/* Copyright 2015, Michele Santullo
 * This file is part of DoorKeeper.
 *
 * DoorKeeper is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * DoorKeeper is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with DoorKeeper.  If not, see <http://www.gnu.org/licenses/>.
 */

namespace dk {
	namespace implem {
		///----------------------------------------------------------------------
		///----------------------------------------------------------------------
		template <uint32_t D, typename O>
		inline bool at_least_one (const Vector<D>& parLeft, const Vector<D>& parRight, O parOp) {
			for (uint32_t z = 0; z < D; ++z) {
				if (parOp(parLeft[z], parRight[z])) {
					return true;
				}
			}
			return false;
		}
	} //namespace implem

	///--------------------------------------------------------------------------
	///--------------------------------------------------------------------------
	template <uint32_t D>
	LayerBase<D>::LayerBase (const coords& parCount, const coords& parTileSize) :
		m_count(parCount),
		m_tilesize(parTileSize),
		m_haveFrom(0),
		m_haveTo(0)
	{
		DK_ASSERT(parCount > 0);
	}

	///--------------------------------------------------------------------------
	///--------------------------------------------------------------------------
	template <uint32_t D>
	void LayerBase<D>::preload (const coords& parFrom, const coords& parTo) {
		using implem::at_least_one;
		using less = std::less<typename coords::scalar_type>;
		using greater = std::greater<typename coords::scalar_type>;

		if (at_least_one<D>(parFrom, m_haveFrom, less()) or at_least_one<D>(parTo, m_haveTo, greater())) {
			this->onPreload(parFrom, parTo);
			m_haveFrom = parFrom;
			m_haveTo = parTo;
		}
	}

	///--------------------------------------------------------------------------
	///--------------------------------------------------------------------------
	template <typename T, uint32_t D>
	Layer<T, D>::Layer (BaseMapSource<D>* parTilemap) :
		LayerBase<D>(parTilemap->mapSize(), parTilemap->tileSize()),
		m_tilemap(parTilemap)
	{
		DK_ASSERT(m_tilemap);
	}

	///--------------------------------------------------------------------------
	///--------------------------------------------------------------------------
	template <typename T, uint32_t D>
	typename Layer<T, D>::iterator Layer<T, D>::begin() {
		return iterator(&m_tiles, m_tilemap->pixel_conv(), coords(0), this->m_count);
	}

	///--------------------------------------------------------------------------
	///--------------------------------------------------------------------------
	template <typename T, uint32_t D>
	typename Layer<T, D>::iterator Layer<T, D>::end() {
		return iterator(&m_tiles, m_tilemap->pixel_conv(), make_past_end_coords<D>(this->m_count - 1), make_past_end_coords<D>(this->m_count - 1));
	}

	///--------------------------------------------------------------------------
	///--------------------------------------------------------------------------
	template <typename T, uint32_t D>
	void Layer<T, D>::onPreload (const coords& parFrom, const coords& parTo) {
		m_tiles.clear();
		m_tilemap->fetch(m_tiles, parFrom, parTo);
#if !defined(NDEBUG)
		std::cout << "Preloading layer from " << parFrom << " to " << parTo << '\n';
#endif
	}
}