# 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
from django.db.models import ProtectedError

from .forms import NewMachineForm, EditMachineForm, EditInterfaceForm, AddInterfaceForm, NewInterfaceForm, MachineTypeForm, DelMachineTypeForm
from .models import Machine, Interface, IpList, MachineType
from users.models import User

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/")
    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_machine.save()
        new_interface = interface.save(commit=False)
        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_machine(request, interfaceid):
    try:
        interface = Interface.objects.get(pk=interfaceid)
    except Interface.DoesNotExist:
        messages.error(request, u"Interface inexistante" )
        return redirect("/machines")
    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():
        machine_form.save()
        interface_form.save()
        messages.success(request, "La machine a été modifiée")
        return redirect("/machines/")
    return form({'machineform': machine_form, 'interfaceform': interface_form}, 'machines/machine.html', request)

@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")
    interface_form = AddInterfaceForm(request.POST or None)
    machine_form = EditMachineForm(request.POST or None, instance=machine)
    if interface_form.is_valid() and machine_form.is_valid():
        machine_form.save()
        new_interface = interface_form.save(commit=False)
        new_interface.machine = 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({'machineform': machine_form, 'interfaceform': interface_form}, 'machines/machine.html', request)

@login_required
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
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
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
def index(request):
    interfaces_list = Interface.objects.order_by('pk')
    return render(request, 'machines/index.html', {'interfaces_list': interfaces_list})

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