### This script will capture a screenshot of a twitter account page

    Usage $ casperjs screenshot.coffee <twitter-account>
###
casper = require('casper').create
    viewportSize:
        width: 1024
        height: 768

twitterAccount = casper.cli.get(0)
filename = casper.cli.get(1)

if not twitterAccount or not filename or not /\.(png|jpg|pdf)$/i.test(filename)
    casper.echo "Usage $ casperjs samples/screenshot.coffee <twitter-account> <filename.[jpg|png|pdf]>"
    casper.exit()

casper.start "https://twitter.com/#!/#{twitterAccount}", ->
    capture = ->
        @captureSelector filename, 'html'
        @echo "Saved screenshot of #{@getCurrentUrl()} to #{filename}"
    @waitForSelector '.tweet-row', capture, null, 12000

casper.run()