import re
import datetime
import string
import random
import urllib2

from django import forms
from django.shortcuts import render_to_response
from django.shortcuts import redirect
from django.template import RequestContext
from django.conf import settings
from django.utils.translation import ugettext_lazy as _

from pyi2phosts.postkey.models import i2phost
from pyi2phosts.lib.utils import get_logger
from pyi2phosts.lib.validation import validate_hostname
from pyi2phosts.lib.validation import validate_b64hash

class AddForm(forms.ModelForm):
    """
    This is our class for host-add form. It's based on django's ModelForm
    and uses our model "i2phost" (see postkey/models.py)
    """
    class Meta:
        model = i2phost
        fields = ('name', 'b64hash', 'description')
        widgets = {
                'name': forms.TextInput(attrs={'size': '67'}),
                'b64hash': forms.Textarea(attrs={'rows': '1', 'cols': '100'}),
                'description': forms.Textarea(attrs={'rows': '2', 'cols': '72'})
                }
    def clean_name(self):
        """Validate hostname"""
        data = self.cleaned_data['name']
        log.debug(u'hostname: %s', self.data['name'])
        data = validate_hostname(data)
        # Another set of reserved hostnames (suggested by zzz)
        if re.search(r'(^|\.)(i2p|i2p2|geti2p|mail|project|i2project|i2pproject|i2p-project).i2p$', data):
            raise forms.ValidationError(_('Trying to use hostname from additional reserved set'))
        return data
    def clean_b64hash(self):
        """Validate base64 hash"""
        data = self.cleaned_data['b64hash']
        log.debug(u'hash: %s', self.data['b64hash'])
        data = validate_b64hash(data)
        return data
    def is_valid(self):
        """Log validation errors"""
        is_valid = super(AddForm, self).is_valid()
        if not is_valid:
            for field in self.errors.keys():
                log.info('ValidationError: [%s]: \"%s\" %s',
                        field, self.data[field], self.errors[field].as_text())
        return is_valid


class SubdomainVerifyForm(forms.Form):
    """Form for displaying verification filename and code when verifying a subdomain"""
    filename = forms.CharField(label=_('Filename'), widget=forms.TextInput(attrs={
        'size': '20',
        'readonly': 'readonly',
        'onclick': 'this.select();',
        }))

def save_host(request):
    """Function for saving hosts after validation or subdomain verification"""
    # avoid race conditions
    try:
        h = i2phost.objects.get(name=request.session['hostname'])
    except i2phost.DoesNotExist:
        host = i2phost(name=request.session['hostname'],
                b64hash=request.session['b64hash'],
                description=request.session['description'],
                date_added=datetime.datetime.utcnow())
        host.save()
        return redirect('pyi2phosts.postkey.views.success')
    else:
        log.warning('refusing to save already existed host: %s', request.session['hostname'])
        request.session.flush()
        return redirect('/')

def addkey(request):
    if request.method == 'POST':
        form = AddForm(request.POST)
        if form.is_valid():
            request.session['hostname'] = form.cleaned_data['name']
            request.session['b64hash'] = form.cleaned_data['b64hash']
            request.session['description'] = form.cleaned_data['description']
            if form.cleaned_data['name'].count('.') > 1:
                return redirect('pyi2phosts.postkey.views.subdomain')
            else:
                log.debug('submit is valid, saving')
                s = save_host(request)
                return s
    else:
        form = AddForm()
    return render_to_response('postkey.html', {
        'title': settings.SITE_NAME,
        'form': form,
        }, context_instance=RequestContext(request))

def success(request):
    if 'hostname' in request.session:
        hn = request.session['hostname']
        request.session.flush()
        return render_to_response('success_submission.html', {
            'title': settings.SITE_NAME,
            'hostname': hn,
            }, context_instance=RequestContext(request))
    else:
        return redirect('/')

def subdomain(request):
    """Subdomain verification"""
    if request.method == 'POST':
        form = SubdomainVerifyForm(request.POST)
        if form.is_valid():
            # do verification here, then redirect to success
            proxy_handler = urllib2.ProxyHandler({'http': settings.EEPROXY_URL})
            opener = urllib2.build_opener(proxy_handler)
            if 'topdomain' in request.session and 'v_filename' in request.session:
                url = 'http://' + request.session['topdomain'] + '/' + request.session['v_filename']
            else:
                log.warning('trying to call subdomain validation without a session')
                return redirect('/')
            log.info('starting http-verification of subdomain: %s', request.session['hostname'])
            try:
                log.debug('trying to open %s', url)
                resp = opener.open(url, timeout=60)
            except urllib2.URLError, e:
                if hasattr(e, 'reason'):
                    log.warning('%s: failed to reach server, reason: %s', request.session['topdomain'], e.reason)
                elif hasattr(e, 'code'):
                    log.warning('%s can\'t finish the request, error code: %s',
                            request.session['topdomain'], e.code)
                return render_to_response('subdomain_http_verify_failure.html', {
                    'title': settings.SITE_NAME,
                    'code': e.code,
                    }, context_instance=RequestContext(request))
            else:
                log.debug('subdomain verification success, saving host')
                s = save_host(request)
                return s
    else:
        # generate verification code and display info page to user
        v_filename = ''.join([random.choice(string.letters + string.digits) for x in xrange(16)])
        if 'hostname' in request.session:
            m = re.match('.+\.(.+\.i2p$)', request.session['hostname'])
            topdomain = m.group(1)
        else:
            return redirect('/')
        # save needed variables in session data because otherwise it will be lost
        request.session['v_filename'] = v_filename
        request.session['topdomain'] = topdomain
        form = SubdomainVerifyForm({'filename': v_filename})
        return render_to_response('subdomain_http_verify.html', {
            'title': settings.SITE_NAME,
            'hostname': request.session['hostname'],
            'topdomain': topdomain,
            'form': form,
            }, context_instance=RequestContext(request))

log = get_logger(filename=settings.LOG_FILE, log_level=settings.LOG_LEVEL)