from django.shortcuts import render, get_object_or_404, redirect
from django.core.exceptions import PermissionDenied, ValidationError
from django.views.generic import ListView, DetailView
from django.views.generic.edit import CreateView, UpdateView, DeleteView
from django.core.urlresolvers import reverse_lazy
from django.contrib import messages
from django.contrib.messages.views import SuccessMessageMixin
from django.contrib.auth.decorators import login_required, permission_required
from django.contrib.auth.models import User
from django.http import HttpResponse, JsonResponse, Http404
from django.forms import modelformset_factory
from gestioncof.models import CofProfile, Clipper
from kfet.models import Account, Checkout, Article
from kfet.forms import *
from collections import defaultdict

@login_required
def home(request):
    return render(request, "kfet/base.html")

def put_cleaned_data_in_dict(dict, form):
    for field in form.cleaned_data:
        dict[field] = form.cleaned_data[field]

# -----
# Account views
# -----

# Account - General

@login_required
@permission_required('account.is_team')
def account(request):
    accounts = Account.objects.order_by('trigramme')
    return render(request, "kfet/account.html", { 'accounts' : accounts })

@login_required
@permission_required('kfet.is_team')
def account_is_validandfree_ajax(request):
    if not request.GET.get("trigramme"):
        raise Http404
    trigramme = request.GET.get("trigramme")
    data = Account.is_validandfree(trigramme)
    return JsonResponse(data)

# Account - Create

@login_required
@permission_required('account.is_team')
def account_create(request):

    # A envoyer au template
    data_template = {
        'account_trigramme_form': AccountTriForm(),
        'errors' : {},
    }

    # Enregistrement
    if request.method == "POST":
        # Pour indiquer la tentative d'enregistrement au template

        # Checking permission
        if not request.user.has_perm('kfet.add_account'):
            raise PermissionDenied

        # Peuplement des forms
        username = request.POST.get('username')
        try:
            user     = User.objects.get(username=username)
            (cof, _) = CofProfile.objects.get_or_create(user=user)
            user_form = UserForm(request.POST, instance=user)
            cof_form  = CofForm(request.POST, instance=cof)
        except User.DoesNotExist:
            user_form = UserForm(request.POST)
            cof_form  = CofForm(request.POST)
        trigramme_form = AccountTriForm(request.POST)
        account_form   = AccountNoTriForm(request.POST)

        # Ajout des erreurs pour le template
        data_template['errors']['user_form'] = user_form.errors
        data_template['errors']['cof_form']  = cof_form.errors
        data_template['errors']['trigramme_form'] = trigramme_form.errors
        data_template['errors']['account_form'] = account_form.errors

        if all((user_form.is_valid(), cof_form.is_valid(),
                trigramme_form.is_valid(), account_form.is_valid())):
            data = {}
            # Fill data for Account.save()
            put_cleaned_data_in_dict(data, user_form)
            put_cleaned_data_in_dict(data, cof_form)

            try:
                account = trigramme_form.save(data = data)
                account_form = AccountNoTriForm(request.POST, instance=account)
                account_form.save()
                messages.success(request, 'Compte créé : %s' % account.trigramme)
            except Account.UserHasAccount as e:
                messages.error(request, \
                    "Cet utilisateur a déjà un compte K-Fêt : %s" % e.trigramme)

    return render(request, "kfet/account_create.html", data_template)

def account_form_set_readonly_fields(user_form, cof_form):
    user_form.fields['username'].widget.attrs['readonly'] = True
    cof_form.fields['login_clipper'].widget.attrs['readonly'] = True
    cof_form.fields['is_cof'].widget.attrs['disabled'] = True

@login_required
@permission_required('kfet.is_team')
def account_create_ajax(request, username=None, login_clipper=None):
    user = None
    if login_clipper:
        # à partir d'un clipper
        # le user associé à ce clipper ne devrait pas encore existé
        clipper = get_object_or_404(Clipper, username = login_clipper)
        try:
            # Vérification que clipper ne soit pas déjà dans User
            user = User.objects.get(username=login_clipper)
            # Ici, on nous a menti, le user existe déjà
            username = user.username
            login_clipper = None
        except User.DoesNotExist:
            # Clipper (sans user déjà existant)

            # UserForm - Prefill + Création
            user_initial_data = {
                    'username' : login_clipper,
                    'email'    : login_clipper + "@clipper.ens.fr"}
            if clipper.fullname:
                # Prefill du nom et prénom
                names = clipper.fullname.split()
                # Le premier, c'est le prénom
                user_initial_data['first_name'] = names[0]
                if len(names) > 1:
                    # Si d'autres noms -> tous dans le nom de famille
                    user_initial_data['last_name'] = " ".join(names[1:])
            user_form = UserForm(initial = user_initial_data)

            # CofForm - Prefill + Création
            cof_initial_data = { 'login_clipper': login_clipper }
            cof_form = CofForm(initial = cof_initial_data)

            # AccountForm
            account_form = AccountForm()

            # Protection (read-only) des champs username et login_clipper
            account_form_set_readonly_fields(user_form, cof_form)
    if username:
        # le user existe déjà
        user = get_object_or_404(User, username=username)
        # récupération du profil cof
        (cof, _) = CofProfile.objects.get_or_create(user=user)
        # UserForm + CofForm - Création à partir des instances existantes
        user_form = UserForm(instance = user)
        cof_form  = CofForm(instance = cof)
        # AccountForm
        account_form = AccountNoTriForm()
        # Protection (read-only) des champs username et login_clipper
        account_form_set_readonly_fields(user_form, cof_form)
    elif not login_clipper:
        # connaît pas du tout, faut tout remplir
        user_form    = UserForm()
        cof_form     = CofForm()
        account_form = AccountNoTriForm()

    return render(request, "kfet/account_create_form.html", {
            'account_form' : account_form,
            'cof_form'     : cof_form,
            'user_form'    : user_form,
            })

# Account - Read

@login_required
def account_read(request, trigramme):
    try:
        account = Account.objects.get(trigramme=trigramme)
    except Account.DoesNotExist:
        raise Http404

    # Checking permissions
    if not request.user.has_perm('kfet.is_team') \
            and request.user != account.user:
        raise PermissionDenied

    return render(request, "kfet/account_read.html", { 'account' : account })

# Account - Update

@login_required
def account_update(request, trigramme):
    try:
        account = Account.objects.get(trigramme=trigramme)
    except Account.DoesNotExist:
        raise Http404

    # Checking permissions
    if not request.user.has_perm('kfet.is_team') \
            and request.user != account.user:
        raise PermissionDenied

    if request.method == "POST":
        # Update attempt

        # Checking permissions
        if not request.user.has_perm('kfet.change_account') \
                and request.user != account.user:
            raise PermissionDenied

        # Peuplement des forms
        if request.user.has_perm('kfet.change_account'):
            account_form = AccountForm(request.POST, instance = account)
        else:
            account_form = AccountRestrictForm(request.POST, instance = account)
        cof_form  = CofRestrictForm(request.POST, instance=account.cofprofile)
        user_form = UserRestrictForm(request.POST, instance=account.user)

        if all((account_form.is_valid(), cof_form.is_valid(), user_form.is_valid())):
            data = {}
            # Fill data for Account.save()
            put_cleaned_data_in_dict(data, user_form)
            put_cleaned_data_in_dict(data, cof_form)

            # Updating
            account_form.save(data = data)
            if request.user == account.user:
                messages.success(request, \
                    'Vos informations ont été mises à jour')
            else:
                messages.success(request, \
                    'Informations du compte %s mises à jour' % account.trigramme)
            return redirect('kfet.account.read', account.trigramme)
        else:
            messages.error(request, \
                'Informations non mises à jour. Corrigez les erreurs')
    else:
        # No update attempt
        if request.user.has_perm('kfet.is_team'):
            account_form = AccountForm(instance = account)
        else:
            account_form = AccountRestrictForm(instance = account)
        cof_form  = CofRestrictForm(instance = account.cofprofile)
        user_form = UserRestrictForm(instance = account.user)

    return render(request, "kfet/account_update.html", {
            'account'      : account,
            'account_form' : account_form,
            'cof_form'     : cof_form,
            'user_form'    : user_form,
            })

# -----
# Checkout views
# -----

# Checkout - General

class CheckoutList(ListView):
    model         = Checkout
    template_name = 'kfet/checkout.html'
    context_object_name = 'checkouts'

# Checkout - Create

class CheckoutCreate(SuccessMessageMixin, CreateView):
    model           = Checkout
    template_name   = 'kfet/checkout_create.html'
    form_class      = CheckoutForm
    success_message = 'Nouvelle caisse : %(name)s'

    # Surcharge de la validation
    def form_valid(self, form):
        # Checking permission
        if not self.request.user.has_perm('add_checkout'):
            raise PermissionDenied
        # Creating
        form.instance.created_by = self.request.user.profile.account_kfet
        return super(CheckoutCreate, self).form_valid(form)

# Checkout - Read

class CheckoutRead(DetailView):
    model = Checkout
    template_name = 'kfet/checkout_read.html'
    context_object_name = 'checkout'

# Checkout - Update

class CheckoutUpdate(SuccessMessageMixin, UpdateView):
    model           = Checkout
    template_name   = 'kfet/checkout_update.html'
    form_class      = CheckoutRestrictForm
    success_message = 'Informations mises à jour pour la caisse : %(name)s'

    # Surcharge de la validation
    def form_valid(self, form):
        # Checking permission
        if not self.request.user.has_perm('change_checkout'):
            raise PermissionDenied
        # Updating
        return super(CheckoutUpdate, self).form_valid(form)

# -----
# Article views
# -----

# Article - General

class ArticleList(ListView):
    model    = Article
    queryset = Article.objects.order_by('category', '-is_sold', 'name')
    template_name = 'kfet/article.html'
    context_object_name = 'articles'

# Article - Create

class ArticleCreate(SuccessMessageMixin, CreateView):
    model           = Article
    template_name   = 'kfet/article_create.html'
    form_class      = ArticleForm
    success_message = 'Nouvel item : %(category)s - %(name)s'

    # Surcharge de la validation
    def form_valid(self, form):
        # Checking permission
        if not self.request.user.has_perm('add_article'):
            raise PermissionDenied
        # Creating
        return super(ArticleCreate, self).form_valid(form)

# Article - Read

class ArticleRead(DetailView):
    model         = Article
    template_name = 'kfet/article_read.html'
    context_object_name = 'article'

# Article - Update

class ArticleUpdate(UpdateView):
    model           = Article
    template_name   = 'kfet/article_update.html'
    form_class      = ArticleRestrictForm
    success_message = "Informations mises à jour pour l'article : %(name)s"

    # Surcharge de la validation
    def form_valid(self, form):
        # Checking permission
        if not self.request.user.has_perm('change_article'):
            raise PermissionDenied
        # Updating
        return super(ArticleUpdate, self).form_valid(form)

# -----
# K-Psul
# -----

@permission_required('kfet.is_team')
def kpsul(request):
    data = {}
    data['operationgroup_form'] = KPsulOperationGroupForm()
    data['trigramme_form'] = KPsulAccountForm()
    data['checkout_form']  = KPsulCheckoutForm()
    operation_formset = KPsulOperationFormSet(queryset=Operation.objects.none())
    data['operation_formset'] = operation_formset
    return render(request, 'kfet/kpsul.html', data)

@permission_required('kfet.is_team')
def kpsul_account_data(request):
    trigramme = request.POST.get('trigramme', '')
    account   = get_object_or_404(Account, trigramme=trigramme)
    data = { 'pk': account.pk, 'name': account.name, 'email': account.email,
        'is_cof': account.is_cof, 'promo': account.promo,
        'balance': account.balance, 'is_frozen': account.is_frozen,
        'departement': account.departement, 'nickname': account.nickname }
    return JsonResponse(data)

@permission_required('kfet.is_team')
def kpsul_checkout_data(request):
    pk       = request.POST.get('pk', 0)
    checkout = get_object_or_404(Checkout, pk=pk)
    data = { 'pk': checkout.pk, 'name': checkout.name, 'balance': checkout.balance,
        'valid_from': checkout.valid_from, 'valid_to': checkout.valid_to }
    return JsonResponse(data)

@permission_required('kfet.is_team')
def kpsul_perform_operations(request):
    # Initializing response data
    data = defaultdict(list)

    # Checking operationgroup
    operationgroup_form = KPsulOperationGroupForm(request.POST)
    if not operationgroup_form.is_valid():
        data['errors'].append({'operation_group': list(operationgroup_form.errors)})

    # Checking operation_formset
    operation_formset   = KPsulOperationFormSet(request.POST)
    if not operation_formset.is_valid():
        data['errors'].append({'operations': list(operation_formset.errors) })

    # Returning bad request if errors
    if 'errors' in data:
        return JsonResponse(data, status=400)

    # Pre-saving (no commit)
    operationgroup = operationgroup_form.save(commit = False)
    operations     = operation_formset.save(commit = False)

    # Calculating amount of each PURCHASE operations
    # and total amount for operation group
    for operation in operations:
        if operation.type == Operation.PURCHASE:
            operation.amount = - operation.article.price * operation.article_nb
        operationgroup.amount += operation.amount

    # Filling cof status for statistics
    operationgroup.is_cof = operationgroup.on_acc.is_cof
    # Saving operation group
    operationgroup.save()
    data['operationgroup'] = operationgroup.pk

    # Filling operationgroup id for each operations and saving
    for operation in operations:
        operation.group = operationgroup
        operation.save()
        data['operations'].append(operation.pk)

    return JsonResponse(data)