ALLOW_TEST = False
DEFAULT_URL = 'http://blog.dantup.com/'

from google.appengine.ext import webapp
from google.appengine.ext.webapp.util import run_wsgi_app
from google.appengine.api import mail
import webob, urlparse, logging

# Old Domain: New Domain, Map urls (else redirects to root)
urls = {
	'www.dantup.com': ('blog.dantup.com', False),
	'www.dantup.me.uk': ('blog.dantup.com', False),
	'www.tuppeny.com': ('blog.dantup.com', False),
	'dantup-redir.appspot.com': ('blog.dantup.com', False),
	'blog.dantup.me.uk': ('blog.dantup.com', True),
	'feeds.dantup.me.uk': ('feeds.dantup.com', True),
	'wavenotifier.dantup.me.uk': ('wavenotifier.dantup.com', True),
	'wavenotifier.tuppeny.com': ('wavenotifier.dantup.com', True),
	'go.dantup.me.uk': ('go.dantup.com', True),
	'go.tuppeny.com': ('go.dantup.com', True),
}

test_urls = [
	'http://www.dantup.me.uk',
	'http://www.dantup.me.uk/',
	'http://www.dantup.me.uk/blah',
	'http://www.dantup.com',
	'http://www.dantup.com/',
	'http://www.dantup.com/blah',
	'http://www.tuppeny.com',
	'http://www.tuppeny.com/',
	'http://www.tuppeny.com/blah',
	'http://blog.dantup.me.uk',
	'http://blog.dantup.me.uk/',
	'http://blog.dantup.me.uk/2010/mytest',
	'http://feeds.dantup.me.uk',
	'http://feeds.dantup.me.uk/',
	'http://feeds.dantup.me.uk/2010/mytest',
	'http://wavenotifier.dantup.me.uk',
	'http://wavenotifier.dantup.me.uk/',
	'http://wavenotifier.dantup.me.uk/2010/mytest',
	'http://wavenotifier.tuppeny.com',
	'http://wavenotifier.tuppeny.com/',
	'http://wavenotifier.tuppeny.com/2010/mytest',
	'http://go.dantup.me.uk',
	'http://go.dantup.me.uk/',
	'http://go.dantup.me.uk/mytest',
	'http://go.tuppeny.com',
	'http://go.tuppeny.com/',
	'http://go.tuppeny.com/mytest',
]

class MainHandler(webapp.RequestHandler):

	def get(self):
		# If we're allowed to test (eg. local), and requested /test, then output the test
		if ALLOW_TEST and self.request.path == '/test':
			self.response.out.write('<h1>testing</h1>')
			self.response.out.write('<table>')
			for test_url in test_urls:
				self.response.out.write('<tr><td>' + test_url + '</td><td>&nbsp;</td><td>' + get_redirect_url(test_url) + '</td></tr>')
			self.response.out.write('</table>')
		# Otherwise, just go ahead and redirect
		else:
			# Perform redirect
			url = get_redirect_url(self.request.url)
			
			if url:
				logging.info('Redirecting ' + self.request.url + ' to ' + url);
				self.redirect(url, permanent=True)
			else:
				# Log that we didn't know what this was, and redirect to a good default
				logging.error('Unable to redirect this url: ' + self.request.url);
				mail.send_mail_to_admins(
					sender='"DanTup Redirect" <myemail@mydomain.com>',
					subject='Redirect Script Error',
					body='Unable to redirect this url: ' + self.request.url
				)
				# Don't do permanent (301), since we don't know what this is.
				# Move it into the dictionary above if needed
				self.redirect(DEFAULT_URL)


def get_redirect_url(url):
	scheme, netloc, path, query, fragment = urlparse.urlsplit(url)
	
	# Discard any port number from the hostname
	netloc = netloc.split(':', 1)[0]
	
	# Fix empty paths to be just '/' for consistency
	if path == '':
		path = '/'
	
	# Check if we have a mapping for this domain
	if netloc in urls:
		# Grab the redirect info tuple
		redirect_info = urls[netloc]
		# Root redirects
		if not redirect_info[1]:
			return 'http://' + redirect_info[0] + '/'
		# Paths
		else:
			return urlparse.urlunsplit(['http', redirect_info[0], path, query, fragment])
	# No mapping, so return None
	else:
		return None
		

application = webapp.WSGIApplication([("/.*", MainHandler)], debug=True)

def main():
	run_wsgi_app(application)

if __name__ == "__main__":
	main()