// resource_loader.hpp
// Singleton resource loader for managing pack and filesystem access

#pragma once

#include <memory>
#include <string>
#include <vector>

#include "resource_pack.hpp"

namespace Resource {

// Singleton class for loading resources from pack or filesystem
class Loader {
    public:
        static auto get() -> Loader&;  // Singleton instance access

        auto initialize(const std::string& pack_file, bool enable_fallback = true) -> bool;  // Initialize loader with pack file

        auto loadResource(const std::string& filename) -> std::vector<uint8_t>;  // Load resource data
        auto resourceExists(const std::string& filename) -> bool;                // Check resource availability

        [[nodiscard]] auto isPackLoaded() const -> bool;  // Pack status queries
        [[nodiscard]] auto getPackResourceCount() const -> size_t;
        [[nodiscard]] auto validatePack() const -> bool;             // Validate pack integrity
        [[nodiscard]] auto loadAssetsConfig() const -> std::string;  // Load assets.yaml from pack

        void shutdown();  // Cleanup

        Loader(const Loader&) = delete;  // Deleted copy/move constructors
        auto operator=(const Loader&) -> Loader& = delete;
        Loader(Loader&&) = delete;
        auto operator=(Loader&&) -> Loader& = delete;

    private:
        Loader() = default;
        ~Loader() = default;

        static auto loadFromFilesystem(const std::string& filepath) -> std::vector<uint8_t>;  // Filesystem helpers
        static auto fileExistsOnFilesystem(const std::string& filepath) -> bool;

        std::unique_ptr<Pack> resource_pack_;  // Member variables
        bool fallback_to_files_{true};
        bool initialized_{false};
};

}  // namespace Resource