#include <psemek/ecs/entity_container.hpp>

namespace psemek::ecs
{

	bool entity_container::alive(handle const & entity) const
	{
		return entity_list_.get_entities()[entity.id].epoch == entity.epoch;
	}

	void entity_container::destroy(handle const & entity)
	{
		do_destroy(entity);
		entity_list_.destroy(entity.id);
	}

	accessor entity_container::get(handle const & entity)
	{
		auto const data = entity_list_.get_entities()[entity.id];
		return {data.table, data.row};
	}

	detail::table * entity_container::insert_table(std::vector<std::unique_ptr<detail::column>> columns)
	{
		auto table = table_container_.insert(std::make_unique<detail::table>(std::move(columns)));

		query_cache_container_.apply([table](detail::query_cache & cache){
			cache.add(table);
		}, [table](util::uuid const & uuid){ return table->column(uuid) != nullptr; });

		return table;
	}

	void entity_container::do_destroy(handle const & entity)
	{
		auto entities = entity_list_.get_entities();
		auto & data = entities[entity.id];
		auto & iteration_data = data.table->get_iteration_data();

		if (!iteration_data || iteration_data->current_row < data.row)
			remove_row(*data.table, data.row, entities);
		else
			data.table->push_remove(data.row);
	}

	void entity_container::remove_row(detail::table & table, std::uint32_t row, util::span<detail::entity_data> entities)
	{
		// Swap with the last row in that table
		auto table_entity_handles = table.entity_handles();
		table.swap_rows(row, table_entity_handles.size() - 1);
		table.pop_row();
		auto swap_handle = table_entity_handles[row];
		entities[swap_handle.id].row = row;
	}

}