# ⁻*- coding: utf-8 -*-
import default_settings

from django.shortcuts import render, redirect
from django.http import HttpResponse, StreamingHttpResponse
from django.conf import settings
from django.contrib import messages

import requests
from datetime import datetime, timedelta

import utils
import forms
import models

def _logout(request):
    try: del request.session["authenticated"]
    except KeyError: pass
    try: del request.session["username"]
    except KeyError: pass
    try: del request.session["warn"]
    except KeyError: pass

def login(request):
    user = None
    form = None
    service_pattern = None
    renewed = False
    warned = False
    if request.method == 'POST':
        service = request.POST.get('service')
        renew = True if request.POST.get('renew') else False
        gateway = request.POST.get('gateway')
        method = request.POST.get('method')

        if not request.session.get("authenticated") or renew:
            form = forms.UserCredential(request.POST, initial={'service':service,'method':method,'warn':request.session.get("warn")})
            if form.is_valid():
                user = models.User.objects.get(username=form.cleaned_data['username'])
                request.session.set_expiry(0)
                request.session["username"] = form.cleaned_data['username']
                request.session["warn"] = True if form.cleaned_data.get("warn") else False
                request.session["authenticated"] = True
                renewed = True
                warned = True
            else:
                _logout(request)
    else:
        service = request.GET.get('service')
        renew = True if request.GET.get('renew') else False
        gateway = request.GET.get('gateway')
        method = request.GET.get('method')

        if not request.session.get("authenticated") or renew:
            form = forms.UserCredential(initial={'service':service,'method':method,'warn':request.session.get("warn")})
            
    # if authenticated and successfully renewed authentication if needed
    if request.session.get("authenticated") and (not renew or renewed):
        try:
            user = models.User.objects.get(username=request.session["username"])
        except models.User.DoesNotExist:
            _logout(request)

        # if login agains a service is requestest
        if service:
            try:
                # is the service allowed
                service_pattern = models.ServicePattern.validate(service)
                # is the current user allowed on this service
                service_pattern.check_user(user)
                # if the user has asked to be warned before any login to a service (no transparent SSO)
                if request.session["warn"] and not warned:
                    return render(request, settings.CAS_WARN_TEMPLATE, {'service_ticket_url':user.get_service_url(service, service_pattern, renew=renew),'service':service, 'name': service_pattern.name})
                else:
                    return redirect(user.get_service_url(service, service_pattern, renew=renew)) # redirect, using method ?
            except models.ServicePattern.DoesNotExist:
                messages.add_message(request, messages.ERROR, u'Service %s non autorisé.' % service)
            except models.BadUsername:
                messages.add_message(request, messages.ERROR, u"Nom d'utilisateur non autorisé")
            except models.BadFilter:
                messages.add_message(request, messages.ERROR, u"Caractéristique utilisateur non autorisé")
            except models.UserFieldNotDefined:
                messages.add_message(request, messages.ERROR, u"L'attribut %s est nécessaire pour utiliser ce service" % service_pattern.user_field)

            # if gateway is set and auth failed redirect to the service without authentication
            if gateway:
                list(messages.get_messages(request)) # clean messages before leaving the django app
                return redirect(service)

        return render(request, settings.CAS_LOGGED_TEMPLATE, {})
    else:
        if service:
            try:
                service_pattern = models.ServicePattern.validate(service)
                if gateway:
                    list(messages.get_messages(request)) # clean messages before leaving the django app
                    return redirect(service)
                if request.session.get("authenticated") and renew:
                    messages.add_message(request, messages.WARNING, u"Demande de réautentification par le service %s (%s)." % (service_pattern.name, service))
                else:
                    messages.add_message(request, messages.WARNING, u"Demande d'autentification par le service %s (%s)." % (service_pattern.name, service))
            except models.ServicePattern.DoesNotExist:
                messages.add_message(request, messages.ERROR, u'Service %s non autorisé.' % service)
        return render(request, settings.CAS_LOGIN_TEMPLATE, {'form':form})

def logout(request):
    service = request.GET.get('service')
    if request.session.get("authenticated"):
        user = models.User.objects.get(username=request.session["username"])
        user.logout(request)
        user.delete()
        _logout(request)
    # if service is set, redirect to service after logout
    if service:
        list(messages.get_messages(request)) # clean messages before leaving the django app
        return redirect(service)
    # else redirect to login page
    else:
        messages.add_message(request, messages.SUCCESS, u'Déconnecté avec succès')
        return redirect("login")

def validate(request):
    service = request.GET.get('service')
    ticket = request.GET.get('ticket')
    renew = True if request.GET.get('renew') else False
    if service and ticket:
        try:
            ticket = models.ServiceTicket.objects.get(value=ticket, service=service, validate=False, renew=renew, creation__gt=(datetime.now() - timedelta(seconds=settings.CAS_TICKET_VALIDITY)))
            ticket.validate = True
            ticket.save()
            return HttpResponse("yes\n", content_type="text/plain")
        except models.ServiceTicket.DoesNotExist:
            return HttpResponse("no\n", content_type="text/plain")
    else:
        return HttpResponse("no\n", content_type="text/plain")

    
def psValidate(request, typ=['ST']):
    service = request.GET.get('service')
    ticket = request.GET.get('ticket')
    pgtUrl = request.GET.get('pgtUrl')
    renew = True if request.GET.get('renew') else False
    if service and ticket:
        for t in typ:
            if ticket.startswith(t):
                break
        else:
            return render(request, "cas_server/serviceValidateError.xml", {'code':'INVALID_TICKET'}, content_type="text/xml; charset=utf-8")
        try:
            proxies = []
            if ticket.startswith("ST"):
                ticket = models.ServiceTicket.objects.get(value=ticket, service=service, validate=False, renew=renew, creation__gt=(datetime.now() - timedelta(seconds=settings.CAS_TICKET_VALIDITY)))
            elif ticket.startswith("PT"):
                ticket = models.ProxyTicket.objects.get(value=ticket, service=service, validate=False, renew=renew, creation__gt=(datetime.now() - timedelta(seconds=settings.CAS_TICKET_VALIDITY)))
                for p in ticket.proxies.all():
                    proxies.add(p.url)
            ticket.validate = True
            ticket.save()
            attributes = []
            for key, value in ticket.attributs.items():
                if isinstance(value, list):
                    for v in value:
                        attributes.append((key, v))
                else:
                    attributes.append((key, value))
            params = {'username':ticket.user.username, 'attributes':attributes, 'proxies':proxies}
            if ticket.service_pattern.user_field and ticket.user.attributs.get(ticket.service_pattern.user_field):
                params['username'] = ticket.user.attributs.get(ticket.service_pattern.user_field)
            if pgtUrl and pgtUrl.startswith("https://"):
                pattern = models.ServicePattern.validate(pgtUrl)
                if pattern.proxy:
                    proxyid = models._gen_ticket('PGTIOU')
                    pticket = models.ProxyGrantingTicket.objects.create(user=ticket.user, service=pgtUrl, service_pattern=pattern)
                    url = utils.update_url(pgtUrl, {'pgtIou':proxyid, 'pgtId':pticket.value})
                    try:
                        r = requests.get(url, verify=settings.CAS_PROXY_CA_CERTIFICATE_PATH)
                        if r.status_code == 200:
                            params['proxyGrantingTicket'] = proxyid
                        else:
                            pticket.delete()
                        return render(request, "cas_server/serviceValidate.xml", params, content_type="text/xml; charset=utf-8")
                    except requests.exceptions.SSLError:
                        return render(request, "cas_server/serviceValidateError.xml", {'code':'INVALID_PROXY_CALLBACK'}, content_type="text/xml; charset=utf-8")
                else:
                    return render(request, "cas_server/serviceValidateError.xml", {'code':'INVALID_PROXY_CALLBACK'}, content_type="text/xml; charset=utf-8")
            else:
                return render(request, "cas_server/serviceValidate.xml", params, content_type="text/xml; charset=utf-8")
        except (models.ServiceTicket.DoesNotExist, models.ProxyTicket.DoesNotExist, models.ServicePattern.DoesNotExist):
            return render(request, "cas_server/serviceValidateError.xml", {'code':'INVALID_TICKET'}, content_type="text/xml; charset=utf-8")
    else:
        return render(request, "cas_server/serviceValidateError.xml", {'code':'INVALID_REQUEST'}, content_type="text/xml; charset=utf-8")

def serviceValidate(request):
    return psValidate(request)
def proxyValidate(request):
    return psValidate(request, ["ST", "PT"])

def proxy(request):
    pgt = request.GET.get('pgt')
    targetService = request.GET.get('targetService')
    if pgt and targetService:
        try:
            pattern = models.ServicePattern.validate(targetService)
            ticket = models.ProxyGrantingTicket.objects.get(value=pgt, creation__gt=(datetime.now() - timedelta(seconds=settings.CAS_TICKET_VALIDITY)))
            pattern.check_user(ticket.user)
            pticket = ticket.user.get_ticket(models.ProxyTicket, targetService, pattern, False)
            pticket.proxies.create(url=ticket.service)
            return render(request, "cas_server/proxy.xml", {'ticket':pticket.value}, content_type="text/xml; charset=utf-8")
        except (models.ProxyGrantingTicket.DoesNotExist, models.ServicePattern.DoesNotExist, models.BadUsername, models.BadFilter):
            return render(request, "cas_server/serviceValidateError.xml", {'code':'INVALID_TICKET'}, content_type="text/xml; charset=utf-8")
    else:
        return render(request, "cas_server/serviceValidateError.xml", {'code':'INVALID_REQUEST'}, content_type="text/xml; charset=utf-8")

def p3_serviceValidate(request):
    return serviceValidate(request)

def p3_proxyValidate(request):
    return proxyValidate(request)