# convenience wrapper for urllib2 & friends
import binascii
import cookielib
import hmac
import json
import random
import string
import time
import urllib
import urllib2
import urlparse

from hashlib import sha1 
from urllib import quote, quote_plus as _quote_plus
from urllib2 import HTTPError, URLError

from lxml import etree, html


ua_skybot = 'Skybot/1.0 http://github.com/rmmh/skybot'

ua_firefox = 'Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.6) ' \
    'Gecko/20070725 Firefox/2.0.0.6'
ua_internetexplorer = 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)'

jar = cookielib.CookieJar()


def get(*args, **kwargs):
    return open(*args, **kwargs).read()


def get_html(*args, **kwargs):
    return html.fromstring(get(*args, **kwargs))


def get_xml(*args, **kwargs):
    return etree.fromstring(get(*args, **kwargs))


def get_json(*args, **kwargs):
    return json.loads(get(*args, **kwargs))


def open(url, query_params=None, user_agent=None, referer=None, post_data=None,
         get_method=None, cookies=False, oauth=False, oauth_keys=None, **kwargs):

    if query_params is None:
        query_params = {}

    if user_agent is None:
        user_agent = ua_skybot

    query_params.update(kwargs)

    url = prepare_url(url, query_params)

    request = urllib2.Request(url, post_data)

    if get_method is not None:
        request.get_method = lambda: get_method

    request.add_header('User-Agent', user_agent)

    if referer is not None:
        request.add_header('Referer', referer)

    if oauth:
        nonce = oauth_nonce()
        timestamp = oauth_timestamp()
        api_url, req_data = string.split(url, "?")
        unsigned_request = oauth_unsigned_request(nonce, timestamp, req_data, oauth_keys['consumer'], oauth_keys['access'])
        
        signature = oauth_sign_request("GET", api_url, req_data, unsigned_request, oauth_keys['consumer_secret'], oauth_keys['access_secret'])
        
        header = oauth_build_header(nonce, signature, timestamp, oauth_keys['consumer'], oauth_keys['access'])
        request.add_header('Authorization', header)

    
    if cookies:
        opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(jar))
    else:
        opener = urllib2.build_opener()
    return opener.open(request)


def prepare_url(url, queries):
    if queries:
        scheme, netloc, path, query, fragment = urlparse.urlsplit(url)

        query = dict(urlparse.parse_qsl(query))
        query.update(queries)
        query = urllib.urlencode(dict((to_utf8(key), to_utf8(value))
                                  for key, value in query.iteritems()))

        url = urlparse.urlunsplit((scheme, netloc, path, query, fragment))

    return url


def to_utf8(s):
    if isinstance(s, unicode):
        return s.encode('utf8', 'ignore')
    else:
        return str(s)


def quote_plus(s):
    return _quote_plus(to_utf8(s))

def oauth_nonce():
    return ''.join([str(random.randint(0, 9)) for i in range(8)])

def oauth_timestamp():
    return str(int(time.time()))

def oauth_unsigned_request(nonce, timestamp, req, consumer, token):
    d = { 'oauth_consumer_key':consumer, 
          'oauth_nonce':nonce,
          'oauth_signature_method':'HMAC-SHA1',
          'oauth_timestamp':timestamp,
          'oauth_token':token,
          'oauth_version':'1.0' }

    k,v = string.split(req, "=")
    d[k] = v
    
    unsigned_req = ''
    
    for x in sorted(d, key=lambda key: key):
        unsigned_req += x + "=" + d[x] + "&"
    
    unsigned_req = quote(unsigned_req[:-1])

    return unsigned_req

def oauth_build_header(nonce, signature, timestamp, consumer, token):
    d = { 'oauth_consumer_key':consumer,
          'oauth_nonce':nonce,
          'oauth_signature':signature,
          'oauth_signature_method':'HMAC-SHA1',
          'oauth_timestamp':timestamp,
          'oauth_token':token,
          'oauth_version':'1.0' }

    header='OAuth '
    
    for x in sorted(d, key=lambda key: key):
        header += x + '="' + d[x] + '", '

    return header[:-1]

def oauth_sign_request(method, url, params, unsigned_request, consumer_secret, token_secret):
    key = consumer_secret + "&" + token_secret

    base = method + "&" + quote(url, '') + "&" + unsigned_request

    hash = hmac.new(key, base, sha1)

    signature = quote(binascii.b2a_base64(hash.digest())[:-1])
    
    return signature

def unescape(s):
    if not s.strip():
        return s
    return html.fromstring(s).text_content()