#! /usr/bin/python

"""

Matches geographic points in a Kasabi dataset to the Ordnance Survey administrative region

that it is in. It uses the OS boundary data to determine whether a given point is in the

region or not.

Usage:

If you don't have os.dat then you need to run parse-boundaries.py first.

This script takes the following parameters:

-d/--dataset the dataset containing the geopoints

-f/--file the name of the output file

-q/--query an alternate sparql query to use

The sparql query must be a select and must select at least three variables

called ?s, ?lat and ?long being the subject, latitude and longitude

The default query is:

select ?s ?lat ?long where {

?s <http://www.w3.org/2003/01/geo/wgs84_pos#lat> ?lat ;

<http://www.w3.org/2003/01/geo/wgs84_pos#long> ?long .

}

Prerequisites:

Set an environment variable KASABI_API_KEY equal to your Kasabi api key. On

Linux you can do this by adding this line to your ~/.profile file:

export KASABI_API_KEY=blah

You also need to install ijson which is a python wrapper for the yajl streaming json parser.

ijson: http://pypi.python.org/pypi/ijson/

yajl: http://lloyd.github.com/yajl/

Install ruby and cmake

sudo apt-get install ruby

sudo apt-get install cmake

Download the version 1 source of yajl (not version 2), unpack and in

the source directory type:

sudo ./configure

sudo make install

sudo ldconfig

Install ijson with:

sudo easy_install ijson

"""

import sys

import os

import re

import optparse

from shapely.geometry import Polygon, Point

from shapely.wkt import loads

from shapely import iterops

from ijson import items

import urllib2

import urllib

import pytassium

p = optparse.OptionParser()

p.add_option("-d", "--dataset", action="store", dest="dataset", metavar="DATASET", help="use dataset DATASET")

p.add_option("-q", "--query", action="store", dest="query", metavar="QUERY", help="use sparql QUERY")

p.add_option("-f", "--file", action="store", dest="filename", metavar="FILENAME", help="output results to FILENAME")

opts, args = p.parse_args()

if not opts.dataset:

print "Please supply the name of a kasabi dataset and make sure you're subscribed to its sparql endpoint"

sys.exit(1)

if not opts.filename:

print "Please supply the name of the output file"

sys.exit(1)

if not opts.query:

query = "select ?s ?lat ?long where {?s <http://www.w3.org/2003/01/geo/wgs84_pos#lat> ?lat ; <http://www.w3.org/2003/01/geo/wgs84_pos#long> ?long . }"

else:

query = opts.sparql

fout = open(opts.filename, "w")

points = []

ds = pytassium.Dataset(opts.dataset, os.environ['KASABI_API_KEY'])

sparql_uri = ds.get_api('sparql').uri

print "Querying dataset for geographic points"

url = "%s?query=%s&apikey=%s" % (sparql_uri, urllib.quote_plus(query), os.environ['KASABI_API_KEY'])

req = urllib2.Request(url, None, {'Accept':'application/json'})

f = urllib2.urlopen(req)

objects = items(f, 'results.bindings.item')

count = 0

for t in objects:

p = Point(float(t['long']['value']), float(t['lat']['value']))

p.uri = t['s']['value']

points.append(p)

count += 1

if count > 0:

if count % 1000 == 0:

print str(count) + " coordinates found"

sys.stdout.flush()

elif count % 25 == 0:

sys.stdout.write('.')

sys.stdout.flush()

print str(count) + " coordinates found"

print "Matching points to regions"

f = open('os.dat', 'r')

count = 0

for line in f:

(region, wkt) = line.split("\t")

polygon = loads(wkt)

for point in iterops.contains(polygon, points, True):

fout.write("<%s> <http://data.ordnancesurvey.co.uk/ontology/spatialrelations/within> <%s> .\n" % (point.uri, region))

fout.write("<%s> <http://data.ordnancesurvey.co.uk/ontology/spatialrelations/contains> <%s> .\n" % (region, point.uri))

count += 1

if count > 0:

if count % 1000 == 0:

print str(count) + " regions checked"

sys.stdout.flush()

elif count % 25 == 0:

sys.stdout.write('.')

sys.stdout.flush()

print str(count) + " regions checked"

f.close()

fout.close()