# App de gestion des machines pour re2o
# Gabriel Détraz
# Gplv2
from django.shortcuts import render, redirect
from django.shortcuts import render_to_response, get_object_or_404
from django.core.context_processors import csrf
from django.template import Context, RequestContext, loader
from django.contrib import messages
from django.contrib.auth.decorators import login_required, permission_required
from django.db.models import ProtectedError
from django.forms import ValidationError

import re
from .forms import NewMachineForm, EditMachineForm, EditInterfaceForm, AddInterfaceForm, NewInterfaceForm, MachineTypeForm, DelMachineTypeForm, ExtensionForm, DelExtensionForm, BaseEditInterfaceForm, BaseEditMachineForm
from .models import Machine, Interface, IpList, MachineType, Extension
from users.models import User

def full_domain_validator(request, interface, machine):
    """ Validation du nom de domaine, extensions dans type de machine, prefixe pas plus long que 63 caractères """
    HOSTNAME_LABEL_PATTERN = re.compile("(?!-)[A-Z\d-]+(?<!-)$", re.IGNORECASE)
    dns = interface.dns.lower()
    allowed_extension = machine.type.extension.name
    if not dns.endswith(allowed_extension):
        messages.error(request,
                "Le nom de domaine %s doit comporter une extension valide en %s" % (dns, allowed_extension) )
        return False
    dns_short=re.sub('%s$' % allowed_extension, '', dns)
    if len(dns_short) > 63:
        messages.error(request,
                "Le nom de domaine %s est trop long (maximum de 63 caractères)." % dns)
        return False
    if not HOSTNAME_LABEL_PATTERN.match(dns_short):
        messages.error(request,
                "Ce nom de domaine %s contient des carractères interdits." % dns)
        return False
    return True

def unassign_ips(user):
    machines = Interface.objects.filter(machine=Machine.objects.filter(user=user))
    for machine in machines:
        unassign_ipv4(machine)
    return

def assign_ips(user):
    """ Assign une ipv4 aux machines d'un user """
    machines = Interface.objects.filter(machine=Machine.objects.filter(user=user))
    for machine in machines:
        if not machine.ipv4:
            interface = assign_ipv4(machine)
            interface.save()
    return

def free_ip():
    """ Renvoie la liste des ip disponibles """
    return IpList.objects.filter(interface__isnull=True)

def assign_ipv4(interface):
    """ Assigne une ip à l'interface """
    free_ips = free_ip()
    if free_ips:
        interface.ipv4 = free_ips[0]
    return interface

def unassign_ipv4(interface):
    interface.ipv4 = None
    interface.save()

def form(ctx, template, request):
    c = ctx
    c.update(csrf(request))
    return render_to_response(template, c, context_instance=RequestContext(request))

@login_required
def new_machine(request, userid):
    try:
        user = User.objects.get(pk=userid)
    except User.DoesNotExist:
        messages.error(request, u"Utilisateur inexistant" )
        return redirect("/machines/")
    if not request.user.has_perms(('cableur',)) and user != request.user:
        messages.error(request, "Vous ne pouvez pas ajouter une machine à un autre user que vous sans droit")
        return redirect("/users/profil/" + str(request.user.id))
    machine = NewMachineForm(request.POST or None)
    interface = AddInterfaceForm(request.POST or None) 
    if machine.is_valid() and interface.is_valid():
        new_machine = machine.save(commit=False)
        new_machine.user = user
        new_interface = interface.save(commit=False)
        if full_domain_validator(request, new_interface, new_machine):
            new_machine.save()
            new_interface.machine = new_machine
            if free_ip() and not new_interface.ipv4:
                new_interface = assign_ipv4(new_interface)
            elif not new_interface.ipv4:
                messages.error(request, u"Il n'y a plus d'ip disponibles")
            new_interface.save()
            messages.success(request, "La machine a été crée")
            return redirect("/users/profil/" + userid)
    return form({'machineform': machine, 'interfaceform': interface}, 'machines/machine.html', request)

@login_required
def edit_interface(request, interfaceid):
    try:
        interface = Interface.objects.get(pk=interfaceid)
    except Interface.DoesNotExist:
        messages.error(request, u"Interface inexistante" )
        return redirect("/machines")
    if not request.user.has_perms(('cableur',)):
        if interface.machine.user != request.user:
            messages.error(request, "Vous ne pouvez pas éditer une machine d'un autre user que vous sans droit")
            return redirect("/users/profil/" + str(request.user.id))
        machine_form = BaseEditMachineForm(request.POST or None, instance=interface.machine)
        interface_form = BaseEditInterfaceForm(request.POST or None, instance=interface)
    else:
        machine_form = EditMachineForm(request.POST or None, instance=interface.machine)
        interface_form = EditInterfaceForm(request.POST or None, instance=interface)
    if machine_form.is_valid() and interface_form.is_valid():
        new_interface = interface_form.save(commit=False)
        new_machine = machine_form.save(commit=False)
        if full_domain_validator(request, new_interface, new_machine):
            new_machine.save()
            new_interface.save()
            messages.success(request, "La machine a été modifiée")
            return redirect("/users/profil/" + str(interface.machine.user.id))
    return form({'machineform': machine_form, 'interfaceform': interface_form}, 'machines/machine.html', request)

@login_required
def del_machine(request, machineid):
    try:
        machine = Machine.objects.get(pk=machineid)
    except Machine.DoesNotExist:
        messages.error(request, u"Machine inexistante" )
        return redirect("/machines")
    if not request.user.has_perms(('cableur',)):
        if machine.user != request.user:
            messages.error(request, "Vous ne pouvez pas éditer une machine d'un autre user que vous sans droit")
            return redirect("/users/profil/" + str(request.user.id))
    machine.delete()
    messages.success(request, "La machine a été détruite")
    return redirect("/users/profil/" + str(request.user.id))

@login_required
def new_interface(request, machineid):
    try:
        machine = Machine.objects.get(pk=machineid)
    except Machine.DoesNotExist:
        messages.error(request, u"Machine inexistante" )
        return redirect("/machines")
    if not request.user.has_perms(('cableur',)):
        if machine.user != request.user:
            messages.error(request, "Vous ne pouvez pas ajouter une interface à une machine d'un autre user que vous sans droit")
            return redirect("/users/profil/" + str(request.user.id))
    interface_form = AddInterfaceForm(request.POST or None)
    if interface_form.is_valid():
        new_interface = interface_form.save(commit=False)
        new_interface.machine = machine
        if full_domain_validator(request, new_interface, machine):
            if free_ip() and not new_interface.ipv4:
                new_interface = assign_ipv4(new_interface)
            elif not new_interface.ipv4:
                messages.error(request, u"Il n'y a plus d'ip disponibles")
            new_interface.save()
            messages.success(request, "L'interface a été ajoutée")
            return redirect("/machines/")
    return form({'interfaceform': interface_form}, 'machines/machine.html', request)

@login_required
def del_interface(request, interfaceid):
    try:
        interface = Interface.objects.get(pk=interfaceid)
    except Interface.DoesNotExist:
        messages.error(request, u"Interface inexistante" )
        return redirect("/machines")
    if not request.user.has_perms(('cableur',)):
        if interface.machine.user != request.user:
            messages.error(request, "Vous ne pouvez pas éditer une machine d'un autre user que vous sans droit")
            return redirect("/users/profil/" + str(request.user.id))
    interface.delete()
    messages.success(request, "L'interface a été détruite")
    return redirect("/users/profil/" + str(request.user.id))

@login_required
@permission_required('infra')
def add_machinetype(request):
    machinetype = MachineTypeForm(request.POST or None)
    if machinetype.is_valid():
        machinetype.save()
        messages.success(request, "Ce type de machine a été ajouté")
        return redirect("/machines/index_machinetype")
    return form({'machineform': machinetype, 'interfaceform': None}, 'machines/machine.html', request)

@login_required
@permission_required('infra')
def edit_machinetype(request, machinetypeid):
    try:
        machinetype_instance = MachineType.objects.get(pk=machinetypeid)
    except MachineType.DoesNotExist:
        messages.error(request, u"Entrée inexistante" )
        return redirect("/machines/index_machinetype/")
    machinetype = MachineTypeForm(request.POST or None, instance=machinetype_instance)
    if machinetype.is_valid():
        machinetype.save()
        messages.success(request, "Type de machine modifié")
        return redirect("/machines/index_machinetype/")
    return form({'machineform': machinetype}, 'machines/machine.html', request)

@login_required
@permission_required('infra')
def del_machinetype(request):
    machinetype = DelMachineTypeForm(request.POST or None)
    if machinetype.is_valid():
        machinetype_dels = machinetype.cleaned_data['machinetypes']
        for machinetype_del in machinetype_dels:
            try:
                machinetype_del.delete()
                messages.success(request, "Le type de machine a été supprimé")
            except ProtectedError:
                messages.error(request, "Le type de machine %s est affectée à au moins une machine, vous ne pouvez pas le supprimer" % machinetype_del)
        return redirect("/machines/index_machinetype")
    return form({'machineform': machinetype, 'interfaceform': None}, 'machines/machine.html', request)

@login_required
@permission_required('infra')
def add_extension(request):
    extension = ExtensionForm(request.POST or None)
    if extension.is_valid():
        extension.save()
        messages.success(request, "Cette extension a été ajoutée")
        return redirect("/machines/index_extension")
    return form({'machineform': extension, 'interfaceform': None}, 'machines/machine.html', request)

@login_required
@permission_required('infra')
def edit_extension(request, extensionid):
    try:
        extension_instance = Extension.objects.get(pk=extensionid)
    except Extension.DoesNotExist:
        messages.error(request, u"Entrée inexistante" )
        return redirect("/machines/index_extension/")
    extension = ExtensionForm(request.POST or None, instance=extension_instance)
    if extension.is_valid():
        extension.save()
        messages.success(request, "Extension modifiée")
        return redirect("/machines/index_extension/")
    return form({'machineform': extension}, 'machines/machine.html', request)

@login_required
@permission_required('infra')
def del_extension(request):
    extension = DelExtensionForm(request.POST or None)
    if extension.is_valid():
        extension_dels = extension.cleaned_data['extensions']
        for extension_del in extension_dels:
            try:
                extension_del.delete()
                messages.success(request, "L'extension a été supprimée")
            except ProtectedError:
                messages.error(request, "L'extension %s est affectée à au moins un type de machine, vous ne pouvez pas la supprimer" % extension_del)
        return redirect("/machines/index_extension")
    return form({'machineform': extension, 'interfaceform': None}, 'machines/machine.html', request)

@login_required
@permission_required('cableur')
def index(request):
    machines_list = Machine.objects.order_by('pk')
    return render(request, 'machines/index.html', {'machines_list': machines_list})

@login_required
@permission_required('cableur')
def index_machinetype(request):
    machinetype_list = MachineType.objects.order_by('type')
    return render(request, 'machines/index_machinetype.html', {'machinetype_list':machinetype_list})

@login_required
@permission_required('cableur')
def index_extension(request):
    extension_list = Extension.objects.order_by('name')
    return render(request, 'machines/index_extension.html', {'extension_list':extension_list})