FeatherMC/src/block/state/BlockState.h

#pragma once

#include "Common.h"

#include <string>
#include <string_view>
#include <functional>
#include <map>

namespace Feather
{
	// Represents the state data of a particular instance of a Block
	class BlockState
	{
		friend struct std::hash<BlockState>;

		// PLACEHOLDER
		std::string_view m_name;
		std::map<std::string_view, std::string_view> m_properties;
	public:
		BlockState(std::string_view name) : m_name(name) {}

		inline const std::string_view GetName() const { return m_name; }

		inline void AddProperty(std::string_view key, std::string_view value) { m_properties.insert({ key, value }); }

		inline bool operator ==(const BlockState that) const
		{
			if (m_name != that.m_name) return false;

			for (auto& [key, value] : that.m_properties)
			{
				if (!m_properties.contains(key) || m_properties.at(key) != value)
					return false;
			}

			return true;
		}
	};
}

template <>
struct std::hash<Feather::BlockState>
{
	size_t operator()(const Feather::BlockState& state) const
	{
		using std::hash;
		using std::string_view;

		size_t accum = 0;
		accum += hash<string_view>()(state.GetName());

		// pretty basic hash, sum of all keys and values + block name
		for (auto& [key, value] : state.m_properties)
			accum += hash<string_view>()(key) + hash<string_view>()(value);

		return accum;
	}
};