# module proj.middleware.translationmiddleware
from django.conf import settings
from django.http import *
from urllib import quote, unquote

import re
CHARSET_RE = re.compile(r'(.+; charset=)(.+)', re.IGNORECASE)
SKIP_CONTENT_FOR = (HttpResponseRedirect, HttpResponsePermanentRedirect, HttpResponseNotModified, HttpResponseNotAllowed)

class TranslationMiddleware(object):
    def __init__(self):
        self.trCset = getattr(settings, 'TRANSLATE_CHARSET', 'UTF-8')
        self.defCset = settings.DEFAULT_CHARSET
   
    def tr(self, data, _from, _to):
        if _to == _from:
            return data
        return data.decode(_from).encode(_to)       
   
    def process_request(self, request):
        GET = request.GET.copy()
        POST = request.POST.copy()
       
        for dic in (GET, POST):
            for key in dic:
                newlist = []
                for val in dic.getlist(key):
                    newlist.append(self.tr(val, self.trCset, self.defCset))
                dic.setlist(key, newlist)
            dic._mutable = False
       
        request.GET, request.POST = GET, POST
        if hasattr(request, '_request'):
            del(request._request)
           
        for key in request.COOKIES:
            request.COOKIES[key] = self.tr(request.COOKIES[key], self.trCset, self.defCset)
       
           
    def process_response(self, request, response):
        klass = response.__class__
        if klass not in SKIP_CONTENT_FOR:
            new_response = klass()
            new_response.content = self.tr(response.content, self.defCset, self.trCset)
        else:
            new_response = response
           
        new_response._charset = self.trCset
       
        for key in response.headers:
            if key == 'Content-Type':
                ctype = CHARSET_RE.sub(r'\1%s' % self.trCset, response.headers[key])
                new_response[key] = ctype
            elif key == 'Location':
                value = unquote(response.headers[key])
                value = self.tr(value, self.defCset, self.trCset)
                new_response[key] = quote(value, RESERVED_CHARS)
            else:
                new_response[key] = self.tr(response.headers[key], self.defCset, self.trCset)
       
        for key in response.cookies:
            value = self.tr(response.cookies[key].value, self.defCset, self.trCset)
            kwargs = {}
            for var in ('max_age', 'path', 'domain', 'secure', 'expires'):
                kwargs[var] = response.cookies[key].get(var.replace('_', '-'), None)
               
            new_response.set_cookie(key, value, **kwargs)       
           
        return new_response