#!/usr/bin/env python
# -*- coding: utf-8 -*-

################################################
#
# MODULE:       t.rast.null
# AUTHOR(S):    Luca Delucchi
# PURPOSE:      Manages NULL-values of a given space time raster dataset.
#
# COPYRIGHT:    (C) 2018 by Luca Delucchi
#
#               This program is free software under the GNU General Public
#               License (>=v2). Read the file COPYING that comes with GRASS
#               for details.
#
################################################

#%module
#% description: Manages NULL-values of a given space time raster dataset.
#% keyword: temporal
#% keyword: raster
#% keyword: null data
#%end

#%option G_OPT_STRDS_INPUT
#%end

#%option
#% key: setnull
#% type: string
#% label: List of cell values to be set to NULL
#% multiple: yes
#% required: no
#%end

#%option
#% key: null
#% type: double
#% label: The value to replace the null value by
#% multiple: no
#% required: no
#%end

#%option G_OPT_T_WHERE
#%end

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

import copy
import sys

import grass.temporal as tgis
import grass.script as gscript
import grass.pygrass.modules as pymod

def main():
    strds = options["input"]
    where = options["where"]
    nprocs = int(options["nprocs"])
    
    nullmod = pymod.Module('r.null')
    nullmod.flags.quiet = True
    if options["null"]:
        nullmod.inputs.null = options["null"]
    elif options["setnull"]:
        nullmod.inputs.setnull = options["setnull"]
    else:
        gscript.fatal(_("Please set 'null' or 'setnull' option"))
        
    tgis.init()
    # We need a database interface
    dbif = tgis.SQLDatabaseInterfaceConnection()
    dbif.connect()

    sp = tgis.open_old_stds(strds, "strds", dbif)
    maps = sp.get_registered_maps_as_objects(where, "start_time", None)
    if maps is None:
        gscript.fatal(_("Space time raster dataset {st} seems to be "
                        "empty".format(st=strds)))
        return 1
    # module queue for parallel execution
    process_queue = pymod.ParallelModuleQueue(int(nprocs))

    count = 0
    num_maps = len(maps)
    
    for mapp in maps:
        count += 1
        mod = copy.deepcopy(nullmod)
        mod.inputs.map = mapp.get_id()
        process_queue.put(mod)

        if count%10 == 0:
            gscript.percent(count, num_maps, 1)

    # Wait for unfinished processes
    process_queue.wait()
    
if __name__ == "__main__":
    options, flags = gscript.parser()
    sys.exit(main())