# Copyright 2020 Tecnativa - Carlos Dauden
# Copyright 2020 Tecnativa - Pedro M. Baeza
# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).

from flectra import _, api, exceptions, fields, models


class IrUiCustomFilter(models.Model):
    _name = "ir.ui.custom.field.filter"
    _description = "Custom UI field filter"
    _order = "model_id, sequence, id"

    sequence = fields.Integer()
    model_id = fields.Many2one(
        comodel_name="ir.model", required=True, ondelete="cascade"
    )
    model_name = fields.Char(
        related="model_id.model",
        store=True,
        readonly=True,
        index=True,
        string="Model name",
    )
    name = fields.Char(required=True, translate=True)
    expression = fields.Char(required=True)
    position_after = fields.Char(
        help="Optional field name for putting the filter after that one. "
        "If empty or not found, it will be put at the end.",
    )

    def _get_related_field(self):
        """Determine the chain of fields."""
        self.ensure_one()
        related = self.expression.split(".")
        target = self.env[self.model_name]
        for name in related:
            field = target._fields[name]
            target = target[name]
        return field

    @api.constrains("model_id", "expression")
    def _check_expression(self):
        for record in self:
            try:
                record._get_related_field()
            except KeyError:
                raise exceptions.ValidationError(_("Incorrect expression."))