#!/usr/bin/env python
# -*- coding: utf-8 -*-
############################################################################
#
# MODULE:       t.rast.algebra
# AUTHOR(S):    Thomas Leppelt, Soeren Gebbert
#
# PURPOSE:      Provide temporal raster algebra to perform spatial an temporal operations
#               for space time datasets by topological relationships to other space time
#               datasets.
# COPYRIGHT:    (C) 2014-2017 by 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: Apply temporal and spatial operations on space time raster datasets using temporal raster algebra.
#% keyword: temporal
#% keyword: algebra
#% keyword: raster
#% keyword: time
#%end

#%option
#% key: expression
#% type: string
#% description: r.mapcalc expression for temporal and spatial analysis of space time raster datasets
#% required : yes
#%end

#%option
#% key: basename
#% type: string
#% label: Basename of the new generated output maps
#% description: A numerical suffix separated by an underscore will be attached to create a unique identifier
#% required: yes
#%end

#%option
#% key: suffix
#% type: string
#% description: Suffix to add at basename: set 'gran' for granularity, 'time' for the full time format, 'num' for numerical suffix with a specific number of digits (default %05)
#% answer: num
#% required: no
#% multiple: no
#%end

#%option
#% key: nprocs
#% type: integer
#% description: Number of r.mapcalc processes to run in parallel
#% required: no
#% multiple: no
#% answer: 1
#%end

#%flag
#% key: s
#% description: Check the spatial topology of temporally related maps and process only spatially related maps
#%end

#%flag
#% key: n
#% description: Register Null maps
#%end

#%flag
#% key: g
#% description: Use granularity sampling instead of the temporal topology approach
#%end

#%flag
#% key: d
#% description: Perform a dry run, compute all dependencies and module calls but don't run them
#%end

import grass.script
import sys


def main():
    # lazy imports
    import grass.temporal as tgis

    expression = options['expression']
    basename = options['basename']
    nprocs = options["nprocs"]
    time_suffix = options["suffix"]
    spatial = flags["s"]
    register_null = flags["n"]
    granularity = flags["g"]
    dry_run = flags["d"]

    # Check for PLY istallation
    try:
        import ply.lex as lex
        import ply.yacc as yacc
    except:
        grass.script.fatal(_("Please install PLY (Lex and Yacc Python implementation) to use the temporal algebra modules. "
                             "You can use t.rast.mapcalc that provides a limited but useful alternative to "
                             "t.rast.algebra without PLY requirement."))

    tgis.init(True)
    p = tgis.TemporalRasterAlgebraParser(run = True,
                                         debug=False,
                                         spatial=spatial,
                                         nprocs=nprocs,
                                         register_null=register_null,
                                         dry_run=dry_run, time_suffix=time_suffix)

    if granularity:
        if not p.setup_common_granularity(expression=expression,  lexer = tgis.TemporalRasterAlgebraLexer()):
            grass.script.fatal(_("Unable to process the expression in granularity algebra mode"))

    pc = p.parse(expression, basename, grass.script.overwrite())

    if dry_run is True:
        import pprint
        pprint.pprint(pc)

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

