Reorganize directory structure

pipeline/src/data_generation/data_downloader.cpp

@@ -0,0 +1,46 @@
+#include "data_generation/data_downloader.h"
+#include "web_client/web_client.h"
+#include <filesystem>
+#include <fstream>
+#include <spdlog/spdlog.h>
+#include <sstream>
+#include <stdexcept>
+
+DataDownloader::DataDownloader(std::shared_ptr<IWebClient> webClient)
+    : m_webClient(std::move(webClient)) {}
+
+DataDownloader::~DataDownloader() {}
+
+bool DataDownloader::FileExists(const std::string &filePath)  {
+  return std::filesystem::exists(filePath);
+}
+
+std::string
+DataDownloader::DownloadCountriesDatabase(const std::string &cachePath,
+                                          const std::string &commit) {
+  if (FileExists(cachePath)) {
+    spdlog::info("[DataDownloader] Cache hit: {}", cachePath);
+    return cachePath;
+  }
+
+  std::string shortCommit = commit;
+  if (commit.length() > 7) {
+    shortCommit = commit.substr(0, 7);
+  }
+
+  std::string url = "https://raw.githubusercontent.com/dr5hn/"
+                    "countries-states-cities-database/" +
+                    shortCommit + "/json/countries+states+cities.json";
+
+  spdlog::info("[DataDownloader] Downloading: {}", url);
+
+  m_webClient->DownloadToFile(url, cachePath);
+
+  std::ifstream fileCheck(cachePath, std::ios::binary | std::ios::ate);
+  std::streamsize size = fileCheck.tellg();
+  fileCheck.close();
+
+  spdlog::info("[DataDownloader] OK: Download complete: {} ({:.2f} MB)",
+               cachePath, (size / (1024.0 * 1024.0)));
+  return cachePath;
+}