/* SPDX-FileCopyrightText: 2021, Aiyion <gluon@aiyionpri.me> */
/* SPDX-FileCopyrightText: 2016, Matthias Schiffer <mschiffer@universe-factory.net> */
/* SPDX-License-Identifier: BSD-2-Clause */

#include <respondd.h>

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

#include <json-c/json.h>
#include <libgluonutil.h>
#include <uci.h>


static struct json_object * get_bandwidth_limit(void) {
	bool enabled = false;
	int egress = -1;
	int ingress = -1;

	struct json_object *ret = json_object_new_object();

	struct uci_context *ctx = uci_alloc_context();
	if (!ctx)
		goto disabled;
	ctx->flags &= ~UCI_FLAG_STRICT;

	struct uci_package *p;
	if (uci_load(ctx, "gluon", &p))
		goto disabled;

	struct uci_section *s = uci_lookup_section(ctx, p, "mesh_vpn");
	if (!s)
		goto disabled;

	const char *enabled_str = uci_lookup_option_string(ctx, s, "limit_enabled");
	if (enabled_str && strcmp(enabled_str, "1"))
		goto disabled;

	enabled = true;

	const char *egress_str = uci_lookup_option_string(ctx, s, "limit_egress");
	if (egress_str && strcmp(egress_str, "-"))
		egress = atoi(egress_str);

	const char *ingress_str = uci_lookup_option_string(ctx, s, "limit_ingress");
	if (ingress_str && strcmp(ingress_str, "-"))
		ingress = atoi(ingress_str);

	if (egress >= 0)
		json_object_object_add(ret, "egress", json_object_new_int(egress));
	if (ingress >= 0)
		json_object_object_add(ret, "ingress", json_object_new_int(ingress));

disabled:
	if (ctx)
		uci_free_context(ctx);

	json_object_object_add(ret, "enabled", json_object_new_boolean(enabled));
	return ret;
}

char * read_stdout(const char *command) {
	FILE *f = popen(command, "r");
	if (!f)
		return NULL;

	char *line = NULL;
	size_t len = 0;

	ssize_t r = getline(&line, &len, f);

	pclose(f);

	if (r < 0) {
		free(line);
		return NULL;
	}

	/* The len given by getline is the buffer size, not the string length */
	len = strlen(line);

	if (len && line[len-1] == '\n')
		line[len-1] = 0;

	return line;
}

static struct json_object * get_mesh_vpn_enabled() {
	int enabled = -1;
	char *line = read_stdout("exec lua -e 'print(require(\"gluon.mesh-vpn\").enabled())'");

	if (!line)
		return NULL;

	if (!strcmp(line, "true"))
		enabled = 1;
	if (!strcmp(line, "false"))
		enabled = 0;
	free(line);

	if (enabled < 0)
		return NULL;

	struct json_object *ret = json_object_new_boolean((json_bool)enabled);
	return ret;
}

static struct json_object * get_active_vpn_provider() {
	char *line = read_stdout("exec lua -e 'name, _ = require(\"gluon.mesh-vpn\").get_active_provider(); print(name)'");

	if (line && !strcmp(line, "nil")) {
		free(line);
		return NULL;
	}

	return gluonutil_wrap_and_free_string(line);
}

static struct json_object * respondd_provider_nodeinfo(void) {
	struct json_object *ret = json_object_new_object();
	struct json_object *network = json_object_new_object();
	struct json_object *mesh_vpn = json_object_new_object();

	json_object_object_add(mesh_vpn, "bandwidth_limit", get_bandwidth_limit());
	json_object_object_add(mesh_vpn, "provider", get_active_vpn_provider());
	json_object_object_add(mesh_vpn, "enabled", get_mesh_vpn_enabled());
	json_object_object_add(network, "mesh_vpn", mesh_vpn);
	json_object_object_add(ret, "network", network);

	return ret;
}

const struct respondd_provider_info respondd_providers[] = {
	{"nodeinfo", respondd_provider_nodeinfo},
	{},
	{}
};