Extract PPBR package path validation

src/assets/brush_package.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include "foundation/result.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <span>
+#include <string>
+#include <string_view>
+
+namespace pp::assets {
+
+constexpr std::size_t ppbr_header_size = 8;
+constexpr std::uint16_t ppbr_legacy_major_version = 0;
+constexpr std::uint16_t ppbr_legacy_minor_version = 1;
+
+enum class PpbrDataDirectoryPolicy {
+    next_to_package,
+    override_directory,
+};
+
+struct PpbrHeader {
+    std::uint16_t major = 0;
+    std::uint16_t minor = 0;
+};
+
+struct PpbrExportPaths {
+    std::string package_path;
+    std::string directory;
+    std::string stem;
+    std::string extension;
+    std::string data_directory;
+    bool data_directory_enabled = false;
+};
+
+[[nodiscard]] pp::foundation::Status validate_ppbr_header(
+    std::string_view magic,
+    std::uint16_t major,
+    std::uint16_t minor) noexcept;
+
+[[nodiscard]] pp::foundation::Result<PpbrHeader> parse_ppbr_header(
+    std::span<const std::byte> bytes) noexcept;
+
+[[nodiscard]] pp::foundation::Result<std::string> normalize_ppbr_export_path(
+    std::string_view requested_path);
+
+[[nodiscard]] pp::foundation::Result<PpbrExportPaths> plan_ppbr_export_paths(
+    std::string_view requested_path,
+    std::string_view override_data_directory,
+    bool export_data,
+    PpbrDataDirectoryPolicy data_directory_policy);
+
+} // namespace pp::assets