/*! \file config.c
 *  \brief Configuration manager code.
 *
 *  Please keep in mind that config file has to be well-formed in order to function properly.
 *
 *  Lines starting with '[' contain section name. No additional whitespace
 *  between braces and name is allowed.
 *
 *  Section CANNOT be declared multiple times.
 *
 *  Lines starting with '#' are ignored.
 * 
 *  All other lines have to look like this one:
 * 
 *    key=value
 * 
 *  All whitespace at beginning, end or around '=' char will belong to key or value.
 *  If multiple '=' are present, the first one is used to split line into key and value.
 *
 *  Keys CANNOT be repeated in the same section.
 *
 *  Rewriting config file removes all comments from it.
 *
 *  If config file is not following this guides, it may be handled incorrectly.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>

/*! \brief One config option in list of options. */
struct ConfigOption {
	char* name; /*!< Name of the config entry. */
	char* value; /*!< Value of the config entry. */
	char* section; /*!< Section of the config entry (including braces). */
	struct ConfigOption *next; /*!< Pointer to next option in list, or NULL if there is no more. */
};

struct ConfigOption *config; /*!< Pointer to first config entry in list. */

/*! \brief Adds new config entry. */
void AppendToConfig(char* section, char* name, char* value) {
	struct ConfigOption *new = malloc(sizeof(struct ConfigOption));
	new->next = NULL;
	new->section = malloc(sizeof(char)*255);
	new->name = malloc(sizeof(char)*255);
	new->value = malloc(sizeof(char)*255);
	strcpy(new->section, section);
	strcpy(new->name, name);
	strcpy(new->value, value);
	if (config==NULL) config = new;
	struct ConfigOption *old = config;
	while (old->next != NULL) {
		if (!strcmp(old->section, section)) break;
		old=old->next;
	}
	if (old->next) {
		new->next = old->next;
		old->next = new;
	} else {
		old->next = new;
	}
}

void InitConfig() {
	FILE *file = fopen("SuperDerpy.ini","r+");
	if (! file) { return; }
	char string[255];
	char section[255] = "[SuperDerpy]";
	struct ConfigOption *old = NULL;
	while ( fgets (string , 255 , file) != NULL ) {
		if ((string[0]=='#') || (string[0]=='\n')) { continue; }
		if (string[strlen(string)-1]=='\n') string[strlen(string)-1]='\0';
		if (string[0]=='[') { strcpy(section, string); continue; }
		bool before=true;
		struct ConfigOption *new = malloc(sizeof(struct ConfigOption));
		if (old==NULL) {
			config = new;
			old = new;
		} else { old->next = new; old = new; }
		new->section = malloc(sizeof(char)*255);
		strcpy(new->section, section);
		new->name = malloc(sizeof(char)*255);
		new->name[0] = '\0';
		new->value = malloc(sizeof(char)*255);
		new->value[0] = '\0';
		new->next = NULL;
		for (int i=0; i<strlen(string); i++) {
			if (string[i]=='=') { before=false; continue; }
			char temp[2];
			temp[0]=string[i];
			temp[1]='\0';
			if (before) strcat(new->name, temp);
			else strcat(new->value, temp);
			//printf("%s", temp);
		}
	}
	fclose(file);
}

void SetConfigOption(char* section, char* name, char* value) {
	struct ConfigOption *old = config;
	while (old!=NULL) {
		if (!strcmp(section, old->section) && !strcmp(name, old->name)) {
			strcpy(old->value, value);
			return;
		}
		old=old->next;
	}
	AppendToConfig(section, name, value);
}

char* GetConfigOption(char* section, char* name) {
	struct ConfigOption *old = config;
	char *ret = malloc(sizeof(char)*255);
	while (old!=NULL) {
		if (!strcmp(section, old->section) && !strcmp(name, old->name)) {
			strcpy(ret, old->value);
			return ret;
		}
		old=old->next;
	}
	free(ret);
	return NULL;
}

char* GetConfigOptionDefault(char* section, char* name, char* def) {
	char* ret = GetConfigOption(section, name);
	if (!ret) return def; else return ret;
}

void DeinitConfig() {
	FILE *file = fopen("SuperDerpy.ini","w");
	char section[255] = {};
	struct ConfigOption *old = config;
	while (old!=NULL) {
		if (strcmp(section, old->section)) {
			strcpy(section, old->section);
			fprintf(file, "%s\n", section);
		}
		fprintf(file, "%s=%s\n", old->name, old->value);
		struct ConfigOption *prev = old;
		old=old->next;
		free(prev->name);
		free(prev->value);
		free(prev->section);
		free(prev);
	}
	fclose(file);
}