#!/usr/bin/env python
###############################################################################
# $Id: get_soundg.py 13097 2007-11-26 21:19:53Z hobu $
#
# Project:  OGR Python samples
# Purpose:  Extract SOUNDGings from an S-57 dataset, and write them to
#           Shapefile format, creating one feature for each sounding, and
#           adding the elevation as an attribute for easier use. 
# Author:   Frank Warmerdam, warmerdam@pobox.com
#
###############################################################################
# Copyright (c) 2003, Frank Warmerdam <warmerdam@pobox.com>
# 
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.
###############################################################################

try:
    from osgeo import osr
    from osgeo import ogr
except ImportError:
    import osr
    import ogr

import string
import sys

#############################################################################
def Usage():
    print 'Usage: get_soundg.py <s57file> <shapefile>'
    print
    sys.exit(1)

#############################################################################
# Argument processing.

if len(sys.argv) != 3:
    Usage()

s57filename = sys.argv[1]
shpfilename = sys.argv[2]

#############################################################################-
# Open the S57 file, and find the SOUNDG layer.

ds = ogr.Open( s57filename )
src_soundg = ds.GetLayerByName( 'SOUNDG' )

#############################################################################-
# Create the output shapefile. 

shp_driver = ogr.GetDriverByName( 'ESRI Shapefile' )
shp_driver.DeleteDataSource( shpfilename )

shp_ds = shp_driver.CreateDataSource( shpfilename )

shp_layer = shp_ds.CreateLayer( 'out', geom_type = ogr.wkbPoint25D )

src_defn = src_soundg.GetLayerDefn()
field_count = src_defn.GetFieldCount()

#############################################################################-
# Copy the SOUNDG schema, and add an ELEV field.

out_mapping = []
for fld_index in range(field_count):
    src_fd = src_defn.GetFieldDefn( fld_index )
    
    fd = ogr.FieldDefn( src_fd.GetName(), src_fd.GetType() )
    fd.SetWidth( src_fd.GetWidth() )
    fd.SetPrecision( src_fd.GetPrecision() )
    if shp_layer.CreateField( fd ) != 0:
        out_mapping.append( -1 )
    else:
        out_mapping.append( shp_layer.GetLayerDefn().GetFieldCount() - 1 )

fd = ogr.FieldDefn( 'ELEV', ogr.OFTReal )
fd.SetWidth( 12 )
fd.SetPrecision( 4 )
shp_layer.CreateField( fd )
    
#############################################################################
# Process all SOUNDG features.

feat = src_soundg.GetNextFeature()
while feat is not None:

    multi_geom = feat.GetGeometryRef()

    for iPnt in range(multi_geom.GetGeometryCount()):
        pnt = multi_geom.GetGeometryRef( iPnt )

        feat2 = ogr.Feature(feature_def=shp_layer.GetLayerDefn())

        for fld_index in range(field_count):
            feat2.SetField( out_mapping[fld_index], feat.GetField( fld_index ) )

        feat2.SetField( 'ELEV', pnt.GetZ( 0 ) )
        feat2.SetGeometry( pnt )
        shp_layer.CreateFeature( feat2 )
        feat2.Destroy()

    feat.Destroy()

    feat = src_soundg.GetNextFeature()

#############################################################################
# Cleanup

shp_ds.Destroy()
ds.Destroy()

