feat: Populate repo

lib/json.c

@@ -0,0 +1,56 @@
+#include <string.h>
+
+#include <json-c/json.h>
+
+// Structs for JSON data to parse
+#include "../include/json.h"
+
+
+/** @brief Casts a JSON object from string to `Envelope`
+ *
+ * Iterates through the fields of `json` and casts the wanted
+ * fields to `Envelope`. Returns the following codes:
+ *  0 = Success
+ *  1 = Malformed json object
+ *  2 = Missing `payload` field
+ *  3 = Missing `auth` field
+ *
+ * @param json The string to cast
+ * @param Envelope the Envelope struct to cast into
+ *
+ * @returns The status code
+*/
+int parse_envelope_json(const char* json, Envelope* envelope) {
+  json_object* parsed = json_tokener_parse(json);
+  if (!parsed) return MISSING_JSON;
+
+  json_object* parsed_payload;
+  if (json_object_object_get_ex(parsed, "payload", &parsed_payload)) {
+    json_object* parsed_sensorId;
+    if (json_object_object_get_ex(parsed_payload, "sensorId", &parsed_sensorId)) {
+      envelope->payload.sensorId = strdup(json_object_get_string(parsed_sensorId));
+    } else {
+      envelope->payload.sensorId = "Nil";
+    }
+
+    json_object* parsed_sensorData;
+    if (json_object_object_get_ex(parsed_payload, "sensorData", &parsed_sensorData)) {
+      envelope->payload.sensorData = strdup(json_object_get_string(parsed_sensorData));
+    } else {
+      envelope->payload.sensorData = "Nil";
+    }
+  } else {
+    return MISSING_PAYLOAD;
+  }
+
+  json_object* parsed_auth;
+  if (json_object_object_get_ex(parsed, "auth", &parsed_auth)) {
+    envelope->auth = strdup(json_object_get_string(parsed_auth));
+  } else {
+    return MISSING_AUTH;
+  }
+
+  json_object_put(parsed);
+
+  return SUCCESS;
+}