#!/usr/bin/env python3
# -*- coding: utf-8 -*-
############################################################################
#
# MODULE:       v.unpack
# AUTHOR(S):    Luca Delucchi
#
# PURPOSE:      Unpack up a vector map packed with v.pack
# COPYRIGHT:    (C) 2010-2017 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: Imports a GRASS GIS specific vector archive file (packed with v.pack) as a vector map
#% keyword: vector
#% keyword: import
#% keyword: copying
#%end
#%option G_OPT_F_BIN_INPUT
#% description: Name of input pack file
#% key_desc: name.pack
#%end
#%option G_OPT_V_OUTPUT
#% label: Name for output vector map
#% description: Default: taken from input file internals
#% required : no
#% guisection: Output settings
#%end
#%flag
#% key: o
#% label: Override projection check (use current location's projection)
#% description: Assume that the dataset has same projection as the current location
#% guisection: Output settings
#%end
#%flag
#% key: p
#% label: Print projection information of input pack file and exit
#% guisection: Print
#%end

import os
import sys
import shutil
import tarfile
import atexit

from grass.script.utils import diff_files, try_rmdir
from grass.script import core as grass
from grass.script import db as grassdb
from grass.exceptions import CalledModuleError


def cleanup():
    try_rmdir(tmp_dir)


def main():
    infile = options['input']

    # create temporary directory
    global tmp_dir
    tmp_dir = grass.tempdir()
    grass.debug('tmp_dir = %s' % tmp_dir)

    # check if the input file exists
    if not os.path.exists(infile):
        grass.fatal(_("File <%s> not found") % infile)

    # copy the files to tmp dir
    input_base = os.path.basename(infile)
    shutil.copyfile(infile, os.path.join(tmp_dir, input_base))
    os.chdir(tmp_dir)
    tar = tarfile.TarFile.open(name=input_base, mode='r')
    try:
        data_name = tar.getnames()[0]
    except:
        grass.fatal(_("Pack file unreadable"))

    if flags['p']:
        # print proj info and exit
        try:
            for fname in ['PROJ_INFO', 'PROJ_UNITS']:
                f = tar.extractfile(fname)
                sys.stdout.write(f.read())
        except KeyError:
            grass.fatal(_("Pack file unreadable: file '{}' missing".format(fname)))
        tar.close()

        return 0

    # set the output name
    if options['output']:
        map_name = options['output']
    else:
        map_name = data_name

    # grass env
    gisenv = grass.gisenv()
    mset_dir = os.path.join(gisenv['GISDBASE'],
                            gisenv['LOCATION_NAME'],
                            gisenv['MAPSET'])

    new_dir = os.path.join(mset_dir, 'vector', map_name)

    gfile = grass.find_file(name=map_name, element='vector', mapset='.')
    overwrite = os.getenv('GRASS_OVERWRITE')
    if gfile['file'] and overwrite != '1':
        grass.fatal(_("Vector map <%s> already exists") % map_name)
    elif overwrite == '1' and gfile['file']:
        grass.warning(_("Vector map <%s> already exists and will be overwritten") % map_name)
        grass.run_command('g.remove', flags='f', quiet=True, type='vector',
                          name=map_name)
        shutil.rmtree(new_dir, True)

    # extract data
    tar.extractall()
    tar.close()
    if os.path.exists(os.path.join(data_name, 'coor')):
        pass
    elif os.path.exists(os.path.join(data_name, 'cell')):
        grass.fatal(_("This GRASS GIS pack file contains raster data. Use "
                      "r.unpack to unpack <%s>" % map_name))
    else:
        grass.fatal(_("Pack file unreadable"))

    # check projection compatibility in a rather crappy way
    loc_proj = os.path.join(mset_dir, '..', 'PERMANENT', 'PROJ_INFO')
    loc_proj_units = os.path.join(mset_dir, '..', 'PERMANENT', 'PROJ_UNITS')

    skip_projection_check = False
    if not os.path.exists(os.path.join(tmp_dir, 'PROJ_INFO')):
        if os.path.exists(loc_proj):
            grass.fatal(
                _("PROJ_INFO file is missing, unpack vector map in XY (unprojected) location."))
        skip_projection_check = True  # XY location

    if not skip_projection_check:
        diff_result_1 = diff_result_2 = None
        if not grass.compare_key_value_text_files(filename_a=os.path.join(tmp_dir, 'PROJ_INFO'),
                                                  filename_b=loc_proj, proj=True):
            diff_result_1 = diff_files(os.path.join(tmp_dir, 'PROJ_INFO'),
                                       loc_proj)

        if not grass.compare_key_value_text_files(filename_a=os.path.join(tmp_dir, 'PROJ_UNITS'),
                                                  filename_b=loc_proj_units,
                                                  units=True):
            diff_result_2 = diff_files(os.path.join(tmp_dir, 'PROJ_UNITS'),
                                       loc_proj_units)

        if diff_result_1 or diff_result_2:
            if flags['o']:
                grass.warning(_("Projection information does not match. Proceeding..."))
            else:
                if diff_result_1:
                    grass.warning(_("Difference between PROJ_INFO file of packed map "
                                    "and of current location:\n{diff}").format(diff=''.join(diff_result_1)))
                if diff_result_2:
                    grass.warning(_("Difference between PROJ_UNITS file of packed map "
                                    "and of current location:\n{diff}").format(diff=''.join(diff_result_2)))
                grass.fatal(_("Projection of dataset does not appear to match current location."
                              " In case of no significant differences in the projection definitions,"
                              " use the -o flag to ignore them and use"
                              " current location definition."))

    # new db
    fromdb = os.path.join(tmp_dir, 'db.sqlite')
    # copy file
    shutil.copytree(data_name, new_dir)
    # exist fromdb
    if os.path.exists(fromdb):
        # the db connection in the output mapset
        dbconn = grassdb.db_connection(force=True)
        todb = dbconn['database']
        # return all tables
        list_fromtable = grass.read_command('db.tables', driver='sqlite',
                                            database=fromdb).splitlines()

        # return the list of old connection for extract layer number and key
        dbln = open(os.path.join(new_dir, 'dbln'), 'r')
        dbnlist = dbln.readlines()
        dbln.close()
        # check if dbf or sqlite directory exists
        if dbconn['driver'] == 'dbf' and not os.path.exists(os.path.join(mset_dir, 'dbf')):
            os.mkdir(os.path.join(mset_dir, 'dbf'))
        elif dbconn['driver'] == 'sqlite' and not os.path.exists(os.path.join(mset_dir, 'sqlite')):
            os.mkdir(os.path.join(mset_dir, 'sqlite'))
        # for each old connection
        for t in dbnlist:
            # it split the line of each connection, to found layer number and key
            if len(t.split('|')) != 1:
                values = t.split('|')
            else:
                values = t.split(' ')

            from_table = values[1]
            layer = values[0].split('/')[0]
            # we need to take care about the table name in case of several layer
            if options["output"]:
                if len(dbnlist) > 1:
                    to_table = "%s_%s" % (map_name, layer)
                else:
                    to_table = map_name
            else:
                to_table = from_table

            grass.verbose(_("Coping table <%s> as table <%s>") % (from_table,
                                                                  to_table))

            # copy the table in the default database
            try:
                grass.run_command('db.copy', to_driver=dbconn['driver'],
                                  to_database=todb, to_table=to_table,
                                  from_driver='sqlite',
                                  from_database=fromdb,
                                  from_table=from_table)
            except CalledModuleError:
                grass.fatal(_("Unable to copy table <%s> as table <%s>") % (from_table, to_table))

            grass.verbose(_("Connect table <%s> to vector map <%s> at layer <%s>") %
                           (to_table, map_name, layer))

            # and connect the new tables with the right layer
            try:
                grass.run_command('v.db.connect', flags='o', quiet=True,
                                  driver=dbconn['driver'], database=todb,
                                  map=map_name, key=values[2],
                                  layer=layer, table=to_table)
            except CalledModuleError:
                grass.fatal(_("Unable to connect table <%s> to vector map <%s>") %
                             (to_table, map_name))

    grass.message(_("Vector map <%s> successfully unpacked") % map_name)

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