/*
 * Copyright (c) 2003-2009 by FlashCode <flashcode@flashtux.org>
 * See README for License detail, AUTHORS for developers list.
 *
 * This program 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.
 *
 * This program 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/>.
 */

/* wee-util.c: some useful functions for WeeChat */


#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>
#include <signal.h>
#include <ctype.h>
#include <time.h>

#include "weechat.h"
#include "wee-util.h"
#include "wee-config.h"
#include "wee-string.h"


/*
 * util_timeval_cmp: compare two timeval structures
 *                   return: -1 if tv1 < tv2
 *                            0 if tv1 == tv2
 *                            1 if tv1 > tv2
 */

int
util_timeval_cmp (struct timeval *tv1, struct timeval *tv2)
{
    if (tv1->tv_sec < tv2->tv_sec)
        return -1;
    if (tv1->tv_sec > tv2->tv_sec)
        return 1;
    if (tv1->tv_usec < tv2->tv_usec)
        return -1;
    if (tv1->tv_usec > tv2->tv_usec)
        return 1;
    return 0;
}

/*
 * util_timeval_diff: calculates difference between two times (return in
 *                    milliseconds)
 */

long
util_timeval_diff (struct timeval *tv1, struct timeval *tv2)
{
    long diff_sec, diff_usec;
    
    diff_sec = tv2->tv_sec - tv1->tv_sec;
    diff_usec = tv2->tv_usec - tv1->tv_usec;
    
    if (diff_usec < 0)
    {
        diff_usec += 1000000;
        diff_sec--;
    }
    return ((diff_usec / 1000) + (diff_sec * 1000));
}

/*
 * util_timeval_add: add interval (in milliseconds) to a timeval struct 
 */

void
util_timeval_add (struct timeval *tv, long interval)
{
    long usec;
    
    tv->tv_sec += (interval / 1000);
    usec = tv->tv_usec + ((interval % 1000) * 1000);
    if (usec > 1000000)
    {
        tv->tv_usec = usec % 1000000;
        tv->tv_sec++;
    }
    else
        tv->tv_usec = usec;
}

/*
 * util_get_time_length: calculates time length with a time format
 */

int
util_get_time_length (const char *time_format)
{
    time_t date;
    struct tm *local_time;
    char text_time[1024];
    
    if (!time_format || !time_format[0])
        return 0;
    
    date = time (NULL);
    local_time = localtime (&date);
    strftime (text_time, sizeof (text_time),
              time_format, local_time);
    return strlen (text_time);
}

/*
 * util_catch_signal: catch a signal
 */

void
util_catch_signal (int signum, void (*handler)(int))
{
    struct sigaction act;
    
    sigemptyset (&act.sa_mask);
    act.sa_flags = 0;
    act.sa_handler = handler;
    sigaction(signum, &act, NULL);
}

/*
 * util_mkdir_home: create a directory in WeeChat home
 *                  return 1 if ok, 0 if error
 */

int
util_mkdir_home (const char *directory, int mode)
{
    char *dir_name;
    int dir_length;
    
    if (!directory)
        return 0;
    
    /* build directory, adding WeeChat home */
    dir_length = strlen (weechat_home) + strlen (directory) + 2;
    dir_name = malloc (dir_length);
    if (!dir_name)
        return 0;
    
    snprintf (dir_name, dir_length, "%s/%s", weechat_home, directory);
    
    if (mkdir (dir_name, mode) < 0)
    {
        if (errno != EEXIST)
        {
            free (dir_name);
            return 0;
        }
    }
    
    free (dir_name);
    return 1;
}

/*
 * util_mkdir: create a directory
 *             return 1 if ok, 0 if error
 */

int
util_mkdir (const char *directory, int mode)
{
    if (!directory)
        return 0;
    
    if (mkdir (directory, mode) < 0)
    {
        if (errno != EEXIST)
            return 0;
    }
    
    return 1;
}

/*
 * util_mkdir_parents: create a directory and make parent directories as needed
 *                     return 1 if ok, 0 if error
 */

int
util_mkdir_parents (const char *directory, int mode)
{
    char *string, *ptr_string, *pos_sep;
    struct stat buf;
    int rc;
    
    if (!directory)
        return 0;
    
    string = strdup (directory);
    if (!string)
        return 0;
    
    ptr_string = string;
    while (ptr_string[0] == DIR_SEPARATOR_CHAR)
    {
        ptr_string++;
    }
    
    while (ptr_string && ptr_string[0])
    {
        pos_sep = strchr (ptr_string, DIR_SEPARATOR_CHAR);
        if (pos_sep)
            pos_sep[0] = '\0';
        
        rc = stat (string, &buf);
        if ((rc < 0) || !S_ISDIR(buf.st_mode))
        {
            /* try to create directory */
            if (!util_mkdir (string, mode))
            {
                free (string);
                return 0;
            }
        }
        
        if (pos_sep)
        {
            pos_sep[0] = DIR_SEPARATOR_CHAR;
            ptr_string = pos_sep + 1;
        }
        else
            ptr_string = NULL;
    }
    
    free (string);
    
    return 1;
}

/*
 * util_exec_on_files: find files in a directory and execute a
 *                     function on each file
 */

void
util_exec_on_files (const char *directory, void *data,
                    void (*callback)(void *data, const char *filename))
{
    char complete_filename[1024];
    DIR *dir;
    struct dirent *entry;
    struct stat statbuf;
    
    if (!directory || !callback)
        return;
    
    dir = opendir (directory);
    if (dir)
    {
        while ((entry = readdir (dir)))
        {
            snprintf (complete_filename, sizeof (complete_filename) - 1,
                      "%s/%s", directory, entry->d_name);
            lstat (complete_filename, &statbuf);
            if (!S_ISDIR(statbuf.st_mode))
            {
                (*callback) (data, complete_filename);
            }
        }
        closedir (dir);
    }
}

/*
 * util_search_full_lib_name: search the full name of a WeeChat library
 *                            file with a part of name
 *                            - look in WeeChat user's dir, then WeeChat
 *                              global lib dir
 *                            - sys_directory is the system directory under
 *                              WeeChat lib prefix, for example "plugins"
 *                            - result has to be free() after use
 */

char *
util_search_full_lib_name (const char *filename, const char *sys_directory)
{
    char *name_with_ext, *final_name;
    int length;
    struct stat st;
    
    /* filename is already a full path */
    if (strchr (filename, '/') || strchr (filename, '\\'))
        return strdup (filename);
    
    length = strlen (filename) + 16;
    if (CONFIG_STRING(config_plugin_extension)
        && CONFIG_STRING(config_plugin_extension)[0])
        length += strlen (CONFIG_STRING(config_plugin_extension));
    name_with_ext = malloc (length);
    if (!name_with_ext)
        return strdup (filename);
    strcpy (name_with_ext, filename);
    if (!strchr (filename, '.')
        && CONFIG_STRING(config_plugin_extension)
        && CONFIG_STRING(config_plugin_extension)[0])
        strcat (name_with_ext, CONFIG_STRING(config_plugin_extension));
    
    /* try WeeChat user's dir */
    length = strlen (weechat_home) + strlen (name_with_ext) +
        strlen (sys_directory) + 16;
    final_name = malloc (length);
    if (!final_name)
    {
        free (name_with_ext);
        return strdup (filename);
    }
    snprintf (final_name, length,
              "%s/%s/%s", weechat_home, sys_directory, name_with_ext);
    if ((stat (final_name, &st) == 0) && (st.st_size > 0))
    {
        free (name_with_ext);
        return final_name;
    }
    free (final_name);
    
    /* try WeeChat global lib dir */
    length = strlen (WEECHAT_LIBDIR) + strlen (name_with_ext) +
        strlen (sys_directory) + 16;
    final_name = malloc (length);
    if (!final_name)
    {
        free (name_with_ext);
        return strdup (filename);
    }
    snprintf (final_name, length,
              "%s/%s/%s", WEECHAT_LIBDIR, sys_directory, name_with_ext);
    if ((stat (final_name, &st) == 0) && (st.st_size > 0))
    {
        free (name_with_ext);
        return final_name;
    }
    free (final_name);

    return name_with_ext;
}

/*
 * util_weechat_version_cmp: compare 2 weechat versions
 *                           return -1 if version1 < version2
 *                                  +1 if version1 > version2
 *                                   0 if version1 = version2
 */

int
util_weechat_version_cmp (const char *version1, const char *version2)
{
    char *v1, *v2, *ptr_v1, *ptr_v2, *pos1, *pos2, *next1, *next2;
    char *error1, *error2;
    int rc;
    long number1, number2;
    
    if (!version1 && !version2)
        return 0;
    if (!version1 && version2)
        return -1;
    if (version1 && !version2)
        return 1;
    
    v1 = strdup (version1);
    v2 = strdup (version2);
    
    rc = 0;
    
    if (v1 && v2)
    {
        ptr_v1 = v1;
        ptr_v2 = v2;
        while (ptr_v1 && ptr_v1[0] && ptr_v2 && ptr_v2[0])
        {
            pos1 = ptr_v1;
            while (pos1[0] && isdigit (pos1[0]))
            {
                pos1++;
            }
            pos2 = ptr_v2;
            while (pos2[0] && isdigit (pos2[0]))
            {
                pos2++;
            }
            next1 = (pos1[0] == '\0') ? NULL : pos1 + 1;
            next2 = (pos2[0] == '\0') ? NULL : pos2 + 1;
            pos1[0] = '\0';
            pos2[0] = '\0';
            
            error1 = NULL;
            number1 = strtol (ptr_v1, &error1, 10);
            error2 = NULL;
            number2 = strtol (ptr_v2, &error2, 10);
            if (error1 && !error1[0] && (!error2 || error2[0]))
            {
                rc = 1;
                break;
            }
            if (error2 && !error2[0] && (!error1 || error1[0]))
            {
                rc = 1;
                break;
            }
            if (error1 && !error1[0] && error2 && !error2[0])
            {
                if (number1 > number2)
                {
                    rc = 1;
                    break;
                }
                if (number1 < number2)
                {
                    rc = -1;
                    break;
                }
            }
            ptr_v1 = next1;
            while (ptr_v1 && ptr_v1[0] && !isdigit (ptr_v1[0]))
            {
                ptr_v1++;
            }
            ptr_v2 = next2;
            while (ptr_v2 && ptr_v2[0] && !isdigit (ptr_v2[0]))
            {
                ptr_v2++;
            }
        }
    }
    
    if (v1)
        free (v1);
    if (v2)
        free (v2);
    
    return rc;
}