/***************************************************************************
                                base_amoeba.h
                             -------------------
                        Trung Dac Nguyen (Northwestern)

  Base class for pair styles needing per-particle data for position,
  charge, and type.

 __________________________________________________________________________
    This file is part of the LAMMPS Accelerator Library (LAMMPS_AL)
 __________________________________________________________________________

    begin                :
    email                : trung.nguyen@northwestern.edu
 ***************************************************************************/

#ifndef LAL_BASE_AMOEBA_H
#define LAL_BASE_AMOEBA_H

#include "lal_device.h"
#include "lal_balance.h"
#include "mpi.h"

#if defined(USE_OPENCL)
#include "geryon/ocl_texture.h"
#elif defined(USE_CUDART)
#include "geryon/nvc_texture.h"
#elif defined(USE_HIP)
#include "geryon/hip_texture.h"
#else
#include "geryon/nvd_texture.h"
#endif

namespace LAMMPS_AL {

template <class numtyp, class acctyp>
class BaseAmoeba {
 public:
  BaseAmoeba();
  virtual ~BaseAmoeba();

  /// Clear any previous data and set up for a new LAMMPS run
  /** \param max_nbors initial number of rows in the neighbor matrix
    * \param cell_size cutoff + skin
    * \param gpu_split fraction of particles handled by device
    * \param k_name name for the kernel for force calculation
    *
    * Returns:
    * -  0 if successful
    * - -1 if fix gpu not found
    * - -3 if there is an out of memory error
    * - -4 if the GPU library was not compiled for GPU
    * - -5 Double precision is not supported on card **/
  int init_atomic(const int nlocal, const int nall, const int max_nbors,
                  const int maxspecial, const int maxspecial15, const double cell_size,
                  const double gpu_split, FILE *screen, const void *pair_program,
                  const char *kname_multipole, const char *kname_udirect2b,
                  const char *kname_umutual2b, const char *kname_polar,
                  const char *kname_short_nbor);

  /// Estimate the overhead for GPU context changes and CPU driver
  void estimate_gpu_overhead(const int add_kernels=0);

  /// Check if there is enough storage for atom arrays and realloc if not
  /** \param success set to false if insufficient memory **/
  inline void resize_atom(const int inum, const int nall, bool &success) {
    if (atom->resize(nall, success)) {
      pos_tex.bind_float(atom->x,4);
      q_tex.bind_float(atom->q,1);
    }
    ans->resize(inum,success);
  }

  /// Check if there is enough storage for neighbors and realloc if not
  /** \param nlocal number of particles whose nbors must be stored on device
    * \param host_inum number of particles whose nbors need to copied to host
    * \param current maximum number of neighbors
    * \note olist_size=total number of local particles **/
  inline void resize_local(const int inum, const int max_nbors, bool &success) {
    nbor->resize(inum,max_nbors,success);
  }

  /// Check if there is enough storage for neighbors and realloc if not
  /** \param nlocal number of particles whose nbors must be stored on device
    * \param host_inum number of particles whose nbors need to copied to host
    * \param current maximum number of neighbors
    * \note host_inum is 0 if the host is performing neighboring
    * \note nlocal+host_inum=total number local particles
    * \note olist_size=0 **/
  inline void resize_local(const int inum, const int host_inum,
                           const int max_nbors, bool &success) {
    nbor->resize(inum,host_inum,max_nbors,success);
  }

  /// Clear all host and device data
  /** \note This is called at the beginning of the init() routine **/
  void clear_atomic();

  /// Returns memory usage on device per atom
  int bytes_per_atom_atomic(const int max_nbors) const;

  /// Total host memory used by library for pair style
  double host_memory_usage_atomic() const;

  /// Accumulate timers
  inline void acc_timers() {
    if (device->time_device()) {
      nbor->acc_timers(screen);
      time_pair.add_to_total();
      atom->acc_timers();
      ans->acc_timers();
    }
  }

  /// Zero timers
  inline void zero_timers() {
    time_pair.zero();
    atom->zero_timers();
    ans->zero_timers();
  }

  /// Copy neighbor list from host
  int * reset_nbors(const int nall, const int inum, int *ilist, int *numj,
                    int **firstneigh, bool &success);

  /// Build neighbor list on device
  int build_nbor_list(const int inum, const int host_inum,
                       const int nall, double **host_x, int *host_type,
                       double *sublo, double *subhi, tagint *tag, int **nspecial,
                       tagint **special, int *nspecial15, tagint **special15,
                       bool &success);

  /// Reallocate per-atom arrays if needed, and build neighbor lists once, if needed
  int** precompute(const int ago, const int inum_full, const int nall,
                double **host_x, int *host_type, int *host_amtype,
                int *host_amgroup, double **host_rpole, double **host_uind,
                double **host_uinp, double *sublo, double *subhi,
                tagint *tag, int **nspecial, tagint **special,
                int *nspecial15, tagint **special15,
                const bool eflag, const bool vflag,
                const bool eatom, const bool vatom, int &host_start,
                int **&ilist, int **&numj, const double cpu_time, bool &success,
                double *charge, double *boxlo, double *prd);

  /// Compute multipole real-space with device neighboring
  int** compute_multipole_real(const int ago, const int inum_full, const int nall,
                double **host_x, int *host_type, int *host_amtype,
                int *host_amgroup, double **host_rpole, double *sublo, double *subhi,
                tagint *tag, int **nspecial, tagint **special,
                int *nspecial15, tagint **special15,
                const bool eflag, const bool vflag,
                const bool eatom, const bool vatom, int &host_start,
                int **ilist, int **numj, const double cpu_time, bool &success,
                const double aewald, const double felec, const double off2_mpole, double *charge,
                double *boxlo, double *prd, void **tep_ptr);

  /// Compute the real space part of the permanent field (udirect2b) with device neighboring
  int** compute_udirect2b(const int ago, const int inum_full, const int nall,
                double **host_x, int *host_type, int *host_amtype,
                int *host_amgroup, double **host_rpole,
                double **host_uind, double **host_uinp,
                double *sublo, double *subhi,
                tagint *tag, int **nspecial, tagint **special,
                int *nspecial15, tagint **special15,
                const bool eflag, const bool vflag,
                const bool eatom, const bool vatom, int &host_start,
                int **ilist, int **numj, const double cpu_time, bool &success,
                const double aewald, const double off2_polar, double *charge,
                double *boxlo, double *prd, void **fieldp_ptr);

  /// Compute the real space part of the induced field (umutual2b) with device neighboring
  int** compute_umutual2b(const int ago, const int inum_full, const int nall,
                double **host_x, int *host_type, int *host_amtype,
                int *host_amgroup, double **host_rpole,
                double **host_uind, double **host_uinp,
                double *sublo, double *subhi,
                tagint *tag, int **nspecial, tagint **special,
                int *nspecial15, tagint **special15,
                const bool eflag, const bool vflag,
                const bool eatom, const bool vatom, int &host_start,
                int **ilist, int **numj, const double cpu_time, bool &success,
                const double aewald, const double off2_polar, double *charge,
                double *boxlo, double *prd, void **fieldp_ptr);

  /// Compute polar real-space with device neighboring
  int** compute_polar_real(const int ago, const int inum_full, const int nall,
                double **host_x, int *host_type, int *host_amtype,
                int *host_amgroup, double **host_rpole, double **host_uind,
                double **host_uinp, double *sublo, double *subhi,
                tagint *tag, int **nspecial, tagint **special,
                int *nspecial15, tagint **special15,
                const bool eflag, const bool vflag,
                const bool eatom, const bool vatom, int &host_start,
                int **ilist, int **numj, const double cpu_time, bool &success,
                const double aewald, const double felec, const double off2_polar,
                double *charge, double *boxlo, double *prd, void **tep_ptr);

  /// Compute polar real-space with host neighboring (not active for now)
  void compute_polar_real_host_nbor(const int f_ago, const int inum_full, const int nall,
               double **host_x, int *host_type, int *host_amtype,
               int *host_amgroup, double **host_rpole, double **host_uind,
               double **host_uinp, int *ilist, int *numj,
               int **firstneigh, const bool eflag, const bool vflag,
               const bool eatom, const bool vatom, int &host_start,
               const double cpu_time, bool &success, const double aewald, const double felec,
               const double off2_polar, double *charge, const int nlocal, double *boxlo,
               double *prd, void **tep_ptr);

  // -------------------------- DEVICE DATA -------------------------

  /// Device Properties and Atom and Neighbor storage
  Device<numtyp,acctyp> *device;

  /// Geryon device
  UCL_Device *ucl_device;

  /// Device Timers
  UCL_Timer time_pair;

  /// Host device load balancer
  Balance<numtyp,acctyp> hd_balancer;

  /// LAMMPS pointer for screen output
  FILE *screen;

  // --------------------------- ATOM DATA --------------------------

  /// Atom Data
  Atom<numtyp,acctyp> *atom;

  UCL_Vector<numtyp,numtyp> polar1, polar2, polar3, polar4, polar5;

  /// cast host arrays into a single array for atom->extra
  void cast_extra_data(int* amtype, int* amgroup, double** rpole,
    double** uind, double** uinp);

  /// Per-atom arrays
  UCL_Vector<numtyp,numtyp> _tep, _fieldp;
  int _nmax, _max_tep_size, _max_fieldp_size;

  // ------------------------ FORCE/ENERGY DATA -----------------------

  Answer<numtyp,acctyp> *ans;

  // --------------------------- NBOR DATA ----------------------------

  /// Neighbor data
  Neighbor *nbor;
  /// Device storage for 1-5 special neighbor counts
  UCL_D_Vec<int> dev_nspecial15;
  /// Device storage for special neighbors
  UCL_D_Vec<tagint> dev_special15, dev_special15_t;

  int add_onefive_neighbors();

  UCL_D_Vec<int> dev_short_nbor;

  // ------------------------- DEVICE KERNELS -------------------------
  UCL_Program *pair_program;
  UCL_Kernel k_multipole, k_udirect2b, k_umutual2b, k_polar, k_special15;
  UCL_Kernel k_short_nbor;
  inline int block_size() { return _block_size; }
  inline void set_kernel(const int eflag, const int vflag) {}

  // --------------------------- TEXTURES -----------------------------
  UCL_Texture pos_tex;
  UCL_Texture q_tex;

 protected:
  bool _compiled;
  int _block_size, _block_bio_size, _threads_per_atom;
  int _extra_fields;
  double _max_bytes, _max_an_bytes, _maxspecial, _maxspecial15, _max_nbors;
  double _gpu_overhead, _driver_overhead;
  bool short_nbor_polar_avail;
  UCL_D_Vec<int> *_nbor_data;

  numtyp _aewald,_felec;
  numtyp _off2_hal,_off2_repulse,_off2_dispersion,_off2_mpole,_off2_polar;

  void compile_kernels(UCL_Device &dev, const void *pair_string,
     const char *kname_multipole, const char *kname_udirect2b,
     const char *kname_umutual2b, const char *kname_polar,
     const char *kname_short_nbor);

  virtual int multipole_real(const int eflag, const int vflag) = 0;
  virtual int udirect2b(const int eflag, const int vflag) = 0;
  virtual int umutual2b(const int eflag, const int vflag) = 0;
  virtual int polar_real(const int eflag, const int vflag) = 0;
  
};

}

#endif