# -*- coding: utf-8 -*-
import base64
import datetime
from decimal import Decimal
from io import BytesIO
import jwt

from django.core.exceptions import ValidationError
from django.utils import timezone

from django.conf import settings
from django.db import models
from django.db.models import Q, F
from django.db.models import Case, When, Value
from django.db.models import Count
from django.db.models.signals import post_save
from django.contrib.auth import get_user_model
import pyqrcode

from symposion import constants
from symposion.text_parser import parse
from registrasion.models import commerce
from registrasion.util import generate_access_code as generate_code

User = get_user_model()


class BoardingPassTemplate(models.Model):

    label = models.CharField(max_length=100, verbose_name="Label")
    from_address = models.EmailField(verbose_name="From address")
    subject = models.CharField(max_length=100, verbose_name="Subject")
    body = models.TextField(verbose_name="Body")
    html_body = models.TextField(verbose_name="HTML Body",null=True)

    class Meta:
        verbose_name = ("Boarding Pass template")
        verbose_name_plural = ("Boarding Pass templates")


class BoardingPass(models.Model):

    template = models.ForeignKey(BoardingPassTemplate, null=True, blank=True,
                                 on_delete=models.SET_NULL, verbose_name="Template")
    created = models.DateTimeField(auto_now_add=True, verbose_name="Created")
    sent = models.DateTimeField(null=True, verbose_name="Sent")
    to_address = models.EmailField(verbose_name="To address")
    from_address = models.EmailField(verbose_name="From address")
    subject = models.CharField(max_length=255, verbose_name="Subject")
    body = models.TextField(verbose_name="Body")
    html_body = models.TextField(verbose_name="HTML Body", null=True)

    class Meta:
        permissions = (
            ("view_boarding_pass", "Can view sent boarding passes"),
            ("send_boarding_pass", "Can send boarding passes"),
        )
        verbose_name = ("Boarding Pass")
        verbose_name_plural = ("Boarding Passes")

    def __unicode__(self):
        return self.checkin.attendee.attendeeprofilebase.attendeeprofile.name + ' ' + self.timestamp.strftime('%Y-%m-%d %H:%M:%S')

    @property
    def email_args(self):
        return (self.subject, self.body, self.from_address, self.user.email)


class CheckIn(models.Model):

    user = models.OneToOneField(User, on_delete=models.CASCADE)
    boardingpass = models.OneToOneField(BoardingPass, null=True,
                                        blank=True, on_delete=models.SET_NULL)
    seen = models.DateTimeField(null=True,blank=True)
    checked_in = models.DateTimeField(null=True,blank=True)
    checkin_code = models.CharField(
        max_length=6,
        unique=True,
        db_index=True,
    )
    _checkin_code_png=models.TextField(max_length=512,null=True,blank=True)
    badge_printed = models.BooleanField(default=False)
    schwag_given = models.BooleanField(default=False)
    checked_in_bool = models.BooleanField(default=False)
    needs_review = models.BooleanField(default=False)
    review_text = models.TextField(blank=True)

    venueless_user_id = models.TextField(max_length=40, null=True, blank=True)
    venueless_traits = models.TextField(max_length=256, null=True, blank=True)
    _venueless_token = models.TextField(null=True, blank=True)

    class Meta:
        permissions = (
            ("view_checkin_details", "Can view the details of other user's checkins"),
        )

    def save(self, *a, **k):
        while not self.checkin_code:
            checkin_code = generate_code()
            if CheckIn.objects.filter(checkin_code=checkin_code).count() == 0:
                self.checkin_code = checkin_code
        return super(CheckIn, self).save(*a, **k)

    def mark_checked_in(self):
        self.checked_in_bool = True
        self.checked_in = timezone.now()
        self.save()

    def mark_badge_printed(self):
        self.badge_printed = True
        self.save()

    def unset_badge(self):
        self.badge_printed = False
        self.save()

    def mark_schwag_given(self):
        self.schwag_given = True
        self.save()

    def bulk_mark_given(self):
        self.checked_in_bool = True
        self.schwag_given = True
        self.save()

    def set_exception(self, text):
        self.needs_review = True
        self.review_text = text
        self.save()

    @property
    def code(self):
        return self.checkin_code

    @property
    def qrcode(self):
        """Returns the QR Code for this checkin's code.

        If this is the first time the QR code has been generated, cache it on the object.
        If a code has already been cached, serve that.

        Returns the raw PNG blob, unless b64=True, in which case the return value
        is the base64encoded PNG blob."""

        if not self.code:
            return None
        if not self._checkin_code_png:
            qrcode = pyqrcode.create(self.code)
            qr_io = BytesIO()
            qrcode.png(qr_io, scale=6)
            qr_io.seek(0)
            self._checkin_code_png = base64.b64encode(qr_io.read()).decode('UTF-8')
            self.save()

        return self._checkin_code_png

    @property
    def venueless_token(self):
        """Returns the Venueless JWT token for this checkin's code."""
        updated = False
        if not self.venueless_user_id:
            self.venueless_user_id = self.checkin_code
            updated = True

        if not self.venueless_traits:
            traits = self._get_venueless_traits()
            self.venueless_traits = ",".join(traits)
            updated = True

        if not self.venueless_traits or not self._venueless_token:
            self._venueless_token = self._generate_venueless_token()
            updated = True

        if updated:
            self.save()

        return self._venueless_token

    def _get_venueless_traits(self):
        """ Returns a list of traits based on the user's ticket """
        ticket_type = self.user.attendee.ticket_type
        if not ticket_type:
            return []

        traits = ["attendee"]

        if ticket_type == "Conference Volunteer":
            traits.append("volunteer")
        elif ticket_type == "Conference Organiser":
            traits.append("organiser")

        if hasattr(self.user, "speaker_profile"):
            best = 0
            for presentation in self.user.speaker_profile.presentations.all():
                if presentation.section.id == 1:
                    # Main Conference Speaker
                    best = 1
                if best == 0 and presentation.section.id == 2:
                    # Miniconf Organiser
                    best = 2

            if best == 1:
                traits.append("speaker")
            elif best == 2:
                traits.append("miniconf_org")
            else:
                traits.append("miniconf_speaker")

        return traits

    def _generate_venueless_token(self):
        """ Generate token for Venueless login """
        if not self.venueless_traits:
            return ""

        issued_at = datetime.datetime.utcnow()
        expiry = settings.LCA_END + datetime.timedelta(days=1)
        if self.user.attendee.ticket_type == "Miniconf Only":
            # Miniconf only ticket holders have limited access
            expiry = settings.LCA_MINICONF_END

        payload = {
            "iss": settings.VENUELESS_TOKEN_ISSUER,
            "aud": settings.VENUELESS_AUDIENCE,
            "iat": issued_at,
            "exp": expiry,
            "uid": self.venueless_user_id,
            "traits": self.venueless_traits.split(','),
        }
        token = jwt.encode(payload, settings.VENUELESS_SECRET, algorithm="HS256")
        return token