/* -*- mode: c; indent-tabs-mode: nil; -*-
 * $Id: config.c,v 1.3 2003/12/28 20:59:21 chrish Exp $
 *
 * config -- read and parse the Plucker config files
 * Copyright (c) 2002, Bill Janssen
 * 
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 */

#if !defined(WIN32)
#include <unistd.h>             /* for lseek, etc. */
#else
#include <io.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>

#include <sys/types.h>
#include <sys/stat.h>           /* for fstat() */
#include <string.h>             /* for strndup() */
#include <errno.h>              /* for errno */
#include <fcntl.h>              /* for O_RDONLY */
#include <assert.h>             /* for assert() */

#include "unpluck.h"
#include "unpluckint.h"

#define STRINGIFY(s)            STRINGIFY2 (s)
#define	STRINGIFY2(s)   	#s

#define MAX_LINE_SIZE           1023

#define COMMENT_CHARS           "#;"
#define SEGMENT_LEAD_CHAR       '['
#define SEGMENT_END_CHAR        ']'
#define OPTION_SEPARATOR_CHARS  "=:"

HashTable *SectionsTable = NULL;

static HashTable* GetOrCreateSegment
    (
    char* name
    )
{
    HashTable* target;

    if (SectionsTable == NULL)
        SectionsTable = _plkr_NewHashTable (23);

    if ((target = (HashTable*)_plkr_FindInTable (SectionsTable, name)) == NULL) {
        target = _plkr_NewHashTable (53);
        _plkr_AddToTable (SectionsTable, name, target);
    }

    return target;
}

static int ReadConfigFile
    (
    char* filename
    )
{
    HashTable*  current_segment = NULL;
    FILE*       fp = fopen (filename, "r");
    char*       ptr;
    char*       str_end;
    char*       str_begin;
    char*       charptr;
    char*       current_option;
    char*       option_value;
    char        linebuf[MAX_LINE_SIZE + 1];
    int         linelen;
    int         len2;
    int         buf_index;
    int         status;
    int         line_number;

    if (fp == NULL) {
        _plkr_message ("Can't open config file %s", filename);
        return 0;
    }

    current_segment = GetOrCreateSegment ("default");
    current_option = NULL;

    status = 1;                 /* optimistic */
    line_number = 0;

    while (1) {

        ptr = fgets (linebuf, sizeof (linebuf) - 1, fp);
        if (ptr == NULL)
            break;

        line_number += 1;
        linebuf[strlen (linebuf) - 1] = 0;      /* strip newline */
        if (linebuf[strlen (linebuf) - 1] == '\r')
            linebuf[strlen (linebuf) - 1] = 0;  /* strip carriage return */

        /* fprintf (stderr, "%s:%d:  line is '%s'\n", filename, line_number, linebuf); */

        linelen = strlen (linebuf);
        for (buf_index = 0; linebuf[buf_index] != 0; buf_index++)
            if (!isspace (linebuf[buf_index]))
                break;

        if (linebuf[buf_index] == 0)
            /* blank line */
            continue;

        if ((strchr (COMMENT_CHARS, linebuf[0]) != NULL) ||
            (strncmp (linebuf, "rem", 3) == 0) ||
            (strncmp (linebuf, "REM", 3) == 0))
            /* comment */
            continue;

        /* At this point we have a valid thing */

        if (linebuf[buf_index] == SEGMENT_LEAD_CHAR) {
            if ((str_end =
                 strchr (linebuf + buf_index + 1,
                         SEGMENT_END_CHAR)) == NULL) {
                /* invalid segment line */
                _plkr_message ("%s:%d:  Invalid segment line '%s'",
                               filename, line_number, linebuf);
                goto error_exit;
            }
            str_begin = linebuf + buf_index + 1;
            for (charptr = str_begin; charptr < str_end; charptr++)
                *charptr = tolower (*charptr);
            *str_end = 0;
            current_segment = GetOrCreateSegment (str_begin);
            /* fprintf (stderr, "Current segment is now %p (%s)\n", current_segment, str_begin); */
            if (current_option)
                free (current_option);
            current_option = NULL;

        }
        else if ((linebuf[0] == ' ' || linebuf[0] == '\t')
                 && current_option != NULL) {
            /* continuation line */
            str_begin =
                (char *) _plkr_RemoveFromTable (current_segment,
                                                current_option);
            for (str_end = linebuf + strlen (linebuf) - 1;
                 str_end > linebuf && isspace (*str_end); str_end--);
            charptr =
                (char *) malloc (strlen (str_begin) +
                                 (str_end - (linebuf + buf_index)) + 2);
            strcpy (charptr, str_begin);
            len2 = strlen (charptr);
            charptr[len2] = '\n';
            strncpy (charptr + len2 + 1, linebuf + buf_index,
                     str_end - (linebuf + buf_index));
            charptr[len2 + (str_end - (linebuf + buf_index)) + 1] = '\0';
            _plkr_AddToTable (current_segment, current_option, charptr);
            free (str_begin);

        }
        else if ((int)strcspn (linebuf, OPTION_SEPARATOR_CHARS) < linelen) {
            /* possible option line */

            for (str_begin = linebuf + buf_index, ptr = str_begin;
                 isalnum (*ptr) || (*ptr == '.') || (*ptr == '_')
                 || (*ptr == '-'); ptr++);
            if (ptr == str_begin) {
                _plkr_message ("%s:%d:  Invalid option line '%s'",
                               filename, line_number, linebuf);
                goto error_exit;
            }

            for (charptr = str_begin; charptr < ptr; charptr++)
                *charptr = tolower (*charptr);
            str_end = ptr;

            while (isspace (*ptr) && (*ptr != '\0'))
                ptr++;

            if (strchr (OPTION_SEPARATOR_CHARS, *ptr) != NULL)
                ptr++;
            else {
                _plkr_message ("%s:%d:  Invalid option line '%s'",
                               filename, line_number, linebuf);
                goto error_exit;
            }

            while (isspace (*ptr) && (*ptr != '\0'))
                ptr++;

            if (*ptr == 0) {
                _plkr_message ("%s:%d:  Invalid option line '%s'",
                               filename, line_number, linebuf);
                goto error_exit;
            }

            if (current_option)
                free (current_option);
            current_option =
                _plkr_strndup (str_begin, str_end - str_begin);

            option_value = _plkr_strndup (ptr, strlen (ptr));

            ptr =
                (char *) _plkr_RemoveFromTable (current_segment,
                                                current_option);
            if (ptr)
                free (ptr);
            _plkr_AddToTable (current_segment, current_option,
                              option_value);
            /* fprintf (stderr, "Added value '%s' for option '%p:%s'\n", option_value, current_segment, current_option); */

        }
        else {
            _plkr_message ("%s:%d:  Bad line '%s'", filename, line_number,
                           linebuf);
            goto error_exit;
        }
    }

  good_exit:

    if (current_option)
        free (current_option);
    fclose (fp);
    return status;

  error_exit:
    status = 0;
    goto good_exit;
}

static void TryReadConfigFile
    (
    char*  dir,
    char*  name
    )
{
    char*  filename;

    if (dir == NULL || name == NULL)
        return;

    filename = (char *) malloc (strlen (dir) + strlen (name) + 2);
    strcpy (filename, dir);
    strcpy (filename + strlen (filename),
            STRINGIFY (FILE_SEPARATOR_CHAR_S));
    strcpy (filename + strlen (filename), name);
    if (!ReadConfigFile (filename))
        _plkr_message ("Error reading config file %s", filename);
    free (filename);
}

static void InitializeConfigInfo ()
{
    char *config_dir = STRINGIFY (PLUCKER_CONFIG_DIR);
    char *system_config_file_name = STRINGIFY (SYS_CONFIG_FILE_NAME);
    char *user_config_filename = STRINGIFY (USER_CONFIG_FILE_NAME);
    char *home = getenv ("HOME");

    TryReadConfigFile (config_dir, system_config_file_name);
    if (home != NULL)
        TryReadConfigFile (home, user_config_filename);
}

char* plkr_GetConfigString
    (
    char*  section_name,
    char*  option_name,
    char*  default_value
    )
{
    char*       value = NULL;
    HashTable*  section;

    if (SectionsTable == NULL)
        InitializeConfigInfo ();

    if (SectionsTable == NULL)
        return default_value;

    if (section_name != NULL) {
        if ((section =
             (HashTable *) _plkr_FindInTable (SectionsTable,
                                              section_name)) != NULL)
            value = (char *) _plkr_FindInTable (section, option_name);
    }
    if (value == NULL && ((section_name == NULL)
                          || (strcmp (section_name, "default") != 0))) {
        if ((section =
             (HashTable *) _plkr_FindInTable (SectionsTable,
                                              STRINGIFY (OS_SECTION_NAME)))
            != NULL)
            value = (char *) _plkr_FindInTable (section, option_name);
    }
    if (value == NULL && ((section_name == NULL)
                          || (strcmp (section_name, "default") != 0))) {
        if ((section =
             (HashTable *) _plkr_FindInTable (SectionsTable,
                                              "default")) != NULL)
            value = (char *) _plkr_FindInTable (section, option_name);
    }

    return ((value == NULL) ? default_value : value);
}

long int plkr_GetConfigInt
    (
    char*     section_name,
    char*     option_name,
    long int  default_value
    )
{
    char*     svalue = plkr_GetConfigString (section_name, option_name, NULL);
    char*     endptr;
    long int  value;

    if (svalue == NULL)
        return default_value;

    value = strtol (svalue, &endptr, 0);
    if (*endptr != 0) {
        _plkr_message ("Bad int value string '%s' for option %s:%s",
                       svalue, (section_name ? section_name : "default"),
                       option_name);
        return default_value;
    }
    else {
        return value;
    }
}

double plkr_GetConfigFloat
    (
    char*   section_name,
    char*   option_name,
    double  default_value
    )
{
    char*   svalue = plkr_GetConfigString (section_name, option_name, NULL);
    char*   endptr;
    double  value;

    if (svalue == NULL)
        return default_value;

    value = strtod (svalue, &endptr);
    if (*endptr != 0) {
        _plkr_message ("Bad float value string '%s' for option %s:%s",
                       svalue, (section_name ? section_name : "default"),
                       option_name);
        return default_value;
    }
    else {
        return value;
    }
}

int plkr_GetConfigBoolean
    (
    char*  section_name,
    char*  option_name,
    int    default_value
    )
{
    char*  svalue = plkr_GetConfigString (section_name, option_name, NULL);

    if (svalue == NULL)
        return default_value;

    if ((strcmp (svalue, "1") == 0) ||
        (strcmp (svalue, "true") == 0) || (strcmp (svalue, "TRUE") == 0) ||
        (strcmp (svalue, "on") == 0) || (strcmp (svalue, "ON") == 0) ||
        (strcmp (svalue, "t") == 0) || (strcmp (svalue, "T") == 0)
        || (strcmp (svalue, "True") == 0))
        return 1;

    else if ((strcmp (svalue, "0") == 0) || (strcmp (svalue, "false") == 0)
             || (strcmp (svalue, "FALSE") == 0)
             || (strcmp (svalue, "off") == 0)
             || (strcmp (svalue, "OFF") == 0)
             || (strcmp (svalue, "F") == 0)
             || (strcmp (svalue, "F") == 0)
             || (strcmp (svalue, "False") == 0))
        return 0;

    else {
        _plkr_message ("Bad boolean value string '%s' for option %s:%s",
                       svalue, (section_name ? section_name : "default"),
                       option_name);
        return default_value;
    }
}