# 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 trytond.model import ModelView, Workflow, ModelSQL, fields
from trytond.pyson import Eval
from trytond.wizard import Wizard, StateTransition
from trytond.pool import Pool
from trytond.transaction import Transaction

__all__ = ['Period', 'OpenPeriod']

STATES = {'readonly': Eval('state') != 'draft'}


class Period(Workflow, ModelSQL, ModelView):
    "Period"
    __name__ = 'staff.payroll.period'
    _rec_name = 'name'
    name = fields.Char('Name', select=True, states=STATES,
            required=True)
    sequence = fields.Integer('Sequence', select=True, states=STATES,
            required=True)
    start = fields.Date('Start', required=True, states=STATES, select=True,
            domain=[('start', '<=', Eval('end', None))],
            depends=['end'])
    end = fields.Date('End', required=True, states=STATES, select=True,
            domain=[('end', '>=', Eval('start', None))],
            depends=['start'])
    state = fields.Selection([
            ('draft', 'Draft'),
            ('open', 'Open'),
            ('closed', 'Closed'),
            ], 'State', readonly=True)
    description = fields.Char('Description', select=True, states=STATES)

    @classmethod
    def __setup__(cls):
        super(Period, cls).__setup__()
        cls._order.insert(0, ('sequence', 'ASC'))
        cls._error_messages.update({
            'wrong_start_end': ('The date end can not smaller than date start'),
            'wrong_period_overlap': ('The period overlap another period!')
                        })
        cls._transitions |= set((
                ('draft', 'open'),
                ('open', 'draft'),
                ('open', 'closed'),
                ))
        cls._buttons.update({
                'open': {
                    'invisible': Eval('state') != 'draft',
                    },
                'close': {
                    'invisible': Eval('state') != 'open',
                    },
                'draft': {
                    'invisible': Eval('state') != 'open',
                    },
                })

    @staticmethod
    def default_state():
        return 'draft'

    @classmethod
    @ModelView.button
    @Workflow.transition('draft')
    def draft(self, periods):
        pass

    @classmethod
    @ModelView.button
    @Workflow.transition('open')
    def open(self, periods):
        pass

    @classmethod
    @ModelView.button
    @Workflow.transition('closed')
    def close(self, periods):
        pass

    @classmethod
    def validate(cls, periods):
        super(Period, cls).validate(periods)
        for period in periods:
            period.check_start_end()
            period.check_date_consistent()

    def check_start_end(self):
        if self.start > self.end:
            self.raise_user_error('wrong_start_end',)

    def check_date_consistent(self):
        periods = self.search([
                ('id', '!=', self.id), ['OR',
                [
                    ('start', '>=', self.start),
                    ('start', '<=', self.end),
                ], [
                    ('end', '>=', self.start),
                    ('end', '<=', self.end),
                ], [
                    ('start', '<=', self.start),
                    ('end', '>=', self.end),
                ]
            ]])
        if periods:
            self.raise_user_error('wrong_period_overlap',)


class OpenPeriod(Wizard):
    "Open Period"
    __name__ = 'staff.payroll.open_period'
    start_state = 'open_period'
    open_period = StateTransition()

    def transition_open_period(self):
        ids = Transaction().context['active_ids']
        Period = Pool().get('staff.payroll.period')
        if ids:
            period = Period(ids[0])
            Period.write([period], {'state': 'open'})
        return 'end'