# -*- coding: utf-8 -*-
# This file is part of the cashbook-module from m-ds for Tryton.
# The COPYRIGHT file at the top level of this repository contains the
# full copyright notices and license terms.

from trytond.model import Workflow, ModelView, ModelSQL, fields, Check
from trytond.pyson import Eval
from trytond.exceptions import UserError
from trytond.i18n import gettext
from trytond.transaction import Transaction


STATES = {
    'readonly': Eval('state', '') != 'open',
    }
DEPENDS=['state']

sel_state_book = [
    ('open', 'Open'),
    ('closed', 'Closed'),
    ('archive', 'Archive'),
    ]


class Book(Workflow, ModelSQL, ModelView):
    'Cashbook'
    __name__ = 'cashbook.book'

    name = fields.Char(string='Name', required=True,
        states=STATES, depends=DEPENDS)
    btype = fields.Many2One(string='Type', required=True,
        model_name='cashbook.type', ondelete='RESTRICT',
        states=STATES, depends=DEPENDS)
    owner = fields.Many2One(string='Owner', required=True, select=True,
        model_name='res.user', ondelete='SET NULL')
    reviewer = fields.Many2One(string='Reviewer', select=True,
        help='Group of users who have write access to the cashbook.',
        model_name='res.group', ondelete='SET NULL')
    observer = fields.Many2One(string='Observer', select=True,
        help='Group of users who have read-only access to the cashbook.',
        model_name='res.group', ondelete='SET NULL')
    lines = fields.One2Many(string='Lines', field='cashbook',
        model_name='cashbook.line',
        states=STATES, depends=DEPENDS)
    account = fields.Many2One(string='Account', select=True,
        model_name='account.account', ondelete='RESTRICT',
        states=STATES, depends=DEPENDS)
    state = fields.Selection(string='State', required=True,
        readonly=True, selection=sel_state_book)
    state_string = state.translated('state')

    @classmethod
    def __setup__(cls):
        super(Book, cls).__setup__()
        cls._order.insert(0, ('name', 'ASC'))
        t = cls.__table__()
        cls._sql_constraints.extend([
            ('state_val',
                Check(t, t.state.in_(['open', 'closed', 'archive'])),
                'cashbook.msg_book_wrong_state_value'),
            ])
        cls._transitions |= set((
                ('open', 'closed'),
                ('closed', 'open'),
                ('closed', 'archive'),
            ))
        cls._buttons.update({
            'wfopen': {
                'invisible': Eval('state', '') != 'closed',
                'depends': ['state'],
                },
            'wfclosed': {
                'invisible': Eval('state') != 'open',
                'depends': ['state'],
                },
            'wfarchive': {
                'invisible': Eval('state') != 'closed',
                'depends': ['state'],
                },
            })

    @classmethod
    def default_state(cls):
        return 'open'

    @classmethod
    def default_owner(cls):
        """ default: current user
        """
        return Transaction().user

    @classmethod
    @ModelView.button
    @Workflow.transition('open')
    def wfopen(cls, books):
        """ open cashbook
        """
        pass

    @classmethod
    @ModelView.button
    @Workflow.transition('closed')
    def wfclosed(cls, books):
        """ cashbook is closed
        """
        pass

    @classmethod
    @ModelView.button
    @Workflow.transition('archive')
    def wfarchive(cls, books):
        """ cashbook is archived
        """
        pass

    @classmethod
    def write(cls, *args):
        """ deny update if book is not 'open'
        """
        actions = iter(args)
        for books, values in zip(actions, actions):
            for book in books:
                if book.state != 'open':
                    # allow state-update, if its the only action
                    if not (('state' in values.keys()) and (len(values.keys()) == 1)):
                        raise UserError(gettext(
                            'cashbook.msg_book_deny_write',
                            bookname = book.rec_name,
                            state_txt = book.state_string,
                            ))
        super(Book, cls).write(*args)

    @classmethod
    def delete(cls, books):
        """ deny delete if book has lines
        """
        for book in books:
            if (len(book.lines) > 0) and (book.state != 'archive'):
                raise UserError(gettext(
                    'cashbook.msg_book_deny_delete',
                    bookname = book.rec_name,
                    booklines = len(book.lines),
                    ))
        return super(Book, cls).delete(books)

# end Book