from twisted.internet import reactor
from twisted.web import proxy as twisted_proxy
from twisted.web import server
from twisted.web import resource
from twisted.web.resource import NoResource
from owsdev.service import active_services


class ServicesResource(resource.Resource):
    isLeaf = False

    def __init__(self, reporter):
        resource.Resource.__init__(self)
        self.reporter = reporter
        self.port_map = {
            service.qa_host(): service.port for service in active_services()}

    def getChild(self, path, request):
        request_host = request.getHeader('host').split(':')[0]
        if request_host not in self.port_map:
            self.reporter.echo(
                'Error: request for {} not proxied.'.format(request_host))
            return NoResource()

        port = self.port_map[request_host]
        proxy_resource = twisted_proxy.ReverseProxyResource(
            'localhost', port, request.path)
        proxy_resource.isLeaf = 1
        return proxy_resource


def run_proxy(reporter):
    site = server.Site(ServicesResource(reporter))
    reactor.listenTCP(80, site)
    reactor.run()