/*
 * Copyright (C) 2015 Matthias Schiffer <mschiffer@universe-factory.net>
 *
 * Based on "procd" by:
 * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
 * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation
 *
 * 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.
 */

#include <sys/utsname.h>
#include <sys/sysinfo.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>

#include <libubox/uloop.h>

#include "unitd.h"
#include "watchdog.h"

static struct blob_buf b;
static int notify;
static struct ubus_context *_ctx;

static int system_board(struct ubus_context *ctx, struct ubus_object *obj,
                 struct ubus_request_data *req, const char *method,
                 struct blob_attr *msg)
{
	char line[256];
	char *key, *val;
	struct utsname utsname;
	FILE *f;

	blob_buf_init(&b, 0);

	if (uname(&utsname) >= 0)
	{
		blobmsg_add_string(&b, "kernel", utsname.release);
		blobmsg_add_string(&b, "hostname", utsname.nodename);
	}

	if ((f = fopen("/proc/cpuinfo", "r")) != NULL)
	{
		while(fgets(line, sizeof(line), f))
		{
			key = strtok(line, "\t:");
			val = strtok(NULL, "\t\n");

			if (!key || !val)
				continue;

			if (!strcasecmp(key, "system type") ||
			    !strcasecmp(key, "processor") ||
			    !strcasecmp(key, "model name"))
			{
				strtoul(val + 2, &key, 0);

				if (key == (val + 2) || *key != 0)
				{
					blobmsg_add_string(&b, "system", val + 2);
					break;
				}
			}
		}

		fclose(f);
	}

	else if ((f = fopen("/proc/cpuinfo", "r")) != NULL)
	{
		while(fgets(line, sizeof(line), f))
		{
			key = strtok(line, "\t:");
			val = strtok(NULL, "\t\n");

			if (!key || !val)
				continue;

			if (!strcasecmp(key, "machine") ||
			    !strcasecmp(key, "hardware"))
			{
				blobmsg_add_string(&b, "model", val + 2);
				break;
			}
		}

		fclose(f);
	}

	ubus_send_reply(ctx, req, b.head);

	return UBUS_STATUS_OK;
}

static int system_info(struct ubus_context *ctx, struct ubus_object *obj,
                struct ubus_request_data *req, const char *method,
                struct blob_attr *msg)
{
	void *c;
	time_t now;
	struct tm *tm;
	struct sysinfo info;

	now = time(NULL);

	if (!(tm = localtime(&now)))
		return UBUS_STATUS_UNKNOWN_ERROR;

	if (sysinfo(&info))
		return UBUS_STATUS_UNKNOWN_ERROR;

	blob_buf_init(&b, 0);

	blobmsg_add_u32(&b, "uptime",    info.uptime);
	blobmsg_add_u32(&b, "localtime", mktime(tm));

	c = blobmsg_open_array(&b, "load");
	blobmsg_add_u32(&b, NULL, info.loads[0]);
	blobmsg_add_u32(&b, NULL, info.loads[1]);
	blobmsg_add_u32(&b, NULL, info.loads[2]);
	blobmsg_close_array(&b, c);

	c = blobmsg_open_table(&b, "memory");
	blobmsg_add_u64(&b, "total",    info.mem_unit * info.totalram);
	blobmsg_add_u64(&b, "free",     info.mem_unit * info.freeram);
	blobmsg_add_u64(&b, "shared",   info.mem_unit * info.sharedram);
	blobmsg_add_u64(&b, "buffered", info.mem_unit * info.bufferram);
	blobmsg_close_table(&b, c);

	c = blobmsg_open_table(&b, "swap");
	blobmsg_add_u64(&b, "total",    info.mem_unit * info.totalswap);
	blobmsg_add_u64(&b, "free",     info.mem_unit * info.freeswap);
	blobmsg_close_table(&b, c);

	ubus_send_reply(ctx, req, b.head);

	return UBUS_STATUS_OK;
}

enum {
	WDT_FREQUENCY,
	WDT_TIMEOUT,
	WDT_STOP,
	__WDT_MAX
};

static const struct blobmsg_policy watchdog_policy[__WDT_MAX] = {
	[WDT_FREQUENCY] = { .name = "frequency", .type = BLOBMSG_TYPE_INT32 },
	[WDT_TIMEOUT] = { .name = "timeout", .type = BLOBMSG_TYPE_INT32 },
	[WDT_STOP] = { .name = "stop", .type = BLOBMSG_TYPE_BOOL },
};

static int watchdog_set(struct ubus_context *ctx, struct ubus_object *obj,
			struct ubus_request_data *req, const char *method,
			struct blob_attr *msg)
{
	struct blob_attr *tb[__WDT_MAX];
	const char *status;

	if (!msg)
		return UBUS_STATUS_INVALID_ARGUMENT;

	blobmsg_parse(watchdog_policy, __WDT_MAX, tb, blob_data(msg), blob_len(msg));
	if (tb[WDT_FREQUENCY]) {
		unsigned int timeout = watchdog_timeout(0);
		unsigned int freq = blobmsg_get_u32(tb[WDT_FREQUENCY]);

		if (freq) {
			if (freq > timeout / 2)
				freq = timeout / 2;
			watchdog_frequency(freq);
		}
	}

	if (tb[WDT_TIMEOUT]) {
		unsigned int timeout = blobmsg_get_u32(tb[WDT_TIMEOUT]);
		unsigned int frequency = watchdog_frequency(0);

		if (timeout <= frequency)
			timeout = frequency * 2;
		 watchdog_timeout(timeout);
	}

	if (tb[WDT_STOP])
		watchdog_set_stopped(blobmsg_get_bool(tb[WDT_STOP]));

	if (watchdog_fd() == NULL)
		status = "offline";
	else if (watchdog_get_stopped())
		status = "stopped";
	else
		status = "running";

	blob_buf_init(&b, 0);
	blobmsg_add_string(&b, "status", status);
	blobmsg_add_u32(&b, "timeout", watchdog_timeout(0));
	blobmsg_add_u32(&b, "frequency", watchdog_frequency(0));
	ubus_send_reply(ctx, req, b.head);

	return 0;
}

enum {
	SIGNAL_PID,
	SIGNAL_NUM,
	__SIGNAL_MAX
};

static const struct blobmsg_policy signal_policy[__SIGNAL_MAX] = {
	[SIGNAL_PID] = { .name = "pid", .type = BLOBMSG_TYPE_INT32 },
	[SIGNAL_NUM] = { .name = "signum", .type = BLOBMSG_TYPE_INT32 },
};

static int proc_signal(struct ubus_context *ctx, struct ubus_object *obj,
			struct ubus_request_data *req, const char *method,
			struct blob_attr *msg)
{
	struct blob_attr *tb[__SIGNAL_MAX];

	if (!msg)
		return UBUS_STATUS_INVALID_ARGUMENT;

	blobmsg_parse(signal_policy, __SIGNAL_MAX, tb, blob_data(msg), blob_len(msg));
	if (!tb[SIGNAL_PID || !tb[SIGNAL_NUM]])
		return UBUS_STATUS_INVALID_ARGUMENT;

	kill(blobmsg_get_u32(tb[SIGNAL_PID]), blobmsg_get_u32(tb[SIGNAL_NUM]));

	return 0;
}

static void
unitd_subscribe_cb(struct ubus_context *ctx, struct ubus_object *obj)
{
	notify = obj->has_subscribers;
}


static const struct ubus_method system_methods[] = {
	UBUS_METHOD_NOARG("board", system_board),
	UBUS_METHOD_NOARG("info",  system_info),
	UBUS_METHOD("watchdog", watchdog_set, watchdog_policy),
	UBUS_METHOD("signal", proc_signal, signal_policy),
};

static struct ubus_object_type system_object_type =
	UBUS_OBJECT_TYPE("system", system_methods);

static struct ubus_object system_object = {
	.name = "system",
	.type = &system_object_type,
	.methods = system_methods,
	.n_methods = ARRAY_SIZE(system_methods),
	.subscribe_cb = unitd_subscribe_cb,
};

void
unitd_bcast_event(char *event, struct blob_attr *msg)
{
	int ret;

	if (!notify)
		return;

	ret = ubus_notify(_ctx, &system_object, event, msg, -1);
	if (ret)
		fprintf(stderr, "Failed to notify log: %s\n", ubus_strerror(ret));
}

void ubus_init_system(struct ubus_context *ctx)
{
	int ret;

	_ctx = ctx;
	ret = ubus_add_object(ctx, &system_object);
	if (ret)
		ERROR("Failed to add object: %s\n", ubus_strerror(ret));
}