#include <iostream>
#include <gtest/gtest.h>
#include "fmt_nlist.h"
#include "env_mat.h"
#include "neighbor_list.h"
#include "soft_min_switch.h"
#include "soft_min_switch_force_grad.h"

class TestSoftMinSwitchForceGrad : public ::testing::Test
{
protected:
  std::vector<double > posi = {12.83, 2.56, 2.18, 
			       12.09, 2.87, 2.74,
			       00.25, 3.32, 1.68,
			       3.36, 3.00, 1.81,
			       3.51, 2.51, 2.60,
			       4.27, 3.22, 1.56
  };
  std::vector<int > atype = {0, 1, 1, 0, 1, 1};
  std::vector<double > posi_cpy;
  std::vector<int > atype_cpy;
  int ntypes = 2;  
  int nloc, nall, nnei, ndescrpt;
  double rc = 6;
  double rc_smth = 0.8;
  double alpha = .5;
  double rmin = 0.8;
  double rmax = 1.5;
  SimulationRegion<double > region;
  std::vector<int> mapping, ncell, ngcell;
  std::vector<int> sec_a = {0, 5, 10};
  std::vector<int> sec_r = {0, 0, 0};
  std::vector<int> nat_stt, ext_stt, ext_end;
  std::vector<std::vector<int>> nlist_a_cpy, nlist_r_cpy;
  std::vector<double> sw_value, sw_deriv, grad;
  std::vector<double> rij;
  std::vector<int> nlist;
  std::vector<int> fmt_nlist_a;
  std::vector<double > expected_grad_net = {
    -0.62289, -0.08638, -1.94404,  0.01995,  0.04023,  0.01040,
  };
  
  void SetUp() override {
    double box[] = {13., 0., 0., 0., 13., 0., 0., 0., 13.};
    region.reinitBox(box);
    copy_coord(posi_cpy, atype_cpy, mapping, ncell, ngcell, posi, atype, rc, region);
    nloc = posi.size() / 3;
    nall = posi_cpy.size() / 3;
    nnei = sec_a.back();
    ndescrpt = nnei * 4;
    nat_stt.resize(3);
    ext_stt.resize(3);
    ext_end.resize(3);
    for (int dd = 0; dd < 3; ++dd){
      ext_stt[dd] = -ngcell[dd];
      ext_end[dd] = ncell[dd] + ngcell[dd];
    }
    build_nlist(nlist_a_cpy, nlist_r_cpy, posi_cpy, nloc, rc, rc, nat_stt, ncell, ext_stt, ext_end, region, ncell);
    nlist.resize(nloc * nnei);
    rij.resize(nloc * nnei * 3);
    for(int ii = 0; ii < nloc; ++ii){      
      // format nlist and record
      format_nlist_i_cpu<double>(fmt_nlist_a, posi_cpy, atype_cpy, ii, nlist_a_cpy[ii], rc, sec_a);
      for (int jj = 0; jj < nnei; ++jj){
	nlist[ii*nnei + jj] = fmt_nlist_a[jj];
      }
      std::vector<double > t_env, t_env_deriv, t_rij;
      // compute env_mat and its deriv, record
      deepmd::env_mat_a_cpu<double>(t_env, t_env_deriv, t_rij, posi_cpy, atype_cpy, ii, fmt_nlist_a, sec_a, rc_smth, rc);    
      for (int jj = 0; jj < nnei * 3; ++jj){
	rij[ii*nnei*3 + jj] = t_rij[jj];
      }      
    }
    sw_value.resize(nloc);
    sw_deriv.resize(nloc * nnei * 3);
    deepmd::soft_min_switch_cpu<double> (&sw_value[0], &sw_deriv[0], &rij[0], &nlist[0], nloc, 
				 nnei, alpha, rmin, rmax);
    grad.resize(nloc * 3);
    for (int ii = 0; ii < nloc; ++ii){
      grad[ii] = 1.0 - ii * 0.1;
    }
  }
  void TearDown() override {
  }
};

TEST_F(TestSoftMinSwitchForceGrad, cpu)
{
  std::vector<double> grad_net(nloc);
  deepmd::soft_min_switch_force_grad_cpu(
      &grad_net[0],
      &grad[0],
      &sw_deriv[0],
      &nlist[0],
      nloc,
      nnei);
  EXPECT_EQ(grad_net.size(), expected_grad_net.size());
  for (int jj = 0; jj < grad_net.size(); ++jj){
    EXPECT_LT(fabs(grad_net[jj] - expected_grad_net[jj]) , 1e-5);
  }  
  // for (int ii = 0; ii < nloc; ++ii){
  //   printf("%8.5f, ", grad_net[ii]);
  // }  
  // printf("\n");
}

