# 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 decimal import Decimal

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

__all__ = ['Journal', 'Payment']
__metaclass__ = PoolMeta


class Journal:
    __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:
    __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')
        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)

        move = Move(journal=self.journal.clearing_journal, origin=self,
            date=date, period=period)
        line = Line()
        line.debit = self.amount if self.line.credit else Decimal(0)
        line.credit = self.amount if self.line.debit else Decimal(0)
        line.account = self.line.account
        line.amount_second_currency = (-self.line.amount_second_currency
            if self.line.amount_second_currency else None)
        line.second_currency = self.line.second_currency
        line.party = (self.line.party
            if self.line.account.party_required else None)
        counterpart = Line()
        counterpart.debit = self.amount if self.line.debit else Decimal(0)
        counterpart.credit = self.amount if self.line.credit else Decimal(0)
        counterpart.account = self.journal.clearing_account
        counterpart.amount_second_currency = self.line.amount_second_currency
        counterpart.second_currency = self.line.second_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})