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


class EducationProgram(models.Model):
    _name = 'education.program'
    _description = 'Program'
    _order = 'name'

    name = fields.Char(required=True, string='Program Name')
    code = fields.Char(required=True, string='Program Code', index=True)
    level_id = fields.Many2one(
        'education.academic.level',
        string='Academic Level',
        required=True,
        ondelete='restrict',
        index=True,
    )
    department_id = fields.Many2one(
        'education.department',
        string='Department',
        required=True,
        ondelete='restrict',
        index=True,
    )
    company_id = fields.Many2one(
        'res.company',
        related='department_id.company_id',
        store=True,
        readonly=True,
        index=True,
    )
    duration = fields.Integer(string='Duration', default=1)
    duration_unit = fields.Selection([
        ('years', 'Years'),
        ('months', 'Months'),
        ('semesters', 'Semesters'),
    ], default='years', required=True)
    active = fields.Boolean(default=True)
    description = fields.Text(string='Description')

    _sql_constraints = [
        ('uniq_program_code_company', 'unique(code, company_id)', 'Program code must be unique per company.'),
    ]

    @api.constrains('duration')
    def _check_duration(self):
        for rec in self:
            if rec.duration <= 0:
                raise ValidationError('Program duration must be greater than zero.')

    @api.constrains('name', 'company_id')
    def _check_name_unique(self):
        for rec in self:
            if self.search_count([
                ('company_id', '=', rec.company_id.id),
                ('name', '=ilike', rec.name),
                ('id', '!=', rec.id),
            ]):
                raise ValidationError('Program name must be unique within a company.')

    @api.onchange('department_id')
    def _onchange_department_id(self):
        if self.department_id:
            self.company_id = self.department_id.company_id.id
            if self.level_id and self.level_id.company_id != self.company_id:
                self.level_id = False