# This file is part of Tryton.  The COPYRIGHT file at the top level of
# this repository contains the full copyright notices and license terms.
import functools
import os

import genshi
import genshi.template
# XXX fix: https://genshi.edgewall.org/ticket/582
from genshi.template.astutil import ASTCodeGenerator, ASTTransformer

from trytond.model import Model
from trytond.pool import Pool
from trytond.rpc import RPC
from trytond.tools import cached_property
from trytond.transaction import Transaction

if not hasattr(ASTCodeGenerator, 'visit_NameConstant'):
    def visit_NameConstant(self, node):
        if node.value is None:
            self._write('None')
        elif node.value is True:
            self._write('True')
        elif node.value is False:
            self._write('False')
        else:
            raise Exception("Unknown NameConstant %r" % (node.value,))
    ASTCodeGenerator.visit_NameConstant = visit_NameConstant
if not hasattr(ASTTransformer, 'visit_NameConstant'):
    # Re-use visit_Name because _clone is deleted
    ASTTransformer.visit_NameConstant = ASTTransformer.visit_Name

loader = genshi.template.TemplateLoader(
    os.path.join(os.path.dirname(__file__), 'template'),
    auto_reload=True)


def has_goods_assets(func):
    @functools.wraps(func)
    def wrapper(self):
        if any(l.product.type in {'goods', 'assets'}
                for l in self.invoice.lines if l.product):
            return func(self)
    return wrapper


def remove_comment(stream):
    for kind, data, pos in stream:
        if kind is genshi.core.COMMENT:
            continue
        yield kind, data, pos


class Invoice(Model):
    "EDocument UN/CEFACT Invoice"
    __name__ = 'edocument.uncefact.invoice'
    __no_slots__ = True  # to work with cached_property

    @classmethod
    def __setup__(cls):
        super(Invoice, cls).__setup__()
        cls.__rpc__.update({
                'render': RPC(instantiate=0),
                })

    def __init__(self, invoice):
        pool = Pool()
        Invoice = pool.get('account.invoice')
        super().__init__()
        if int(invoice) >= 0:
            invoice = Invoice(int(invoice))
            with Transaction().set_context(language=invoice.party_lang):
                self.invoice = invoice.__class__(int(invoice))
        else:
            self.invoice = invoice

    def render(self, template):
        if self.invoice.state not in {'posted', 'paid'}:
            raise ValueError("Invoice must be posted")
        tmpl = self._get_template(template)
        if not tmpl:
            raise NotImplementedError
        return (tmpl.generate(this=self)
            .filter(remove_comment)
            .render()
            .encode('utf-8'))

    def _get_template(self, version):
        return loader.load(os.path.join(version, 'CrossIndustryInvoice.xml'))

    @cached_property
    def type_code(self):
        if self.invoice.type == 'out':
            if all(l.amount < 0 for l in self.lines):
                return '381'
            else:
                return '380'
        else:
            if all(l.amount < 0 for l in self.lines):
                return '261'
            else:
                return '389'

    @cached_property
    def type_sign(self):
        "The sign of the quantity depending of the type code"
        if self.type_code in {'381', '261'}:
            return -1
        return 1

    @cached_property
    def lines(self):
        return [l for l in self.invoice.lines if l.type == 'line']

    @cached_property
    def seller_trade_party(self):
        if self.invoice.type == 'out':
            return self.invoice.company.party
        else:
            return self.invoice.party

    @cached_property
    def seller_trade_address(self):
        if self.invoice.type == 'out':
            return self.invoice.company.party.address_get('invoice')
        else:
            return self.invoice.invoice_address

    @cached_property
    def seller_trade_tax_identifier(self):
        if self.invoice.type == 'out':
            return self.invoice.tax_identifier
        else:
            return self.invoice.party_tax_identifier

    @cached_property
    def buyer_trade_party(self):
        if self.invoice.type == 'out':
            return self.invoice.party
        else:
            return self.invoice.company.party

    @cached_property
    def buyer_trade_address(self):
        if self.invoice.type == 'out':
            return self.invoice.invoice_address
        else:
            return None

    @cached_property
    def buyer_trade_tax_identifier(self):
        if self.invoice.type == 'out':
            return self.invoice.party_tax_identifier
        else:
            return self.invoice.tax_identifier

    @cached_property
    @has_goods_assets
    def ship_to_trade_party(self):
        if self.invoice.type == 'out':
            if getattr(self.invoice, 'sales', None):
                sale = self.invoice.sales[0]  # XXX
                if sale.shipment_party != self.buyer_trade_party:
                    return sale.shipment_party
        else:
            if getattr(self.invoice, 'purchases', None):
                purchase = self.invoice.purchases[0]  # XXX
                address = purchase.warehouse.address
                if (address and address.party != self.buyer_trade_party):
                    return address.party

    @cached_property
    @has_goods_assets
    def ship_to_trade_address(self):
        if self.invoice.type == 'out':
            if getattr(self.invoice, 'sales', None):
                sale = self.invoice.sales[0]  # XXX
                if sale.shipment_party != self.buyer_trade_party:
                    return sale.shipment_address
        else:
            if getattr(self.invoice, 'purchases', None):
                purchase = self.invoice.purchases[0]  # XXX
                address = purchase.warehouse.address
                if (address and address.party != self.buyer_trade_party):
                    return address

    @cached_property
    @has_goods_assets
    def ship_from_trade_party(self):
        if self.invoice.type == 'out':
            if getattr(self.invoice, 'sales', None):
                sale = self.invoice.sales[0]  # XXX
                address = sale.warehouse.address
                if address and address.party != self.seller_trade_party:
                    return address.shipment_party

    @cached_property
    @has_goods_assets
    def ship_from_trade_address(self):
        if self.invoice.type == 'out':
            if getattr(self.invoice, 'sales', None):
                sale = self.invoice.sales[0]  # XXX
                address = sale.warehouse.address
                if address and address.party != self.seller_trade_party:
                    return address

    @cached_property
    def payment_reference(self):
        return self.invoice.number

    @classmethod
    def party_legal_ids(cls, party, address):
        return []