#ifndef ARBUTILS_BASICSTRINGVIEW_HPP
#define ARBUTILS_BASICSTRINGVIEW_HPP
#include <cstdint>
#include <sstream>
#include <string_view>

/// \defgroup Strings Strings
/// \brief Group of non-editable strings with faster hashing.

namespace ArbUt {

    /// \ingroup Strings
    /// @brief Abstract base class of the string views.
    class BasicStringView {
    protected:
        size_t _length = 0;
        uint32_t _hash = 0;

        /// @brief Construct a basic string view.
        constexpr BasicStringView(size_t length, uint32_t hash) : _length(length), _hash(hash) {}

    public:
        /// @brief The amount of characters of the string.
        [[nodiscard]] inline constexpr size_t Length() const noexcept { return _length; }
        /// @brief The unique hash of the string.
        [[nodiscard]] inline constexpr uint32_t GetHash() const noexcept { return _hash; }
        /// @brief The unique hash of the string.
        [[nodiscard]] inline constexpr std::size_t operator()() const noexcept { return _hash; }
        /// @brief The unique hash of the string.
        [[nodiscard]] inline constexpr operator uint32_t() const noexcept { return _hash; }
        /// @brief Check whether two StringViews are equal
        [[nodiscard]] inline constexpr bool operator==(const BasicStringView& rhs) const noexcept {
            return _hash == rhs._hash;
        }
        /// @brief Check whether two StringViews are unequal
        inline constexpr bool operator!=(const BasicStringView& rhs) const noexcept { return _hash != rhs._hash; }
        /// @brief Check whether a string view has a length of 0.
        inline constexpr bool IsEmpty() const noexcept { return Length() == 0; }
        /// @brief The C string interpretation of the string.
        [[nodiscard]] virtual constexpr const char* c_str() const noexcept = 0;
        /// @brief The C++ std string interpretation of the string.
        [[nodiscard]] virtual constexpr std::string_view std_str() const noexcept = 0;

        /// @brief Check the equality between a std string_view and our StringViews.
        virtual constexpr bool operator==(const std::string_view& rhs) const noexcept = 0;
        /// @brief Check the inequality between a std string_view and our StringViews.
        virtual constexpr bool operator!=(const std::string_view& rhs) const noexcept = 0;
        /// @brief Check the equality between a C string and our StringViews.
        virtual constexpr bool operator==(const char* rhs) const noexcept = 0;
        /// @brief Check the equality between a C string and our StringViews.
        virtual constexpr bool operator!=(const char* rhs) const noexcept = 0;

        /// @brief Pipe the current string into an output stream.
        friend std::ostream& operator<<(std::ostream& out, const BasicStringView& c) {
            out << c.c_str();
            return out;
        }
    };
}
#endif // ARBUTILS_BASICSTRINGVIEW_HPP