/*
  Copyright 2013--2018 James E. McClure, Virginia Polytechnic & State University
  Copyright Equnior ASA

  This file is part of the Open Porous Media project (OPM).
  OPM 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.
  OPM 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 OPM.  If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef Analysis_H_INC
#define Analysis_H_INC

#include "common/Array.h"
#include "common/Communication.h"

#include <set>
#include <map>
#include <vector>

// Define types to use for blob ids
typedef int32_t BlobIDType;
typedef Array<BlobIDType> BlobIDArray;

/*!
 * @brief  Compute the blob
 * @details  Compute the blob (F>vf|S>vs) starting from (i,j,k) - oil blob
 * @return  Returns the number of cubes in the blob
 * @param[in] Phase         Phase
 * @param[in] SignDist      SignDist
 * @param[in] vF            vF
 * @param[in] vS            vS
 * @param[out] LocalBlobID  The ids of the blobs
 * @param[in] periodic      Optional value
 * @return  Returns the number of blobs
 */
int ComputeLocalBlobIDs(const DoubleArray &Phase, const DoubleArray &SignDist,
                        double vF, double vS, BlobIDArray &LocalBlobID,
                        bool periodic = true);

/*!
 *  @brief Compute blob of an arbitrary phase
 *  @details Compute the connected components for Phase(i,j,k)=VALUE
 *  @return the number of connected components of the phase
 *  @param[in] PhaseID
 *  @param[in] VALUE
 *  @param[out] ComponentLabel
 *  @param[in] periodic
 */
int ComputeLocalPhaseComponent(const IntArray &PhaseID, int &VALUE,
                               IntArray &ComponentLabel, bool periodic);

/*!
 * @brief  Compute the blob
 * @details  Compute the blob (F>vf|S>vs) starting from (i,j,k) - oil blob
 * @return  Returns the number of cubes in the blob
 * @param[in] nx            Number of elements in the x-direction
 * @param[in] ny            Number of elements in the y-direction
 * @param[in] nz            Number of elements in the z-direction
 * @param[in] rank_info     MPI communication info
 * @param[in] Phase         Phase
 * @param[in] SignDist      SignDist
 * @param[in] vF            vF
 * @param[in] vS            vS
 * @param[out] GlobalBlobID The ids of the blobs
 * @param[in] comm          MPI communicator
 * @return  Returns the number of blobs
 */
int ComputeGlobalBlobIDs(int nx, int ny, int nz,
                         const RankInfoStruct &rank_info,
                         const DoubleArray &Phase, const DoubleArray &SignDist,
                         double vF, double vS, BlobIDArray &GlobalBlobID,
                         const Utilities::MPI &comm);

/*!
 * @brief Compute component of the specified phase
 * @details Compute component of specified phase PhaseID=VALUE
 * @return  Returns the number of cubes in the blob
 * @param[in] nx            Number of elements in the x-direction
 * @param[in] ny            Number of elements in the y-direction
 * @param[in] nz            Number of elements in the z-direction
 * @param[in] rank_info     MPI communication info
 * @param[in] PhaseID       Array that identifies the phases
 * @param[in] VALUE         Identifier for the phase to decompose
 * @param[out] GlobalBlobID The ids of the blobs for the phase
 * @param[in] comm          The communicator to use
 * @return Return the number of components in the specified phase
 */
int ComputeGlobalPhaseComponent(int nx, int ny, int nz,
                                const RankInfoStruct &rank_info,
                                const IntArray &PhaseID, int &VALUE,
                                BlobIDArray &GlobalBlobID,
                                const Utilities::MPI &comm);

/*!
 * @brief  Reorder the blobs
 * @details  Reorder the blobs based on the number of cells they contain
 *    largest first.
 * @param[in,out] ID        The ids of the blobs
 * @param[in] comm          MPI communicator
 */
void ReorderBlobIDs(BlobIDArray &ID, const Utilities::MPI &comm);

typedef std::pair<BlobIDType, std::vector<BlobIDType>> BlobIDSplitStruct;
typedef std::pair<std::vector<BlobIDType>, BlobIDType> BlobIDMergeStruct;
typedef std::pair<std::vector<BlobIDType>, std::vector<BlobIDType>>
    BlobIDMergeSplitStruct;
typedef std::pair<BlobIDType, BlobIDType> OverlapID;
struct ID_map_struct {
    std::vector<BlobIDType> created;   // list of new blobs that were created
    std::vector<BlobIDType> destroyed; // list of blobs that disappeared
    std::vector<std::pair<BlobIDType, BlobIDType>>
        src_dst; // one-one mapping of blobs (first,second timestep id)
    std::vector<BlobIDSplitStruct> split; // list of blobs that split
    std::vector<BlobIDMergeStruct> merge; // list of blobs that merged
    std::vector<BlobIDMergeSplitStruct>
        merge_split; // list of blobs that both merged and split
    std::map<OverlapID, int64_t>
        overlap; // for ids that are not a 1-1 mapping, this is a list of the overlaps <src,dst>
    //! Empty constructor
    ID_map_struct() {}
    //! Create initial map from N blobs (ordered 1:N-1)
    ID_map_struct(int N) {
        created.resize(N);
        for (int i = 0; i < N; i++) {
            created[i] = i;
        }
    }
};

/*!
 * @brief  Get the mapping of blob ids between iterations
 * @details  This functions computes the map of blob ids between iterations
 * @return  Returns the map of the blob ids.  Each final blob may have no source
 *    ids, one parent, or multiple parents.  Each src id may be a parent for multiple blobs.
 * @param[in] nx            Number of elements in the x-direction
 * @param[in] ny            Number of elements in the y-direction
 * @param[in] nz            Number of elements in the z-direction
 * @param[in] ID1           The blob ids at the first timestep
 * @param[in] ID2           The blob ids at the second timestep
 * @param[in] comm          The communicator to use
 */
ID_map_struct computeIDMap(int nx, int ny, int nz, const BlobIDArray &ID1,
                           const BlobIDArray &ID2, const Utilities::MPI &comm);

/*!
 * @brief  Compute the new global ids based on the map
 * @details  This functions computes the time-consistent global ids for the
 *     current global id index
 * @param[in,out] map       The timestep mapping for the ids
 * @param[in] id_max        The globally largest id used previously
 * @param[out] new_ids      The newly renumbered blob ids (0:ids.max())
 */
void getNewIDs(ID_map_struct &map, BlobIDType &id_max,
               std::vector<BlobIDType> &new_ids);

/*!
 * @brief  Update the blob ids based on mapping
 * @details  This functions computes the map of blob ids between iterations.
 *    Note: we also update the map to reflect the new ids
 * @param[out] new_ids          The newly renumbered blob ids (0:ids.max())
 * @param[in,out] IDs           The blob ids to renumber
 */
void renumberIDs(const std::vector<BlobIDType> &new_ids, BlobIDArray &IDs);

/*!
 * @brief  Write the ID map
 * @details  This functions writes the id map fo an iteration.
 *    If no ids changed, then nothing will be written
 *    Note: only rank 0 writes, and the file is created on timestep 0.
 * @param[in] map           The timestep mapping for the ids
 * @param[in] timestep      The current timestep (timestep 0 creates the file)
 * @param[in] filename      The filename to write/append
 */
void writeIDMap(const ID_map_struct &map, long long int timestep,
                const std::string &filename);

#endif