#!/usr/bin/env python

############################################################################
#
# MODULE:       i.spectral
# AUTHOR(S):    Markus Neteler, 18. August 1998
#               Converted to Python by Glynn Clements
# PURPOSE:      displays spectral response at user specified locations in
#               group or images
# COPYRIGHT:    (C) 1999 by the GRASS Development Team
#
#               This program is free software under the GNU General Public
#               License (>=v2). Read the file COPYING that comes with GRASS
#               for details.
#
#############################################################################

# written by Markus Neteler 18. August 1998
#            neteler geog.uni-hannover.de
# 
# bugfix: 25. Nov.98/20. Jan. 1999
# 3 March 2006: Added multiple images and group support by Francesco Pirotti - CIRGEO
# this script needs gnuplot

#%Module
#%  description: Displays spectral response at user specified locations in group or images.
#%  keywords: imagery
#%  keywords: querying
#%  keywords: raster
#%  keywords: multispectral
#%End
#%option G_OPT_I_GROUP
#% required : no
#%end
#%option G_OPT_R_INPUTS
#% key: raster
#% required : no
#%end
#%option G_OPT_F_OUTPUT
#% key: output
#% description: Name for output PNG image
#% required : no
#%end
#%option G_OPT_M_COORDS
#% multiple: yes
#% required: yes
#%end
#%flag
#%key: c
#%description: Label with coordinates instead of numbering
#%end
#%flag
#%key: g
#%description: Use gnuplot for display
#%end

import os
import atexit
from grass.script import core as grass


def cleanup():
    grass.try_rmdir(tmp_dir)


def draw_gnuplot(what, xlabels, output, label):
    xrange = 0

    for i, row in enumerate(what):
        outfile = os.path.join(tmp_dir, 'data_%d' % i)
        outf = open(outfile, 'w')
        xrange = max(xrange, len(row) - 2)
        for j, val in enumerate(row[3:]):
            outf.write("%d %s\n" % (j + 1, val))
        outf.close()

    # build gnuplot script
    lines = []
    if output:
        lines += [
            "set term png large",
            "set output '%s'" % output
        ]
    lines += [
        "set xtics (%s)" % xlabels,
        "set grid",
        "set title 'Spectral signatures'",
        "set xrange [0:%d]" % xrange,
        "set noclabel",
        "set xlabel 'Bands'",
        "set ylabel 'DN Value'",
        "set style data lines"
    ]

    cmd = []
    for i, row in enumerate(what):
        if not label:
            title = str(i + 1)
        else:
            title = str(tuple(row[0:2]))
        cmd.append("'data_%d' title '%s'" % (i, title))
    cmd = ','.join(cmd)
    cmd = ' '.join(['plot', cmd, "with linespoints pt 779"])
    lines.append(cmd)

    plotfile = os.path.join(tmp_dir, 'spectrum.gnuplot')
    plotf = open(plotfile, 'w')
    for line in lines:
        plotf.write(line + '\n')
    plotf.close()

    if output:
        grass.call(['gnuplot', plotfile])
    else:
        grass.call(['gnuplot', '-persist', plotfile])


def draw_linegraph(what):
    yfiles = []

    xfile = os.path.join(tmp_dir, 'data_x')

    xf = open(xfile, 'w')
    for j, val in enumerate(what[0][3:]):
        xf.write("%d\n" % (j + 1))
    xf.close()

    for i, row in enumerate(what):
        yfile = os.path.join(tmp_dir, 'data_y_%d' % i)
        yf = open(yfile, 'w')
        for j, val in enumerate(row[3:]):
            yf.write("%s\n" % val)
        yf.close()
        yfiles.append(yfile)

    sienna = '#%02x%02x%02x' % (160,  82, 45)
    coral = '#%02x%02x%02x' % (255, 127, 80)
    gp_colors = ['red', 'green', 'blue', 'magenta', 'cyan', sienna, 'orange',
                 coral]

    colors = gp_colors
    while len(what) > len(colors):
        colors += gp_colors
    colors = colors[0:len(what)]

    grass.run_command('d.linegraph', x_file=xfile, y_file=yfiles,
                      y_color=colors, title='Spectral signatures',
                      x_title='Bands', y_title='DN Value')


def main():
    group = options['group']
    raster = options['raster']
    output = options['output']
    coords = options['coordinates']
    label = flags['c']
    gnuplot = flags['g']
    
    global tmp_dir
    tmp_dir = grass.tempdir()
    
    if not group and not raster:
        grass.fatal(_("Either group= or raster= is required"))

    if group and raster:
        grass.fatal(_("group= and raster= are mutually exclusive"))

    #check if present
    if gnuplot and not grass.find_program('gnuplot'):
        grass.fatal(_("gnuplot required, please install first"))

    # get y-data for gnuplot-data file
    # get data from group files and set the x-axis labels

    if group:
        # ## PARSES THE GROUP FILES - gets rid of ugly header info from group
        #list output
        s = grass.read_command('i.group', flags='g', group=group, quiet=True)
        rastermaps = s.splitlines()
    else:
        # ## get data from list of files and set the x-axis labels
        rastermaps = raster.split(',')

    xlabels = ["'%s' %d" % (n, i + 1) for i, n in enumerate(rastermaps)]
    xlabels = ','.join(xlabels)

    what = []
    s = grass.read_command('r.what', map=rastermaps, coordinates=coords,
                           quiet=True)
    for l in s.splitlines():
        f = l.split('|')
        for i, v in enumerate(f):
            if v in ['', '*']:
                f[i] = 0
            else:
                f[i] = float(v)
        what.append(f)

    # build data files
    if gnuplot:
        draw_gnuplot(what, xlabels, output, label)
    else:
        draw_linegraph(what)

if __name__ == "__main__":
    options, flags = grass.parser()
    atexit.register(cleanup)
    main()