feat: add structures for MTR arrival and station information handling

main/external/mtr/arrival.h

@@ -0,0 +1,55 @@
+#pragma once
+#include "external/mtr/arrival.h"
+#include "cJSON.h"
+#include "external/mtr/mtr.h"
+#include <string>
+#include <vector>
+
+// Forward declaration
+class MTRNextTrainHandler;
+
+struct ArrivalInfo {
+public:
+  // Caller transfers ownership of arrival_time to ArrivalInfo
+  ArrivalInfo(
+    const std::string& arrival_time,
+    const std::string& destination_name
+  ) : _arrival_time(arrival_time)
+    , _destination_name(destination_name) { }
+
+  const char* arrival_time() const {
+    return _arrival_time.c_str();
+  }
+
+private:
+  const std::string _arrival_time;
+  const std::string _destination_name; // not the code of the station
+};
+
+
+enum StatusEnum {
+  SUCCESSFUL_WITHOUT_DELAY = 0,
+  SUCCESSFUL_WITH_DELAY = 1,
+  FAILED_WITH_MESSAGE = 2,
+  UNKNOWN_STATUS = 3
+};
+
+struct StationArrivalInfo {
+public:
+  friend class MTRNextTrainHandler;
+
+private:
+  StationArrivalInfo(
+    cJSON* mtr_line_station_json,
+    cJSON* arrival_json,
+    const std::string& train_line_code,
+    const std::string& train_station_code
+  );
+
+  StatusEnum _status;
+  std::string _message; // only valid if status == FAILED_WITH_MESSAGE
+  std::string _train_line;
+  std::string _train_station;
+  std::vector<ArrivalInfo> _up_arrivals;
+  std::vector<ArrivalInfo> _down_arrivals;
+};