#pragma once

#include <iosfwd>
#include <memory>

class BaseValue
{
public:
	enum Kind
	{
		KD_Numeric,
		KD_Text,
		KD_DateTime,

		/// An unspecified type, otherwise known as "any" in some contexts.
		InvalidKind,
		KindCount = InvalidKind,
	};

private:
	Kind mKind;

public:
	static const char* FormatKind(Kind kind);
	static std::unique_ptr<BaseValue> CreateByKind(Kind kind);

	BaseValue(Kind kind);
	virtual ~BaseValue() = default;

	BaseValue(const BaseValue&) = delete;
	BaseValue& operator=(const BaseValue&) = delete;
	BaseValue(BaseValue&&) = default;
	BaseValue& operator=(BaseValue&&) = default;

	Kind GetKind() const;

	// TODO get constant editor

	/// The functions \c ReadFrom, \c WriteTo will only be valid to call if this function returns true.
	virtual bool SupportsConstant() const;
	virtual void ReadFrom(std::istream& stream);
	virtual void WriteTo(std::ostream& stream);
};