# -*- coding: utf-8 -*-
##############################################################################
#
#    OpenERP, Open Source Management Solution
#    Copyright (C) 2004-2010 Tiny SPRL (<http://tiny.be>).
#
#    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 import models, fields, _
from openerp.exceptions import UserError


class DocumentPageShowDiff(models.TransientModel):
    """Display Difference for History."""

    _name = 'wizard.document.page.history.show_diff'

    def _get_diff(self):
        """Return the Difference between two document."""
        history = self.env["document.page.history"]
        ids = self.env.context.get('active_ids', [])
        diff = False
        if len(ids) == 2:
            if ids[0] > ids[1]:
                diff = history.getDiff(ids[1], ids[0])
            else:
                diff = history.getDiff(ids[0], ids[1])
        elif len(ids) == 1:
            diff = history.browse(ids[0]).diff
        else:
            raise UserError(
                _("Select one or maximum two history revisions!"))
        return diff

    diff = fields.Text(
        readonly=True,
        default=_get_diff,
    )