#!/usr/bin/env python

############################################################################
#
# MODULE:       db.in.ogr
# AUTHOR(S):   	Markus Neteler
# PURPOSE:      Imports attribute tables in various formats
#               Converted to Python by Glynn Clements
# COPYRIGHT:    (C) 2007-2016 by Markus Neteler and 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 attribute tables in various formats.
#% keyword: database
#% keyword: import
#% keyword: attribute table
#% overwrite: yes
#%End

#%option G_OPT_F_BIN_INPUT
#% description: Table file to be imported or DB connection string
#%end

#%option
#% key: db_table
#% type: string
#% key_desc : name
#% description: Name of table from given DB to be imported
#% required : no
#%end

#%option G_OPT_DB_TABLE
#% key: output
#% description: Name for output table
#% required : no
#% guisection: Output
#% gisprompt: new,dbtable,dbtable
#%end

#%option
#% key: key
#% type: string
#% description: Name for auto-generated unique key column
#% required : no
#% guisection: Output
#%end

#%option
#% key: encoding
#% type: string
#% label: Encoding value for attribute data
#% descriptions: Overrides encoding interpretation, useful when importing DBF tables
#% guisection: Output
#%end

import os
import grass.script as grass
from grass.script.utils import decode
from grass.exceptions import CalledModuleError


def main():
    input = options['input']
    db_table = options['db_table']
    output = options['output']
    key = options['key']

    mapset = grass.gisenv()['MAPSET']

    if db_table:
        input = db_table

    if not output:
        tmpname = input.replace('.', '_')
        output = grass.basename(tmpname)

    # check if table exists
    try:
        nuldev = open(os.devnull, 'w+')
        s = grass.read_command('db.tables', flags='p', quiet=True, stderr=nuldev)
        nuldev.close()
    except CalledModuleError:
        # check connection parameters, set if uninitialized
        grass.read_command('db.connect', flags='c')
        s = grass.read_command('db.tables', flags='p', quiet=True)

    for l in decode(s).splitlines():
        if l == output:
            if grass.overwrite():
                grass.warning(_("Table <%s> already exists and will be "
                                "overwritten") % output)
                grass.write_command('db.execute', input='-',
                                    stdin="DROP TABLE %s" % output)
                break
            else:
                grass.fatal(_("Table <%s> already exists") % output)

    # treat DB as real vector map...
    layer = db_table if db_table else None

    vopts = {}
    if options['encoding']:
        vopts['encoding'] = options['encoding']

    try:
        grass.run_command('v.in.ogr', flags='o', input=input, output=output,
                          layer=layer, quiet=True, **vopts)
    except CalledModuleError:
        if db_table:
            grass.fatal(
                _("Input table <%s> not found or not readable") %
                input)
        else:
            grass.fatal(_("Input DSN <%s> not found or not readable") % input)

    # rename ID col if requested from cat to new name
    if key:
        grass.write_command('db.execute', quiet=True, input='-',
                            stdin="ALTER TABLE %s ADD COLUMN %s integer" %
                                  (output, key))
        grass.write_command('db.execute', quiet=True, input='-',
                            stdin="UPDATE %s SET %s=cat" % (output, key))

    # ... and immediately drop the empty geometry
    vectfile = grass.find_file(output, element='vector', mapset=mapset)['file']
    if not vectfile:
        grass.fatal(_("Something went wrong. Should not happen"))
    else:
        # remove the vector part
        grass.run_command('v.db.connect', quiet=True, map=output, layer='1',
                          flags='d')
        grass.run_command('g.remove', flags='f', quiet=True, type='vector',
                          name=output)

    # get rid of superfluous auto-added cat column (and cat_ if present)
    nuldev = open(os.devnull, 'w+')
    grass.run_command('db.dropcolumn', quiet=True, flags='f', table=output,
                      column='cat', stdout=nuldev, stderr=nuldev)
    nuldev.close()

    records = grass.db_describe(output)['nrows']
    grass.message(_("Imported table <%s> with %d rows") % (output, records))

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