from plugins.external.sergio_proxy.plugins.plugin import Plugin

class CacheKill(Plugin):
    name = "CacheKill Plugin"
    optname = "cachekill"
    desc = "Kills page caching by modifying headers."
    implements = ["handleHeader","connectionMade"]
    has_opts = True
    bad_headers = ['if-none-match','if-modified-since']
    def add_options(self,options):
        options.add_argument("--preserve-cookies",action="store_true",
                help="Preserve cookies (will allow caching in some situations).")
    def handleHeader(self,request,key,value):
        '''Handles all response headers'''
        request.client.headers['Expires'] = "0"
        request.client.headers['Cache-Control'] = "no-cache"
    def connectionMade(self,request):
        '''Handles outgoing request'''
        request.headers['Pragma'] = 'no-cache'
        for h in self.bad_headers:
            if h in request.headers:
                request.headers[h] = ""