#===============================================================================
# Copyright (C) 2014 Ryan Holmes
#
# This file is part of pyfa.
#
# pyfa 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 3 of the License, or
# (at your option) any later version.
#
# pyfa 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 pyfa.  If not, see <http://www.gnu.org/licenses/>.
#===============================================================================

from service.settings import NetworkSettings
import urllib2
import urllib
import config
import socket

# network timeout, otherwise pyfa hangs for a long while if no internet connection
timeout = 3
socket.setdefaulttimeout(timeout)

class Error(StandardError):
    def __init__(self, msg=None):
        self.message = msg

class RequestError(StandardError):
    pass

class AuthenticationError(StandardError):
    pass

class ServerError(StandardError):
    pass

class TimeoutError(StandardError):
    pass


class Network():
    # Request constants - every request must supply this, as it is checked if
    # enabled or not via settings
    ENABLED = 1
    EVE = 2  # Mostly API, but also covers CREST requests
    PRICES = 4
    UPDATE = 8

    _instance = None
    @classmethod
    def getInstance(cls):
        if cls._instance == None:
            cls._instance = Network()

        return cls._instance

    def request(self, url, type, data=None):
        # URL is required to be https as of right now
        #print "Starting request: %s\n\tType: %s\n\tPost Data: %s"%(url,type,data)

        # Make sure request is enabled
        access = NetworkSettings.getInstance().getAccess()

        if not self.ENABLED & access or not type & access:
            raise Error("Access not enabled - please enable in Preferences > Network")

        # Set up some things for the request
        versionString = "{0} {1} - {2} {3}".format(config.version, config.tag, config.expansionName, config.expansionVersion)
        headers = {"User-Agent" : "pyfa {0} (Python-urllib2)".format(versionString)}

        proxy = NetworkSettings.getInstance().getProxySettings()
        if proxy is not None:
            # proxy is a tuple of (host, port):  (u'192.168.20.1', 3128)
            proxy_auth = NetworkSettings.getInstance().getProxyAuthDetails()
            # proxy_auth is a tuple of (login, password) or None
            if proxy_auth is not None:
                # add login:password@ in front of proxy address
                proxy_handler = urllib2.ProxyHandler({'https': '{0}:{1}@{2}:{3}'.format(
                    proxy_auth[0], proxy_auth[1], proxy[0], proxy[1])})
            else:
                # build proxy handler with no login/pass info
                proxy_handler = urllib2.ProxyHandler({'https': "{0}:{1}".format(proxy[0], proxy[1])})
            opener = urllib2.build_opener(proxy_handler)
            urllib2.install_opener(opener)
        else:
            # This is a bug fix, explicitly disable possibly previously installed
            # opener with proxy, by urllib2.install_opener() a few lines above in code.
            # Now this explicitly disables proxy handler, "uninstalling" opener.
            # This is used in case when user had proxy enabled, so proxy_handler was already
            # installed globally, and then user had disabled the proxy, so we should clear that opener
            urllib2.install_opener(None)
            # another option could be installing a default opener:
            # urllib2.install_opener(urllib2.build_opener())

        request = urllib2.Request(url, headers=headers, data=urllib.urlencode(data) if data else None)
        try:
            return urllib2.urlopen(request)
        except urllib2.HTTPError, error:
            if error.code == 404:
                raise RequestError()
            elif error.code == 403:
                raise AuthenticationError()
            elif error.code >= 500:
                raise ServerError()
        except urllib2.URLError, error:
            if "timed out" in error.reason:
                raise TimeoutError()
            else:
                raise Error(error)