#!/usr/bin/env python3
#
# Authors: Christoph Lehner 2020
#
# Desc.: Illustrate core concepts and features
#
import gpt as g
import numpy as np
import sys
import time

# load configuration
U = g.load("/hpcgpfs01/work/clehner/configs/openQCD/A250t000n54")

# do everything in single-precision
U = g.convert(U, g.single)

# use the gauge configuration grid
grid = U[0].grid

# quark
w = g.qcd.fermion.wilson_clover(
    U,
    {
        "kappa": 0.13565,
        "csw_r": 2.0171,
        "csw_t": 2.0171,
        "xi_0": 1,
        "nu": 1,
        "isAnisotropic": False,
        "boundary_phases": [1.0, 1.0, 1.0, 1.0],
    },
)

# create point source
src = g.mspincolor(grid)
g.create.point(src, [0, 0, 0, 0])

# build solver
pc = g.qcd.fermion.preconditioner
inv = g.algorithms.inverter
cg = inv.cg({"eps": 1e-6, "maxiter": 200})
slv = w.propagator(inv.preconditioned(pc.eo2_ne(), cg))

# propagator
dst = g.mspincolor(grid)
slv(dst, src)

# two-point
correlator = g.slice(g.trace(dst * g.adj(dst)), 3)

# output
for t, c in enumerate(correlator):
    g.message(t, c.real)