#!/usr/bin/env python
# -- coding: utf-8 --
#
############################################################################
#
# MODULE:      r.green.hydro.potential
# AUTHOR(S):   Pietro Zambelli
# PURPOSE:     Calculate the hydropower energy potential for each basin
# COPYRIGHT:   (C) 2014 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.
#
#############################################################################
#

#%module
#% description: Move points to the closest vector map
#% keyword: vector
#% keyword: hydropower
#% keyword: renewable energy
#%end
#%option G_OPT_V_INPUT
#% key: points
#% required: yes
#%end
#%option G_OPT_V_INPUT
#% key: lines
#% required: yes
#%end
#%option G_OPT_V_OUTPUT
#% key: output
#% required: yes
#%end
#%option
#% key: max_dist
#% type: double
#% description: Maximum distance from points to river
#% required: yes
#% answer: 10
#%end
from __future__ import print_function

# import system libraries
import os
import sys

from grass.pygrass.messages import get_msgr
from grass.pygrass.vector import VectorTopo
from grass.script import core as gcore

if "GISBASE" not in os.environ:
    print("You must be in GRASS GIS to run this program.")
    sys.exit(1)


def get_new_points(points, lines, output, maxdist=50):
    skipped = []
    ovwr = gcore.overwrite()
    msgr = get_msgr()
    points, pmset = points.split('@') if '@' in points else (points, '')
    lines, lmset = lines.split('@') if '@' in lines else (lines, '')
    with VectorTopo(points, mapset=pmset, mode='r') as pts:
        cols = pts.table.columns.items() if pts.table else None
        with VectorTopo(lines, mapset=lmset, mode='r') as lns:
            with VectorTopo(output, mode='w', tab_cols=cols,
                            overwrite=ovwr) as out:
                for pnt in pts:
                    line = lns.find['by_point'].geo(pnt, maxdist=maxdist)
                    if line is None:
                        msg = ("Not found any line in the radius of %.2f "
                               "for the point with cat: %d. The point "
                               "will be skipped!")
                        msgr.warning(msg % (maxdist, pnt.cat))
                        skipped.append(pnt.cat)
                        continue
                    # find the new point
                    newpnt, dist, _, _ = line.distance(pnt)
                    # get the attributes
                    attrs = (None if pnt.attrs is None
                             else pnt.attrs.values()[1:])
                    # write the new point in the new vector map
                    out.write(newpnt, attrs)
                # save the changes on the output table
                out.table.conn.commit()


def main(opts, flgs):
    get_new_points(opts['points'], opts['lines'], opts['output'],
                   float(opts['max_dist']))


if __name__ == "__main__":
    options, flags = gcore.parser()
    sys.exit(main(options, flags))