"""Rough brute-force script to extract coordinates for specific search
results from Google Maps. Should really have used a proper XML parser,
but the XML is embedded in a string inside JavaScript code in the
returned HTML page, which makes it kind of awkward. Anyway, this works
for now.

$Id: gxy.py,v 1.4 2009/08/04 20:15:20 larsga Exp $
"""

import sys, urllib, string, re

def extract_point(reg, data, pos):
    m = reg.search(data, pos)
    assert m, "Latitude/longitude not found for point"
    return m.group(1)

def get_multihit_info(data, hitno):
    reg_point = re.compile("<point ")
    start = 0
    while hitno > 0:
        m = reg_point.search(data, start)
        if not m:
            break

        hitno = hitno - 1
        start = m.end()

    if not m:
        print "No match found"
        sys.exit(1)

    pos = m.end()

    reg_lat = re.compile('lat="([^"]+)"')
    reg_long = re.compile('lng="([^"]+)"')

    lat = extract_point(reg_lat, data, pos)
    long = extract_point(reg_long, data, pos)

    print "Longitude: %s, latitude: %s" % (long, lat)

def try_address_marker(data):
    if string.find(data, 'id:"addr"') == -1:
        return None

    # {id:"addr",lat:59.323132999999999,lng:18.071866,
    reg_marker = re.compile("\\{id:\s*(\"|')addr(\"|'),\s*lat:\s*([^,]+),\s*lng:\s*([^,]+)")
    m = reg_marker.search(data)
    assert m
    return (m.group(4), m.group(3))

def try_approx_hit(data):
    if string.find(data, ",approx:true,") == -1:
        return None

    # markers:[{id:"cent",lat:59.317428,lng:18.050695999999999,
    reg_marker = re.compile("markers:\\[\\{id:(\"|')cent(\"|'),lat:([^,]+),lng:([^,]+),")
    m = reg_marker.search(data)
    assert m
    return (float(m.group(4)), float(m.group(3)))

def try_new_format(data):
    if string.find(data, ',geocode:"') == -1:
        return None

    reg_marker = re.compile("latlng:{lat:(-?\d+\\.\d+),lng:(-?\d+\\.\d+)")
    m = reg_marker.search(data)
    assert m
    return (m.group(2), m.group(1))

def prettify(num):
    if len(num) > 10:
        last = num[-1]
        num = num[ : -1] # remove last random digit
        while num[-1] in "09":
            last = num[-1]
            num = num[ : -1]

        if last == "9":
            num = num[ : -1] + str(int(num[-1]) + 1)

    return num

# ---

query = urllib.quote(sys.argv[1])
if len(sys.argv) > 2:
    hitno = ord(string.upper(sys.argv[2])) - 64
else:
    hitno = -1

file = urllib.urlopen("http://maps.google.com/local?q=%s&output=js" % query)
data = file.read()
print data

point = try_approx_hit(data)
if not point:
    point = try_address_marker(data)
if not point:
    point = try_new_format(data)
point = (prettify(point[0]), prettify(point[1]))
print "Longitude: %s, latitude: %s" % point

# if hitno != -1:
#     get_multihit_info(data, hitno)
# else:
#     get_address_marker(data)