from django.http import HttpResponseRedirect
from django.shortcuts import render, get_object_or_404
from django.utils.translation import ugettext_lazy as _
from django.urls import reverse
from libvirt import libvirtError
from computes.models import Compute
from vrtManager import util
from vrtManager.nwfilters import wvmNWFilters, wvmNWFilter
from vrtManager.instance import wvmInstances, wvmInstance
from logs.views import addlogmsg


def nwfilters(request, compute_id):
    """
    :param request:
    :param compute_id:
    :return:
    """

    if not request.user.is_superuser:
        return HttpResponseRedirect(reverse('index'))

    error_messages = []
    nwfilters_all = []
    compute = get_object_or_404(Compute, pk=compute_id)

    try:
        conn = wvmNWFilters(compute.hostname,
                            compute.login,
                            compute.password,
                            compute.type)

        if request.method == 'POST':
            if 'create_nwfilter' in request.POST:
                xml = request.POST.get('nwfilter_xml', '')
                if xml:
                    try:
                        util.etree.fromstring(xml)
                        name = util.get_xml_path(xml, '/filter/@name')
                        uuid = util.get_xml_path(xml, '/filter/uuid')
                    except util.etree.ParseError:
                        name = None

                    for nwf in nwfilters:
                        if name == nwf.name():
                            error_msg = _("A network filter with this name already exists")
                            raise Exception(error_msg)
                        if uuid == nwf.UUIDString():
                            error_msg = _("A network filter with this uuid already exists")
                            raise Exception(error_msg)
                    else:
                        try:
                            msg = _("Creating NWFilter: %s" % name)
                            conn.create_nwfilter(xml)
                            addlogmsg(request.user.username, compute.hostname, msg)
                        except libvirtError as lib_err:
                            error_messages.append(lib_err)
                            addlogmsg(request.user.username, compute.hostname, lib_err)

            if 'del_nwfilter' in request.POST:
                name = request.POST.get('nwfiltername', '')
                msg = _(f"Deleting NWFilter: {name}")
                in_use = False
                nwfilter = conn.get_nwfilter(name)

                is_conn = wvmInstances(compute.hostname, compute.login, compute.password, compute.type)
                instances = is_conn.get_instances()
                for inst in instances:
                    i_conn = wvmInstance(compute.hostname, compute.login, compute.password, compute.type, inst)
                    dom_filterrefs = i_conn.get_filterrefs()

                    if name in dom_filterrefs:
                        in_use = True
                        msg = _(f"NWFilter is in use by {inst}. Cannot be deleted.")
                        error_messages.append(msg)
                        addlogmsg(request.user.username, compute.hostname, msg)
                        i_conn.close()
                        break

                is_conn.close()
                if nwfilter and not in_use:
                    nwfilter.undefine()
                    addlogmsg(request.user.username, compute.hostname, msg)

            if 'cln_nwfilter' in request.POST:

                name = request.POST.get('nwfiltername', '')
                cln_name = request.POST.get('cln_name', name + '-clone')

                conn.clone_nwfilter(name, cln_name)
                msg = _(f"Cloning NWFilter {name} as {cln_name}")
                addlogmsg(request.user.username, compute.hostname, msg)

        for nwf in conn.get_nwfilters():
            nwfilters_all.append(conn.get_nwfilter_info(nwf))

        conn.close()
    except libvirtError as lib_err:
        error_messages.append(lib_err)
        addlogmsg(request.user.username, compute.hostname, lib_err)
    except Exception as err:
        error_messages.append(err)
        addlogmsg(request.user.username, compute.hostname, err)

    return render(request, 'nwfilters.html', {'error_messages': error_messages,
                                              'nwfilters': nwfilters_all,
                                              'compute': compute})


def nwfilter(request, compute_id, nwfltr):
    """
    :param request:
    :param compute_id:
    :param nwfltr:
    :return:
    """
    error_messages = []
    nwfilters_all = []
    compute = get_object_or_404(Compute, pk=compute_id)

    try:
        nwfilter = wvmNWFilter(compute.hostname,
                               compute.login,
                               compute.password,
                               compute.type,
                               nwfltr)
        conn = wvmNWFilters(compute.hostname,
                            compute.login,
                            compute.password,
                            compute.type)

        for nwf in conn.get_nwfilters():
            nwfilters_all.append(conn.get_nwfilter_info(nwf))

        uuid = nwfilter.get_uuid()
        name = nwfilter.get_name()
        xml = nwfilter.get_xml()
        rules = nwfilter.get_rules()
        refs = nwfilter.get_filter_refs()

        if request.method == 'POST':

            if 'edit_nwfilter' in request.POST:
                new_xml = request.POST.get('edit_xml', '')

                if new_xml:
                    nwfilter.delete()
                    try:
                        conn.create_nwfilter(new_xml)
                    except libvirtError as lib_err:
                        conn.create_nwfilter(xml)
                        raise libvirtError(lib_err)

            if 'del_nwfilter_rule' in request.POST:
                action = request.POST.get('action', '')
                direction = request.POST.get('direction', '')
                priority = request.POST.get('priority', '')

                new_xml = nwfilter.delete_rule(action, direction, priority)
                nwfilter.delete()
                try:
                    conn.create_nwfilter(new_xml)
                except libvirtError as lib_err:
                    conn.create_nwfilter(xml)
                    raise libvirtError(lib_err)

            if 'del_nwfilter_ref' in request.POST:
                ref_name = request.POST.get('ref')
                new_xml = nwfilter.delete_ref(ref_name)
                nwfilter.delete()
                try:
                    conn.create_nwfilter(new_xml)
                except libvirtError as lib_err:
                    conn.create_nwfilter(xml)
                    raise libvirtError(lib_err)

            if 'add_nwfilter_rule' in request.POST:
                rule_xml = request.POST.get('nwfilterrule_xml', '')
                if not rule_xml:
                    return HttpResponseRedirect(request.get_full_path())
                new_xml = nwfilter.add_rule(rule_xml)
                nwfilter.delete()
                try:
                    conn.create_nwfilter(new_xml)
                except libvirtError as lib_err:
                    conn.create_nwfilter(xml)
                    raise libvirtError(lib_err)

            if 'add_nwfilter_ref' in request.POST:
                ref_name = request.POST.get('nwfilters_select', '')
                if not ref_name:
                    return HttpResponseRedirect(request.get_full_path())
                new_xml = nwfilter.add_ref(ref_name)
                nwfilter.delete()
                try:
                    conn.create_nwfilter(new_xml)
                except libvirtError as lib_err:
                    conn.create_nwfilter(xml)
                    raise libvirtError(lib_err)

            return HttpResponseRedirect(request.get_full_path())
        conn.close()
        nwfilter.close()
    except libvirtError as lib_err:
        error_messages.append(lib_err)
    except Exception as error_msg:
        error_messages.append(error_msg)

    return render(request, 'nwfilter.html', locals())