/*
   Common strings utilities

   Copyright (C) 2007-2018
   Free Software Foundation, Inc.

   Written by:
   Rostislav Benes, 2007

   This file is part of the Midnight Commander.

   The Midnight Commander is free software: you can redistribute it
   and/or modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation, either version 3 of the License,
   or (at your option) any later version.

   The Midnight Commander 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>

#include <stdlib.h>
#include <langinfo.h>
#include <string.h>
#include <errno.h>

#include "lib/global.h"
#include "lib/util.h"           /* MC_PTR_FREE */
#include "lib/strutil.h"

/*** global variables ****************************************************************************/

GIConv str_cnv_to_term;
GIConv str_cnv_from_term;
GIConv str_cnv_not_convert = INVALID_CONV;

/*** file scope macro definitions ****************************************************************/

/*** file scope type declarations ****************************************************************/

/*** file scope variables ************************************************************************/

/* names, that are used for utf-8 */
static const char *const str_utf8_encodings[] = {
    "utf-8",
    "utf8",
    NULL
};

/* standard 8bit encodings, no wide or multibytes characters */
static const char *const str_8bit_encodings[] = {
    "cp-1251",
    "cp1251",
    "cp-1250",
    "cp1250",
    "cp-866",
    "cp866",
    "ibm-866",
    "ibm866",
    "cp-850",
    "cp850",
    "cp-852",
    "cp852",
    "iso-8859",
    "iso8859",
    "koi8",
    NULL
};

/* terminal encoding */
static char *codeset = NULL;
static char *term_encoding = NULL;
/* function for encoding specific operations */
static struct str_class used_class;

/* --------------------------------------------------------------------------------------------- */
/*** file scope functions ************************************************************************/
/* --------------------------------------------------------------------------------------------- */

/* if enc is same encoding like on terminal */
static int
str_test_not_convert (const char *enc)
{
    return g_ascii_strcasecmp (enc, codeset) == 0;
}

/* --------------------------------------------------------------------------------------------- */

static estr_t
_str_convert (GIConv coder, const char *string, int size, GString * buffer)
{
    estr_t state = ESTR_SUCCESS;
    gssize left;
    gsize bytes_read = 0;
    gsize bytes_written = 0;

    errno = 0;                  /* FIXME: is it really needed? */

    if (coder == INVALID_CONV)
        return ESTR_FAILURE;

    if (string == NULL || buffer == NULL)
        return ESTR_FAILURE;

    /*
       if (! used_class.is_valid_string (string))
       {
       return ESTR_FAILURE;
       }
     */
    if (size < 0)
        size = strlen (string);
    else
    {
        left = strlen (string);
        if (left < size)
            size = left;
    }

    left = size;
    g_iconv (coder, NULL, NULL, NULL, NULL);

    while (left != 0)
    {
        gchar *tmp_buff;
        GError *mcerror = NULL;

        tmp_buff = g_convert_with_iconv ((const gchar *) string,
                                         left, coder, &bytes_read, &bytes_written, &mcerror);
        if (mcerror != NULL)
        {
            int code = mcerror->code;

            g_error_free (mcerror);
            mcerror = NULL;

            switch (code)
            {
            case G_CONVERT_ERROR_NO_CONVERSION:
                /* Conversion between the requested character sets is not supported. */
                tmp_buff = g_strnfill (strlen (string), '?');
                g_string_append (buffer, tmp_buff);
                g_free (tmp_buff);
                return ESTR_FAILURE;

            case G_CONVERT_ERROR_ILLEGAL_SEQUENCE:
                /* Invalid byte sequence in conversion input. */
                if ((tmp_buff == NULL) && (bytes_read != 0))
                    /* recode valid byte sequence */
                    tmp_buff = g_convert_with_iconv ((const gchar *) string,
                                                     bytes_read, coder, NULL, NULL, NULL);

                if (tmp_buff != NULL)
                {
                    g_string_append (buffer, tmp_buff);
                    g_free (tmp_buff);
                }

                if ((int) bytes_read >= left)
                    return ESTR_PROBLEM;

                string += bytes_read + 1;
                size -= (bytes_read + 1);
                left -= (bytes_read + 1);
                g_string_append_c (buffer, *(string - 1));
                state = ESTR_PROBLEM;
                break;

            case G_CONVERT_ERROR_PARTIAL_INPUT:
                /* Partial character sequence at end of input. */
                g_string_append (buffer, tmp_buff);
                g_free (tmp_buff);
                if ((int) bytes_read < left)
                {
                    left = left - bytes_read;
                    tmp_buff = g_strnfill (left, '?');
                    g_string_append (buffer, tmp_buff);
                    g_free (tmp_buff);
                }
                return ESTR_PROBLEM;

            case G_CONVERT_ERROR_BAD_URI:      /* Don't know how handle this error :( */
            case G_CONVERT_ERROR_NOT_ABSOLUTE_PATH:    /* Don't know how handle this error :( */
            case G_CONVERT_ERROR_FAILED:       /* Conversion failed for some reason. */
            default:
                g_free (tmp_buff);
                return ESTR_FAILURE;
            }
        }
        else if (tmp_buff == NULL)
        {
            g_string_append (buffer, string);
            return ESTR_PROBLEM;
        }
        else if (*tmp_buff == '\0')
        {
            g_free (tmp_buff);
            g_string_append (buffer, string);
            return state;
        }
        else
        {
            g_string_append (buffer, tmp_buff);
            g_free (tmp_buff);
            string += bytes_read;
            left -= bytes_read;
        }
    }

    return state;
}

/* --------------------------------------------------------------------------------------------- */

static int
str_test_encoding_class (const char *encoding, const char *const *table)
{
    int result = 0;

    if (encoding != NULL)
    {
        int t;

        for (t = 0; table[t] != NULL; t++)
            if (g_ascii_strncasecmp (encoding, table[t], strlen (table[t])) == 0)
                result++;
    }

    return result;
}

/* --------------------------------------------------------------------------------------------- */

static void
str_choose_str_functions (void)
{
    if (str_test_encoding_class (codeset, str_utf8_encodings))
        used_class = str_utf8_init ();
    else if (str_test_encoding_class (codeset, str_8bit_encodings))
        used_class = str_8bit_init ();
    else
        used_class = str_ascii_init ();
}

/* --------------------------------------------------------------------------------------------- */
/*** public functions ****************************************************************************/
/* --------------------------------------------------------------------------------------------- */

GIConv
str_crt_conv_to (const char *to_enc)
{
    return (!str_test_not_convert (to_enc)) ? g_iconv_open (to_enc, codeset) : str_cnv_not_convert;
}

/* --------------------------------------------------------------------------------------------- */

GIConv
str_crt_conv_from (const char *from_enc)
{
    return (!str_test_not_convert (from_enc))
        ? g_iconv_open (codeset, from_enc) : str_cnv_not_convert;
}

/* --------------------------------------------------------------------------------------------- */

void
str_close_conv (GIConv conv)
{
    if (conv != str_cnv_not_convert)
        g_iconv_close (conv);
}

/* --------------------------------------------------------------------------------------------- */

estr_t
str_convert (GIConv coder, const char *string, GString * buffer)
{
    return _str_convert (coder, string, -1, buffer);
}

/* --------------------------------------------------------------------------------------------- */

estr_t
str_nconvert (GIConv coder, const char *string, int size, GString * buffer)
{
    return _str_convert (coder, string, size, buffer);
}

/* --------------------------------------------------------------------------------------------- */

gchar *
str_conv_gerror_message (GError * mcerror, const char *def_msg)
{
    return used_class.conv_gerror_message (mcerror, def_msg);
}

/* --------------------------------------------------------------------------------------------- */

estr_t
str_vfs_convert_from (GIConv coder, const char *string, GString * buffer)
{
    estr_t result = ESTR_SUCCESS;

    if (coder == str_cnv_not_convert)
        g_string_append (buffer, string != NULL ? string : "");
    else
        result = _str_convert (coder, string, -1, buffer);

    return result;
}

/* --------------------------------------------------------------------------------------------- */

estr_t
str_vfs_convert_to (GIConv coder, const char *string, int size, GString * buffer)
{
    return used_class.vfs_convert_to (coder, string, size, buffer);
}

/* --------------------------------------------------------------------------------------------- */

void
str_printf (GString * buffer, const char *format, ...)
{
    va_list ap;
    va_start (ap, format);

    g_string_append_vprintf (buffer, format, ap);
    va_end (ap);
}

/* --------------------------------------------------------------------------------------------- */

void
str_insert_replace_char (GString * buffer)
{
    used_class.insert_replace_char (buffer);
}

/* --------------------------------------------------------------------------------------------- */

estr_t
str_translate_char (GIConv conv, const char *keys, size_t ch_size, char *output, size_t out_size)
{
    size_t left;
    size_t cnv;

    g_iconv (conv, NULL, NULL, NULL, NULL);

    left = (ch_size == (size_t) (-1)) ? strlen (keys) : ch_size;

    cnv = g_iconv (conv, (gchar **) & keys, &left, &output, &out_size);
    if (cnv == (size_t) (-1))
        return (errno == EINVAL) ? ESTR_PROBLEM : ESTR_FAILURE;

    output[0] = '\0';
    return ESTR_SUCCESS;
}

/* --------------------------------------------------------------------------------------------- */

const char *
str_detect_termencoding (void)
{
    if (term_encoding == NULL)
    {
        /* On Linux, nl_langinfo (CODESET) returns upper case UTF-8 whether the LANG is set
           to utf-8 or UTF-8.
           On Mac OS X, it returns the same case as the LANG input.
           So let tranform result of nl_langinfo (CODESET) to upper case  unconditionally. */
        term_encoding = g_ascii_strup (nl_langinfo (CODESET), -1);
    }

    return term_encoding;
}

/* --------------------------------------------------------------------------------------------- */

gboolean
str_isutf8 (const char *codeset_name)
{
    return (str_test_encoding_class (codeset_name, str_utf8_encodings) != 0);
}

/* --------------------------------------------------------------------------------------------- */

void
str_init_strings (const char *termenc)
{
    codeset = termenc != NULL ? g_ascii_strup (termenc, -1) : g_strdup (str_detect_termencoding ());

    str_cnv_not_convert = g_iconv_open (codeset, codeset);
    if (str_cnv_not_convert == INVALID_CONV)
    {
        if (termenc != NULL)
        {
            g_free (codeset);
            codeset = g_strdup (str_detect_termencoding ());
            str_cnv_not_convert = g_iconv_open (codeset, codeset);
        }

        if (str_cnv_not_convert == INVALID_CONV)
        {
            g_free (codeset);
            codeset = g_strdup (DEFAULT_CHARSET);
            str_cnv_not_convert = g_iconv_open (codeset, codeset);
        }
    }

    str_cnv_to_term = str_cnv_not_convert;
    str_cnv_from_term = str_cnv_not_convert;

    str_choose_str_functions ();
}

/* --------------------------------------------------------------------------------------------- */

void
str_uninit_strings (void)
{
    if (str_cnv_not_convert != INVALID_CONV)
        g_iconv_close (str_cnv_not_convert);
    /* NULL-ize pointers to avoid double free in unit tests */
    MC_PTR_FREE (term_encoding);
    MC_PTR_FREE (codeset);
}

/* --------------------------------------------------------------------------------------------- */

const char *
str_term_form (const char *text)
{
    return used_class.term_form (text);
}

/* --------------------------------------------------------------------------------------------- */

const char *
str_fit_to_term (const char *text, int width, align_crt_t just_mode)
{
    return used_class.fit_to_term (text, width, just_mode);
}

/* --------------------------------------------------------------------------------------------- */

const char *
str_term_trim (const char *text, int width)
{
    return used_class.term_trim (text, width);
}

/* --------------------------------------------------------------------------------------------- */

const char *
str_term_substring (const char *text, int start, int width)
{
    return used_class.term_substring (text, start, width);
}

/* --------------------------------------------------------------------------------------------- */

char *
str_get_next_char (char *text)
{

    used_class.cnext_char ((const char **) &text);
    return text;
}

/* --------------------------------------------------------------------------------------------- */

const char *
str_cget_next_char (const char *text)
{
    used_class.cnext_char (&text);
    return text;
}

/* --------------------------------------------------------------------------------------------- */

void
str_next_char (char **text)
{
    used_class.cnext_char ((const char **) text);
}

/* --------------------------------------------------------------------------------------------- */

void
str_cnext_char (const char **text)
{
    used_class.cnext_char (text);
}

/* --------------------------------------------------------------------------------------------- */

char *
str_get_prev_char (char *text)
{
    used_class.cprev_char ((const char **) &text);
    return text;
}

/* --------------------------------------------------------------------------------------------- */

const char *
str_cget_prev_char (const char *text)
{
    used_class.cprev_char (&text);
    return text;
}

/* --------------------------------------------------------------------------------------------- */

void
str_prev_char (char **text)
{
    used_class.cprev_char ((const char **) text);
}

/* --------------------------------------------------------------------------------------------- */

void
str_cprev_char (const char **text)
{
    used_class.cprev_char (text);
}

/* --------------------------------------------------------------------------------------------- */

char *
str_get_next_char_safe (char *text)
{
    used_class.cnext_char_safe ((const char **) &text);
    return text;
}

/* --------------------------------------------------------------------------------------------- */

const char *
str_cget_next_char_safe (const char *text)
{
    used_class.cnext_char_safe (&text);
    return text;
}

/* --------------------------------------------------------------------------------------------- */

void
str_next_char_safe (char **text)
{
    used_class.cnext_char_safe ((const char **) text);
}

/* --------------------------------------------------------------------------------------------- */

void
str_cnext_char_safe (const char **text)
{
    used_class.cnext_char_safe (text);
}

/* --------------------------------------------------------------------------------------------- */

char *
str_get_prev_char_safe (char *text)
{
    used_class.cprev_char_safe ((const char **) &text);
    return text;
}

/* --------------------------------------------------------------------------------------------- */

const char *
str_cget_prev_char_safe (const char *text)
{
    used_class.cprev_char_safe (&text);
    return text;
}

/* --------------------------------------------------------------------------------------------- */

void
str_prev_char_safe (char **text)
{
    used_class.cprev_char_safe ((const char **) text);
}

/* --------------------------------------------------------------------------------------------- */

void
str_cprev_char_safe (const char **text)
{
    used_class.cprev_char_safe (text);
}

/* --------------------------------------------------------------------------------------------- */

int
str_next_noncomb_char (char **text)
{
    return used_class.cnext_noncomb_char ((const char **) text);
}

/* --------------------------------------------------------------------------------------------- */

int
str_cnext_noncomb_char (const char **text)
{
    return used_class.cnext_noncomb_char (text);
}

/* --------------------------------------------------------------------------------------------- */

int
str_prev_noncomb_char (char **text, const char *begin)
{
    return used_class.cprev_noncomb_char ((const char **) text, begin);
}

/* --------------------------------------------------------------------------------------------- */

int
str_cprev_noncomb_char (const char **text, const char *begin)
{
    return used_class.cprev_noncomb_char (text, begin);
}

/* --------------------------------------------------------------------------------------------- */

int
str_is_valid_char (const char *ch, size_t size)
{
    return used_class.is_valid_char (ch, size);
}

/* --------------------------------------------------------------------------------------------- */

int
str_term_width1 (const char *text)
{
    return used_class.term_width1 (text);
}

/* --------------------------------------------------------------------------------------------- */

int
str_term_width2 (const char *text, size_t length)
{
    return used_class.term_width2 (text, length);
}

/* --------------------------------------------------------------------------------------------- */

int
str_term_char_width (const char *text)
{
    return used_class.term_char_width (text);
}

/* --------------------------------------------------------------------------------------------- */

int
str_offset_to_pos (const char *text, size_t length)
{
    return used_class.offset_to_pos (text, length);
}

/* --------------------------------------------------------------------------------------------- */

int
str_length (const char *text)
{
    return used_class.length (text);
}

/* --------------------------------------------------------------------------------------------- */

int
str_length_char (const char *text)
{
    return str_cget_next_char_safe (text) - text;
}

/* --------------------------------------------------------------------------------------------- */

int
str_length2 (const char *text, int size)
{
    return used_class.length2 (text, size);
}

/* --------------------------------------------------------------------------------------------- */

int
str_length_noncomb (const char *text)
{
    return used_class.length_noncomb (text);
}

/* --------------------------------------------------------------------------------------------- */

int
str_column_to_pos (const char *text, size_t pos)
{
    return used_class.column_to_pos (text, pos);
}

/* --------------------------------------------------------------------------------------------- */

gboolean
str_isspace (const char *ch)
{
    return used_class.char_isspace (ch);
}

/* --------------------------------------------------------------------------------------------- */

gboolean
str_ispunct (const char *ch)
{
    return used_class.char_ispunct (ch);
}

/* --------------------------------------------------------------------------------------------- */

gboolean
str_isalnum (const char *ch)
{
    return used_class.char_isalnum (ch);
}

/* --------------------------------------------------------------------------------------------- */

gboolean
str_isdigit (const char *ch)
{
    return used_class.char_isdigit (ch);
}

/* --------------------------------------------------------------------------------------------- */

gboolean
str_toupper (const char *ch, char **out, size_t * remain)
{
    return used_class.char_toupper (ch, out, remain);
}

/* --------------------------------------------------------------------------------------------- */

gboolean
str_tolower (const char *ch, char **out, size_t * remain)
{
    return used_class.char_tolower (ch, out, remain);
}

/* --------------------------------------------------------------------------------------------- */

gboolean
str_isprint (const char *ch)
{
    return used_class.char_isprint (ch);
}

/* --------------------------------------------------------------------------------------------- */

gboolean
str_iscombiningmark (const char *ch)
{
    return used_class.char_iscombiningmark (ch);
}

/* --------------------------------------------------------------------------------------------- */

const char *
str_trunc (const char *text, int width)
{
    return used_class.trunc (text, width);
}

/* --------------------------------------------------------------------------------------------- */

char *
str_create_search_needle (const char *needle, gboolean case_sen)
{
    return used_class.create_search_needle (needle, case_sen);
}

/* --------------------------------------------------------------------------------------------- */

void
str_release_search_needle (char *needle, gboolean case_sen)
{
    used_class.release_search_needle (needle, case_sen);
}

/* --------------------------------------------------------------------------------------------- */

const char *
str_search_first (const char *text, const char *search, gboolean case_sen)
{
    return used_class.search_first (text, search, case_sen);
}

/* --------------------------------------------------------------------------------------------- */

const char *
str_search_last (const char *text, const char *search, gboolean case_sen)
{
    return used_class.search_last (text, search, case_sen);
}

/* --------------------------------------------------------------------------------------------- */

gboolean
str_is_valid_string (const char *text)
{
    return used_class.is_valid_string (text);
}

/* --------------------------------------------------------------------------------------------- */

int
str_compare (const char *t1, const char *t2)
{
    return used_class.compare (t1, t2);
}

/* --------------------------------------------------------------------------------------------- */

int
str_ncompare (const char *t1, const char *t2)
{
    return used_class.ncompare (t1, t2);
}

/* --------------------------------------------------------------------------------------------- */

int
str_casecmp (const char *t1, const char *t2)
{
    return used_class.casecmp (t1, t2);
}

/* --------------------------------------------------------------------------------------------- */

int
str_ncasecmp (const char *t1, const char *t2)
{
    return used_class.ncasecmp (t1, t2);
}

/* --------------------------------------------------------------------------------------------- */

int
str_prefix (const char *text, const char *prefix)
{
    return used_class.prefix (text, prefix);
}

/* --------------------------------------------------------------------------------------------- */

int
str_caseprefix (const char *text, const char *prefix)
{
    return used_class.caseprefix (text, prefix);
}

/* --------------------------------------------------------------------------------------------- */

void
str_fix_string (char *text)
{
    used_class.fix_string (text);
}

/* --------------------------------------------------------------------------------------------- */

char *
str_create_key (const char *text, gboolean case_sen)
{
    return used_class.create_key (text, case_sen);
}

/* --------------------------------------------------------------------------------------------- */

char *
str_create_key_for_filename (const char *text, gboolean case_sen)
{
    return used_class.create_key_for_filename (text, case_sen);
}

/* --------------------------------------------------------------------------------------------- */

int
str_key_collate (const char *t1, const char *t2, gboolean case_sen)
{
    return used_class.key_collate (t1, t2, case_sen);
}

/* --------------------------------------------------------------------------------------------- */

void
str_release_key (char *key, gboolean case_sen)
{
    used_class.release_key (key, case_sen);
}

/* --------------------------------------------------------------------------------------------- */

void
str_msg_term_size (const char *text, int *lines, int *columns)
{
    char *p, *tmp;
    char *q;
    char c = '\0';

    *lines = 1;
    *columns = 0;

    tmp = g_strdup (text);
    p = tmp;

    while (TRUE)
    {
        int width;

        q = strchr (p, '\n');
        if (q != NULL)
        {
            c = q[0];
            q[0] = '\0';
        }

        width = str_term_width1 (p);
        if (width > *columns)
            *columns = width;

        if (q == NULL)
            break;

        q[0] = c;
        p = q + 1;
        (*lines)++;
    }

    g_free (tmp);
}

/* --------------------------------------------------------------------------------------------- */

char *
strrstr_skip_count (const char *haystack, const char *needle, size_t skip_count)
{
    char *semi;
    ssize_t len;

    len = strlen (haystack);

    do
    {
        semi = g_strrstr_len (haystack, len, needle);
        if (semi == NULL)
            return NULL;
        len = semi - haystack - 1;
    }
    while (skip_count-- != 0);

    return semi;
}

/* --------------------------------------------------------------------------------------------- */
/* Interprete string as a non-negative decimal integer, optionally multiplied by various values.
 *
 * @param str input value
 * @param invalid set to TRUE if "str" does not represent a number in this format
 *
 * @return non-integer representation of "str", 0 in case of error.
 */

uintmax_t
parse_integer (const char *str, gboolean * invalid)
{
    uintmax_t n;
    char *suffix;
    strtol_error_t e;

    e = xstrtoumax (str, &suffix, 10, &n, "bcEGkKMPTwYZ0");
    if (e == LONGINT_INVALID_SUFFIX_CHAR && *suffix == 'x')
    {
        uintmax_t multiplier;

        multiplier = parse_integer (suffix + 1, invalid);
        if (multiplier != 0 && n * multiplier / multiplier != n)
        {
            *invalid = TRUE;
            return 0;
        }

        n *= multiplier;
    }
    else if (e != LONGINT_OK)
    {
        *invalid = TRUE;
        n = 0;
    }

    return n;
}

/* --------------------------------------------------------------------------------------------- */