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

class AccountAnalyticLine(models.Model):
    _inherit = 'account.analytic.line'

    stage_id = fields.Many2one(
        'project.task.type',
        string="Stage",
        domain="[('id', 'in', stage_ids)]"
    )

    stage_ids = fields.Many2many('project.task.type',related="task_id.project_id.type_ids")

    @api.constrains('stage_id', 'task_id')
    def _check_stage_required(self):
        for line in self:
            if line.task_id.show_approval_flow and not line.stage_id:
                raise ValidationError(_("Stage is required when Approval Flow is enabled for this task."))