        break;
        }
        /* we want the cases to match */
        if (islower(c)) {
                if (strcmp(p, "b") != 0)
                        goto out_err;
        } else {
                if (strcmp(p, "B") != 0)
                        goto out_err;
        }
        return length;

out_err:
        return -1;
}

/*
 * Helper function for splitting a string into an argv-like array.
 * originally copied from lib/argv_split.c
 */
static const char *skip_sep(const char *cp)
{
        while (*cp && isspace(*cp))
                cp++;

        return cp;
}

static const char *skip_arg(const char *cp)
{
        while (*cp && !isspace(*cp))
                cp++;

        return cp;
}

static int count_argc(const char *str)
{
        int count = 0;

        while (*str) {
                str = skip_sep(str);
                if (*str) {
                        count++;
                        str = skip_arg(str);
                }
        }

        return count;
}

/**
 * argv_free - free an argv
 * @argv - the argument vector to be freed
 *
 * Frees an argv and the strings it points to.
 */
void argv_free(char **argv)
{
        char **p;
        for (p = argv; *p; p++)
                zfree(p);

        free(argv);
}

/**
 * argv_split - split a string at whitespace, returning an argv
 * @str: the string to be split
 * @argcp: returned argument count
 *
 * Returns an array of pointers to strings which are split out from
 * @str.  This is performed by strictly splitting on white-space; no
 * quote processing is performed.  Multiple whitespace characters are
 * considered to be a single argument separator.  The returned array
 * is always NULL-terminated.  Returns NULL on memory allocation
 * failure.
 */
char **argv_split(const char *str, int *argcp)
{
        int argc = count_argc(str);
        char **argv = zalloc(sizeof(*argv) * (argc+1));
        char **argvp;

        if (argv == NULL)
                goto out;

        if (argcp)
                *argcp = argc;

        argvp = argv;

        while (*str) {
                str = skip_sep(str);

                if (*str) {
                        const char *p = str;
                        char *t;

                        str = skip_arg(str);

                        t = strndup(p, str-p);
                        if (t == NULL)
                                goto fail;
                        *argvp++ = t;
                }
        }
        *argvp = NULL;

out:
        return argv;

fail:
        argv_free(argv);
        return NULL;
}

/* Character class matching */
static bool __match_charclass(const char *pat, char c, const char **npat)
{
        bool complement = false, ret = true;

        if (*pat == '!') {
                complement = true;
                pat++;
        }
        if (*pat++ == c)        /* First character is special */
                goto end;

        while (*pat && *pat != ']') {   /* Matching */
                if (*pat == '-' && *(pat + 1) != ']') { /* Range */
                        if (*(pat - 1) <= c && c <= *(pat + 1))
                                goto end;
                        if (*(pat - 1) > *(pat + 1))
                                goto error;
                        pat += 2;
                } else if (*pat++ == c)
                        goto end;
        }
        if (!*pat)
                goto error;
        ret = false;

end:
        while (*pat && *pat != ']')     /* Searching closing */
                pat++;
        if (!*pat)
                goto error;
        *npat = pat + 1;
        return complement ? !ret : ret;

error:
        return false;
}

/* Glob/lazy pattern matching */
static bool __match_glob(const char *str, const char *pat, bool ignore_space)
{
        while (*str && *pat && *pat != '*') {
                if (ignore_space) {
                        /* Ignore spaces for lazy matching */
                        if (isspace(*str)) {
                                str++;
                                continue;
                        }
                        if (isspace(*pat)) {
                                pat++;
                                continue;
                        }
                }
                if (*pat == '?') {      /* Matches any single character */
                        str++;
                        pat++;
                        continue;
                } else if (*pat == '[') /* Character classes/Ranges */
                        if (__match_charclass(pat + 1, *str, &pat)) {
                                str++;
                                continue;
                        } else
                                return false;
                else if (*pat == '\\') /* Escaped char match as normal char */
                        pat++;
                if (*str++ != *pat++)
                        return false;
        }
        /* Check wild card */
        if (*pat == '*') {
                while (*pat == '*')
                        pat++;
                if (!*pat)      /* Tail wild card matches all */
                        return true;
                while (*str)
                        if (__match_glob(str++, pat, ignore_space))
                                return true;
        }
        return !*str && !*pat;
}

/**
 * strglobmatch - glob expression pattern matching
 * @str: the target string to match
 * @pat: the pattern string to match
 *
 * This returns true if the @str matches @pat. @pat can includes wildcards
 * ('*','?') and character classes ([CHARS], complementation and ranges are
 * also supported). Also, this supports escape character ('\') to use special
 * characters as normal character.
 *
 * Note: if @pat syntax is broken, this always returns false.
 */
bool strglobmatch(const char *str, const char *pat)
{
        return __match_glob(str, pat, false);
}

/**
 * strlazymatch - matching pattern strings lazily with glob pattern
 * @str: the target string to match
 * @pat: the pattern string to match
 *
 * This is similar to strglobmatch, except this ignores spaces in
 * the target string.
 */
bool strlazymatch(const char *str, const char *pat)
{
        return __match_glob(str, pat, true);
}

/**
 * strtailcmp - Compare the tail of two strings
 * @s1: 1st string to be compared
 * @s2: 2nd string to be compared
 *
 * Return 0 if whole of either string is same as another's tail part.
 */
int strtailcmp(const char *s1, const char *s2)
{
        int i1 = strlen(s1);
        int i2 = strlen(s2);
        while (--i1 >= 0 && --i2 >= 0) {
                if (s1[i1] != s2[i2])
                        return s1[i1] - s2[i2];
        }
        return 0;
}

/**
 * strxfrchar - Locate and replace character in @s
 * @s:    The string to be searched/changed.
 * @from: Source character to be replaced.
 * @to:   Destination character.
 *
 * Return pointer to the changed string.
 */
char *strxfrchar(char *s, char from, char to)
{
        char *p = s;

        while ((p = strchr(p, from)) != NULL)
                *p++ = to;

        return s;
}

/**
 * ltrim - Removes leading whitespace from @s.
 * @s: The string to be stripped.
 *
 * Return pointer to the first non-whitespace character in @s.
 */
char *ltrim(char *s)
{
        int len = strlen(s);

        while (len && isspace(*s)) {
                len--;
                s++;
        }

        return s;
}

/**
 * rtrim - Removes trailing whitespace from @s.
 * @s: The string to be stripped.
 *
 * Note that the first trailing whitespace is replaced with a %NUL-terminator
 * in the given string @s. Returns @s.
 */
char *rtrim(char *s)
{
        size_t size = strlen(s);
        char *end;

        if (!size)
                return s;

        end = s + size - 1;
        while (end >= s && isspace(*end))
                end--;
        *(end + 1) = '\0';

        return s;
}

/**
 * memdup - duplicate region of memory
 * @src: memory region to duplicate
 * @len: memory region length
 */
void *memdup(const void *src, size_t len)
{
        void *p;

        p = malloc(len);
        if (p)
                memcpy(p, src, len);

        return p;
}