/*

 * internal.c: internal data structures and helpers

 *

 * Copyright (C) 2007-2016 David Lutterkort

 *

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

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

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

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA

 *

 * Author: David Lutterkort <dlutter@redhat.com>

 */

#include <config.h>

#include <ctype.h>

#include <stdio.h>

#include <stdarg.h>

#include <locale.h>

#include "internal.h"

#include "memory.h"

#include "fa.h"

#ifndef MIN

# define MIN(a, b) ((a) < (b) ? (a) : (b))

#endif

/* Cap file reads somwhat arbitrarily at 32 MB */

#define MAX_READ_LEN (32*1024*1024)

int pathjoin(char **path, int nseg, ...) {

    va_list ap;

    va_start(ap, nseg);

    for (int i=0; i < nseg; i++) {

        const char *seg = va_arg(ap, const char *);

        if (seg == NULL)

            seg = "()";

        int len = strlen(seg) + 1;

        if (*path != NULL) {

            len += strlen(*path) + 1;

            if (REALLOC_N(*path, len) == -1) {

                FREE(*path);

                va_end(ap);

                return -1;

            }

            if (strlen(*path) == 0 || (*path)[strlen(*path)-1] != SEP)

                strcat(*path, "/");

            if (seg[0] == SEP)

                seg += 1;

            strcat(*path, seg);

        } else {

            if ((*path = malloc(len)) == NULL) {

                va_end(ap);

                return -1;

            }

            strcpy(*path, seg);

        }

    }

    va_end(ap);

    return 0;

}

/* Like gnulib's fread_file, but read no more than the specified maximum

   number of bytes.  If the length of the input is <= max_len, and

   upon error while reading that data, it works just like fread_file.

   Taken verbatim from libvirt's util.c

*/

static char *

fread_file_lim (FILE *stream, size_t max_len, size_t *length)

{

    char *buf = NULL;

    size_t alloc = 0;

    size_t size = 0;

    int save_errno;

    for (;;) {

        size_t count;

        size_t requested;

        if (size + BUFSIZ + 1 > alloc) {

            char *new_buf;

            alloc += alloc / 2;

            if (alloc < size + BUFSIZ + 1)

                alloc = size + BUFSIZ + 1;

            new_buf = realloc (buf, alloc);

            if (!new_buf) {

                save_errno = errno;

                break;

            }

            buf = new_buf;

        }

        /* Ensure that (size + requested <= max_len); */

        requested = MIN (size < max_len ? max_len - size : 0,

                         alloc - size - 1);

        count = fread (buf + size, 1, requested, stream);

        size += count;

        if (count != requested || requested == 0) {

            save_errno = errno;

            if (ferror (stream))

                break;

            buf[size] = '\0';

            *length = size;

            return buf;

        }

    }

    free (buf);

    errno = save_errno;

    return NULL;

}

char* xfread_file(FILE *fp) {

    char *result;

    size_t len;

    if (!fp)

        return NULL;

    result = fread_file_lim(fp, MAX_READ_LEN, &len;;

    if (result != NULL

        && len <= MAX_READ_LEN

        && (int) len == len)

        return result;

    free(result);

    return NULL;

}

char* xread_file(const char *path) {

    FILE *fp;

    char *result;

    fp = fopen(path, "r");

    if (!fp)

        return NULL;

    result = xfread_file(fp);

    fclose(fp);

    return result;

}

/*

 * Escape/unescape of string literals

 */

static const char *const escape_chars = "\a\b\t\n\v\f\r";

static const char *const escape_names = "abtnvfr";

char *unescape(const char *s, int len, const char *extra) {

    size_t size;

    const char *n;

    char *result, *t;

    int i;

    if (len < 0 || len > strlen(s))

        len = strlen(s);

    size = 0;

    for (i=0; i < len; i++, size++) {

        if (s[i] == '\\' && strchr(escape_names, s[i+1])) {

            i += 1;

        } else if (s[i] == '\\' && extra && strchr(extra, s[i+1])) {

            i += 1;

        }

    }

    if (ALLOC_N(result, size + 1) < 0)

        return NULL;

    for (i = 0, t = result; i < len; i++, size++) {

        if (s[i] == '\\' && (n = strchr(escape_names, s[i+1])) != NULL) {

            *t++ = escape_chars[n - escape_names];

            i += 1;

        } else if (s[i] == '\\' && extra && strchr(extra, s[i+1]) != NULL) {

            *t++ = s[i+1];

            i += 1;

        } else {

            *t++ = s[i];

        }

    }

    return result;

}

char *escape(const char *text, int cnt, const char *extra) {

    int len = 0;

    char *esc = NULL, *e;

    if (cnt < 0 || cnt > strlen(text))

        cnt = strlen(text);

    for (int i=0; i < cnt; i++) {

        if (text[i] && (strchr(escape_chars, text[i]) != NULL))

            len += 2;  /* Escaped as '\x' */

        else if (text[i] && extra && (strchr(extra, text[i]) != NULL))

            len += 2;  /* Escaped as '\x' */

        else if (! isprint(text[i]))

            len += 4;  /* Escaped as '\ooo' */

        else

            len += 1;

    }

    if (ALLOC_N(esc, len+1) < 0)

        return NULL;

    e = esc;

    for (int i=0; i < cnt; i++) {

        char *p;

        if (text[i] && ((p = strchr(escape_chars, text[i])) != NULL)) {

            *e++ = '\\';

            *e++ = escape_names[p - escape_chars];

        } else if (text[i] && extra && (strchr(extra, text[i]) != NULL)) {

            *e++ = '\\';

            *e++ = text[i];

        } else if (! isprint(text[i])) {

            sprintf(e, "\\%03o", (unsigned char) text[i]);

            e += 4;

        } else {

            *e++ = text[i];

        }

    }

    return esc;

}

int print_chars(FILE *out, const char *text, int cnt) {

    int total = 0;

    char *esc;

    if (text == NULL) {

        fprintf(out, "nil");

        return 3;

    }

    if (cnt < 0)

        cnt = strlen(text);

    esc = escape(text, cnt, "\"");

    total = strlen(esc);

    if (out != NULL)

        fprintf(out, "%s", esc);

    free(esc);

    return total;

}

char *format_pos(const char *text, int pos) {

    static const int window = 28;

    char *buf = NULL, *left = NULL, *right = NULL;

    int before = pos;

    int llen, rlen;

    int r;

    if (before > window)

        before = window;

    left = escape(text + pos - before, before, NULL);

    if (left == NULL)

        goto done;

    right = escape(text + pos, window, NULL);

    if (right == NULL)

        goto done;

    llen = strlen(left);

    rlen = strlen(right);

    if (llen < window && rlen < window) {

        r = asprintf(&buf, "%*s%s|=|%s%-*s\n", window - llen, "<", left,

                     right, window - rlen, ">");

    } else if (strlen(left) < window) {

        r = asprintf(&buf, "%*s%s|=|%s>\n", window - llen, "<", left, right);

    } else if (strlen(right) < window) {

        r = asprintf(&buf, "<%s|=|%s%-*s\n", left, right, window - rlen, ">");

    } else {

        r = asprintf(&buf, "<%s|=|%s>\n", left, right);

    }

    if (r < 0) {

        buf = NULL;

    }

 done:

    free(left);

    free(right);

    return buf;

}

void print_pos(FILE *out, const char *text, int pos) {

    char *format = format_pos(text, pos);

    if (format != NULL) {

        fputs(format, out);

        FREE(format);

    }

}

int __aug_init_memstream(struct memstream *ms) {

    MEMZERO(ms, 1);

#if HAVE_OPEN_MEMSTREAM

    ms->stream = open_memstream(&(ms->buf), &(ms->size));

    return ms->stream == NULL ? -1 : 0;

#else

    ms->stream = tmpfile();

    if (ms->stream == NULL) {

        return -1;

    }

    return 0;

#endif

}

int __aug_close_memstream(struct memstream *ms) {

#if !HAVE_OPEN_MEMSTREAM

    rewind(ms->stream);

    ms->buf = fread_file_lim(ms->stream, MAX_READ_LEN, &(ms->size));

#endif

    if (fclose(ms->stream) == EOF) {

        FREE(ms->buf);

        ms->size = 0;

        return -1;

    }

    return 0;

}

int tree_sibling_index(struct tree *tree) {

    struct tree *siblings = tree->parent->children;

    int cnt = 0, ind = 0;

    list_for_each(t, siblings) {

        if (streqv(t->label, tree->label)) {

            cnt += 1;

            if (t == tree)

                ind = cnt;

        }

    }

    if (cnt > 1) {

        return ind;

    } else {

        return 0;

    }

}

char *path_expand(struct tree *tree, const char *ppath) {

    char *path;

    const char *label;

    char *escaped = NULL;

    int r;

    int ind = tree_sibling_index(tree);

    if (ppath == NULL)

        ppath = "";

    if (tree->label == NULL)

        label = "(none)";

    else

        label = tree->label;

    r = pathx_escape_name(label, &escaped);

    if (r < 0)

        return NULL;

    if (escaped != NULL)

        label = escaped;

    if (ind > 0) {

        r = asprintf(&path, "%s/%s[%d]", ppath, label, ind);

    } else {

        r = asprintf(&path, "%s/%s", ppath, label);

    }

    free(escaped);

    if (r == -1)

        return NULL;

    return path;

}

char *path_of_tree(struct tree *tree) {

    int depth, i;

    struct tree *t, **anc;

    char *path = NULL;

    for (t = tree, depth = 1; ! ROOT_P(t); depth++, t = t->parent);

    if (ALLOC_N(anc, depth) < 0)

        return NULL;

    for (t = tree, i = depth - 1; i >= 0; i--, t = t->parent)

        anc[i] = t;

    for (i = 0; i < depth; i++) {

        char *p = path_expand(anc[i], path);

        free(path);

        path = p;

    }

    FREE(anc);

    return path;

}

/* User-facing path cleaning */

static char *cleanstr(char *path, const char sep) {

    if (path == NULL || strlen(path) == 0)

        return path;

    char *e = path + strlen(path) - 1;

    while (e >= path && (*e == sep || isspace(*e)))

        *e-- = '\0';

    return path;

}

char *cleanpath(char *path) {

    if (path == NULL || strlen(path) == 0)

        return path;

    if (STREQ(path, "/"))

        return path;

    return cleanstr(path, SEP);

}

const char *xstrerror(int errnum, char *buf, size_t len) {

#ifdef HAVE_STRERROR_R

# ifdef __USE_GNU

    /* Annoying linux specific API contract */

    return strerror_r(errnum, buf, len);

# else

    strerror_r(errnum, buf, len);

    return buf;

# endif

#else

    int n = snprintf(buf, len, "errno=%d", errnum);

    return (0 < n && n < len

            ? buf : "internal error: buffer too small in xstrerror");

#endif

}

int xasprintf(char **strp, const char *format, ...) {

  va_list args;

  int result;

  va_start (args, format);

  result = vasprintf (strp, format, args);

  va_end (args);

  if (result < 0)

      *strp = NULL;

  return result;

}

/* From libvirt's src/xen/block_stats.c */

int xstrtoint64(char const *s, int base, int64_t *result) {

    long long int lli;

    char *p;

    errno = 0;

    lli = strtoll(s, &p, base);

    if (errno || !(*p == 0 || *p == '\n') || p == s || (int64_t) lli != lli)

        return -1;

    *result = lli;

    return 0;

}

void calc_line_ofs(const char *text, size_t pos, size_t *line, size_t *ofs) {

    *line = 1;

    *ofs = 0;

    for (const char *t = text; t < text + pos; t++) {

        *ofs += 1;

        if (*t == '\n') {

            *ofs = 0;

            *line += 1;

        }

    }

}

#if HAVE_USELOCALE

int regexp_c_locale(ATTRIBUTE_UNUSED char **u, ATTRIBUTE_UNUSED size_t *len) {

    /* On systems with uselocale, we are ok, since we make sure that we

     * switch to the "C" locale any time we enter through the public API

     */

    return 0;

}

#else

int regexp_c_locale(char **u, size_t *len) {

    /* Without uselocale, we need to expand character ranges */

    int r;

    char *s = *u;

    size_t s_len, u_len;

    if (len == NULL) {

        len = &u_len;

        s_len = strlen(s);

    } else {

        s_len = *len;

    }

    r = fa_expand_char_ranges(s, s_len, u, len);

    if (r != 0) {

        *u = s;

        *len = s_len;

    }

    if (r < 0)

        return -1;

    /* Syntax errors will be caught when the result is compiled */

    if (r > 0)

        return 0;

    free(s);

    return 1;

}

#endif

#if ENABLE_DEBUG

bool debugging(const char *category) {

    const char *debug = getenv("AUGEAS_DEBUG");

    const char *s;

    if (debug == NULL)

        return false;

    for (s = debug; s != NULL; ) {

        if (STREQLEN(s, category, strlen(category)))

            return true;

        s = strchr(s, ':');

        if (s != NULL)

            s+=1;

    }

    return false;

}

FILE *debug_fopen(const char *format, ...) {

    va_list ap;

    FILE *result = NULL;

    const char *dir;

    char *name = NULL, *path = NULL;

    int r;

    dir = getenv("AUGEAS_DEBUG_DIR");

    if (dir == NULL)

        goto error;

    va_start(ap, format);

    r = vasprintf(&name, format, ap);

    va_end(ap);

    if (r < 0)

        goto error;

    r = xasprintf(&path, "%s/%s", dir, name);

    if (r < 0)

        goto error;

    result = fopen(path, "w");

 error:

    free(name);

    free(path);

    return result;

}

#endif

/*

 * Local variables:

 *  indent-tabs-mode: nil

 *  c-indent-level: 4

 *  c-basic-offset: 4

 *  tab-width: 4

 * End:

 */