/*
 * Copyright (c) 2024 Jonas 'Sortie' Termansen.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * service.c
 * Start and stop services.
 */

#include <sys/socket.h>
#include <sys/un.h>

#include <err.h>
#include <getopt.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>

static int open_local_client_socket(const char* path, int flags)
{
	size_t path_length = strlen(path);
	size_t addr_size = offsetof(struct sockaddr_un, sun_path) + path_length + 1;
	struct sockaddr_un* sockaddr = malloc(addr_size);
	if ( !sockaddr )
		return -1;
	sockaddr->sun_family = AF_LOCAL;
	strcpy(sockaddr->sun_path, path);
	int fd = socket(AF_LOCAL, SOCK_STREAM | flags, 0);
	if ( fd < 0 )
		return free(sockaddr), -1;
	if ( connect(fd, (const struct sockaddr*) sockaddr, addr_size) < 0 )
		return close(fd), free(sockaddr), -1;
	free(sockaddr);
	return fd;
}

int main(int argc, char* argv[])
{
	const char* init_socket = getenv("INIT_SOCKET");
	if ( !init_socket )
		init_socket = "/var/run/init";

	bool raw = false;
	const char* source = "local";
	
	const struct option longopts[] =
	{
		{"source", required_argument, NULL, 't'},
		{"raw", no_argument, NULL, 'r'},
		{0, 0, 0, 0}
	};
	const char* opts = "rs:";
	int opt;
	while ( (opt = getopt_long(argc, argv, opts, longopts, NULL)) != -1 )
	{
		switch ( opt )
		{
		case 'r': raw = true; break;
		case 's': source = optarg; break;
		default: return 2;
		}
	}

	int fd = open_local_client_socket(init_socket, 0);
	if ( fd < 0 )
		err(1, "%s", init_socket);

	if ( raw )
	{
		for ( int i = optind; i < argc; i++ )
		{
			if ( dprintf(fd, "%s%c", argv[i], i + 1 == argc ? '\n' : ' ') < 0 )
				err(1, "%s", init_socket);
		}
		return 0;
	}

	if ( argc - optind < 2 )
		errx(1, "usage: <daemon> <command>");

	const char* daemon = argv[optind++];
	const char* command = argv[optind++];

	if ( !strcmp(command, "enable") )
	{
		// TODO: Write out new config.
		if ( dprintf(fd, "require %s %s start\n", source, daemon) < 0 )
			err(1, "%s", init_socket);
	}
	else if ( !strcmp(command, "disable") )
	{
		// TODO: Write out new config.
		if ( dprintf(fd, "unrequire %s %s\n", source, daemon) < 0 )
			err(1, "%s", init_socket);
	}
	else if ( !strcmp(command, "start") )
	{
		if ( dprintf(fd, "require %s %s start\n", source, daemon) < 0 )
			err(1, "%s", init_socket);
	}
	else if ( !strcmp(command, "stop") )
	{
		if ( dprintf(fd, "unrequire %s %s\n", source, daemon) < 0 )
			err(1, "%s", init_socket);
	}
	else if ( !strcmp(command, "restart") )
	{
		if ( dprintf(fd, "restart %s\n", daemon) < 0 )
			err(1, "%s", init_socket);
	}
	else if ( !strcmp(command, "reload") )
	{
		if ( dprintf(fd, "reload %s\n", daemon) < 0 )
			err(1, "%s", init_socket);
	}
	else if ( !strcmp(command, "reconfigure") )
	{
		if ( dprintf(fd, "reconfigure %s\n", daemon) < 0 )
			err(1, "%s", init_socket);
	}
	else if ( !strcmp(command, "terminate") )
	{
		if ( dprintf(fd, "terminate %s\n", daemon) < 0 )
			err(1, "%s", init_socket);
	}
	else if ( !strcmp(command, "kill") )
	{
		if ( dprintf(fd, "kill %s\n", daemon) < 0 )
			err(1, "%s", init_socket);
	}
	// TODO: --list
	// TODO: status
	// TODO: signal
	// TODO: pid
	// TODO: requirements
	// TODO: log
	else
		errx(1, "unknown command: %s", command);

	return 0;
}