1 files changed, 142 insertions, 0 deletions
diff --git a/src/http.cpp b/src/http.cpp
new file mode 100644
index 0000000..409fa6a
--- /dev/null
+++ b/src/http.cpp
@@ -0,0 +1,142 @@
+#include "http.hpp"
+
+#include <curl/curl.h>
+
+#include <algorithm>
+#include <cctype>
+#include <cstddef>
+#include <memory>
+#include <mutex>
+#include <string>
+
+namespace cepis::detail {
+namespace {
+
+class GlobalInit {
+ public:
+  GlobalInit() { curl_global_init(CURL_GLOBAL_DEFAULT); }
+  ~GlobalInit() { curl_global_cleanup(); }
+
+  GlobalInit(const GlobalInit&) = delete;
+  GlobalInit& operator=(const GlobalInit&) = delete;
+  GlobalInit(GlobalInit&&) = delete;
+  GlobalInit& operator=(GlobalInit&&) = delete;
+};
+
+void ensure_global_init() {
+  static const GlobalInit init;
+  (void)init;
+}
+
+struct EasyDeleter {
+  void operator()(CURL* handle) const noexcept { curl_easy_cleanup(handle); }
+};
+
+struct SlistDeleter {
+  void operator()(curl_slist* list) const noexcept { curl_slist_free_all(list); }
+};
+
+using EasyHandle = std::unique_ptr<CURL, EasyDeleter>;
+using HeaderList = std::unique_ptr<curl_slist, SlistDeleter>;
+
+std::size_t write_body(char* data, std::size_t size, std::size_t count, void* user_data) {
+  const std::size_t total = size * count;
+  static_cast<std::string*>(user_data)->append(data, total);
+  return total;
+}
+
+std::size_t read_header(char* data, std::size_t size, std::size_t count, void* user_data) {
+  const std::size_t total = size * count;
+  const std::string_view line(data, total);
+  const std::size_t colon = line.find(':');
+  if (colon != std::string_view::npos) {
+    std::string name(line.substr(0, colon));
+    std::transform(name.begin(), name.end(), name.begin(),
+                   [](unsigned char c) { return static_cast<char>(std::tolower(c)); });
+    if (name == "retry-after") {
+      std::string_view value = line.substr(colon + 1);
+      while (!value.empty() && (value.front() == ' ' || value.front() == '\t')) {
+        value.remove_prefix(1);
+      }
+      while (!value.empty() && (value.back() == '\r' || value.back() == '\n' ||
+                                value.back() == ' ' || value.back() == '\t')) {
+        value.remove_suffix(1);
+      }
+      *static_cast<std::string*>(user_data) = std::string(value);
+    }
+  }
+  return total;
+}
+
+}  // namespace
+
+HttpResult perform_get(const HttpRequest& request) {
+  ensure_global_init();
+
+  HttpResult result;
+  const EasyHandle handle(curl_easy_init());
+  if (!handle) {
+    result.curl_error = "could not initialise libcurl";
+    return result;
+  }
+
+  HeaderList headers;
+  const auto add_header = [&headers](const char* value) {
+    curl_slist* owned = headers.release();
+    curl_slist* grown = curl_slist_append(owned, value);
+    headers.reset(grown != nullptr ? grown : owned);
+  };
+  add_header("Accept: application/json, text/csv;q=0.9, */*;q=0.1");
+  add_header("Accept-Encoding: identity");
+
+  char error_buffer[CURL_ERROR_SIZE] = {};
+  const long timeout_ms = static_cast<long>(request.timeout.count());
+
+  curl_easy_setopt(handle.get(), CURLOPT_URL, request.url.c_str());
+  curl_easy_setopt(handle.get(), CURLOPT_HTTPGET, 1L);
+  curl_easy_setopt(handle.get(), CURLOPT_USERAGENT, request.user_agent.c_str());
+  curl_easy_setopt(handle.get(), CURLOPT_HTTPHEADER, headers.get());
+  curl_easy_setopt(handle.get(), CURLOPT_WRITEFUNCTION, write_body);
+  curl_easy_setopt(handle.get(), CURLOPT_WRITEDATA, &result.body);
+  curl_easy_setopt(handle.get(), CURLOPT_HEADERFUNCTION, read_header);
+  curl_easy_setopt(handle.get(), CURLOPT_HEADERDATA, &result.retry_after);
+  curl_easy_setopt(handle.get(), CURLOPT_TIMEOUT_MS, timeout_ms);
+  curl_easy_setopt(handle.get(), CURLOPT_CONNECTTIMEOUT_MS, timeout_ms);
+  curl_easy_setopt(handle.get(), CURLOPT_NOSIGNAL, 1L);
+  curl_easy_setopt(handle.get(), CURLOPT_FOLLOWLOCATION, 1L);
+  curl_easy_setopt(handle.get(), CURLOPT_MAXREDIRS, 5L);
+  curl_easy_setopt(handle.get(), CURLOPT_ERRORBUFFER, error_buffer);
+
+  const CURLcode code = curl_easy_perform(handle.get());
+  if (code != CURLE_OK) {
+    result.curl_error = error_buffer[0] != '\0' ? error_buffer : curl_easy_strerror(code);
+    return result;
+  }
+
+  long status = 0;
+  curl_easy_getinfo(handle.get(), CURLINFO_RESPONSE_CODE, &status);
+  result.completed = true;
+  result.status = static_cast<int>(status);
+  return result;
+}
+
+std::string url_escape(std::string_view value) {
+  static constexpr char kHex[] = "0123456789ABCDEF";
+  std::string out;
+  out.reserve(value.size());
+  for (const char raw : value) {
+    const auto c = static_cast<unsigned char>(raw);
+    const bool unreserved = (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') ||
+                            (c >= '0' && c <= '9') || c == '-' || c == '.' || c == '_' || c == '~';
+    if (unreserved) {
+      out.push_back(static_cast<char>(c));
+    } else {
+      out.push_back('%');
+      out.push_back(kHex[c >> 4]);
+      out.push_back(kHex[c & 0x0F]);
+    }
+  }
+  return out;
+}
+
+}  // namespace cepis::detail