#include <sys/types.h>
#include <stdio.h>
#include <unistd.h>
#include <limits.h>
#include <pwd.h>
#include <stdlib.h>

#include "config.h"

void fix_config_file_owner(const char *config_path) {
    char *sudo_uid_str = getenv("SUDO_UID");
    char *sudo_gid_str = getenv("SUDO_GID");

    if (sudo_uid_str && sudo_gid_str) {
        uid_t original_uid = atoi(sudo_uid_str);
        gid_t original_gid = atoi(sudo_gid_str);
        
        chown(config_path, original_uid, original_gid);
    }
}

struct config* prepare_config_file() {
    struct config* cfg = malloc(sizeof(struct config));
    if (!cfg) {
	return NULL;
    }

    char* sudo_user = getenv("SUDO_USER");
    cfg->home = malloc(PATH_MAX);
    if (!cfg->home) {
	return NULL;
    }

    snprintf(cfg->home, PATH_MAX, "/home/%s", sudo_user);

    cfg->config_file_path = malloc(strlen(cfg->home) + strlen("/.klrc"));

    snprintf(cfg->config_file_path, PATH_MAX, "%s/.klrc", cfg->home);

    if (access(cfg->config_file_path, F_OK) == -1) {
	FILE* fp = fopen(cfg->config_file_path, "a");
	if (!fp) {
	    return NULL;
	}
	fputs(CONFIG_FILE_COMMENT, fp);
	fix_config_file_owner(cfg->config_file_path);
	printf("%s\n", cfg->config_file_path);
	fclose(fp);
    }
    return cfg;
}

struct config* parese_config(struct config* cfg) {
    if (!cfg) {
	return NULL;
    }

    FILE* fp = fopen(cfg->config_file_path, "r");
    if (!fp) {
	return NULL;
    }


    int line_count = 0;
    char line[128];
    char key[64] = {0};
    char val[64] = {0};

    while (fgets(line, sizeof(line), fp)) {
	line_count++;
	/* Skip comment and blank lines */
	if (line[0] == '#' || line[0] == '\n' || line[0] == '\r') {
	    continue;
	}

	int count = sscanf(line, "%s = %s", key, val);
	if (count != 2) {
	    printf("Error at %s:%d\n invalid token: %s", cfg->config_file_path, line_count, line);
	    return NULL;
	}

	if (CFG_COMPLETE(key, "device")) {
	    strncpy(cfg->device, val, sizeof(cfg->device) - 1);
	    cfg->device[sizeof(cfg->device) - 1] = '\0';
	} else if (CFG_COMPLETE(key, "enable_time")) {
	    if (CFG_COMPLETE(val, "true")) {
		cfg->enable_time = true;
	    } else {
		cfg->enable_time = false;
	    }
	} else if (CFG_COMPLETE(key, "enable_key_counter")) {
	    if (CFG_COMPLETE(val, "true")) {
		cfg->enable_keys_counter = true;
	    } else {
		cfg->enable_keys_counter = false;
	    }
	}  
    }

    fclose(fp);

    return cfg;
}

struct config* config_init() {
    struct config *cfg = prepare_config_file();
    if (!cfg) {
	return NULL;
    }

    if (parese_config(cfg) == NULL)  {
	return NULL;
    }


    return cfg;
}