import base64
import logging
from datetime import datetime
from email.mime.image import MIMEImage

from django.core.exceptions import ValidationError
from django.core.mail import EmailMultiAlternatives
from django.conf import settings
from django.contrib import messages
from django.contrib.auth.decorators import permission_required, user_passes_test, login_required
from django.contrib.auth.models import User, Group
from django.db import transaction
from django.db.models import F, Q
from django.db.models import Count, Max, Sum
from django.http import Http404
from django.http import HttpResponse, HttpResponseBadRequest
from django.shortcuts import redirect, render
from django.template import Template, Context
from django.urls import reverse

from registrasion import util
from registrasion.models import commerce, people
from registrasion.templatetags.registrasion_tags import items_purchased, items_pending
from registrasion.templatetags.registrasion_tags import invoices, missing_categories
from symposion.conference.models import Conference

from regidesk import forms
from regidesk.models import BoardingPass, BoardingPassTemplate, CheckIn



AttendeeProfile = util.get_object_from_name(settings.ATTENDEE_PROFILE_MODEL)

def _staff_only(user):
    ''' Returns true if the user is staff. '''
    return user.is_staff

@login_required
def boardingpass(request):

    user=request.user
    checkin = CheckIn.objects.get_or_create(user=user)[0]
    if not checkin.boardingpass:
        messages.add_message(request, messages.WARNING, 'Your boarding pass has not been prepared. Please try again later.')
        return redirect('/')

    boardingpass = checkin.boardingpass.html_body
    qrcode_url = request.build_absolute_uri(reverse("regidesk:checkin_png", args=[checkin.code]))
    qrcode = checkin.qrcode
    qrcode_string ='<img src="data:image/png;base64,' + qrcode + '"/>'
    not_qrcode_string = '<img src="cid:qrcode.png"/>'

    boardingpass = boardingpass.replace(not_qrcode_string, qrcode_string)
    ctx = { 'attendee': user.attendee,
        'boardingpass': boardingpass
    }

    response = render(request, "regidesk/boardingpass.html", ctx)
    return response


@permission_required("regidesk.view_boarding_pass")
def boarding_overview(request, boarding_state="pending"):

    tickets = commerce.LineItem.objects.select_related(
        "invoice","invoice__user__attendee","product__category"
    ).filter(
        invoice__status=commerce.Invoice.STATUS_PAID,
        product__category=settings.TICKET_PRODUCT_CATEGORY,
        price__gte=0
    )

    ticketholders = { ticket.invoice.user: ticket.product.name for ticket in tickets }

    attendees = people.Attendee.objects.select_related(
            "attendeeprofilebase",
            "attendeeprofilebase__attendeeprofile",
            "user",
            "user__checkin"
        ).filter(user__in=ticketholders)

    profiles = AttendeeProfile.objects.filter(
        attendee__in=attendees
    ).select_related(
        "attendee", "attendee__user",
    )
    profiles_by_attendee = dict((i.attendee, i) for i in profiles)

    bp_templates = BoardingPassTemplate.objects.all()

    ctx = {
        "boarding_state": boarding_state,
        "attendees": attendees,
        "profiles": profiles_by_attendee,
        "templates": bp_templates,
    }

    return render(request, "regidesk/boardingpass_overview.html", ctx)

@login_required
def checkin_png(request, checkin_code):

    checkin = CheckIn.objects.get(checkin_code=checkin_code)
    if not checkin:
        raise Http404()

    if not request.user.has_perm("regidesk.view_checkin_details"):
        if request.user != checkin.user:
            raise Http404()

    response = HttpResponse()
    response["Content-Type"] = "image/png"
    response["Content-Disposition"] = 'inline; filename="qrcode.png"'

    qrcode = base64.b64decode(checkin.qrcode)
    response.write(qrcode)

    return response

@permission_required("regidesk.send_boarding_pass")
def boarding_prepare(request):

    attendee_pks = []
    try:
        for pk in request.POST.getlist("_selected_action"):
            attendee_pks.append(int(pk))
    except ValueError:
        return HttpResponseBadRequest()
    attendees = people.Attendee.objects.filter(pk__in=attendee_pks)
    attendees = attendees.select_related(
        "user", "attendeeprofilebase", "attendeeprofilebase__attendeeprofile")

    sample_checkin = CheckIn.objects.get_or_create(user=attendees[0].user)[0]
    rendered_template = {}
    sample_ctx = {}

    bp_template_pk = request.POST.get("template", "")
    if bp_template_pk:
        bp_template = BoardingPassTemplate.objects.get(pk=bp_template_pk)

        sample_ctx = {
            "user": sample_checkin.user,
            "boardingpass": sample_checkin.boardingpass,
            "code": sample_checkin.code,
            "qrcode": '<img src="data:image/png;base64,' + sample_checkin.qrcode + '"/>',
            "qrcode_url": request.build_absolute_uri(
                reverse("regidesk:checkin_png", args=[sample_checkin.code])),
        }
        ctx = Context(sample_ctx)
        ctx["invoices"] = invoices(ctx)
        ctx["items_pending"] = items_pending(ctx)
        ctx["items_purchased"] = items_purchased(ctx)
        ctx["missing_categories"] = missing_categories(ctx)

        subject = Template(bp_template.subject).render(ctx)
        rendered_template['plain'] = Template(bp_template.body).render(ctx)
        rendered_template['html'] = Template(bp_template.html_body).render(ctx)
    else:
        bp_template = None
        subject = None

    ctx = {
        "attendees": attendees,
        "template": bp_template,
        "attendee_pks": attendee_pks,
        "rendered_template": rendered_template,
        "subject": subject,
        "sample": sample_ctx,
    }

    request.session.set_expiry=(300)
    request.session['boarding_attendees'] = attendee_pks
    request.session['template'] = bp_template.pk
    response = render(request, "regidesk/boardingpass_prepare.html", ctx)

    return response

@permission_required("regidesk.send_boarding_pass")
def boarding_send(request):

    BOARDING_GROUP = getattr(settings, "REGIDESK_BOARDING_GROUP", None)
    if BOARDING_GROUP and Group.objects.filter(name=BOARDING_GROUP):
        boarding_users = User.objects.filter(groups__name=BOARDING_GROUP)
    else:
        boarding_users = User.objects.all()

    attendees = people.Attendee.objects.filter(pk__in=request.session['boarding_attendees'])
    attendees = attendees.select_related(
        "user", "attendeeprofilebase", "attendeeprofilebase__attendeeprofile")

    logging.debug(attendees)

    template_pk = request.session['template']
    template = BoardingPassTemplate.objects.get(pk=template_pk)

    for attendee in attendees:

        user = attendee.user
        checkin = CheckIn.objects.get_or_create(user=user)
        ctx = {
            "user": user,
            "checkin": user.checkin,
            "code": user.checkin.code,
            "qrcode": user.checkin.qrcode,
            "qrcode_url": request.build_absolute_uri(
                reverse("regidesk:checkin_png", args=[user.checkin.code])),
        }
        ctx = Context(ctx)
        ctx["invoices"] = invoices(ctx)
        ctx["items_pending"] = items_pending(ctx)
        ctx["items_purchased"] = items_purchased(ctx)
        ctx["missing_categories"] = missing_categories(ctx)

        subject = Template(template.subject).render(ctx)
        body = Template(template.body).render(ctx)
        if template.html_body:
            html_body = Template(template.html_body).render(ctx)
        else:
            html_body = None

        bpass = BoardingPass(template=template, to_address=user.email,
                             from_address=template.from_address,
                             subject=subject, body=body,
                             html_body=html_body
        )
        bpass.save()

        if user.checkin.boardingpass:
            user.checkin.boardingpass.delete()
        user.checkin.boardingpass = bpass
        user.checkin.save()

        msg = EmailMultiAlternatives(
            bpass.subject,
            bpass.body,
            bpass.from_address,
            [bpass.to_address,],
        )
        msg.content_subtype="plain"
        msg.mixed_subtype="related"
        if bpass.html_body:
            msg.attach_alternative(bpass.html_body, "text/html")

        msg.attach(filename="qrcode.png", content=user.checkin.qrcode, mimetype="image/png")

        if user in boarding_users:
            with transaction.atomic():
                msg.send()
                bpass.sent = datetime.now()
                bpass.save()
                messages.success(request, "Sent boarding pass to %s" % attendee)

        request.session['boarding_attendees'].remove(attendee.pk)

    return redirect("regidesk:boarding_overview")