#!/usr/bin/env python

############################################################################
#
# MODULE:    r.vect.stats
# AUTHOR(S): Vaclav Petras <wenzeslaus gmail com>
# PURPOSE:
# COPYRIGHT: (C) 2017 by Vaclav Petras 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: Bins vector points into a raster map.
#% keyword: raster
#% keyword: vector
#% keyword: points
#% keyword: binning
#%end
#%option G_OPT_V_INPUT
#%end
#%option G_OPT_R_OUTPUT
#%end
#%option G_OPT_DB_COLUMN
#% description: Name of attribute column for statistics
#% guisection: Attributes
#%end
#%option
#% key: method
#% type: string
#% required: no
#% multiple: no
#% options: n,min,max,range,sum,mean,stddev,variance,coeff_var,median,percentile,skewness,trimmean
#% description: Statistic to use for raster values
#% descriptions: n;Number of points in cell;min;Minimum value of point values in cell;max;Maximum value of point values in cell;range;Range of point values in cell;sum;Sum of point values in cell;mean;Mean (average) value of point values in cell;stddev;Standard deviation of point values in cell;variance;Variance of point values in cell;coeff_var;Coefficient of variance of point values in cell;median;Median value of point values in cell;percentile;Pth (nth) percentile of point values in cell;skewness;Skewness of point values in cell;trimmean;Trimmed mean of point values in cell
#% answer: mean
#% guisection: Attributes
#%end

import sys

import grass.script as gs
from grass.exceptions import CalledModuleError

def main():
    options, flags = gs.parser()

    vector = options['input']
    layer = 1
    raster = options['output']
    method = options['method']
    z = 3
    sep = 'pipe'
    out_args = {}

    if not gs.find_file(vector, element='vector')['fullname']:
        gs.fatal('Vector map <{0}> not found'.format(vector))

    if options['column']:
        z = 4
        out_args['column'] = options['column']
        out_args['where'] = '{0} IS NOT NULL'.format(options['column'])

        columns = gs.vector_columns(vector)

        if options['column'] not in columns:
            gs.fatal(_('Column <{0}> not found'.format(options['column']))) 
        if columns[options['column']]['type'] not in ('INTEGER', 'DOUBLE PRECISION'):
            gs.fatal(_('Column <{0}> is not numeric'.format(options['column']))) 


    out_process = gs.pipe_command(
        'v.out.ascii', input=vector, layer=layer, format='point',
        separator=sep, flags='r', **out_args)
    in_process = gs.start_command(
        'r.in.xyz', input='-', output=raster, method=method, z=z,
        separator=sep, stdin=out_process.stdout)
    in_process.communicate()
    out_process.wait()

    return 0

if __name__ == "__main__":
    sys.exit(main())