class TestLiHBackFlowPySCF(unittest.TestCase):
    def setUp(self):

        torch.manual_seed(0)
        np.random.seed(0)
        set_torch_double_precision()

        # molecule
        self.mol = Molecule(atom='Li 0 0 0; H 0 0 3.015',
                            unit='bohr',
                            calculator='pyscf',
                            basis='sto-3g')

        # wave function
        self.wf = SlaterJastrowBackFlow(self.mol,
                                        kinetic='jacobi',
                                        configs='single_double(2,2)',
                                        orbital_dependent_backflow=True,
                                        include_all_mo=True)

        # fc weights
        self.wf.fc.weight.data = torch.rand(self.wf.fc.weight.shape)

        # jastrow weights
        self.wf.jastrow.jastrow_kernel.weight.data = torch.rand(
            self.wf.jastrow.jastrow_kernel.weight.shape)

        # sampler
        self.sampler = Metropolis(nwalkers=500,
                                  nstep=200,
                                  step_size=0.05,
                                  ndim=self.wf.ndim,
                                  nelec=self.wf.nelec,
                                  init=self.mol.domain('normal'),
                                  move={
                                      'type': 'all-elec',
                                      'proba': 'normal'
                                  })

        # optimizer
        self.opt = optim.Adam(self.wf.parameters(), lr=0.01)

        # solver
        self.solver = SolverSlaterJastrow(wf=self.wf,
                                          sampler=self.sampler,
                                          optimizer=self.opt)

        # artificial pos
        self.nbatch = 10
        self.pos = torch.as_tensor(
            np.random.rand(self.nbatch, self.wf.nelec * 3))
        self.pos.requires_grad = True

    def test_0_wavefunction(self):

        eauto = self.wf.kinetic_energy_autograd(self.pos)
        ejac = self.wf.kinetic_energy_jacobi(self.pos)
        print(torch.stack([eauto, ejac], axis=1).squeeze())
        assert torch.allclose(eauto.data, ejac.data, rtol=1E-4, atol=1E-4)

    def test1_single_point(self):

        # sample and compute observables
        obs = self.solver.single_point()
        e, v = obs.energy, obs.variance

    def test2_wf_opt_grad_auto(self):
        self.solver.sampler = self.sampler

        self.solver.configure(track=['local_energy'],
                              loss='energy',
                              grad='auto')
        obs = self.solver.run(5)

    def test3_wf_opt_grad_manual(self):
        self.solver.sampler = self.sampler

        self.solver.configure(track=['local_energy', 'parameters'],
                              loss='energy',
                              grad='manual')
        obs = self.solver.run(5)
class TestSlaterJastrowBackFlow(unittest.TestCase):
    def setUp(self):

        torch.manual_seed(101)
        np.random.seed(101)

        set_torch_double_precision()

        # molecule
        mol = Molecule(atom='Li 0 0 0; H 0 0 3.015',
                       unit='bohr',
                       calculator='pyscf',
                       basis='sto-3g',
                       redo_scf=True)

        self.wf = SlaterJastrowBackFlow(mol,
                                        kinetic='jacobi',
                                        jastrow_kernel=PadeJastrowKernel,
                                        include_all_mo=True,
                                        configs='single_double(2,2)',
                                        backflow_kernel=BackFlowKernelInverse,
                                        orbital_dependent_backflow=False)

        self.random_fc_weight = torch.rand(self.wf.fc.weight.shape)
        self.wf.fc.weight.data = self.random_fc_weight

        self.nbatch = 5
        self.pos = torch.Tensor(np.random.rand(self.nbatch, self.wf.nelec * 3))
        self.pos.requires_grad = True

    def test_forward(self):
        wfvals = self.wf(self.pos)

    def test_antisymmetry(self):
        """Test that the wf values are antisymmetric
        wrt exchange of 2 electrons of same spin."""
        wfvals_ref = self.wf(self.pos)

        if self.wf.nelec < 4:
            print('Warning : antisymmetry cannot be tested with \
                    only %d electrons' % self.wf.nelec)
            return

        # test spin up
        pos_xup = self.pos.clone()
        perm_up = list(range(self.wf.nelec))
        perm_up[0] = 1
        perm_up[1] = 0
        pos_xup = pos_xup.reshape(self.nbatch, self.wf.nelec, 3)
        pos_xup = pos_xup[:, perm_up, :].reshape(self.nbatch,
                                                 self.wf.nelec * 3)

        wfvals_xup = self.wf(pos_xup)
        assert (torch.allclose(wfvals_ref, -1. * wfvals_xup))

    def test_jacobian_mo(self):
        """Jacobian of the BF MOs."""

        mo = self.wf.pos2mo(self.pos)
        dmo = self.wf.pos2mo(self.pos, derivative=1)

        dmo_grad = grad(mo, self.pos, grad_outputs=torch.ones_like(mo))[0]
        assert (torch.allclose(dmo.sum(), dmo_grad.sum()))

        psum_mo = dmo.sum(-1).sum(-1)
        psum_mo_grad = dmo_grad.view(self.nbatch, self.wf.nelec, 3).sum(-1)
        psum_mo_grad = psum_mo_grad.T
        assert (torch.allclose(psum_mo, psum_mo_grad))

    def test_grad_mo(self):
        """Gradients of the BF MOs."""

        mo = self.wf.pos2mo(self.pos)

        dao = self.wf.ao(self.pos, derivative=1, sum_grad=False)
        dmo = self.wf.ao2mo(dao)

        dmo_grad = grad(mo, self.pos, grad_outputs=torch.ones_like(mo))[0]
        assert (torch.allclose(dmo.sum(), dmo_grad.sum()))

        dmo = dmo.sum(-1).sum(-1)
        dmo_grad = dmo_grad.T

        assert (torch.allclose(dmo, dmo_grad))

    def test_hess_mo(self):
        """Hessian of the MOs."""
        val = self.wf.pos2mo(self.pos)

        d2val_grad = hess(val, self.pos)
        d2ao = self.wf.ao(self.pos, derivative=2, sum_hess=False)
        d2val = self.wf.ao2mo(d2ao)

        assert (torch.allclose(d2val.sum(), d2val_grad.sum()))

        d2val = d2val.reshape(4, 3, 5, 4, 6).sum(1).sum(-1).sum(-1)
        d2val_grad = d2val_grad.view(self.nbatch, self.wf.nelec, 3).sum(-1)
        d2val_grad = d2val_grad.T
        assert (torch.allclose(d2val, d2val_grad))

    def test_grad_wf(self):
        pass

        # grad_auto = self.wf.gradients_autograd(self.pos)
        # grad_jac = self.wf.gradients_jacobi(self.pos)

        # assert torch.allclose(
        #     grad_auto.data, grad_jac.data, rtol=1E-4, atol=1E-4)

    def test_local_energy(self):

        self.wf.kinetic_energy = self.wf.kinetic_energy_autograd
        eloc_auto = self.wf.local_energy(self.pos)

        self.wf.kinetic_energy = self.wf.kinetic_energy_jacobi
        eloc_jac = self.wf.local_energy(self.pos)

        assert torch.allclose(eloc_auto.data,
                              eloc_jac.data,
                              rtol=1E-4,
                              atol=1E-4)

    def test_kinetic_energy(self):

        eauto = self.wf.kinetic_energy_autograd(self.pos)
        ejac = self.wf.kinetic_energy_jacobi(self.pos)

        print(ejac)
        print(eauto)

        assert torch.allclose(eauto.data, ejac.data, rtol=1E-4, atol=1E-4)