from django.core.xheaders import populate_xheaders

from django.template import loader

from django import oldforms

from django.db.models import FileField

from django.contrib.auth.views import redirect_to_login

from django.template import RequestContext

from django.http import Http404, HttpResponse, HttpResponseRedirect

from django.core.exceptions import ObjectDoesNotExist, ImproperlyConfigured

from django.utils.translation import ugettext

def create_object(request, model, template_name=None,

        template_loader=loader, extra_context=None, post_save_redirect=None,

        login_required=False, follow=None, context_processors=None):

    """

    Generic object-creation function.

    Templates: ``<app_label>/<model_name>_form.html``

    Context:

        form

            the form wrapper for the object

    """

    if extra_context is None: extra_context = {}

    if login_required and not request.user.is_authenticated():

        return redirect_to_login(request.path)

    manipulator = model.AddManipulator(follow=follow)

    if request.POST:

        # If data was POSTed, we're trying to create a new object

        new_data = request.POST.copy()

        if model._meta.has_field_type(FileField):

            new_data.update(request.FILES)

        # Check for errors

        errors = manipulator.get_validation_errors(new_data)

        manipulator.do_html2python(new_data)

        if not errors:

            # No errors -- this means we can save the data!

            new_object = manipulator.save(new_data)

            if request.user.is_authenticated():

                request.user.message_set.create(message=ugettext("The %(verbose_name)s was created successfully.") % {"verbose_name": model._meta.verbose_name})

            # Redirect to the new object: first by trying post_save_redirect,

            # then by obj.get_absolute_url; fail if neither works.

            if post_save_redirect:

                return HttpResponseRedirect(post_save_redirect % new_object.__dict__)

            elif hasattr(new_object, 'get_absolute_url'):

                return HttpResponseRedirect(new_object.get_absolute_url())

            else:

                raise ImproperlyConfigured("No URL to redirect to from generic create view.")

    else:

        # No POST, so we want a brand new form without any data or errors

        errors = {}

        new_data = manipulator.flatten_data()

    # Create the FormWrapper, template, context, response

    form = oldforms.FormWrapper(manipulator, new_data, errors)

    if not template_name:

        template_name = "%s/%s_form.html" % (model._meta.app_label, model._meta.object_name.lower())

    t = template_loader.get_template(template_name)

    c = RequestContext(request, {

        'form': form,

    }, context_processors)

    for key, value in extra_context.items():

        if callable(value):

            c[key] = value()

        else:

            c[key] = value

    return HttpResponse(t.render(c))

def update_object(request, model, object_id=None, slug=None,

        slug_field='slug', template_name=None, template_loader=loader,

        extra_context=None, post_save_redirect=None,

        login_required=False, follow=None, context_processors=None,

        template_object_name='object'):

    """

    Generic object-update function.

    Templates: ``<app_label>/<model_name>_form.html``

    Context:

        form

            the form wrapper for the object

        object

            the original object being edited

    """

    if extra_context is None: extra_context = {}

    if login_required and not request.user.is_authenticated():

        return redirect_to_login(request.path)

    # Look up the object to be edited

    lookup_kwargs = {}

    if object_id:

        lookup_kwargs['%s__exact' % model._meta.pk.name] = object_id

    elif slug and slug_field:

        lookup_kwargs['%s__exact' % slug_field] = slug

    else:

        raise AttributeError("Generic edit view must be called with either an object_id or a slug/slug_field")

    try:

        object = model.objects.get(**lookup_kwargs)

    except ObjectDoesNotExist:

        raise Http404, "No %s found for %s" % (model._meta.verbose_name, lookup_kwargs)

    manipulator = model.ChangeManipulator(getattr(object, object._meta.pk.attname), follow=follow)

    if request.POST:

        new_data = request.POST.copy()

        if model._meta.has_field_type(FileField):

            new_data.update(request.FILES)

        errors = manipulator.get_validation_errors(new_data)

        manipulator.do_html2python(new_data)

        if not errors:

            object = manipulator.save(new_data)

            if request.user.is_authenticated():

                request.user.message_set.create(message=ugettext("The %(verbose_name)s was updated successfully.") % {"verbose_name": model._meta.verbose_name})

            # Do a post-after-redirect so that reload works, etc.

            if post_save_redirect:

                return HttpResponseRedirect(post_save_redirect % object.__dict__)

            elif hasattr(object, 'get_absolute_url'):

                return HttpResponseRedirect(object.get_absolute_url())

            else:

                raise ImproperlyConfigured("No URL to redirect to from generic create view.")

    else:

        errors = {}

        # This makes sure the form acurate represents the fields of the place.

        new_data = manipulator.flatten_data()

    form = oldforms.FormWrapper(manipulator, new_data, errors)

    if not template_name:

        template_name = "%s/%s_form.html" % (model._meta.app_label, model._meta.object_name.lower())

    t = template_loader.get_template(template_name)

    c = RequestContext(request, {

        'form': form,

        template_object_name: object,

    }, context_processors)

    for key, value in extra_context.items():

        if callable(value):

            c[key] = value()

        else:

            c[key] = value

    response = HttpResponse(t.render(c))

    populate_xheaders(request, response, model, getattr(object, object._meta.pk.attname))

    return response

def delete_object(request, model, post_delete_redirect,

        object_id=None, slug=None, slug_field='slug', template_name=None,

        template_loader=loader, extra_context=None,

        login_required=False, context_processors=None, template_object_name='object'):

    """

    Generic object-delete function.

    The given template will be used to confirm deletetion if this view is

    fetched using GET; for safty, deletion will only be performed if this

    view is POSTed.

    Templates: ``<app_label>/<model_name>_confirm_delete.html``

    Context:

        object

            the original object being deleted

    """

    if extra_context is None: extra_context = {}

    if login_required and not request.user.is_authenticated():

        return redirect_to_login(request.path)

    # Look up the object to be edited

    lookup_kwargs = {}

    if object_id:

        lookup_kwargs['%s__exact' % model._meta.pk.name] = object_id

    elif slug and slug_field:

        lookup_kwargs['%s__exact' % slug_field] = slug

    else:

        raise AttributeError("Generic delete view must be called with either an object_id or a slug/slug_field")

    try:

        object = model._default_manager.get(**lookup_kwargs)

    except ObjectDoesNotExist:

        raise Http404, "No %s found for %s" % (model._meta.app_label, lookup_kwargs)

    if request.method == 'POST':

        object.delete()

        if request.user.is_authenticated():

            request.user.message_set.create(message=ugettext("The %(verbose_name)s was deleted.") % {"verbose_name": model._meta.verbose_name})

        return HttpResponseRedirect(post_delete_redirect)

    else:

        if not template_name:

            template_name = "%s/%s_confirm_delete.html" % (model._meta.app_label, model._meta.object_name.lower())

        t = template_loader.get_template(template_name)

        c = RequestContext(request, {

            template_object_name: object,

        }, context_processors)

        for key, value in extra_context.items():

            if callable(value):

                c[key] = value()

            else:

                c[key] = value

        response = HttpResponse(t.render(c))

        populate_xheaders(request, response, model, getattr(object, object._meta.pk.attname))

        return response