/*
 * Copyright 2015-2020 Michele "King_DuckZ" Santullo
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include "vectorwrapper/vectorwrapper.hpp"
#include "vectorwrapper/size_type.hpp"
#include <type_traits>
#include <cstddef>

#if defined VWR_OUTER_NAMESPACE
namespace VWR_OUTER_NAMESPACE {
#endif

namespace vwr {
	template <typename V1, typename V2, size_type S>
	typename std::common_type<typename Vec<V1>::scalar_type, typename Vec<V2>::scalar_type>::type dot ( const Vec<V1, S>& parLeft, const Vec<V2, S>& parRight );

	template <typename V1, typename V2>
	typename std::common_type<typename Vec<V1>::scalar_type, typename Vec<V2>::scalar_type>::type cross ( const Vec<V1, 2>& parLeft, const Vec<V2, 2>& parRight );
	template <typename V1, typename V2>
	Vec<typename std::common_type<V1, V2>::type> cross ( const Vec<V1, 3>& parLeft, const Vec<V2, 3>& parRight );

	template <typename V1, typename V2, size_type S>
	Vec<typename std::common_type<V1, V2>::type> min ( const Vec<V1, S>& parLeft, const Vec<V2, S>& parRight );
	template <typename V1, typename V2, size_type S>
	Vec<typename std::common_type<V1, V2>::type> max ( const Vec<V1, S>& parLeft, const Vec<V2, S>& parRight );

	namespace implem {
		template <typename V1, typename V2, size_type S, size_type... Indices>
		inline Vec<typename std::common_type<V1, V2>::type> min ( bt::number_seq<size_type, Indices...>, const Vec<V1, S>& parLeft, const Vec<V2, S>& parRight ) {
			return {parLeft[Indices] < parRight[Indices] ? parLeft[Indices] : parRight[Indices]...};
		}

		template <typename V1, typename V2, size_type S, size_type... Indices>
		inline Vec<typename std::common_type<V1, V2>::type> max ( bt::number_seq<size_type, Indices...>, const Vec<V1, S>& parLeft, const Vec<V2, S>& parRight ) {
			return {parLeft[Indices] < parRight[Indices] ? parRight[Indices] : parLeft[Indices]...};
		}
	} //namespace implem

	template <typename V1, typename V2, size_type S>
	inline typename std::common_type<typename Vec<V1>::scalar_type, typename Vec<V2>::scalar_type>::type dot (const Vec<V1, S>& parLeft, const Vec<V2, S>& parRight) {
		auto retval = parLeft.x() * parRight.x();
		for (size_type z = 1; z < S; ++z) {
			retval += parLeft[z] * parRight[z];
		}
		return retval;
	}

	template <typename V1, typename V2>
	inline typename std::common_type<typename Vec<V1>::scalar_type, typename Vec<V2>::scalar_type>::type cross (const Vec<V1, 2>& parLeft, const Vec<V2, 2>& parRight) {
		return parLeft.x() * parRight.y() - parLeft.y() * parRight.x();
	}
	template <typename V1, typename V2>
	inline Vec<typename std::common_type<V1, V2>::type> cross (const Vec<V1, 3>& parLeft, const Vec<V2, 3>& parRight) {
		return Vec<typename std::common_type<V1, V2>::type>(
			parLeft.y() * parRight.z() - parLeft.z() * parRight.y(),
			parLeft.z() * parRight.x() - parLeft.x() * parRight.z(),
			parLeft.x() * parRight.y() - parLeft.y() * parRight.x()
		);
	}

	template <typename V1, typename V2, size_type S>
	inline Vec<typename std::common_type<V1, V2>::type> min ( const Vec<V1, S>& parLeft, const Vec<V2, S>& parRight ) {
		return implem::min(bt::number_range<size_type, 0, S>(), parLeft, parRight);
	}

	template <typename V1, typename V2, size_type S>
	inline Vec<typename std::common_type<V1, V2>::type> max ( const Vec<V1, S>& parLeft, const Vec<V2, S>& parRight ) {
		return implem::max(bt::number_range<size_type, 0, S>(), parLeft, parRight);
	}
} //namespace vwr

#if defined VWR_OUTER_NAMESPACE
} //namespace VWR_OUTER_NAMESPACE
#endif