# -*- coding: utf-8 -*-
##############################################################################
#
#    Copyright 2012 Camptocamp SA (Guewen Baconnier)
#    Copyright (C) 2010   Sébastien Beau
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU Affero General Public License as
#    published by the Free Software Foundation, either version 3 of the
#    License, or (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU Affero General Public License for more details.
#
#    You should have received a copy of the GNU Affero General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
##############################################################################

from openerp.osv.orm import AbstractModel
from openerp.osv import fields
from operator import itemgetter, attrgetter


class easy_reconcile_base(AbstractModel):
    """Abstract Model for reconciliation methods"""

    _name = 'easy.reconcile.base'

    _columns = {
        'easy_reconcile_id': fields.many2one('account.easy.reconcile',
            string='Easy Reconcile')
    }

    def automatic_reconcile(self, cr, uid, ids, context=None):
        if isinstance(ids, (int, long)):
            ids = [ids]
        assert len(ids) == 1, "Has to be called on one id"
        rec = self.browse(cr, uid, ids[0], context=context)
        return self._action_rec(cr, uid, rec, context=context)

    def _action_rec(self, cr, uid, rec, context=None):
        """Must be inherited to implement the reconciliation"""
        raise NotImplementedError

    def _base_columns(self, rec):
        """Mandatory columns for move lines queries
        An extra column aliased as `key` should be defined
        in each query."""
        aml_cols = (
            'id',
            'debit',
            'credit',
            'date',
            'period_id',
            'ref',
            'name',
            'partner_id',
            'account_id',
            'move_id')
        return ["account_move_line.%s" % col for col in aml_cols]

    def _select(self, rec, *args, **kwargs):
        return "SELECT %s" % ', '.join(self._base_columns(rec))

    def _from(self, rec, *args, **kwargs):
        return "FROM account_move_line"

    def _where(self, rec, *args, **kwargs):
        where = ("WHERE account_move_line.account_id = %s "
                 "AND account_move_line.reconcile_id IS NULL ")
        # it would be great to use dict for params
        # but as we use _where_calc in _get_filter
        # which returns a list, we have to
        # accomodate with that
        params = [rec.easy_reconcile_id.account.id]
        return where, params

    def _get_filter(self, cr, uid, rec, context):
        ml_obj = self.pool.get('account.move.line')
        where = ''
        params = []
        if context.get('filter'):
            dummy, where, params = ml_obj._where_calc(
                cr, uid, context['filter'], context=context).get_sql()
            if where:
                where = " AND %s" % where
        return where, params

    def _below_writeoff_limit(self, cr, uid, lines,
                               writeoff_limit, context=None):
        precision = self.pool.get('decimal.precision').precision_get(
            cr, uid, 'Account')
        keys = ('debit', 'credit')
        sums = reduce(
            lambda line, memo:
                dict((key, value + memo[key])
                for key, value
                in line.iteritems()
                if key in keys), lines)

        debit, credit = sums['debit'], sums['credit']
        writeoff_amount = round(debit - credit, precision)
        return bool(writeoff_limit >= abs(writeoff_amount)), debit, credit

    def _get_rec_date(self, cr, uid, lines, based_on='end_period_last_credit', context=None):
        period_obj = self.pool.get('account.period')

        def last_period(mlines):
            period_ids = [ml['period_id'] for ml in mlines]
            periods = period_obj.browse(
                cr, uid, period_ids, context=context)
            return max(periods, key=attrgetter('date_stop'))

        def last_date(mlines):
            return max(mlines, key=itemgetter('date'))

        def credit(mlines):
            return [l for l in mlines if l['credit'] > 0]

        def debit(mlines):
            return [l for l in mlines if l['debit'] > 0]

        if based_on == 'end_period_last_credit':
            return last_period(credit(lines)).date_stop
        if based_on == 'end_period':
            return last_period(lines).date_stop
        elif based_on == 'newest':
            return last_date(lines)['date']
        elif based_on == 'newest_credit':
            return last_date(credit(lines))['date']
        elif based_on == 'newest_debit':
            return last_date(debit(lines))['date']
        # reconcilation date will be today
        # when date is None
        return None

    def _reconcile_lines(self, cr, uid, lines, allow_partial=False, context=None):
        if context is None:
            context = {}

        ml_obj = self.pool.get('account.move.line')
        writeoff = context.get('write_off', 0.)

        keys = ('debit', 'credit')

        line_ids = [l['id'] for l in lines]
        below_writeoff, sum_debit, sum_credit = self._below_writeoff_limit(
            cr, uid, lines, writeoff, context=context)
        date = self._get_rec_date(
            cr, uid, lines, context.get('date_base_on'), context=context)

        rec_ctx = dict(context, date_p=date)
        if below_writeoff:
            if sum_credit < sum_debit:
                writeoff_account_id = context.get('account_profit_id', False)
            else:
                writeoff_account_id = context.get('account_lost_id', False)

            period_id = self.pool.get('account.period').find(
                cr, uid, dt=date, context=context)[0]

            ml_obj.reconcile(
                cr, uid,
                line_ids,
                type='auto',
                writeoff_acc_id=writeoff_account_id,
                writeoff_period_id=period_id,
                writeoff_journal_id=context.get('journal_id'),
                context=rec_ctx)
            return True
        elif allow_partial:
            ml_obj.reconcile_partial(
                cr, uid,
                line_ids,
                type='manual',
                context=rec_ctx)
            return True

        return False