# Copyright (C) 2015-2016: The University of Edinburgh
#                 Authors: Craig Warren and Antonis Giannopoulos
#
# This file is part of gprMax.
#
# gprMax is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# gprMax is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with gprMax.  If not, see <http://www.gnu.org/licenses/>.

import os, argparse
import h5py
import numpy as np
import matplotlib.pyplot as plt

from gprMax.exceptions import CmdInputError


def make_plot(filename, output):
    """Plots a B-scan image.
        
        Args:
        filename (string): Filename (including path) of output file.
        output (string): Field/current component to plot.
    """

    # Open output file and read some attributes
    f = h5py.File(filename, 'r')
    nrx = f.attrs['nrx']

    # Check there are any receivers
    if nrx == 0:
        raise CmdInputError('No receivers found in {}'.format(filename))

    for rx in range(1, nrx + 1):
        path = '/rxs/rx' + str(rx) + '/'
        availableoutputs = list(f[path].keys())

        # Check if requested output is in file
        if output not in availableoutputs:
            raise CmdInputError('{} output requested to plot, but the available output for receiver 1 is {}'.format(output, ', '.join(availableoutputs)))

        outputdata = f[path + '/' + output]

        # Check that there is more than one A-scan present
        if outputdata.shape[1] == 1:
            raise CmdInputError('{} contains only a single A-scan.'.format(filename))

        # Plot B-scan image
        fig = plt.figure(num='rx' + str(rx), figsize=(20, 10), facecolor='w', edgecolor='w')
        plt.imshow(outputdata, extent=[0, outputdata.shape[1], outputdata.shape[0]*f.attrs['dt'], 0], interpolation='nearest', aspect='auto', cmap='seismic', vmin=-np.amax(np.abs(outputdata)), vmax=np.amax(np.abs(outputdata)))
        plt.xlabel('Trace number')
        plt.ylabel('Time [s]')
        plt.grid()
        cb = plt.colorbar()
        if 'E' in args.output:
            cb.set_label('Field strength [V/m]')
        elif 'H' in args.output:
            cb.set_label('Field strength [A/m]')
        elif 'I' in args.output:
            cb.set_label('Current [A]')

        # Save a PDF/PNG of the figure
        #fig.savefig(os.path.splitext(os.path.abspath(args.outputfile))[0] + '.pdf', dpi=None, format='pdf', bbox_inches='tight', pad_inches=0.1)
        #fig.savefig(os.path.splitext(os.path.abspath(args.outputfile))[0] + '.png', dpi=150, format='png', bbox_inches='tight', pad_inches=0.1)

    plt.show()


if __name__ == "__main__":

    # Parse command line arguments
    parser = argparse.ArgumentParser(description='Plots a B-scan image.', usage='cd gprMax; python -m tools.plot_Bscan outputfile output')
    parser.add_argument('outputfile', help='name of output file including path')
    parser.add_argument('output', help='name of output component to be plotted', choices=['Ex', 'Ey', 'Ez', 'Hx', 'Hy', 'Hz', 'Ix', 'Iy', 'Iz'])
    args = parser.parse_args()

    make_plot(args.outputfile, args.output)