# -*- coding: utf-8 -*-
# © 2011 Raphaël Valyi, Renato Lima, Guewen Baconnier, Sodexis
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).

import time

from odoo import api, models, fields, _
from odoo.exceptions import UserError, ValidationError
from odoo.tools.safe_eval import safe_eval
from odoo import osv


class ExceptionRule(models.Model):
    _name = 'exception.rule'
    _description = "Exception Rules"
    _order = 'active desc, sequence asc'

    name = fields.Char('Exception Name', required=True, translate=True)
    description = fields.Text('Description', translate=True)
    sequence = fields.Integer(
        string='Sequence',
        help="Gives the sequence order when applying the test")
    model = fields.Selection(
        selection=[],
        string='Apply on', required=True)
    exception_type = fields.Selection(
        selection=[('by_domain', 'By domain'),
                   ('by_py_code', 'By python code')],
        string='Exception Type', required=True, default='by_py_code',
        help="By python code: allow to define any arbitrary check\n"
             "By domain: limited to a selection by an odoo domain:\n"
             "           performance can be better when exceptions "
             "           are evaluated with several records")
    domain = fields.Char('Domain')
    active = fields.Boolean('Active', default=True)
    code = fields.Text(
        'Python Code',
        help="Python code executed to check if the exception apply or "
             "not. The code must apply failed = True to apply the "
             "exception.",
        default="""
# Python code. Use failed = True to block the base.exception.
# You can use the following variables :
#  - self: ORM model of the record which is checked
#  - object: same as order or line, browse_record of the base.exception or
#    base.exception line
#  - pool: ORM model pool (i.e. self.pool, deprecated in new api)
#  - obj: same as object
#  - env: ORM model pool (i.e. self.env)
#  - time: Python time module
#  - cr: database cursor
#  - uid: current user id
#  - context: current context
""")

    @api.constrains('exception_type', 'domain', 'code')
    def check_exception_type_consistency(self):
        for rule in self:
            if ((rule.exception_type == 'by_py_code' and not rule.code) or
                    (rule.exception_type == 'by_domain' and not rule.domain)):
                raise ValidationError(
                    _("There is a problem of configuration, python code or "
                      "domain is missing to match the exception type.")
                )

    @api.multi
    def _get_domain(self):
        """ override me to customize domains according exceptions cases """
        self.ensure_one()
        return safe_eval(self.domain)


class BaseExceptionMethod(models.AbstractModel):
    _name = 'base.exception.method'

    @api.multi
    def _get_main_records(self):
        """
            Used in case we check exception on a record but write these
            exceptions on a parent record. Typical example is with
            sale.order.line. We check exceptions on some sale order lines but
            write these exceptions on the sale order, so they are visible.
        """
        return self

    @api.multi
    def _reverse_field(self):
        raise NotImplementedError()

    def _rule_domain(self):
        """Filter exception.rules.

        By default, only the rules with the correct model
        will be used.
        """
        return [('model', '=', self._name)]

    @api.multi
    def detect_exceptions(self):
        """List all exception_ids applied on self
        Exception ids are also written on records
        """
        rules = self.env['exception.rule'].sudo().search(
            self._rule_domain())
        all_exception_ids = []
        rules_to_remove = {}
        rules_to_add = {}
        for rule in rules:
            records_with_exception = self._detect_exceptions(rule)
            reverse_field = self._reverse_field()
            main_records = self._get_main_records()
            commons = main_records & rule[reverse_field]
            to_remove = commons - records_with_exception
            to_add = records_with_exception - commons
            # we expect to always work on the same model type
            rules_to_remove.setdefault(
                rule.id, main_records.browse()
            ).update(to_remove)
            rules_to_add.setdefault(
                rule.id, main_records.browse()
            ).update(to_add)
            if records_with_exception:
                all_exception_ids.append(rule.id)
        # Cumulate all the records to attach to the rule
        # before linking. We don't want to call "rule.write()"
        # which would:
        # * write on write_date so lock the expection.rule
        # * trigger the recomputation of "main_exception_id" on
        #   all the sale orders related to the rule, locking them all
        #   and preventing concurrent writes
        # Reversing the write by writing on SaleOrder instead of
        # ExceptionRule fixes the 2 kinds of unexpected locks.
        # It should not result in more queries than writing on ExceptionRule:
        # the "to remove" part generates one DELETE per rule on the relation
        # table and the "to add" part generates one INSERT (with unnest) per
        # rule.
        for rule_id, records in rules_to_remove.iteritems():
            records.write({'exception_ids': [(3, rule_id,)]})
        for rule_id, records in rules_to_add.iteritems():
            records.write(({'exception_ids': [(4, rule_id,)]}))
        return all_exception_ids

    @api.model
    def _exception_rule_eval_context(self, rec):
        return {'self': self.pool.get(rec._name),
                'object': rec,
                'obj': rec,
                'pool': self.pool,
                'env': self.env,
                'cr': self.env.cr,
                'uid': self.env.uid,
                'user': self.env.user,
                'time': time,
                # copy context to prevent side-effects of eval
                'context': self.env.context.copy()}

    @api.model
    def _rule_eval(self, rule, rec):
        expr = rule.code
        space = self._exception_rule_eval_context(rec)
        try:
            safe_eval(expr,
                      space,
                      mode='exec',
                      nocopy=True)  # nocopy allows to return 'result'
        except Exception, e:
            raise UserError(
                _('Error when evaluating the exception.rule '
                  'rule:\n %s \n(%s)') % (rule.name, e))
        return space.get('failed', False)

    @api.multi
    def _detect_exceptions(self, rule):
        if rule.exception_type == 'by_py_code':
            return self._detect_exceptions_by_py_code(rule)
        elif rule.exception_type == 'by_domain':
            return self._detect_exceptions_by_domain(rule)

    @api.multi
    def _get_base_domain(self):
        return [('ignore_exception', '=', False), ('id', 'in', self.ids)]

    @api.multi
    def _detect_exceptions_by_py_code(self, rule):
        """
            Find exceptions found on self.
        """
        domain = self._get_base_domain()
        records = self.search(domain)
        records_with_exception = self.env[self._name]
        for record in records:
            if self._rule_eval(rule, record):
                records_with_exception |= record
        return records_with_exception

    @api.multi
    def _detect_exceptions_by_domain(self, rule):
        """
            Find exceptions found on self.
        """
        base_domain = self._get_base_domain()
        rule_domain = rule._get_domain()
        domain = osv.expression.AND([base_domain, rule_domain])
        return self.search(domain)


class BaseException(models.AbstractModel):
    _inherit = 'base.exception.method'
    _name = 'base.exception'

    _order = 'main_exception_id asc'

    main_exception_id = fields.Many2one(
        'exception.rule',
        compute='_compute_main_error',
        string='Main Exception',
        store=True)
    exception_ids = fields.Many2many(
        'exception.rule',
        string='Exceptions')
    ignore_exception = fields.Boolean('Ignore Exceptions', copy=False)

    @api.depends('exception_ids', 'ignore_exception')
    def _compute_main_error(self):
        for obj in self:
            if not obj.ignore_exception and obj.exception_ids:
                obj.main_exception_id = obj.exception_ids[0]
            else:
                obj.main_exception_id = False

    @api.multi
    def _popup_exceptions(self):
        action = self._get_popup_action()
        action = action.read()[0]
        action.update({
            'context': {
                'active_model': self._name,
                'active_id': self.ids[0],
                'active_ids': self.ids
            }
        })
        return action

    @api.model
    def _get_popup_action(self):
        action = self.env.ref('base_exception.action_exception_rule_confirm')
        return action

    @api.multi
    def _check_exception(self):
        """
        This method must be used in a constraint that must be created in the
        object that inherits for base.exception.
        for sale :
        @api.constrains('ignore_exception',)
        def sale_check_exception(self):
            ...
            ...
            self._check_exception
        """
        exception_ids = self.detect_exceptions()
        if exception_ids:
            exceptions = self.env['exception.rule'].browse(exception_ids)
            raise ValidationError('\n'.join(exceptions.mapped('name')))