#include <assert.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <unistd.h>

#ifndef NDEBUG
#include <wlr/util/log.h>
#endif

#include <hikari/server.h>

#include "version.h"

static char *
get_default_path(char *path)
{
	char *prefix = getenv("XDG_CONFIG_HOME");
	char *subdirectory;

	if (prefix == NULL) {
		prefix = getenv("HOME");
		subdirectory = "/.config/hikari/";
	} else {
		subdirectory = "/hikari/";
	}

	size_t len = strlen(prefix) + strlen(subdirectory) + strlen(path);

	char *ret = malloc(len + 1);

	strcpy(ret, prefix);
	strcat(ret, subdirectory);
	strcat(ret, path);

	return ret;
}

static char *
get_user_autostart(void)
{
	return get_default_path("autostart");
}

static char *
get_user_config_path(void)
{
	return get_default_path("hikari.conf");
}

#define STR(s) #s
#define DEFAULT_CONFIG(s) STR(s) "/etc/hikari/hikari.conf"
#define DEFAULT_CONFIG_FILE DEFAULT_CONFIG(HIKARI_ETC_PREFIX)

static char *
get_default_config_path(void)
{
	return strdup(DEFAULT_CONFIG_FILE);
}

#undef STR
#undef DEFAULT_CONFIG
#undef DEFAULT_CONFIG_FILE

static bool
check_perms(char *path, int mode)
{
	struct stat s;
	return stat(path, &s) == 0 && S_ISREG(s.st_mode) && !access(path, mode);
}

static char *
check_path(char *path, int mode)
{
	char *check = path;

	if (!check_perms(check, mode)) {
		free(path);
		check = NULL;
	}

	return check;
}

static char *
get_config_path(char *path)
{
	char *config;

	if (path != NULL) {
		char *option_config = check_path(path, R_OK);

		config = option_config;
	} else {
		char *user_config = check_path(get_user_config_path(), R_OK);

		if (user_config == NULL) {
			char *default_config = check_path(get_default_config_path(), R_OK);

			config = default_config;
		} else {
			config = user_config;
		}
	}

	return config;
}

static char *
get_autostart(char *path)
{
	char *autostart;
	int mode = R_OK | X_OK;

	if (path != NULL) {
		char *option_autostart = check_path(path, mode);

		autostart = option_autostart;
	} else {
		char *user_autostart = check_path(get_user_autostart(), mode);

		autostart = user_autostart;
	}

	return autostart;
}

const char *usage = "Usage: hikari [options]\n"
										"\n"
										"Options: \n"
										"	 -a <executable> Specify an autostart executable.\n"
										"	 -c <config>		 Specify a configuration file.\n"
										"	 -h							 Show this message and quit.\n"
										"	 -v							 Show version and quit.\n"
										"\n";

struct options {
	char *config_path;
	char *autostart;
};

static void
parse_options(int argc, char **argv, struct options *options)
{
	char *config_path = NULL;
	char *autostart = NULL;

	char flag;
	while ((flag = getopt(argc, argv, "vhc:a:")) != -1) {
		switch (flag) {
			case 'a':
				free(autostart);
				autostart = strdup(optarg);
				break;

			case 'c':
				free(config_path);
				config_path = strdup(optarg);
				break;

			case 'v':
				free(config_path);
				free(autostart);

				printf("%s\n", HIKARI_VERSION);
				exit(EXIT_SUCCESS);
				break;

			case 'h':
				free(config_path);
				free(autostart);

				printf("%s", usage);
				exit(EXIT_SUCCESS);
				break;

			case '?':
			default:
				free(config_path);
				free(autostart);

				printf("%s", usage);
				exit(EXIT_FAILURE);
				break;
		}
	}

	options->config_path = get_config_path(config_path);
	options->autostart = get_autostart(autostart);
}

int
main(int argc, char **argv)
{
#ifndef NDEBUG
	wlr_log_init(WLR_DEBUG, NULL);
#endif
	struct options options;
	parse_options(argc, argv, &options);

	if (options.config_path == NULL) {
		free(options.autostart);

		fprintf(stderr, "could not load configuration\n");

		return EXIT_FAILURE;
	} else {
		hikari_server_prepare_privileged();

		assert(geteuid() != 0 && geteuid() == getuid());
		assert(getegid() != 0 && getegid() == getgid());

		hikari_server_start(options.config_path, options.autostart);
		hikari_server_stop();

		return EXIT_SUCCESS;
	}
}