feat: implement MTR Next Train Handler with arrival and line info parsing

main/external/mtr/arrival.cpp

@@ -0,0 +1,98 @@
+#include "external/mtr/arrival.h"
+#include "cJSON.h"
+#include "esp_log.h"
+#include <string>
+
+static const char* TAG = "StationArrivalInfo";
+
+StationArrivalInfo::StationArrivalInfo(
+  cJSON* mtr_line_station_json,
+  cJSON* arrival_json,
+  const std::string& train_line_code,
+  const std::string& train_station_code
+) : _status(UNKNOWN_STATUS)
+, _train_line(train_line_code)
+, _train_station(train_station_code) {
+
+  if (!arrival_json) {
+    ESP_LOGE(TAG, "arrival_json is null");
+    _status = FAILED_WITH_MESSAGE;
+    _message = "No arrival data received";
+    return;
+  }
+
+  // Parse status
+  cJSON* status_json = cJSON_GetObjectItem(arrival_json, "status");
+  if (status_json && cJSON_IsNumber(status_json)) {
+    int status_value = status_json->valueint;
+    if (status_value >= 0 && status_value <= 3) {
+      _status = static_cast<StatusEnum>(status_value);
+    }
+  }
+
+  // TODO: verify the arrival json parsing
+
+      // Parse message (if present)
+  cJSON* message_json = cJSON_GetObjectItem(arrival_json, "message");
+  if (message_json && cJSON_IsString(message_json)) {
+    _message = message_json->valuestring;
+  }
+
+  // Parse UP direction arrivals
+  cJSON* up_json = cJSON_GetObjectItem(arrival_json, "UP");
+  if (up_json && cJSON_IsArray(up_json)) {
+    int up_count = cJSON_GetArraySize(up_json);
+    for (int i = 0; i < up_count; i++) {
+      cJSON* arrival_item = cJSON_GetArrayItem(up_json, i);
+      if (arrival_item) {
+        std::string time_str = "";
+        std::string dest_str = "";
+
+        cJSON* time_json = cJSON_GetObjectItem(arrival_item, "time");
+        if (time_json && cJSON_IsString(time_json)) {
+          time_str = time_json->valuestring;
+        }
+
+        cJSON* dest_json = cJSON_GetObjectItem(arrival_item, "dest");
+        if (dest_json && cJSON_IsString(dest_json)) {
+          dest_str = dest_json->valuestring;
+        }
+
+        if (!time_str.empty()) {
+          _up_arrivals.emplace_back(time_str, dest_str);
+        }
+      }
+    }
+  }
+
+  // Parse DOWN direction arrivals
+  cJSON* down_json = cJSON_GetObjectItem(arrival_json, "DOWN");
+  if (down_json && cJSON_IsArray(down_json)) {
+    int down_count = cJSON_GetArraySize(down_json);
+    for (int i = 0; i < down_count; i++) {
+      cJSON* arrival_item = cJSON_GetArrayItem(down_json, i);
+      if (arrival_item) {
+        std::string time_str = "";
+        std::string dest_str = "";
+
+        cJSON* time_json = cJSON_GetObjectItem(arrival_item, "time");
+        if (time_json && cJSON_IsString(time_json)) {
+          time_str = time_json->valuestring;
+        }
+
+        cJSON* dest_json = cJSON_GetObjectItem(arrival_item, "dest");
+        if (dest_json && cJSON_IsString(dest_json)) {
+          dest_str = dest_json->valuestring;
+        }
+
+        if (!time_str.empty()) {
+          _down_arrivals.emplace_back(time_str, dest_str);
+        }
+      }
+    }
+  }
+
+  ESP_LOGI(TAG, "Parsed arrival info for %s/%s: %zu UP, %zu DOWN trains",
+    train_line_code.c_str(), train_station_code.c_str(),
+    _up_arrivals.size(), _down_arrivals.size());
+}

main/external/mtr/arrival.h

@@ -21,6 +21,10 @@ public:
     return _arrival_time.c_str();
   }
 
+  const char* destination() const {
+    return _destination_name.c_str();
+  }
+
 private:
   const std::string _arrival_time;
   const std::string _destination_name; // not the code of the station
@@ -38,6 +42,14 @@ struct StationArrivalInfo {
 public:
   friend class MTRNextTrainHandler;
 
+  // Public accessors
+  StatusEnum status() const { return _status; }
+  const char* message() const { return _message.c_str(); }
+  const char* train_line() const { return _train_line.c_str(); }
+  const char* train_station() const { return _train_station.c_str(); }
+  const std::vector<ArrivalInfo>* up_arrivals() const { return &_up_arrivals; }
+  const std::vector<ArrivalInfo>* down_arrivals() const { return &_down_arrivals; }
+
 private:
   StationArrivalInfo(
     cJSON* mtr_line_station_json,

main/external/mtr/line_info.cpp

@@ -0,0 +1,45 @@
+#include "external/mtr/line_info.h"
+#include "external/mtr/station_info.h"
+#include "cJSON.h"
+#include "esp_log.h"
+
+LineInfo::LineInfo(cJSON* line_json) {
+  if (!line_json) {
+    ESP_LOGE(LINE_INFO_TAG, "line_json is null");
+    return;
+  }
+
+  // Parse line code
+  cJSON* code_json = cJSON_GetObjectItem(line_json, "code");
+  if (code_json && cJSON_IsString(code_json)) {
+    _code = code_json->valuestring;
+  } else {
+    ESP_LOGW(LINE_INFO_TAG, "Missing or invalid 'code' field");
+  }
+
+  // Parse line color (note: field is 'line_color' in JSON, not 'color')
+  cJSON* color_json = cJSON_GetObjectItem(line_json, "line_color");
+  if (color_json && cJSON_IsString(color_json)) {
+    _color = color_json->valuestring;
+  } else {
+    ESP_LOGW(LINE_INFO_TAG, "Missing or invalid 'line_color' field");
+  }
+
+  // Parse stations array
+  cJSON* stations_json = cJSON_GetObjectItem(line_json, "stations");
+  if (stations_json && cJSON_IsArray(stations_json)) {
+    int station_count = cJSON_GetArraySize(stations_json);
+    _stations.reserve(station_count);
+
+    for (int i = 0; i < station_count; i++) {
+      cJSON* station_json = cJSON_GetArrayItem(stations_json, i);
+      if (station_json) {
+        _stations.emplace_back(station_json);
+      }
+    }
+
+    ESP_LOGI(LINE_INFO_TAG, "Created LineInfo: %s with %d stations", _code.c_str(), station_count);
+  } else {
+    ESP_LOGW(LINE_INFO_TAG, "Missing or invalid 'stations' array");
+  }
+}

main/external/mtr/line_info.h

@@ -4,8 +4,9 @@
 #include "external/mtr/station_info.h"
 #include "external/mtr/mtr.h"
 #include <string>
+#include <vector>
 
-static const char* LINE_INFO_TAG = "LineInfo";
+#define LINE_INFO_TAG "LineInfo"
 
 // Forward declaration
 class MTRNextTrainHandler;

main/external/mtr/mtr.cpp

@@ -0,0 +1,167 @@
+#include "external/mtr/mtr.h"
+#include "external/mtr/line_info.h"
+#include "external/mtr/station_info.h"
+#include "external/mtr/arrival.h"
+#include "assets/MTR_LINE_STATION.h"
+#include "network/network.h"
+#include "network/http_handler.h"
+#include "cJSON.h"
+#include "esp_log.h"
+#include <string>
+#include <sstream>
+
+static const char* TAG = "MTRNextTrainHandler";
+
+// MTR Next Train API endpoint
+// Note: This is a placeholder - replace with actual MTR API endpoint
+static const char* MTR_API_BASE = "https://rt.data.gov.hk/v1/transport/mtr/getSchedule.php";
+
+MTRNextTrainHandler::MTRNextTrainHandler() {
+  ESP_LOGI(TAG, "Initializing MTR Next Train Handler");
+  mtr_data = cJSON_Parse(MTR_LINE_STATION_JSON);
+  if (!mtr_data) {
+    ESP_LOGE(TAG, "Failed to parse MTR line station JSON");
+  } else {
+    ESP_LOGI(TAG, "Successfully parsed MTR line station JSON");
+  }
+}
+
+MTRNextTrainHandler::~MTRNextTrainHandler() {
+  if (mtr_data) {
+    cJSON_Delete(mtr_data);
+    mtr_data = nullptr;
+  }
+  ESP_LOGI(TAG, "MTR Next Train Handler destroyed");
+}
+
+std::vector<LineInfo> MTRNextTrainHandler::get_lines() {
+  std::vector<LineInfo> lines;
+
+  if (!mtr_data) {
+    ESP_LOGE(TAG, "MTR data not initialized");
+    return lines;
+  }
+
+  // Iterate through all line objects in the JSON
+  cJSON* line_json = mtr_data->child;
+  while (line_json) {
+    if (cJSON_IsObject(line_json)) {
+      lines.push_back(LineInfo(line_json));
+    }
+    line_json = line_json->next;
+  }
+
+  ESP_LOGI(TAG, "Retrieved %zu MTR lines", lines.size());
+  return lines;
+}
+
+MtrArrivalErrorCode MTRNextTrainHandler::get_next_arrival_info(
+  NetworkHandler* network_handler,
+  std::string& line_code,
+  std::string& station_code,
+  StationArrivalInfo*& out_info,
+  Language lang
+) {
+  if (!network_handler) {
+    ESP_LOGE(TAG, "NetworkHandler is null");
+    return MtrArrivalErrorCode::UNKNOWN;
+  }
+
+  if (!mtr_data) {
+    ESP_LOGE(TAG, "MTR data not initialized");
+    return MtrArrivalErrorCode::UNKNOWN;
+  }
+
+  // Verify line exists
+  cJSON* line_json = cJSON_GetObjectItem(mtr_data, line_code.c_str());
+  if (!line_json) {
+    ESP_LOGW(TAG, "Line not found: %s", line_code.c_str());
+    return MtrArrivalErrorCode::LINE_NOT_FOUND;
+  }
+
+  // Verify station exists in line
+  bool station_found = false;
+  cJSON* stations_json = cJSON_GetObjectItem(line_json, "stations");
+  if (stations_json && cJSON_IsArray(stations_json)) {
+    int station_count = cJSON_GetArraySize(stations_json);
+    for (int i = 0; i < station_count; i++) {
+      cJSON* station = cJSON_GetArrayItem(stations_json, i);
+      cJSON* code_json = cJSON_GetObjectItem(station, "code");
+      if (code_json && cJSON_IsString(code_json)) {
+        if (station_code == code_json->valuestring) {
+          station_found = true;
+          break;
+        }
+      }
+    }
+  }
+
+  if (!station_found) {
+    ESP_LOGW(TAG, "Station not found: %s in line %s", station_code.c_str(), line_code.c_str());
+    return MtrArrivalErrorCode::STATION_NOT_FOUND;
+  }
+
+  // Build API URL
+  std::ostringstream url;
+  url << MTR_API_BASE << "?line=" << line_code << "&sta=" << station_code;
+  if (lang == Language::EN) {
+    url << "&lang=en";
+  }
+
+  std::string url_str = url.str();
+  ESP_LOGI(TAG, "Fetching arrival info from: %s", url_str.c_str());
+
+  // Create HTTP client configuration
+  esp_http_client_config_t http_config = {};
+  http_config.url = url_str.c_str();
+  http_config.timeout_ms = 10000;
+  http_config.transport_type = HTTP_TRANSPORT_OVER_SSL;
+  http_config.use_global_ca_store = true;
+  http_config.skip_cert_common_name_check = false;
+
+  // Get HTTP handler and perform request
+  auto http_handler = network_handler->get_http_handler(std::move(http_config));
+  if (!http_handler) {
+    ESP_LOGE(TAG, "Failed to create HTTP handler");
+    return MtrArrivalErrorCode::UNKNOWN;
+  }
+
+  esp_err_t err = http_handler->perform_request();
+  if (err != ESP_OK) {
+    ESP_LOGE(TAG, "HTTP request failed: %s", esp_err_to_name(err));
+    return MtrArrivalErrorCode::NO_ARRIVAL_INFO;
+  }
+
+  // Get response body
+  char* buffer = nullptr;
+  int total_len = 0;
+  http_handler->get_body(buffer, total_len);
+
+  if (!buffer || total_len <= 0) {
+    ESP_LOGE(TAG, "Empty response from MTR API");
+    if (buffer) {
+      free(buffer);
+    }
+    return MtrArrivalErrorCode::NO_ARRIVAL_INFO;
+  }
+
+  ESP_LOGI(TAG, "Received %d bytes from MTR API", total_len);
+  ESP_LOGD(TAG, "Response: %s", buffer);
+
+  // Parse JSON response
+  cJSON* arrival_json = cJSON_Parse(buffer);
+  free(buffer);
+
+  if (!arrival_json) {
+    ESP_LOGE(TAG, "Failed to parse MTR API response");
+    return MtrArrivalErrorCode::NO_ARRIVAL_INFO;
+  }
+
+  // Create StationArrivalInfo object
+  out_info = new StationArrivalInfo(mtr_data, arrival_json, line_code, station_code);
+
+  cJSON_Delete(arrival_json);
+
+  ESP_LOGI(TAG, "Successfully retrieved arrival info for %s/%s", line_code.c_str(), station_code.c_str());
+  return MtrArrivalErrorCode::NONE;
+}

main/external/mtr/mtr.h

@@ -1,4 +1,6 @@
-#include "assets/mtr_line_station_json.h"
+#pragma once
+
+#include "assets/MTR_LINE_STATION.h"
 #include "cJSON.h"
 #include <string>
 #include "esp_log.h"
@@ -45,8 +47,8 @@ public:
     NetworkHandler* network_handler,
     std::string& line_code,
     std::string& station_code,
-    Language lang = Language::TC,
+    StationArrivalInfo*& out_info,
-    StationArrivalInfo*& out_info
+    Language lang = Language::TC
   );
 
 private:

main/external/mtr/station_info.cpp

@@ -0,0 +1,28 @@
+#include "external/mtr/station_info.h"
+#include "cJSON.h"
+#include "esp_log.h"
+
+StationInfo::StationInfo(cJSON* station_json) {
+  if (!station_json) {
+    ESP_LOGE(STATION_INFO_TAG, "station_json is null");
+    return;
+  }
+
+  // Parse station code
+  cJSON* code_json = cJSON_GetObjectItem(station_json, "code");
+  if (code_json && cJSON_IsString(code_json)) {
+    _code = code_json->valuestring;
+  } else {
+    ESP_LOGW(STATION_INFO_TAG, "Missing or invalid 'code' field");
+  }
+
+  // Parse station name
+  cJSON* name_json = cJSON_GetObjectItem(station_json, "name");
+  if (name_json && cJSON_IsString(name_json)) {
+    _name = name_json->valuestring;
+  } else {
+    ESP_LOGW(STATION_INFO_TAG, "Missing or invalid 'name' field");
+  }
+
+  ESP_LOGD(STATION_INFO_TAG, "Created StationInfo: %s (%s)", _name.c_str(), _code.c_str());
+}

main/external/mtr/station_info.h

@@ -1,8 +1,9 @@
 #pragma once
 #include "esp_log.h"
 #include "external/mtr/line_info.h"
+#include <string>
 
-static const char* STATION_INFO_TAG = "StationInfo";
+#define STATION_INFO_TAG "StationInfo"
 
 // Forward declaration
 struct LineInfo;