#pragma once

#include <cstdint> //uint64_t
//#include <stdexcept> // std::runtime_error

#include "utils/vector.h"
#include "utils/matrix.h"

namespace numerics::detail{
	
	// ---------------- (Scalar, Scalar) -> Scalar ----------------
	template <typename T>
	T min_serial(const T a, const T b) {
		if (a >= b){
			return a;
		}
		return b;
	}

	// ---------------- Matrix -> Scalar ----------------
	template <typename T>
	T min_serial(const utils::Matrix<T>& A) {
	    const uint64_t rows = A.rows();
	    const uint64_t cols = A.cols();
		T min = A(0,0);
		for (uint64_t i = 0; i < rows; ++i){
			for (uint64_t j = 0; j < cols; ++j){
				if (min > A(i,j)){
					min = A(i,j);
				}
			}
		}
		return min;
	}

	// ---------------- Vector -> Scalar ----------------
	template <typename T>
	T min_serial(const utils::Vector<T>& v) {
		const uint64_t N = v.size();
		T min = v[0];
		for (uint64_t i = 0; i < N; ++i){
			if (min > v[i]){
				min = v[i];
			}
		}
		return min;
	}

	// ---------------- Matrix -> Vector ----------------
	template <typename T>
	utils::Vector<T> min_rowwise_serial(const utils::Matrix<T>& A) {
	    const uint64_t rows = A.rows();
	    const uint64_t cols = A.cols();
		utils::Vector<T> min(rows, T{0});
		for (uint64_t i = 0; i < rows; ++i){
			min[i] = A(i,0);
			for (uint64_t j = 1; j < cols; ++j){
				if (min[i] > A(i,j)){
					min[i] = A(i,j);
				}
			}
		}
		return min;
	}

	template <typename T>
	utils::Vector<T> min_colwise_serial(const utils::Matrix<T>& A) {
	    const uint64_t rows = A.rows();
	    const uint64_t cols = A.cols();
		utils::Vector<T> min(cols, T{0});
		for (uint64_t j = 0; j < cols; ++j){
			min[j] = A(0, j);
			for (uint64_t i = 1; i < rows; ++i){
				if (min[j] > A(i,j)){
					min[j] = A(i,j);
				}
			}
		}
		return min;
	}
} // namespace numerics