#!/usr/bin/env python
# -*- coding: utf-8 -*-
from django.db import models
from django.conf import settings
from django.http import QueryDict
from django.utils.http import urlencode
from six.moves.urllib.request import urlopen
from six.moves.urllib.parse import unquote_plus

from paypal.standard.models import PayPalStandardBase
from paypal.standard.conf import POSTBACK_ENDPOINT, SANDBOX_POSTBACK_ENDPOINT
from paypal.standard.pdt.signals import pdt_successful, pdt_failed

# ### Todo: Move this logic to conf.py:
# if paypal.standard.pdt is in installed apps
# ... then check for this setting in conf.py
class PayPalSettingsError(Exception):
    """Raised when settings are incorrect."""


try:
    IDENTITY_TOKEN = settings.PAYPAL_IDENTITY_TOKEN
except:
    raise PayPalSettingsError(
        "You must set PAYPAL_IDENTITY_TOKEN in settings.py. Get this token by enabling PDT in your PayPal account.")


class PayPalPDT(PayPalStandardBase):
    format = "<PDT: %s %s>"

    amt = models.DecimalField(max_digits=64, decimal_places=2, default=0, blank=True, null=True)
    cm = models.CharField(max_length=255, blank=True)
    sig = models.CharField(max_length=255, blank=True)
    tx = models.CharField(max_length=255, blank=True)
    st = models.CharField(max_length=32, blank=True)

    class Meta:
        db_table = "paypal_pdt"
        verbose_name = "PayPal PDT"

    def _postback(self):
        """
        Perform PayPal PDT Postback validation.
        Sends the transaction ID and business token to PayPal which responses with
        SUCCESS or FAILED.

        """
        postback_dict = dict(cmd="_notify-synch", at=IDENTITY_TOKEN, tx=self.tx)
        postback_params = urlencode(postback_dict)
        return urlopen(self.get_endpoint(), postback_params).read()

    def get_endpoint(self):
        if getattr(settings, 'PAYPAL_TEST', True):
            return SANDBOX_POSTBACK_ENDPOINT
        else:
            return POSTBACK_ENDPOINT

    def _verify_postback(self):
        # ### Now we don't really care what result was, just whether a flag was set or not.
        from paypal.standard.pdt.forms import PayPalPDTForm

        # TODO: this needs testing and probably fixing under Python 3
        result = False
        response_list = self.response.split('\n')
        response_dict = {}
        for i, line in enumerate(response_list):
            unquoted_line = unquote_plus(line).strip()
            if i == 0:
                self.st = unquoted_line
                if self.st == "SUCCESS":
                    result = True
            else:
                if self.st != "SUCCESS":
                    self.set_flag(line)
                    break
                try:
                    if not unquoted_line.startswith(' -'):
                        k, v = unquoted_line.split('=')
                        response_dict[k.strip()] = v.strip()
                except ValueError:
                    pass

        qd = QueryDict('', mutable=True)
        qd.update(response_dict)
        qd.update(dict(ipaddress=self.ipaddress, st=self.st, flag_info=self.flag_info, flag=self.flag,
                       flag_code=self.flag_code))
        pdt_form = PayPalPDTForm(qd, instance=self)
        pdt_form.save(commit=False)

    def send_signals(self):
        # Send the PDT signals...
        if self.flag:
            pdt_failed.send(sender=self)
        else:
            pdt_successful.send(sender=self)