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

from trytond.pool import PoolMeta, Pool
from trytond.model import ModelView, Workflow, fields
from trytond.pyson import Eval, Bool
from trytond.transaction import Transaction

__all__ = ['Journal', 'Payment']


class Journal:
    __metaclass__ = PoolMeta
    __name__ = 'account.payment.journal'
    clearing_account = fields.Many2One('account.account', 'Clearing Account',
        domain=[('party_required', '=', False)],
        states={
            'required': Bool(Eval('clearing_journal')),
            },
        depends=['clearing_journal'])
    clearing_journal = fields.Many2One('account.journal', 'Clearing Journal',
        states={
            'required': Bool(Eval('clearing_account')),
            },
        depends=['clearing_account'])


class Payment:
    __metaclass__ = PoolMeta
    __name__ = 'account.payment'
    clearing_move = fields.Many2One('account.move', 'Clearing Move',
        readonly=True)

    @classmethod
    @ModelView.button
    @Workflow.transition('succeeded')
    def succeed(cls, payments):
        pool = Pool()
        Move = pool.get('account.move')
        Line = pool.get('account.move.line')

        super(Payment, cls).succeed(payments)

        moves = []
        for payment in payments:
            move = payment.create_clearing_move()
            if move:
                moves.append(move)
        if moves:
            Move.save(moves)
            cls.write(*sum((([m.origin], {'clearing_move': m.id})
                        for m in moves), ()))

        to_reconcile = []
        for payment in payments:
            if (payment.line
                    and not payment.line.reconciliation
                    and payment.clearing_move):
                lines = [l for l in payment.clearing_move.lines
                    if l.account == payment.line.account] + [payment.line]
                if not sum(l.debit - l.credit for l in lines):
                    to_reconcile.append(lines)
        for lines in to_reconcile:
            Line.reconcile(lines)

    def create_clearing_move(self, date=None):
        pool = Pool()
        Move = pool.get('account.move')
        Line = pool.get('account.move.line')
        Currency = pool.get('currency.currency')
        Period = pool.get('account.period')
        Date = pool.get('ir.date')

        if not self.line:
            return
        if (not self.journal.clearing_account
                or not self.journal.clearing_journal):
            return
        if self.clearing_move:
            return self.clearing_move

        if date is None:
            date = Date.today()
        period = Period.find(self.company.id, date=date)

        local_currency = self.journal.currency == self.company.currency
        if not local_currency:
            with Transaction().set_context(date=self.date):
                local_amount = Currency.compute(
                    self.journal.currency, self.amount, self.company.currency)
        else:
            local_amount = self.amount

        move = Move(journal=self.journal.clearing_journal, origin=self,
            date=date, period=period)
        line = Line()
        if self.kind == 'payable':
            line.debit, line.credit = local_amount, 0
        else:
            line.debit, line.credit = 0, local_amount
        line.account = self.line.account
        if not local_currency:
            line.amount_second_currency = self.amount
            line.second_currency = self.journal.currency

        line.party = (self.line.party
            if self.line.account.party_required else None)
        counterpart = Line()
        if self.kind == 'payable':
            counterpart.debit, counterpart.credit = 0, local_amount
        else:
            counterpart.debit, counterpart.credit = local_amount, 0
        counterpart.account = self.journal.clearing_account
        if not local_currency:
            counterpart.amount_second_currency = -self.amount
            counterpart.second_currency = self.journal.currency
        move.lines = (line, counterpart)
        return move

    @classmethod
    @ModelView.button
    @Workflow.transition('failed')
    def fail(cls, payments):
        pool = Pool()
        Move = pool.get('account.move')
        Line = pool.get('account.move.line')
        Reconciliation = pool.get('account.move.reconciliation')

        super(Payment, cls).fail(payments)

        to_delete = []
        to_reconcile = defaultdict(lambda: defaultdict(list))
        to_unreconcile = []
        for payment in payments:
            if payment.clearing_move:
                if payment.clearing_move.state == 'draft':
                    to_delete.append(payment.clearing_move)
                    for line in payment.clearing_move.lines:
                        if line.reconciliation:
                            to_unreconcile.append(line.reconciliation)
                else:
                    cancel_move = payment.clearing_move.cancel()
                    for line in (payment.clearing_move.lines
                            + cancel_move.lines):
                        if line.reconciliation:
                            to_unreconcile.append(line.reconciliation)
                        if line.account.reconcile:
                            to_reconcile[payment.party][line.account].append(
                                line)
        if to_unreconcile:
            Reconciliation.delete(to_unreconcile)
        if to_delete:
            Move.delete(to_delete)
        for party in to_reconcile:
            for lines in to_reconcile[party].itervalues():
                Line.reconcile(lines)

        cls.write(payments, {'clearing_move': None})
