/* SPDX-FileCopyrightText: 2020, Leonardo Mörlein <me@irrelefant.net> */
/* SPDX-FileCopyrightText: 2016, Matthias Schiffer <mschiffer@universe-factory.net> */
/* SPDX-License-Identifier: BSD-2-Clause */


#include <respondd.h>

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

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

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

#include "libubus.h"

static struct json_object * stdout_read(const char *cmd, const char *skip, bool oneword) {
	FILE *f = popen(cmd, "r");
	if (!f)
		return NULL;

	char *line = NULL;
	size_t len = 0;
	size_t skiplen = strlen(skip);

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

	pclose(f);

	if (read_chars < 1) {
		free(line);
		return NULL;
	}

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

	const char *content = line;
	if (strncmp(content, skip, skiplen) == 0)
		content += skiplen;

	if (oneword) {
		for (int i = 0; i < len; i++) {
			if (isspace(line[i])) {
				line[i] = 0;
			}
		}
	}

	struct json_object *ret = gluonutil_wrap_string(content);
	free(line);
	return ret;
}

static struct json_object * get_wireguard_public_key(void) {
	return stdout_read("exec /lib/gluon/mesh-vpn/wireguard_pubkey.sh", "", false);
}

static struct json_object * get_wireguard_version(void) {
	return stdout_read("exec wg -v", "wireguard-tools ", true);
}

static bool wireguard_enabled(void) {
	bool enabled = true;

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

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

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

	const char *disabled_str = uci_lookup_option_string(ctx, s, "disabled");
	if (!disabled_str || !strcmp(disabled_str, "1"))
		enabled = false;

disabled:
	uci_free_context(ctx);

disabled_nofree:
	return enabled;
}

static bool get_pubkey_privacy(void) {
	bool ret = true;
	struct json_object *site = NULL;

	site = gluonutil_load_site_config();
	if (!site)
		goto end;

	struct json_object *mesh_vpn;
	if (!json_object_object_get_ex(site, "mesh_vpn", &mesh_vpn))
		goto end;

	struct json_object *pubkey_privacy;
	if (!json_object_object_get_ex(mesh_vpn, "pubkey_privacy", &pubkey_privacy))
		goto end;

	ret = json_object_get_boolean(pubkey_privacy);

end:
	json_object_put(site);

	return ret;
}

static struct json_object * get_wireguard(void) {
	bool wg_enabled = wireguard_enabled();

	struct json_object *ret = json_object_new_object();
	json_object_object_add(ret, "version", get_wireguard_version());
	json_object_object_add(ret, "enabled", json_object_new_boolean(wg_enabled));
	if (wg_enabled && !get_pubkey_privacy())
		json_object_object_add(ret, "public_key", get_wireguard_public_key());
	return ret;
}

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

	struct json_object *software = json_object_new_object();
	json_object_object_add(software, "wireguard", get_wireguard());
	json_object_object_add(ret, "software", software);

	return ret;
}

static json_object *blobmsg_attr2json(struct blob_attr *attr, int type)
{
	int len = blobmsg_data_len(attr);
	struct blobmsg_data *data = blobmsg_data(attr);
	struct blob_attr *inner_attr;
	json_object *res = NULL;
	switch(type) {
		case BLOBMSG_TYPE_STRING:
			return gluonutil_wrap_string(blobmsg_get_string(attr));
		case BLOBMSG_TYPE_BOOL:
			return json_object_new_boolean(blobmsg_get_bool(attr));
		case BLOBMSG_TYPE_INT16:
			return json_object_new_double(blobmsg_get_u16(attr));
		case BLOBMSG_TYPE_INT32:
			return json_object_new_double(blobmsg_get_u32(attr));
		case BLOBMSG_TYPE_INT64:
			return json_object_new_double(blobmsg_get_u64(attr));
		case BLOBMSG_TYPE_DOUBLE:
			return json_object_new_double(blobmsg_get_double(attr));
		case BLOBMSG_TYPE_TABLE:
			res = json_object_new_object();
			__blob_for_each_attr(inner_attr, data, len) {
				json_object_object_add(res, blobmsg_name(inner_attr), blobmsg_attr2json(inner_attr, blobmsg_type(inner_attr)));
			};
			break;
		case BLOBMSG_TYPE_ARRAY:
			res = json_object_new_array();
			__blob_for_each_attr(inner_attr, data, len) {
				json_object_array_add(res, blobmsg_attr2json(inner_attr, blobmsg_type(inner_attr)));
			}
			break;
	}

	return res;
}

static void cb_wgpeerselector_vpn(struct ubus_request *req, int type, struct blob_attr *msg)
{
	json_object_object_add(req->priv, "mesh_vpn", blobmsg_attr2json(msg, type));
}

static struct json_object * respondd_provider_statistics(void) {
	struct json_object *ret = json_object_new_object();
	struct ubus_context *ctx = ubus_connect(NULL);
	uint32_t ubus_path_id;

	if (!ctx) {
		fprintf(stderr, "Error in gluon-mesh-vpn-wireguard.so: Failed to connect to ubus.\n");
		goto err;
	}

	if (ubus_lookup_id(ctx, "wgpeerselector.wg_mesh", &ubus_path_id)) {
		goto err;
	}

	ubus_invoke(ctx, ubus_path_id, "status", NULL, cb_wgpeerselector_vpn, ret, 1000);

err:
	if (ctx)
		ubus_free(ctx);
	return ret;
}


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