Cleanup

src/vamp_pico/remote_display.cpp

@@ -0,0 +1,86 @@
+#include <vamp_pico/http_client.hpp>
+
+#include <algorithm>
+#include <charconv>
+#include <cstring>
+#include <limits>
+#include <system_error>
+
+namespace {
+
+auto copy_value(std::string_view value, std::char_t* output, std::size_t capacity) -> void {
+  if (capacity == 0U) {
+    return;
+  }
+  auto count = std::min(capacity - 1U, value.size());
+  std::memcpy(output, value.data(), count);
+  output[count] = '\0';
+}
+
+auto parse_uint(std::string_view value, std::uint32_t& output) -> std::bool_t {
+  if (value.empty()) {
+    return false;
+  }
+  auto parsed = std::uint64_t{};
+  auto const* begin = value.data();
+  auto const* end = value.data() + value.size();
+  auto result = std::from_chars(begin, end, parsed, 10);
+  if (result.ec != std::errc{} || result.ptr != end || parsed > std::numeric_limits<std::uint32_t>::max()) {
+    return false;
+  }
+  output = static_cast<std::uint32_t>(parsed);
+  return true;
+}
+
+auto strip_cr(std::string_view line) -> std::string_view {
+  if (!line.empty() && line.back() == '\r') {
+    line.remove_suffix(1U);
+  }
+  return line;
+}
+
+}
+
+auto vamp_pico::parse_remote_display_body(std::string_view body, vamp_pico::remote_display_state& state) -> std::bool_t {
+  auto parsed = vamp_pico::remote_display_state{};
+  auto saw_version = std::bool_t{};
+  auto cursor = std::size_t{};
+  while (cursor <= body.size()) {
+    auto line_end = body.find('\n', cursor);
+    auto line = line_end == std::string_view::npos ? body.substr(cursor) : body.substr(cursor, line_end - cursor);
+    line = strip_cr(line);
+    auto equals = line.find('=');
+    if (equals != std::string_view::npos) {
+      auto key = line.substr(0U, equals);
+      auto value = line.substr(equals + 1U);
+      if (key == "version") {
+        saw_version = true;
+      } else if (key == "active") {
+        parsed.active = value == "1";
+      } else if (key == "title") {
+        copy_value(value, parsed.title, sizeof(parsed.title));
+      } else if (key == "part") {
+        copy_value(value, parsed.part, sizeof(parsed.part));
+      } else if (key == "mode") {
+        copy_value(value, parsed.mode, sizeof(parsed.mode));
+      } else if (key == "page") {
+        if (!parse_uint(value, parsed.page)) {
+          return false;
+        }
+      } else if (key == "pages") {
+        if (!parse_uint(value, parsed.pages)) {
+          return false;
+        }
+      }
+    }
+    if (line_end == std::string_view::npos) {
+      break;
+    }
+    cursor = line_end + 1U;
+  }
+  if (!saw_version) {
+    return false;
+  }
+  state = parsed;
+  return true;
+}