#!/usr/bin/python

import sys
import urllib2
import StringIO
import struct
import ReseekFile

def getImageSize(url):
    datastream = urllib2.urlopen(url)
    datastream = ReseekFile.ReseekFile(datastream)
    data = str(datastream.read(24))
    size = len(data)
    height = -1
    width = -1
    content_type = ''

    # handle GIFs
    if (size >= 10) and data[:6] in ('GIF87a', 'GIF89a'):
        # Check to see if content_type is correct
        content_type = 'image/gif'
        w, h = struct.unpack("<HH", data[6:10])
        width = int(w)
        height = int(h)

    # See PNG 2. Edition spec (http://www.w3.org/TR/PNG/)
    # Bytes 0-7 are below, 4-byte chunk length, then 'IHDR'
    # and finally the 4-byte width, height
    elif ((size >= 24) and data.startswith('\211PNG\r\n\032\n')
          and (data[12:16] == 'IHDR')):
        content_type = 'image/png'
        w, h = struct.unpack(">LL", data[16:24])
        width = int(w)
        height = int(h)

    # Maybe this is for an older PNG version.
    elif (size >= 16) and data.startswith('\211PNG\r\n\032\n'):
        # Check to see if we have the right content type
        content_type = 'image/png'
        w, h = struct.unpack(">LL", data[8:16])
        width = int(w)
        height = int(h)

    # handle JPEGs
    elif (size >= 2) and data.startswith('\377\330'):
        content_type = 'image/jpeg'
        datastream.seek(0)
        datastream.read(2)
        b = datastream.read(1)
        try:
            while (b and ord(b) != 0xDA):
                while (ord(b) != 0xFF): b = datastream.read(1)
                while (ord(b) == 0xFF): b = datastream.read(1)
                if (ord(b) >= 0xC0 and ord(b) <= 0xC3):
                    datastream.read(3)
                    h, w = struct.unpack(">HH", datastream.read(4))
                    break
                else:
                    datastream.read(int(struct.unpack(">H", datastream.read(2))[0])-2)
                b = datastream.read(1)
            width = int(w)
            height = int(h)
        except struct.error:
            pass
        except ValueError:
            pass

    return content_type, width, height

if len(sys.argv) != 2:
    print 'usage: ./image_size.py <url>'
    sys.exit()

print getImageSize(sys.argv[1])