/*!
 * \file
 * \brief   Distributed bitonic implementation header
 *
 * \author
 *    Christos Choutouridis AEM:8997
 *    <cchoutou@ece.auth.gr>
 */

#ifndef DISTBITONIC_H_
#define DISTBITONIC_H_

#if !defined DEBUG
#define NDEBUG
#endif
#include <cassert>

#include <vector>
#if !defined TESTING
  #include <mpi.h>
#endif

/*!
 * Enumerator for the different versions of the sorting method
 */
enum class SortMode {
    Bubbletonic,    //!< The v0.5 of the algorithm where we use a bubble-sort like approach
    Bitonic         //!< The v1.0 of the algorithm where we use the bitonic data-exchange approach
};

using Data_t    = std::vector<uint8_t>;
using AllData_t = std::vector<Data_t>;

struct mpi_t {
    size_t world_size{};
    size_t world_rank{};
    std::string processor_name {};
};

extern mpi_t mpi;

/*
 * ============================== Sort utilities ==============================
 */

/*!
 * The primary function template of ascending(). It is DISABLED since , it is explicitly specialized
 * for each of the \c SortMode
 */
template <SortMode Mode> bool ascending(size_t, [[maybe_unused]] size_t) noexcept = delete;
template <> bool ascending<SortMode::Bubbletonic>(size_t node, [[maybe_unused]] size_t depth) noexcept;
template <> bool ascending<SortMode::Bitonic>(size_t node, size_t depth) noexcept;

/*!
 * The primary function template of partner(). It is DISABLED since , it is explicitly specialized
 * for each of the \c SortMode
 */
template <SortMode Mode> size_t partner(size_t, size_t) noexcept = delete;
template <> size_t partner<SortMode::Bubbletonic>(size_t node, size_t step) noexcept;
template <> size_t partner<SortMode::Bitonic>(size_t node, size_t step) noexcept;

/*!
 * The primary function template of keepsmall(). It is DISABLED since , it is explicitly specialized
 * for each of the \c SortMode
 */
template<SortMode Mode> bool keepsmall(size_t, size_t, [[maybe_unused]] size_t) noexcept = delete;
template<> bool keepsmall<SortMode::Bubbletonic>(size_t node, size_t partner, [[maybe_unused]] size_t depth) noexcept;
template<> bool keepsmall<SortMode::Bitonic>(size_t node, size_t partner, size_t depth) noexcept;

bool isActive(size_t node, size_t nodes) noexcept;

/*
 * ============================== Data utilities ==============================
 */
void exchange(size_t node, size_t partner);
void minmax(AllData_t& data, size_t node, size_t partner, bool keepsmall);

/*
 * ============================== Sort algorithms ==============================
 */
void bubbletonic_network(AllData_t& data, size_t nodes);
void distbubbletonic(size_t P, AllData_t& data);

void bitonic_network(AllData_t& data, size_t nodes, size_t depth);
void distbitonic(size_t P, AllData_t& data);

#endif //DISTBITONIC_H_