#!/usr/bin/env python

############################################################################
#
# MODULE:       v.what.rast.multi
# AUTHOR(S):    Pierre Roudier
# PURPOSE:      Uploads values of multiple rasters at positions of vector
#               points to the table.
# COPYRIGHT:    (C) 2017 by Pierre Roudier, and the GRASS Development Team
#
#  This program 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 2 of the License, or
#  (at your option) any later version.
#
#  This program 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.
#
############################################################################

#%module
#% description: Uploads values of multiple rasters at positions of vector points to the table.
#% keyword: vector
#% keyword: sampling
#% keyword: raster
#% keyword: position
#% keyword: querying
#% keyword: attribute table
#% keyword: surface information
#%end

#%flag
#% key: i
#% description: Interpolate values from the nearest four cells
#%end

#%option
#% key: map
#% type: string
#% required: yes
#% multiple: no
#% key_desc: name
#% label: Name of vector points map for which to edit attributes
#% description: Or data source for direct OGR access
#% gisprompt: old,vector,vector
#%end

#%option
#% key: layer
#% type: string
#% required: no
#% multiple: no
#% label: Layer number or name
#% description: Vector features can have category values in different layers.
# This number determines which layer to use. When used with direct OGR access
# this is the layer name.
#% answer: 1
#% gisprompt: old,layer,layer
#%end

#%option
#% key: type
#% type: string
#% required: no
#% multiple: yes
#% options: point,centroid
#% description: Input feature type
#% answer: point
#%end

#%option
#% key: raster
#% type: string
#% required: yes
#% multiple: yes
#% key_desc: name
#% description: Name of existing raster map to be queried
#% gisprompt: old,cell,raster
#%end

#%option
#% key: columns
#% type: string
#% required: no
#% multiple: no
#% key_desc: name
#% description: Names of attribute columns to be updated with the query result
#% gisprompt: old,dbcolumn,dbcolumn
#%end

#%option
#% key: where
#% type: string
#% required: no
#% multiple: no
#% key_desc: sql_query
#% label: WHERE conditions of SQL statement without 'where' keyword
#% description: Example: income < 1000 and population >= 10000
#%end

import sys
import os
import grass.script as grass
from grass.pygrass.modules.shortcuts import vector as v

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


def main():

    # Get options
    vmap = options["map"]  # Vector points
    layer = options["layer"]
    vtype = options["type"]
    rasters = options["raster"].split(',')  # List of rasters to sample
    columns = options["columns"].split(',')  # List of column names
    where = options["where"]

    # If length(columns) != length(rasters), throw error
    if columns != ['']:
        if len(columns) != len(rasters):
            grass.fatal(_(
            "The number of rasters and the number of column names do not match"
            ))

    # Get flags
    if flags["i"]:
        fl = "i"
    else:
        fl = ""

    # For each raster
    for i in range(len(rasters)):

        r = rasters[i]

        if columns != ['']:
            c = columns[i]
        else:
            c = r

        # Sample using v.what.rast
        v.what_rast(
          map=vmap,
          layer=layer,
          type=vtype,
          raster=r,
          column=c,
          where=where,
          flags=fl
        )

    return 0

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