from django.shortcuts import render, get_object_or_404
from django.http import HttpResponseRedirect, Http404
from django.contrib.auth.decorators import login_required
from django.contrib import messages
from django.db import transaction


from .models import *
from .forms import *


def log(user, what):
    l = Log()
    l.user = user
    l.what = what
    l.save()


def noaccess(request):
    return HttpResponse("Access to this site is only for pre-approved users")


@login_required
def home(request):
    admperm = request.user.is_superuser or \
        VirtualUser.objects.extra(where=["EXISTS (SELECT 1 FROM mailmgr_userpermissions p WHERE p.user_id=%s AND p.domain_id = local_domain_id AND local_part ~* ('^'||p.pattern||'$'))" % request.user.id]).exists() or \
        Forwarder.objects.extra(where=["EXISTS (SELECT 1 FROM mailmgr_userpermissions p WHERE p.user_id=%s AND p.domain_id = local_domain_id AND local_part ~* ('^'||p.pattern||'$'))" % request.user.id]).exists()
    mailboxes = VirtualUser.objects.filter(account=request.user.id)

    return render(request, 'home.html', {
        'admperm': admperm,
        'mailboxes': mailboxes,
    })


@login_required
def mailbox(request, virtualid):
    mailbox = get_object_or_404(VirtualUser, virtual_user_id=virtualid, account=request.user.id)

    if request.method == 'POST':
        form = PasswordChangeForm(data=request.POST, mailbox=mailbox)
        if form.is_valid():
            with transaction.atomic():
                curs = connection.cursor()
                curs.execute("UPDATE mail.virtual_user SET passwd=public.crypt(%(pwd)s, public.gen_salt('md5')) WHERE virtual_user_id=%(id)s", {
                    'id': mailbox.virtual_user_id,
                    'pwd': form.cleaned_data['password'],
                })
                log(request.user, "Changed password for own mailbox {}".format(mailbox.fulladdr))
            messages.info(request, "Changed password of {}".format(mailbox.fulladdr))
            return HttpResponseRedirect('/')
    else:
        form = PasswordChangeForm(mailbox=mailbox)

    return render(request, 'mailbox.html', {
        'mailbox': mailbox,
        'form': form,
        'extrabuttons': [
            ('Cancel', '/'),
        ],
    })


@login_required
def adm_home(request):
    if request.user.is_superuser:
        users = VirtualUser.objects.all()
        forwards = Forwarder.objects.all()
    else:
        users = VirtualUser.objects.extra(where=["EXISTS (SELECT 1 FROM mailmgr_userpermissions p WHERE p.user_id=%s AND p.domain_id = local_domain_id AND local_part ~* ('^'||p.pattern||'$'))" % request.user.id])
        forwards = Forwarder.objects.extra(where=["EXISTS (SELECT 1 FROM mailmgr_userpermissions p WHERE p.user_id=%s AND p.domain_id = local_domain_id AND local_part ~* ('^'||p.pattern||'$'))" % request.user.id])

    if not forwards and not users:
        return render(request, 'noadm.html', {
        })

    return render(request, 'adm.html', {
        'users': users,
        'forwarders': forwards,
    })


def _get_virtualuser(request, userparam):
    if request.user.is_superuser:
        return get_object_or_404(VirtualUser, pk=userparam)
    else:
        vulist = VirtualUser.objects.filter(pk=userparam).extra(where=["EXISTS (SELECT 1 FROM mailmgr_userpermissions p WHERE p.user_id=%s AND p.domain_id = local_domain_id AND local_part ~* ('^'||p.pattern||'$'))" % request.user.id])
        if len(vulist) != 1:
            raise Http404("Not found or no permissions!")
        return vulist[0]


@transaction.atomic
@login_required
def userform(request, userparam):
    if userparam == 'add':
        vu = VirtualUser()
    else:
        vu = _get_virtualuser(request, userparam)

    if request.method == 'POST':
        form = VirtualUserForm(data=request.POST, instance=vu, user=request.user)
        if request.POST['passwd'] != vu.passwd:
            password_changed = True
        else:
            password_changed = False
        if form.is_valid():
            form.save()
            messages.add_message(request, messages.INFO, 'User %s updated' % vu)
            if password_changed:
                messages.add_message(request, messages.INFO, 'Password changed for user %s' % vu)
                log(request.user, "%s user %s, including changing the password" % (userparam == 'add' and 'Added' or 'Updated', vu))
            else:
                log(request.user, "%s user %s, without changing the password" % (userparam == 'add' and 'Added' or 'Updated', vu))
            return HttpResponseRedirect('/adm/')
    else:
        # Generate a new form
        form = VirtualUserForm(instance=vu, user=request.user)

    return render(request, 'form.html', {
        'form': form,
        'savebutton': (userparam == 'new') and "New" or "Save",
        'extrabuttons': [
            ('Cancel', '/adm/'),
        ],
    })


def _get_forwarder(request, userparam):
    if request.user.is_superuser:
        return get_object_or_404(Forwarder, pk=userparam)
    else:
        fwdlist = Forwarder.objects.filter(pk=userparam).extra(where=["EXISTS (SELECT 1 FROM mailmgr_userpermissions p WHERE p.user_id=%s AND p.domain_id = local_domain_id AND local_part ~* ('^'||p.pattern||'$'))" % request.user.id])
        if len(fwdlist) != 1:
            raise Http404("Not found or no permissions!")
        return fwdlist[0]


@transaction.atomic
@login_required
def forwarderform(request, userparam):
    if userparam == 'add':
        fwd = Forwarder()
    else:
        fwd = _get_forwarder(request, userparam)

    if request.method == 'POST':
        form = ForwarderForm(data=request.POST, instance=fwd, user=request.user)
        if form.is_valid():
            form.save()
            log(request.user, "%s forwarding %s -> %s" % (userparam == 'add' and 'Added' or 'Updated', fwd, fwd.remote_name))
            messages.add_message(request, messages.INFO, 'Forwarder %s updated' % fwd)
            return HttpResponseRedirect('/adm/')
    else:
        # Generate a new form
        form = ForwarderForm(instance=fwd, user=request.user)

    extrabuttons = [
        ('Cancel', '/adm/'),
    ]
    if userparam != 'add':
        extrabuttons.append(('Delete', 'delete/'))

    return render(request, 'form.html', {
        'form': form,
        'savebutton': (userparam == 'new') and "New" or "Save",
        'extrabuttons': extrabuttons,
    })


@transaction.atomic
@login_required
def deleteforwarder(request, userparam):
    fwd = _get_forwarder(request, userparam)

    if request.method == 'POST':
        form = ConfirmForm(data=request.POST)
        if form.is_valid():
            fwdname = str(fwd)
            fwd.delete()
            log(request.user, "Deleted forwarder {}".format(fwdname))
            messages.info(request, "Deleted forwarder {}".format(fwdname))
            return HttpResponseRedirect("/adm/")
    else:
        form = ConfirmForm()

    return render(request, 'confirm.html', {
        'form': form,
        'object': 'forwarder',
        'what': 'delete',
        'name': fwd,
        'savebutton': 'Delete',
        'extrabuttons': [
            ('Cancel', '../'),
        ],
    })