# constants

from PIL import Image

# needed for web support
import urllib.request, io

# process image acquistion and display

''' Function get_web_image() return image at web resource indicated by link
'''
def get_web_image( link ) :

    # get access to module Image
    from PIL import Image
    ''' Returns a pil image of the image named by link '''

    # get a connection to the web resource name by link
    stream = urllib.request.urlopen( link )

    # get the conents of the web resource
    data = stream.read()

    # convert the data to bytes
    bytes = io.BytesIO( data )

    # get the image represented by the bytes
    image = Image.open( bytes )

    # convert the image to RGB format
    image = image.convert('RGB')

    # hand back the image
    return image

''' Function get_selfie() returns a selfie of the indicated id
'''
def get_selfie( id ) :

    REPOSITORY = 'http://www.cs.virginia.edu/~cs1112/people/'

    link = REPOSITORY + id + '/selfie.jpg'

    return get_web_image( link )


''' Function get_image() returns a image from online or local source or an existing Image
'''
def get_image( source ) :
    try :
        if ( str( type( source ) ) == "<class 'PIL.Image.Image'>" ) :
            # check to if source is an existing Image
            image = source
        elif ( 'http://' == source[ 0 : 7 ].lower() ) :
            # look at the initial characters of source to see if its on the web
            # initial characters indicate the image is out on the web
            image = get_web_image( source )
        else :
            # initial characters indicate the image is a local file
            image = Image.open( source )
    except :
        image = None

    return image.copy()