def model_fields_form_factory(model):

    ''' Creates a form for specifying fields from a model to display. '''

    fields = model._meta.get_fields()

    choices = []

    for field in fields:

        if hasattr(field, "verbose_name"):

            choices.append((field.name, field.verbose_name))

    class ModelFieldsForm(forms.Form):

        fields = forms.MultipleChoiceField(

            choices=choices,

            required=False,

        )

    return ModelFieldsForm

class AttendeeListReport(ListReport):

    def get_link(self, argument):

        return reverse(self._link_view) + "?user=%d" % int(argument)

    return AttendeeListReport("Attendees", headings, data, link_view=attendee)

ProfileForm = forms.model_fields_form_factory(AttendeeProfile)

class ProductCategoryProfileForm(forms.ProductAndCategoryForm, ProfileForm):

    pass

@report_view(

    "Attendees By Product/Category",

    form_type=ProductCategoryProfileForm,

)

def attendee_data(request, form, user_id=None):

    ''' Lists attendees for a given product/category selection along with

    profile data.'''

    status_display = {

        commerce.Cart.STATUS_ACTIVE: "Unpaid",

        commerce.Cart.STATUS_PAID: "Paid",

        commerce.Cart.STATUS_RELEASED: "Refunded",

    }

    output = []

    products = form.cleaned_data["product"]

    categories = form.cleaned_data["category"]

    fields = form.cleaned_data["fields"]

    name_field = AttendeeProfile.name_field()

    items = commerce.ProductItem.objects.filter(

        Q(product__in=products) | Q(product__category__in=categories),

    ).exclude(

        cart__status=commerce.Cart.STATUS_RELEASED

    ).select_related(

        "cart", "product"

    ).order_by("cart__status")

    # Get all of the relevant attendee profiles in one hit.

    profiles = AttendeeProfile.objects.filter(

        attendee__user__cart__productitem__in=items

    ).select_related("attendee__user")

    by_user = {}

    for profile in profiles:

        by_user[profile.attendee.user] = profile

    for field in fields:

        field_verbose = AttendeeProfile._meta.get_field(field).verbose_name

        cart = "attendee__user__cart"

        cart_status = cart + "__status"

        product = cart + "__productitem__product"

        product_name = product + "__name"

        category_name = product + "__category__name"

        p = profiles.order_by(product, field).values(

            cart_status, product, product_name, category_name, field

        ).annotate(count=Count("id"))

        output.append(ListReport(

            "Grouped by %s" % field_verbose,

            ["Product", "Status", field_verbose, "count"],

            [

                (

                    "%s - %s" % (i[category_name], i[product_name]),

                    status_display[i[cart_status]],

                    i[field],

                    i["count"] or 0,

                )

                for i in p

            ],

        ))

    # DO the report for individual attendees

    field_names = [

        AttendeeProfile._meta.get_field(field).verbose_name for field in fields

    ]

    headings = ["User ID", "Name", "Product", "Item Status"] + field_names

    data = []

    for item in items:

        profile = by_user[item.cart.user]

        line = [

            item.cart.user.id,

            getattr(profile, name_field),

            item.product,

            status_display[item.cart.status],

        ] + [

            getattr(profile, field) for field in fields

        ]

        data.append(line)

    output.append(AttendeeListReport(

        "Attendees by item with profile data", headings, data, link_view=attendee

    ))

    return output

    url(r"^attendee_data/?$", rv.attendee_data, name="attendee_data"),