# -*- coding: utf-8 -*-
#
# Copyright (C) 2006  Ali Sabil <ali.sabil@gmail.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#

from papyon.gnet.constants import *
from papyon.gnet.errors import *
from papyon.gnet.proxy import ProxyInfos
from papyon.gnet.message.HTTP import HTTPRequest
from papyon.gnet.io import TCPClient
from papyon.gnet.parser import HTTPParser
from papyon.gnet.proxy.factory import ProxyFactory

from urlparse import urlsplit

import gobject
import base64
import logging
import platform

__all__ = ['HTTP']

logger = logging.getLogger('papyon.gnet.HTTP')


class HTTP(gobject.GObject):
    """HTTP protocol client class."""
    
    __gsignals__ = {
            "error" : (gobject.SIGNAL_RUN_FIRST,
                gobject.TYPE_NONE,
                (object,)), # IoError

            "response-received": (gobject.SIGNAL_RUN_FIRST,
                gobject.TYPE_NONE,
                (object,)), # HTTPResponse

            "request-sent": (gobject.SIGNAL_RUN_FIRST,
                gobject.TYPE_NONE,
                (object,)), # HTTPRequest
            }

    def __init__(self, host, port=80, proxies={}):
        """Connection initialization
        
            @param host: the host to connect to.
            @type host: string

            @param port: the port number to connect to
            @type port: integer

            @param proxies: proxies that we can use to connect
            @type proxies: L{gnet.proxy.ProxyInfos}"""
        gobject.GObject.__init__(self)
        self._host = host
        self._port = port
        self._proxies = proxies
        self._http_proxy = None
        self._transport = None
        self._http_parser = None
        self._outgoing_queue = []
        self._redirected = False
        self._waiting_response = False
        self._parser_handles = []
        self._transport_handles = []

        if self._proxies and self._proxies.get('http', None):
            if self._proxies['http'].type == 'http':
                self._http_proxy = self._proxies['http']

        self._errored = False
        self.connect("error", self._on_self_error)

    def _on_self_error(self, *args):
        self._errored = True

    def _setup_transport(self):
        if self._transport is None:
            if self._http_proxy:
                self._transport = TCPClient(self._http_proxy.host,
                        self._http_proxy.port)
            else:
                self._transport = TCPClient(self._host, self._port)
                if self._proxies:
                    self._transport = ProxyFactory(self._transport,
                            self._proxies, 'http')
            self._setup_parser()
        
        if self._transport.get_property("status") != IoStatus.OPEN:
            self._transport.open()

    def _setup_parser(self):
        self._http_parser = HTTPParser(self._transport)
        self._parser_handles.append(self._http_parser.connect("received",
            self._on_response_received))

        self._transport_handles.append(self._transport.connect("notify::status",
            self._on_status_change))
        self._transport_handles.append(self._transport.connect("error",
            self._on_error))
        self._transport_handles.append(self._transport.connect("sent",
            self._on_request_sent))

    def _clean_transport(self):
        if self._http_parser:
            self._http_parser.disable()
            for handle in self._parser_handles:
                self._http_parser.disconnect(handle)
            self._http_parser = None
        if self._transport:
            for handle in self._transport_handles:
                self._transport.disconnect(handle)

    def _on_status_change(self, transport, param):
        if transport.get_property("status") == IoStatus.OPEN:
            self._process_queue()
        elif transport.get_property("status") == IoStatus.CLOSED and\
                (self._waiting_response or len(self._outgoing_queue) > 0) and\
                not (self._errored or self._redirected):
            self._waiting_response = False
            self._setup_transport()

    def _on_request_sent(self, transport, request, length):
        self._waiting_response = True
        assert(str(self._outgoing_queue[0]) == request)
        self.emit("request-sent", self._outgoing_queue[0])

    def _on_response_received(self, parser, response):
        if response.status >= 100 and response.status < 200:
            return
        if not self._waiting_response:
            logger.warning("Received response but wasn't waiting for one")
            logger.warning("<<< " + str(response))
            return

        self._waiting_response = False

        if response.status in (301, 302):
            self.close()
            location = response.headers['Location']
            logger.info("Server moved to %s" % location)
            logger.info("<<< " + str(response))

            protocol, host, path, query, fragment = urlsplit(location)
            self._redirected = True
            self._outgoing_queue[0].headers['Host'] = host

            try:
                host, port = host.rsplit(":", 1)
                port = int(port)
            except (TypeError, ValueError):
                port = None
            self._host = host
            self._redirected = False
            self._setup_transport()
            return

        if len(self._outgoing_queue) > 0:
            self._outgoing_queue.pop(0) # pop the request from the queue
        if response.status >= 400:
            logger.error("Received error code %i (%s) from %s:%i" %
                (response.status, response.reason, self._host, self._port))
            self.emit("error", HTTPError(response))
        else:
            self.emit("response-received", response)
        self._process_queue() # next request ?

    def _on_error(self, transport, error):
        self.emit("error", error)

    def _process_queue(self):
        if len(self._outgoing_queue) == 0 or \
                self._waiting_response: # no pipelining
            return
        if self._transport is None or \
                self._transport.get_property("status") != IoStatus.OPEN:
            self._setup_transport()
            return
        self._transport.send(str(self._outgoing_queue[0]))

    def request(self, resource='/', headers=None, data='', method='GET'):
        if headers is None:
            headers = {}
        headers['Host'] = self._host + ':' + str(self._port)
        headers['Content-Length'] = str(len(data))
        if 'User-Agent' not in headers:
            user_agent = GNet.NAME, GNet.VERSION, platform.system(), platform.machine()
            headers['User-Agent'] = "%s/%s (%s %s)" % user_agent

        if self._http_proxy is not None:
            url = 'http://%s:%d%s' % (self._host, self._port, resource)
            if self._http_proxy.user:
                auth = self._http_proxy.user + ':' + self._http_proxy.password
                credentials = base64.encodestring(auth).strip()
                headers['Proxy-Authorization'] = 'Basic ' + credentials
        else:
            url = resource
        request  = HTTPRequest(headers, data, method, url)
        self._outgoing_queue.append(request)
        self._process_queue()

    def close(self):
        self._clean_transport()
        if self._transport:
            self._transport.close()
        self._transport = None
