binding: weather: add initial openweathermap binding

Bug-AGL: SPEC-1273
Change-Id: Idf6f12148df840ad8cfe2c1bc8eb35c1bc759876
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>

2 files changed, 303 insertions, 0 deletions

diff --git a/binding/CMakeLists.txt b/binding/CMakeLists.txt
new file mode 100644
index 0000000..bdd5d5b
--- /dev/null
+++ b/binding/CMakeLists.txt
@@ -0,0 +1,39 @@
+###########################################################################
+# Copyright 2015, 2016, 2017 IoT.bzh
+#
+# author: Fulup Ar Foll <fulup@iot.bzh>
+# contrib: Romain Forlot <romain.forlot@iot.bzh>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+###########################################################################
+
+# Add target to project dependency list
+PROJECT_TARGET_ADD(afm-weather-binding)
+
+	# Define project Targets
+	add_library(afm-weather-binding MODULE afm-weather-binding.c)
+
+	# Binder exposes a unique public entry point
+	SET_TARGET_PROPERTIES(${TARGET_NAME} PROPERTIES
+		LABELS "BINDING"
+		LINK_FLAGS ${BINDINGS_LINK_FLAG}
+		OUTPUT_NAME ${TARGET_NAME}
+	)
+
+	# Library dependencies (include updates automatically)
+	TARGET_LINK_LIBRARIES(${TARGET_NAME} ${link_libraries})
+
+	# installation directory
+	INSTALL(TARGETS ${TARGET_NAME}
+		LIBRARY DESTINATION ${BINDINGS_INSTALL_DIR})
+
diff --git a/binding/afm-weather-binding.c b/binding/afm-weather-binding.c
new file mode 100644
index 0000000..e2094c0
--- /dev/null
+++ b/binding/afm-weather-binding.c
@@ -0,0 +1,264 @@
+/*
+ * Copyright (C) 2018 Konsulko Group
+ * Author: Matt Ranostay <matt.ranostay@konsulko.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <curl/curl.h>
+#include <json-c/json.h>
+
+#define AFB_BINDING_VERSION 2
+#include <afb/afb-binding.h>
+
+#define OPENWEATHER_API_KEY     "a860fa437924aec3d0360cc749e25f0e"
+#define OPENWEATHER_URL         "http://api.openweathermap.org/data/2.5/weather?lat=%.4f&lon=%.4f&units=imperial&APPID=%s"
+
+struct {
+	char *api_key;
+	char url[128];
+	char buffer[1024];
+} data;
+
+static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+static struct afb_event weather_event;
+
+static int init()
+{
+	json_object *response, *query;
+	int ret;
+
+	ret = afb_daemon_require_api("persistence", 1);
+	if (ret < 0) {
+		AFB_ERROR("Cannot request data persistence service");
+		return ret;
+	}
+
+	query = json_object_new_object();
+	json_object_object_add(query, "key", json_object_new_string("OPENWEATHERMAP_API_KEY"));
+
+	ret = afb_service_call_sync("persistence", "read", query, &response);
+
+	if (ret < 0) {
+		data.api_key = strdup(OPENWEATHER_API_KEY);
+		AFB_WARNING("Cannot get OPENWEATHERMAP_API_KEY from persistence storage, defaulting to %s", data.api_key);
+	} else {
+		json_object *jresp = NULL;
+
+		json_object_object_get_ex(response, "response", &jresp);
+		json_object_object_get_ex(jresp, "value", &jresp);
+
+		data.api_key = strdup(json_object_get_string(jresp));
+
+		AFB_NOTICE("OPENWEATHERMAP_API_KEY retrieved from persistence: %s", data.api_key);
+	}
+
+	json_object_put(response);
+
+	ret = afb_daemon_require_api("geoclue", 1);
+	if (ret < 0) {
+		AFB_ERROR("Cannot request GeoClue service");
+		return ret;
+	}
+
+	query = json_object_new_object();
+	json_object_object_add(query, "value", json_object_new_string("location"));
+
+	ret = afb_service_call_sync("geoclue", "subscribe", query, &response);
+	json_object_put(response);
+
+	if (ret < 0) {
+		AFB_ERROR("Cannot subscribe to GeoClue service");
+		return ret;
+	}
+
+	weather_event = afb_daemon_make_event("weather");
+
+	return 0;
+}
+
+static size_t weather_cb(char *ptr, size_t size, size_t nmemb, void *usr)
+{
+	json_object *jresp = NULL;
+	size_t realsize = size * nmemb;
+
+	if (realsize > (sizeof(data.buffer) - 1))
+		return -ENOMEM;
+
+	pthread_mutex_lock(&mutex);
+
+	memcpy(data.buffer, ptr, realsize);
+	data.buffer[realsize] = '\0';
+
+	jresp = json_tokener_parse(data.buffer);
+
+	if (jresp)
+		json_object_object_add(jresp, "url", json_object_new_string(data.url));
+
+	pthread_mutex_unlock(&mutex);
+	afb_event_push(weather_event, jresp);
+
+	return realsize;
+}
+
+static void onevent(const char *event, struct json_object *object)
+{
+	json_object *val = NULL;
+	CURL *ch = NULL;
+	double latitude, longitude;
+	int ret;
+
+	if (strcasecmp(event, "geoclue/location") || data.api_key == NULL)
+		return;
+
+	ret = json_object_object_get_ex(object, "latitude", &val);
+	if (!ret)
+		return;
+	latitude = json_object_get_double(val);
+
+	ret = json_object_object_get_ex(object, "longitude", &val);
+	if (!ret)
+		return;
+	longitude = json_object_get_double(val);
+
+	sprintf(data.url, OPENWEATHER_URL, latitude, longitude, data.api_key);
+
+	ch = curl_easy_init();
+	if (ch == NULL)
+		return;
+
+	curl_easy_setopt(ch, CURLOPT_URL, data.url);
+	curl_easy_setopt(ch, CURLOPT_WRITEFUNCTION, weather_cb);
+
+	(void) curl_easy_perform(ch);
+	curl_easy_cleanup(ch);
+}
+
+static void current_weather(struct afb_req request)
+{
+	json_object *jresp = NULL;
+
+	pthread_mutex_lock(&mutex);
+	jresp = json_tokener_parse(data.buffer);
+
+	if (jresp)
+		json_object_object_add(jresp, "url", json_object_new_string(data.url));
+
+	pthread_mutex_unlock(&mutex);
+
+	if (jresp == NULL) {
+		afb_req_fail(request, "failed", "No weather data currently");
+		return;
+	}
+
+	afb_req_success(request, jresp, "weather data");
+}
+
+static int validate_key(const char *value)
+{
+	int i;
+
+	for (i = 0; i < strlen(value); i++)
+		if (!isxdigit(value[i])) return -EINVAL;
+
+	return 0;
+}
+
+static void api_key(struct afb_req request)
+{
+	const char *value = afb_req_value(request, "value");
+	json_object *jresp = NULL;
+	int ret;
+
+	if (!value) {
+		jresp = json_object_new_object();
+		json_object_object_add(jresp, "api_key", json_object_new_string(data.api_key));
+		afb_req_success(request, jresp, "application key");
+		return;
+	}
+
+	if (strlen(value) != strlen(OPENWEATHER_API_KEY) || validate_key(value)) {
+		afb_req_fail(request, "failed", "Invalid OpenWeatherMap API key");
+		return;
+	}
+
+	jresp = json_object_new_object();
+	json_object_object_add(jresp, "key", json_object_new_string("OPENWEATHERMAP_API_KEY"));
+	json_object_object_add(jresp, "value", json_object_new_string(value));
+
+	ret = afb_service_call_sync("persistence", "update", jresp, NULL);
+	if (ret < 0) {
+		afb_req_fail(request, "failed", "Couldn't store API key");
+		return;
+	}
+
+	if (data.api_key != NULL) {
+		free(data.api_key);
+		data.api_key = strdup(value);
+	}
+
+	afb_req_success(request, jresp, NULL);
+}
+
+static void subscribe(struct afb_req request)
+{
+	const char *value = afb_req_value(request, "value");
+
+	if (value && !strcasecmp(value, "weather")) {
+		afb_req_subscribe(request, weather_event);
+		afb_req_success(request, NULL, NULL);
+		return;
+	}
+
+	afb_req_fail(request, "failed", "Invalid event");
+}
+
+static void unsubscribe(struct afb_req request)
+{
+	const char *value = afb_req_value(request, "value");
+
+	if (value && !strcasecmp(value, "weather")) {
+		afb_req_unsubscribe(request, weather_event);
+		afb_req_success(request, NULL, NULL);
+		return;
+	}
+
+	afb_req_fail(request, "failed", "Invalid event");
+}
+
+static const struct afb_verb_v2 binding_verbs[] = {
+	{ .verb = "current_weather", .callback = current_weather, .info = "Current weather data" },
+	{ .verb = "api_key",     .callback = api_key,      .info = "Get/set OpenWeatherMap API key" },
+	{ .verb = "subscribe",   .callback = subscribe,    .info = "Subscribe to weather events" },
+	{ .verb = "unsubscribe", .callback = unsubscribe,  .info = "Unsubscribe to weather events" },
+	{ }
+};
+
+/*
+ * binder API description
+ */
+const struct afb_binding_v2 afbBindingV2 = {
+	.api		= "weather",
+	.specification  = "Weather service API",
+	.verbs		= binding_verbs,
+	.init 		= init,
+	.onevent	= onevent,
+};