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

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;
+}