#!/usr/bin/env python3

# Python script to run and analyse MMS test

# requires: all_tests
# cores: 2

from __future__ import division
from __future__ import print_function
from builtins import str

from boututils.run_wrapper import shell, build_and_log, launch_safe
from boutdata.collect import collect

from numpy import sqrt, max, abs, mean, array, log, concatenate


build_and_log("MMS test")

# List of NX values to use
nxlist = [16, 32, 64, 128, 256]

nout = 1
timestep = 0.1

nproc = 2

error_2 = []  # The L2 error (RMS)
error_inf = []  # The maximum error

for nx in nxlist:
    args = "mesh:nx=" + str(nx + 4) + " MZ=" + str(nx)

    print("Running with " + args)

    # Delete old data
    shell("rm data/BOUT.dmp.*.nc")

    # Command to run
    cmd = "./laplace " + args
    # Launch using MPI
    s, out = launch_safe(cmd, nproc=nproc, pipe=True)

    # Save output to log file
    f = open("run.log." + str(nx), "w")
    f.write(out)
    f.close()

    # Collect data
    E = collect("error", tind=[nout, nout], path="data")
    E = E[1:-1, 0, :]

    l2 = sqrt(mean(E**2))
    linf = max(abs(E))

    error_2.append(l2)
    error_inf.append(linf)

    print("Error norm: l-2 %f l-inf %f" % (l2, linf))

# Calculate grid spacing
dx = 1.0 / (array(nxlist) - 2.0)

# plot errors


order = log(error_2[-1] / error_2[-2]) / log(dx[-1] / dx[-2])
try:
    import matplotlib.pyplot as plt

    plt.plot(dx, error_2, "-o", label=r"$l^2$")
    plt.plot(dx, error_inf, "-x", label=r"$l^\infty$")

    print("Convergence order = %f" % (order))

    plt.plot(
        dx, error_2[-1] * (dx / dx[-1]) ** order, "--", label="Order %.1f" % (order)
    )

    plt.legend(loc="upper left")
    plt.grid()

    plt.yscale("log")
    plt.xscale("log")

    plt.xlabel(r"Mesh spacing $\delta x$")
    plt.ylabel("Error norm")

    plt.savefig("norm.pdf")

    # plt.show()
except:
    pass

if 1.9 < order < 2.1:
    # check for success
    exit(0)
else:
    print("MMS test failed")
    exit(1)
