#!/usr/bin/env python
############################################################################
#
# MODULE:       v.neighborhoodmatrix
# AUTHOR:       Moritz Lennert
# PURPOSE:      Exports a csv file with the neighborhood matrix of polygons
#
# COPYRIGHT:    (c) 2014 Moritz Lennert, and 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.
#
#############################################################################

#%module
#% description: Exports the neighborhood matrix of polygons in a vector map
#% keyword: vector
#% keyword: neighborhood matrix
#%end
#%option G_OPT_V_INPUT
#%end
#%option
#% key: player
#% type: integer
#% description: Layer in map where polygons are to be found
#% answer: 1
#% required: no
#%end
#%option G_OPT_DB_COLUMN
#% key: idcolumn
#% description: Name of column containing polygon ids
#% required: no
#%end
#%option G_OPT_F_OUTPUT
#% description: Name for output file (if omitted or "-" output to stdout)
#% required: no
#%end
#%option G_OPT_F_SEP
#%end
#%flag
#% key: b
#% description: create bidirectional matrix (same neighborhood relation repeated twice)
#%end

import sys
import os
import atexit
import grass.script as gscript
from grass.script.utils import separator

def cleanup():
    gscript.run_command('g.remove', flags='f', type='vector',
                      pat=tempmapname, quiet=True)

def main():
    # if no output filename, output to stdout
    input = options['input']
    player = int(options['player'])
    output = options['output']
    idcolumn = options['idcolumn'] if options['idcolumn'] else False
    sep = separator(options['separator'])
    bidirectional = flags['b']
    global tempmapname
    tempmapname='neighborhoodmatrix_tempmap_%d' % os.getpid() 
    #TODO: automatically determine the first available layer in file
    blayer = player+1

    gscript.run_command('v.category', input=input, output=tempmapname,
            option='add', layer=blayer, type='boundary', quiet=True,
            overwrite=True)
    vtodb_results=gscript.read_command('v.to.db', flags='p', map=tempmapname,
            type='boundary', option='sides', layer=blayer, qlayer=player, quiet=True)

    #put result into a list of integer pairs
    temp_neighbors=[]
    for line in vtodb_results.splitlines():
        if line.split('|')[1]!='-1' and line.split('|')[2]!='-1':
            temp_neighbors.append([int(line.split('|')[1]), int(line.split('|')[2])])

    #temp_neighbors.sort()

    #if user wants bidirectional matrix, add the inversed pairs to the original
    if bidirectional:
        neighbors_reversed=[]
        for pair in temp_neighbors:
            neighbors_reversed.append([pair[1], pair[0]])
        temp_neighbors += neighbors_reversed

    #uniqify the list of integer pairs
    neighbors = [list(x) for x in set(tuple(x) for x in temp_neighbors)]
    neighbors.sort()

    currentcat=''
    if output and output != '-':
        out=open(output, 'w')
    for pair in neighbors:
        if idcolumn:
            # While pair[0] stays the same we don't have to call v.db.select
            # again and again to get the id
            if currentcat != pair[0]:
                currentcat = pair[0]
                fromid=gscript.read_command('v.db.select',
                                 map=input,
                                 column=idcolumn,
                                 where="cat=%d" % pair[0],
                                 layer=player,
                                 flags="c",
                                 quiet=True).rstrip()
            toid=gscript.read_command('v.db.select',
                             map=input,
                             column=idcolumn,
                             where="cat=%d" % pair[1],
                             layer=player,
                             flags="c",
                             quiet=True).rstrip()
            if output and output != '-':
                out.write(fromid + sep + toid + '\n')
            else:
                print((fromid + sep + toid))
        else:
            if output and output != '-':
                out.write(str(pair[0]) + sep + str(pair[1])+'\n')
            else:
                print((str(pair[0]) + sep + str(pair[1])))
    if output and output != '-':
        out.close()



    sys.exit()

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