# -*- coding: utf-8 -*-
##############################################################################
#
#    OpenERP, Open Source Management Solution
#    Copyright (C) 2015 Akretion (<http://www.akretion.com>).
#
#    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/>.
#
##############################################################################

import StringIO
import base64
import datetime
import re
from openerp.osv.orm import Model
from openerp.osv import fields, orm
from openerp.tools.translate import _
from openerp.tools import DEFAULT_SERVER_DATETIME_FORMAT


class SqlExport(Model):
    _name = "sql.export"
    _description = "SQL export"

    PROHIBITED_WORDS = [
        'delete',
        'drop',
        'insert',
        'alter',
        'truncate',
        'execute',
        'create',
        'update'
    ]

    def _check_query_allowed(self, cr, uid, ids, context=None):
        for obj in self.browse(cr, uid, ids, context=context):
            query = obj.query.lower()
            for word in self.PROHIBITED_WORDS:
                expr = r'\b%s\b' % word
                is_not_safe = re.search(expr, query)
                if is_not_safe:
                    return False
        return True

    def _get_editor_group(self, cr, uid, *args):
        model_data_obj = self.pool['ir.model.data']
        return [model_data_obj.get_object_reference(
            cr, uid, 'sql_export', 'group_sql_request_editor')[1]]

    _columns = {
        'name': fields.char('Name', required=True),
        'query': fields.text(
            'Query',
            required=True,
            help="You can't use the following word : delete, drop, create, "
                 "insert, alter, truncate, execute, update"),
        'copy_options': fields.char(
            'Copy Options',
            required=True),
        'group_ids': fields.many2many(
            'res.groups',
            'groups_sqlquery_rel',
            'sql_id',
            'group_id',
            'Allowed Groups'),
        'user_ids': fields.many2many(
            'res.users',
            'users_sqlquery_rel',
            'sql_id',
            'user_id',
            'Allowed Users'),
    }

    _defaults = {
        'group_ids': _get_editor_group,
        'copy_options': "CSV HEADER DELIMITER ';'",
    }

    _constraints = [(_check_query_allowed,
                     'The query you want make is not allowed : prohibited '
                     'actions (%s)' % ', '.join(PROHIBITED_WORDS),
                     ['query'])]

    def export_sql_query(self, cr, uid, ids, context=None):
        if not context:
            context = {}
        for obj in self.browse(cr, uid, ids, context=context):
            today = datetime.datetime.now()
            today_tz = fields.datetime.context_timestamp(
                cr, uid, today, context=context)
            date = today_tz.strftime(DEFAULT_SERVER_DATETIME_FORMAT)
            output = StringIO.StringIO()
            query = "COPY (" + obj.query + ")  TO STDOUT WITH " + \
                    obj.copy_options
            cr.copy_expert(query, output)
            output.getvalue()
            new_output = base64.b64encode(output.getvalue())
            output.close()
            wiz = self.pool.get('sql.file.wizard').create(
                cr, uid,
                {
                    'file': new_output,
                    'file_name': obj.name + '_' + date + '.csv'})
        return {
            'view_type': 'form',
            'view_mode': 'form',
            'res_model': 'sql.file.wizard',
            'res_id': wiz,
            'type': 'ir.actions.act_window',
            'target': 'new',
            'context': context,
            'nodestroy': True,
        }

    def check_query_syntax(self, cr, uid, vals, context=None):
        if vals.get('query', False):
            vals['query'] = vals['query'].strip()
            if vals['query'][-1] == ';':
                vals['query'] = vals['query'][:-1]
            try:
                cr.execute(vals['query'])
            except:
                cr.rollback()
                raise orm.except_orm(_("Invalid Query"),
                                     _("The Sql query is not valid."))
        return vals

    def write(self, cr, uid, ids, vals, context=None):
        vals = self.check_query_syntax(cr, uid, vals, context=context)
        return super(SqlExport, self).write(
            cr, uid, ids, vals, context=context)

    def create(self, cr, uid, vals, context=None):
        vals = self.check_query_syntax(cr, uid, vals, context=context)
        return super(SqlExport, self).create(cr, uid, vals, context=context)