#!/usr/bin/env python3

############################################################################
#
# MODULE:	v.in.wfs
# AUTHOR(S):	Markus Neteler. neteler itc it
#               Hamish Bowman
#               Converted to Python by Glynn Clements
# PURPOSE:	WFS support
# COPYRIGHT:	(C) 2006-2012 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.
#
# GetFeature example:
# http://mapserver.gdf-hannover.de/cgi-bin/grassuserwfs?REQUEST=GetFeature&SERVICE=WFS&VERSION=1.0.0
#############################################################################

#
# TODO: suggest to depend on the OWSLib for OGC web service needs
#       http://pypi.python.org/pypi/OWSLib
#

# %Module
# % description: Imports GetFeature from a WFS server.
# % keyword: vector
# % keyword: import
# % keyword: OGC web services
# % keyword: OGC WFS
# %end
# %option
# % key: url
# % type: string
# % description: Base URL starting with 'http' and ending in '?'
# % required: yes
# %end
# %option G_OPT_V_OUTPUT
# %end
# %option
# % key: name
# % type: string
# % description: Comma separated names of data layers to download
# % multiple: yes
# % required: no
# %end
# %option
# % key: srs
# % type: string
# % label: Specify alternate spatial reference system (example: EPSG:4326)
# % description: The given code must be supported by the server, consult the capabilities file
# % required: no
# %end
# %option
# % key: maximum_features
# % type: integer
# % label: Maximum number of features to download
# % description: (default: unlimited)
# %end
# %option
# % key: start_index
# % type: integer
# % label: Skip earlier feature IDs and start downloading at this one
# % description: (default: start with the first feature)
# %end
# %option
# % key: username
# % type: string
# % required: no
# % multiple: no
# % label: Username or file with username or environment variable name with username
# %end
# %option
# % key: password
# % type: string
# % required: no
# % multiple: no
# % label: Password or file with password or environment variable name with password
# %end
# %flag
# % key: l
# todo #% description: List available layers and exit
# % description: Download server capabilities to 'wms_capabilities.xml' in the current directory and exit
# % suppress_required: yes
# %end
# %flag
# % key: r
# % description: Restrict fetch to features which touch the current region
# %end


import os
import sys
from grass.script.utils import try_remove
from grass.script import core as grass

try:
    from urllib2 import urlopen, URLError, HTTPError
    from urllib2 import build_opener, install_opener
    from urllib2 import HTTPPasswordMgrWithDefaultRealm, HTTPBasicAuthHandler
except ImportError:
    from urllib.request import urlopen
    from urllib.request import build_opener, install_opener
    from urllib.request import HTTPPasswordMgrWithDefaultRealm, HTTPBasicAuthHandler
    from urllib.error import URLError, HTTPError


def main():
    out = options["output"]
    wfs_url = options["url"]

    request_base = "REQUEST=GetFeature&SERVICE=WFS&VERSION=1.0.0"
    wfs_url += request_base

    if options["name"]:
        wfs_url += "&TYPENAME=" + options["name"]

    if options["srs"]:
        wfs_url += "&SRS=" + options["srs"]

    if options["maximum_features"]:
        wfs_url += "&MAXFEATURES=" + options["maximum_features"]
        if int(options["maximum_features"]) < 1:
            # GTC Invalid WFS maximum features parameter
            grass.fatal(_("Invalid maximum number of features"))

    if options["start_index"]:
        wfs_url += "&STARTINDEX=" + options["start_index"]
        if int(options["start_index"]) < 1:
            # GTC Invalid WFS start index parameter
            grass.fatal(_('Features begin with index "1"'))

    if flags["r"]:
        bbox = grass.read_command("g.region", flags="w").split("=")[1]
        wfs_url += "&BBOX=" + bbox

    if flags["l"]:
        wfs_url = options["url"] + "REQUEST=GetCapabilities&SERVICE=WFS&VERSION=1.0.0"

    tmp = grass.tempfile()
    tmpxml = tmp + ".xml"

    grass.debug(wfs_url)

    # Set user and password if given
    if options["username"] and options["password"]:
        grass.message(_("Setting username and password..."))
        if os.path.isfile(options["username"]):
            with open(options["username"]) as f:
                filecontent = f.read()
                user = filecontent.strip()
        elif options["username"] in os.environ:
            user = os.environ[options["username"]]
        else:
            user = options["username"]
        if os.path.isfile(options["password"]):
            with open(options["password"]) as f:
                filecontent = f.read()
                pw = filecontent.strip()
        elif options["password"] in os.environ:
            pw = os.environ[options["password"]]
        else:
            pw = options["password"]

        passmgr = HTTPPasswordMgrWithDefaultRealm()
        passmgr.add_password(None, wfs_url, user, pw)
        authhandler = HTTPBasicAuthHandler(passmgr)
        opener = build_opener(authhandler)
        install_opener(opener)

    # GTC Downloading WFS features
    grass.message(_("Retrieving data..."))
    try:
        inf = urlopen(wfs_url)
    except HTTPError as e:
        # GTC WFS request HTTP failure
        grass.fatal(
            _("The server couldn't fulfill the request.\nError code: %s") % e.code
        )
    except URLError as e:
        # GTC WFS request network failure
        grass.fatal(_("Failed to reach the server.\nReason: %s") % e.reason)

    outf = open(tmpxml, "wb")
    while True:
        s = inf.read()
        if not s:
            break
        outf.write(s)
    inf.close()
    outf.close()

    if flags["l"]:
        import shutil

        if os.path.exists("wms_capabilities.xml"):
            grass.fatal(_('A file called "wms_capabilities.xml" already exists here'))
        # os.move() might fail if the temp file is on another volume, so we copy instead
        shutil.copy(tmpxml, "wms_capabilities.xml")
        try_remove(tmpxml)
        sys.exit(0)

    grass.message(_("Importing data..."))
    try:
        grass.run_command("v.in.ogr", flags="o", input=tmpxml, output=out)
        grass.message(_("Vector map <%s> imported from WFS.") % out)
    except Exception:
        grass.message(_("WFS import failed"))
    finally:
        try_remove(tmpxml)


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