class UserIdForm(forms.Form):

    user = forms.IntegerField(

        label="User ID",

        required=False,

    )

from django.db.models import Count, Sum

from registrasion.models import people

@report_view("Attendee", form_type=forms.UserIdForm)

def attendee(request, form, attendee_id=None):

    ''' Returns a list of all manifested attendees if no attendee is specified,

    else displays the attendee manifest. '''

    if attendee_id is None and not form.has_changed():

        return attendee_list(request)

    reports = []

    # TODO: METADATA.

    # Paid products

    headings = ["Product", "Quantity"]

    data = []

    reports.append(Report("Paid Products", headings, data))

    # Unpaid products

    headings = ["Product", "Quantity"]

    data = []

    reports.append( Report("Unpaid Products", headings, data))

    # Invoices

    headings = ["Invoice ID", "Status", "Amount"]

    data = []

    reports.append( Report("Invoices", headings, data))

    # Credit Notes

    headings = ["Note ID", "Status", "Value"]

    data = []

    reports.append( Report("Credit Notes", headings, data))

    return reports

def attendee_list(request):

    ''' Returns a list of all attendees. '''

    attendees = people.Attendee.objects.all().select_related(

        "attendeeprofilebase",

    )

    attendees = attendees.annotate(

        has_registered=Count(

            Q(user__invoice__status=commerce.Invoice.STATUS_PAID)

        ),

    )

    headings = [

        "User ID", "Email", "Has registered",

    ]

    data = []

    for attendee in attendees:

        data.append([

            attendee.user.id,

            attendee.user.email,

            attendee.has_registered > 0,

        ])

    # Sort by whether they've registered, then ID.

    data.sort(key=lambda attendee: (-attendee[2], attendee[0]))

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