#!/usr/bin/env python2
#
############################################################################
#
# MODULE:       r.fillnulls
# AUTHOR(S):    Markus Neteler
#               Updated to GRASS 5.7 by Michael Barton
#               Updated to GRASS 6.0 by Markus Neteler
#               Ring and zoom improvements by Hamish Bowman
#               Converted to Python by Glynn Clements
#               Added support for r.resamp.bspline by Luca Delucchi
#               Per hole filling with RST by Maris Nartiss
#               Speedup for per hole filling with RST by Stefan Blumentrath
# PURPOSE:      fills NULL (no data areas) in raster maps
#               The script respects a user mask (MASK) if present.
#
# COPYRIGHT:    (C) 2001-2016 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: Fills no-data areas in raster maps using spline interpolation.
#% keyword: raster
#% keyword: surface
#% keyword: elevation
#% keyword: interpolation
#% keyword: splines
#% keyword: no-data filling
#%end
#%option G_OPT_R_INPUT
#%end
#%option G_OPT_R_OUTPUT
#%end
#%option
#% key: method
#% type: string
#% description: Interpolation method to use
#% required: yes
#% options: bilinear,bicubic,rst
#% answer: rst
#%end
#%option
#% key: tension
#% type: double
#% description: Spline tension parameter
#% required : no
#% answer : 40.
#% guisection: RST options
#%end
#%option
#% key: smooth
#% type: double
#% description: Spline smoothing parameter
#% required : no
#% answer : 0.1
#% guisection: RST options
#%end
#%option
#% key: edge
#% type: integer
#% description: Width of hole edge used for interpolation (in cells)
#% required : no
#% answer : 3
#% options : 2-100
#% guisection: RST options
#%end
#%option
#% key: npmin
#% type: integer
#% description: Minimum number of points for approximation in a segment (>segmax)
#% required : no
#% answer : 600
#% options : 2-10000
#% guisection: RST options
#%end
#%option
#% key: segmax
#% type: integer
#% description: Maximum number of points in a segment
#% required : no
#% answer : 300
#% options : 2-10000
#% guisection: RST options
#%end
#%option
#% key: lambda
#% type: double
#% required: no
#% multiple: no
#% label: Tykhonov regularization parameter (affects smoothing)
#% description: Used in bilinear and bicubic spline interpolation
#% answer: 0.01
#% guisection: Spline options
#%end


import sys
import os
import atexit

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

# i18N
import gettext
gettext.install('grassmods', os.path.join(os.getenv("GISBASE"), 'locale'))

tmp_rmaps = list()
tmp_vmaps = list()
usermask = None
mapset = None

# what to do in case of user break:


def cleanup():
    # delete internal mask and any TMP files:
    if len(tmp_vmaps) > 0:
        grass.run_command('g.remove', quiet=True, flags='fb', type='vector', name=tmp_vmaps)
    if len(tmp_rmaps) > 0:
        grass.run_command('g.remove', quiet=True, flags='fb', type='raster', name=tmp_rmaps)
    if usermask and mapset:
        if grass.find_file(usermask, mapset=mapset)['file']:
            grass.run_command('g.rename', quiet=True, raster=(usermask, 'MASK'), overwrite=True)


def main():
    global usermask, mapset, tmp_rmaps, tmp_vmaps

    input = options['input']
    output = options['output']
    tension = options['tension']
    smooth = options['smooth']
    method = options['method']
    edge = int(options['edge'])
    segmax = int(options['segmax'])
    npmin = int(options['npmin'])
    lambda_ = float(options['lambda'])
    quiet = True  # FIXME
    mapset = grass.gisenv()['MAPSET']
    unique = str(os.getpid())  # Shouldn't we use temp name?
    prefix = 'r_fillnulls_%s_' % unique
    failed_list = list()  # a list of failed holes. Caused by issues with v.surf.rst. Connected with #1813

    # check if input file exists
    if not grass.find_file(input)['file']:
        grass.fatal(_("Raster map <%s> not found") % input)

    # save original region
    reg_org = grass.region()

    # check if a MASK is already present
    # and remove it to not interfere with NULL lookup part
    # as we don't fill MASKed parts!
    if grass.find_file('MASK', mapset=mapset)['file']:
        usermask = "usermask_mask." + unique
        grass.message(_("A user raster mask (MASK) is present. Saving it..."))
        grass.run_command('g.rename', quiet=quiet, raster=('MASK', usermask))

    # check if method is rst to use v.surf.rst
    if method == 'rst':
        # idea: filter all NULLS and grow that area(s) by 3 pixel, then
        # interpolate from these surrounding 3 pixel edge
        filling = prefix + 'filled'

        grass.use_temp_region()
        grass.run_command('g.region', align=input, quiet=quiet)
        region = grass.region()
        ns_res = region['nsres']
        ew_res = region['ewres']

        grass.message(_("Using RST interpolation..."))
        grass.message(_("Locating and isolating NULL areas..."))

        # creating binary (0/1) map
        if usermask:
            grass.message(_("Skipping masked raster parts"))
            grass.mapcalc("$tmp1 = if(isnull(\"$input\") && !($mask == 0 || isnull($mask)),1,null())",
                          tmp1=prefix + 'nulls', input=input, mask=usermask)
        else:
            grass.mapcalc("$tmp1 = if(isnull(\"$input\"),1,null())",
                          tmp1=prefix + 'nulls', input=input)
        tmp_rmaps.append(prefix + 'nulls')

        # restoring user's mask, if present
        # to ignore MASKed original values
        if usermask:
            grass.message(_("Restoring user mask (MASK)..."))
            try:
                grass.run_command('g.rename', quiet=quiet, raster=(usermask, 'MASK'))
            except CalledModuleError:
                grass.warning(_("Failed to restore user MASK!"))
            usermask = None

        # grow identified holes by X pixels
        grass.message(_("Growing NULL areas"))
        tmp_rmaps.append(prefix + 'grown')
        try:
            grass.run_command('r.grow', input=prefix + 'nulls',
                              radius=edge + 0.01, old=1, new=1,
                              out=prefix + 'grown', quiet=quiet)
        except CalledModuleError:
            grass.fatal(_("abandoned. Removing temporary map, restoring "
                          "user mask if needed:"))

        # assign unique IDs to each hole or hole system (holes closer than edge distance)
        grass.message(_("Assigning IDs to NULL areas"))
        tmp_rmaps.append(prefix + 'clumped')
        try:
            grass.run_command(
                'r.clump',
                input=prefix +
                'grown',
                output=prefix +
                'clumped',
                quiet=quiet)
        except CalledModuleError:
            grass.fatal(_("abandoned. Removing temporary map, restoring "
                          "user mask if needed:"))

        # get a list of unique hole cat's
        grass.mapcalc("$out = if(isnull($inp), null(), $clumped)",
                      out=prefix + 'holes', inp=prefix + 'nulls', clumped=prefix + 'clumped')
        tmp_rmaps.append(prefix + 'holes')

        # use new IDs to identify holes
        try:
            grass.run_command('r.to.vect', flags='v',
                              input=prefix + 'holes', output=prefix + 'holes',
                              type='area', quiet=quiet)
        except:
            grass.fatal(_("abandoned. Removing temporary maps, restoring "
                          "user mask if needed:"))
        tmp_vmaps.append(prefix + 'holes')

        # get a list of unique hole cat's
        cats_file_name = grass.tempfile(False)
        grass.run_command(
            'v.db.select',
            flags='c',
            map=prefix + 'holes',
            columns='cat',
            file=cats_file_name,
            quiet=quiet)
        cat_list = list()
        cats_file = file(cats_file_name)
        for line in cats_file:
            cat_list.append(line.rstrip('\n'))
        cats_file.close()
        os.remove(cats_file_name)

        if len(cat_list) < 1:
            grass.fatal(_("Input map has no holes. Check region settings."))

        # GTC Hole is NULL area in a raster map
        grass.message(_("Processing %d map holes") % len(cat_list))
        first = True
        hole_n = 1
        for cat in cat_list:
            holename = prefix + 'hole_' + cat
            # GTC Hole is a NULL area in a raster map
            grass.message(_("Filling hole %s of %s") % (hole_n, len(cat_list)))
            hole_n = hole_n + 1
            # cut out only CAT hole for processing
            try:
                grass.run_command('v.extract', input=prefix + 'holes',
                                  output=holename + '_pol',
                                  cats=cat, quiet=quiet)
            except CalledModuleError:
                grass.fatal(_("abandoned. Removing temporary maps, restoring "
                              "user mask if needed:"))
            tmp_vmaps.append(holename + '_pol')

            # zoom to specific hole with a buffer of two cells around the hole to
            # remove rest of data
            try:
                grass.run_command('g.region',
                                  vector=holename + '_pol', align=input,
                                  w='w-%d' % (edge * 2 * ew_res),
                                  e='e+%d' % (edge * 2 * ew_res),
                                  n='n+%d' % (edge * 2 * ns_res),
                                  s='s-%d' % (edge * 2 * ns_res),
                                  quiet=quiet)
            except CalledModuleError:
                grass.fatal(_("abandoned. Removing temporary maps, restoring "
                              "user mask if needed:"))

            # remove temporary map to not overfill disk
            try:
                grass.run_command('g.remove', flags='fb', type='vector',
                                  name=holename + '_pol', quiet=quiet)
            except CalledModuleError:
                grass.fatal(_("abandoned. Removing temporary maps, restoring "
                              "user mask if needed:"))
            tmp_vmaps.remove(holename + '_pol')

            # copy only data around hole
            grass.mapcalc("$out = if($inp == $catn, $inp, null())",
                          out=holename, inp=prefix + 'holes', catn=cat)
            tmp_rmaps.append(holename)

            # If here loop is split into two, next part of loop can be run in parallel
            # (except final result patching)
            # Downside - on large maps such approach causes large disk usage

            # grow hole border to get it's edge area
            tmp_rmaps.append(holename + '_grown')
            try:
                grass.run_command('r.grow', input=holename, radius=edge + 0.01,
                                  old=-1, out=holename + '_grown', quiet=quiet)
            except CalledModuleError:
                grass.fatal(_("abandoned. Removing temporary map, restoring "
                              "user mask if needed:"))

            # no idea why r.grow old=-1 doesn't replace existing values with NULL
            grass.mapcalc("$out = if($inp == -1, null(), \"$dem\")",
                          out=holename + '_edges', inp=holename + '_grown', dem=input)
            tmp_rmaps.append(holename + '_edges')

            # convert to points for interpolation
            tmp_vmaps.append(holename)
            try:
                grass.run_command('r.to.vect',
                                  input=holename + '_edges', output=holename,
                                  type='point', flags='z', quiet=quiet)
            except CalledModuleError:
                grass.fatal(_("abandoned. Removing temporary maps, restoring "
                              "user mask if needed:"))

            # count number of points to control segmax parameter for interpolation:
            pointsnumber = grass.vector_info_topo(map=holename)['points']
            grass.verbose(_("Interpolating %d points") % pointsnumber)

            if pointsnumber < 2:
                grass.verbose(_("No points to interpolate"))
                failed_list.append(holename)
                continue

            # Avoid v.surf.rst warnings
            if pointsnumber < segmax:
                use_npmin = pointsnumber
                use_segmax = pointsnumber * 2
            else:
                use_npmin = npmin
                use_segmax = segmax

            # launch v.surf.rst
            tmp_rmaps.append(holename + '_dem')
            try:
                grass.run_command('v.surf.rst', quiet=quiet,
                                  input=holename, elev=holename + '_dem',
                                  tension=tension, smooth=smooth,
                                  segmax=use_segmax, npmin=use_npmin)
            except CalledModuleError:
                # GTC Hole is NULL area in a raster map
                grass.fatal(_("Failed to fill hole %s") % cat)

            # v.surf.rst sometimes fails with exit code 0
            # related bug #1813
            if not grass.find_file(holename + '_dem')['file']:
                try:
                    tmp_rmaps.remove(holename)
                    tmp_rmaps.remove(holename + '_grown')
                    tmp_rmaps.remove(holename + '_edges')
                    tmp_rmaps.remove(holename + '_dem')
                    tmp_vmaps.remove(holename)
                except:
                    pass
                grass.warning(
                    _("Filling has failed silently. Leaving temporary maps "
                      "with prefix <%s> for debugging.") %
                    holename)
                failed_list.append(holename)
                continue

            # append hole result to interpolated version later used to patch into original DEM
            if first:
                tmp_rmaps.append(filling)
                grass.run_command('g.region', align=input, raster=holename + '_dem', quiet=quiet)
                grass.mapcalc("$out = if(isnull($inp), null(), $dem)",
                              out=filling, inp=holename, dem=holename + '_dem')
                first = False
            else:
                tmp_rmaps.append(filling + '_tmp')
                grass.run_command(
                    'g.region', align=input, raster=(
                        filling, holename + '_dem'), quiet=quiet)
                grass.mapcalc(
                    "$out = if(isnull($inp), if(isnull($fill), null(), $fill), $dem)",
                    out=filling + '_tmp',
                    inp=holename,
                    dem=holename + '_dem',
                    fill=filling)
                try:
                    grass.run_command('g.rename',
                                      raster=(filling + '_tmp', filling),
                                      overwrite=True, quiet=quiet)
                except CalledModuleError:
                    grass.fatal(
                        _("abandoned. Removing temporary maps, restoring user "
                          "mask if needed:"))
                # this map has been removed. No need for later cleanup.
                tmp_rmaps.remove(filling + '_tmp')

            # remove temporary maps to not overfill disk
            try:
                tmp_rmaps.remove(holename)
                tmp_rmaps.remove(holename + '_grown')
                tmp_rmaps.remove(holename + '_edges')
                tmp_rmaps.remove(holename + '_dem')
            except:
                pass
            try:
                grass.run_command('g.remove', quiet=quiet,
                                  flags='fb', type='raster',
                                  name=(holename,
                                        holename + '_grown',
                                        holename + '_edges',
                                        holename + '_dem'))
            except CalledModuleError:
                grass.fatal(_("abandoned. Removing temporary maps, restoring "
                              "user mask if needed:"))
            try:
                tmp_vmaps.remove(holename)
            except:
                pass
            try:
                grass.run_command('g.remove', quiet=quiet, flags='fb',
                                  type='vector', name=holename)
            except CalledModuleError:
                grass.fatal(_("abandoned. Removing temporary maps, restoring user mask if needed:"))

    # check if method is different from rst to use r.resamp.bspline
    if method != 'rst':
        grass.message(_("Using %s bspline interpolation") % method)

        # clone current region
        grass.use_temp_region()
        grass.run_command('g.region', align=input)

        reg = grass.region()
        # launch r.resamp.bspline
        tmp_rmaps.append(prefix + 'filled')
        if usermask:
            grass.run_command('r.resamp.bspline', input=input, mask=usermask,
                              output=prefix + 'filled', method=method,
                              ew_step=3 * reg['ewres'], ns_step=3 * reg['nsres'],
                              lambda_=lambda_, flags='n')
        else:
            grass.run_command('r.resamp.bspline', input=input,
                              output=prefix + 'filled', method=method,
                              ew_step=3 * reg['ewres'], ns_step=3 * reg['nsres'],
                              lambda_=lambda_, flags='n')

    # restoring user's mask, if present:
    if usermask:
        grass.message(_("Restoring user mask (MASK)..."))
        try:
            grass.run_command('g.rename', quiet=quiet, raster=(usermask, 'MASK'))
        except CalledModuleError:
            grass.warning(_("Failed to restore user MASK!"))
        usermask = None

    # set region to original extents, align to input
    grass.run_command('g.region', n=reg_org['n'], s=reg_org['s'],
                      e=reg_org['e'], w=reg_org['w'], align=input)

    # patch orig and fill map
    grass.message(_("Patching fill data into NULL areas..."))
    # we can use --o here as g.parser already checks on startup
    grass.run_command('r.patch', input=(input, prefix + 'filled'),
                      output=output, overwrite=True)

    # restore the real region
    grass.del_temp_region()

    grass.message(_("Filled raster map is: %s") % output)

    # write cmd history:
    grass.raster_history(output)

    if len(failed_list) > 0:
        grass.warning(
            _("Following holes where not filled. Temporary maps with are left "
              "in place to allow examination of unfilled holes"))
        outlist = failed_list[0]
        for hole in failed_list[1:]:
            outlist = ', ' + outlist
        grass.message(outlist)

    grass.message(_("Done."))

if __name__ == "__main__":
    options, flags = grass.parser()
    atexit.register(cleanup)
    main()
