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


class AcademicYear(models.Model):
    _name = 'education.academic.year'
    _description = 'Academic Year'
    _order = 'start_date desc, name desc'

    name = fields.Char(required=True, string='Academic Year')
    code = fields.Char(string='Code', required=True, index=True)
    start_date = fields.Date(string='Start Date', required=True)
    end_date = fields.Date(string='End Date', required=True)
    active = fields.Boolean(default=True)
    company_id = fields.Many2one(
        'res.company',
        string='Company',
        required=True,
        default=lambda self: self.env.company,
        index=True,
    )
    current_year = fields.Boolean(string='Current Year', default=False)
    state = fields.Selection([
        ('draft', 'Draft'),
        ('active', 'Active'),
        ('closed', 'Closed'),
    ], default='draft', required=True, tracking=True)
    term_ids = fields.One2many('education.academic.term', 'academic_year_id', string='Terms')

    _sql_constraints = [
        ('uniq_year_code_company', 'unique(code, company_id)', 'Academic year code must be unique per company.'),
    ]

    @api.constrains('start_date', 'end_date')
    def _check_year_dates(self):
        for rec in self:
            if rec.start_date and rec.end_date and rec.start_date > rec.end_date:
                raise ValidationError('End date must be later than start date.')

    @api.constrains('current_year')
    def _check_single_current_year(self):
        for rec in self:
            if rec.current_year:
                existing = self.search([
                    ('company_id', '=', rec.company_id.id),
                    ('current_year', '=', True),
                    ('id', '!=', rec.id),
                ])
                if existing:
                    raise ValidationError('Only one academic year can be marked as current for a company.')

    @api.model_create_multi
    def create(self, vals_list):
        for vals in vals_list:
            if vals.get('state') == 'active':
                vals['current_year'] = True
        return super().create(vals_list)

    def action_activate(self):
        for rec in self:
            if rec.start_date and rec.end_date and rec.start_date > rec.end_date:
                raise ValidationError('Academic year dates are invalid.')
            rec.state = 'active'
            rec.current_year = True

    def action_close(self):
        self.write({'state': 'closed'})

    def action_set_draft(self):
        self.write({'state': 'draft'})