from django.db import models
from django.contrib.auth import get_user_model
from django.core.files.base import ContentFile
from django.utils import timezone
from django.conf import settings

from dateutil.relativedelta import relativedelta

from pyinvoice.models import InvoiceInfo, ServiceProviderInfo, ClientInfo, Item, Transaction, PDFInfo
from pyinvoice.templates import SimpleInvoice

from polymorphic.models import PolymorphicModel
from django_countries.fields import CountryField

from io import BytesIO

import uuid

import urllib.request

from dbsettings.functions import getValue

from .functions import invoice_upload_path
from .signals import initiate_payment

from auction.models import Inquiry
from localauth.models import PersonMixin, AddressMixin

class BillingAddress(PersonMixin, AddressMixin):
    user = models.ForeignKey(get_user_model(), models.CASCADE)

    @classmethod
    def from_profile(cls, profile):
        return cls.objects.create(
            company = profile.company,
            vat_id = profile.vat_id,
            first_name = profile.first_name,
            last_name = profile.last_name,
            street = profile.street,
            city = profile.city,
            zip = profile.zip,
            state = profile.state,
            country = profile.country,
            user = profile.user
        )

class Invoice(models.Model):
    uuid = models.UUIDField(default=uuid.uuid4)
    user = models.ForeignKey(get_user_model(), models.PROTECT)
    billing_address = models.ForeignKey(BillingAddress, models.PROTECT)
    currency = models.CharField(max_length=3)
    tax_rate = models.DecimalField(max_digits=4, decimal_places=2)
    invoice = models.FileField(null=True, blank=True, upload_to=invoice_upload_path)
    inquiry = models.OneToOneField(Inquiry, null=True, blank=True, on_delete=models.SET_NULL)
    created = models.DateTimeField(auto_now_add=True)

    @property
    def price_net(self):
        price = 0

        for item in self.invoiceitem_set.all():
            price += item.net_total

        return price

    @property
    def tax(self):
        return round(self.price_net * self.tax_rate / 100, 2)

    @property
    def price_gross(self):
        return self.price_net + self.tax

    @property
    def payment_instructions(self):
        return "Alle Preise in %s." % self.currency

    @property
    def url(self):
        return False

    @property
    def balance(self):
        paid_amount = 0

        for payment in self.invoicepayment_set.all():
            paid_amount += payment.amount

        return paid_amount - self.price_gross
    
    @property
    def is_paid(self):
        return self.balance >= 0

    def finalize(self, *args, **kwargs):
        if self.is_paid:
            try:
                self.inquiry.process_payment(*args, **kwargs)
            except Inquiry.DoesNotExist:
                pass

            self.generate_invoice()

    def generate_invoice(self):
        output = BytesIO()

        pdfinfo = PDFInfo(title='Rechnung', author='Kumi Media Ltd.', subject='Rechnung')
        doc = SimpleInvoice(output, pdfinfo)

        doc.is_paid = self.is_paid

        doc.invoice_info = InvoiceInfo("%s%i" % (getValue("billing.prefix", ""), self.id), timezone.now().date(), timezone.now().date()) 

        provider_data = { key: value for key, value in {
            "name": getValue("billing.provider.name", False),
            "street": getValue("billing.provider.street", False),
            "city": getValue("billing.provider.city", False),
            "state": getValue("billing.provider.state", False),
            "country": getValue("billing.provider.country", False),
            "post_code": getValue("billing.provider.zip", False),
            "vat_tax_number": getValue("billing.provider.vat_id", False)
        }.items() if value}

        doc.service_provider_info = ServiceProviderInfo(**provider_data)

        logo_url = getValue("billing.logo_url", False)
        if logo_url:
            try:
                logo = BytesIO(urllib.request.urlopen(logo_url).read())
                doc.logo(logo)
            except:
                pass

        profile = self.user.clientprofile if self.inquiry else self.user.partnerprofile

        client_data = { key: value for key, value in {
            "name": profile.full_name,
            "street": profile.street,
            "city": profile.city,
            "state": profile.state,
            "country": profile.country,
            "post_code": profile.zip,
            "email": self.user.email,
        }.items() if value}

        doc.client_info = ClientInfo(**client_data)

        for item in self.invoiceitem_set.all():
            doc.add_item(Item(item.name, item.description, item.count, item.net_each))

        doc.set_item_tax_rate(self.tax_rate)

        for payment in self.invoicepayment_set.all():
            doc.add_transaction(Transaction(payment.gateway, payment.gateway_id, payment.timestamp, payment.amount))

        bottom_tip = ("Kunden-UID: %s<br /><br />" % profile.vat_id) if profile.vat_id else ""        
        bottom_tip += (f"{ self.payment_instructions }<br /><br />" if self.payment_instructions else "") + getValue("billing.bottom_tip", "")
        bottom_tip += "<br /><br />" if bottom_tip else ""
        bottom_tip +=  "Rechnung erstellt: %s" % str(timezone.now())

        doc.set_bottom_tip(bottom_tip)

        doc.finish()

        self.invoice = ContentFile(output.getvalue(), "invoice.pdf")
        self.save()

    @classmethod
    def from_inquiry(cls, inquiry):
        invoice = cls.objects.create(
            user = inquiry.client.user,
            billing_address = BillingAddress.from_profile(inquiry.client),
            currency = settings.CURRENCY_CODE,
            tax_rate = 0,
            inquiry = inquiry
        )

        InvoiceItem.objects.create(
            invoice = invoice,
            name = "Sicherheitsleistung",
            description = "Rückzahlbare Sicherheitsleistung zu JourneyJoker-Anfrage #%i" % inquiry.id,
            count = 1,
            net_each = inquiry.budget
        )

        return invoice

class InvoiceItem(models.Model):
    invoice = models.ForeignKey(Invoice, models.CASCADE)
    name = models.CharField(max_length=64)
    description = models.CharField(max_length=256, null=True, blank=True)
    count = models.IntegerField()
    net_each = models.DecimalField(max_digits=11, decimal_places=2)

    @property
    def net_total(self):
        return self.net_each * self.count

class InvoicePayment(PolymorphicModel):
    uuid = models.UUIDField(default=uuid.uuid4)
    invoice = models.ForeignKey(Invoice, models.PROTECT)
    amount = models.DecimalField(max_digits=9, decimal_places=2)
    gateway_id = models.CharField(max_length=256)
    timestamp = models.DateTimeField(default=timezone.now)

    @property
    def gateway(self):
        raise NotImplementedError("%s does not implement gateway" % type(self))

    @property
    def status(self):
        raise NotImplementedError("%s does not implement status" % type(self))

    @classmethod
    def initiate(cls, invoice):
        raise NotImplementedError("%s does not implement initiate()" % cls.__name__)

    def finalize(self, *args, **kwargs):
        return self.invoice.finalize(*args, **kwargs)

    @classmethod
    def from_invoice(cls, invoice, gateway):
        if not invoice.is_paid:
            responses = initiate_payment.send_robust(sender=cls, invoice=invoice, gateway=gateway)
            for handler, response in responses:
                try:
                    return response["redirect"]
                except:
                    continue
        return False