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


class McAcademicTerm(models.Model):
    _name = "mc.academic.term"
    _inherit = ["mail.thread"]
    _description = "Academic Term"
    _order = "year_id, sequence, date_start"
    _rec_name = "name"

    name = fields.Char(string="Name", required=True, tracking=True)
    year_id = fields.Many2one(
        "mc.academic.year", string="Academic Year", required=True,
        ondelete="cascade", tracking=True,
    )
    date_start = fields.Date(string="Start Date", required=True, tracking=True)
    date_end = fields.Date(string="End Date", required=True, tracking=True)
    sequence = fields.Integer(string="Sequence", default=10)
    company_id = fields.Many2one(
        related="year_id.company_id", string="Company", store=True, readonly=True,
    )

    _name_year_uniq = models.Constraint(
        "unique(name, year_id)",
        "A term with this name already exists for this academic year.",
    )

    @api.constrains("date_start", "date_end")
    def _check_dates(self):
        for term in self:
            if term.date_start and term.date_end and term.date_end <= term.date_start:
                raise ValidationError(
                    "Term '%s' end date must be after its start date." % term.name
                )

    @api.constrains("date_start", "date_end", "year_id")
    def _check_within_year(self):
        for term in self:
            year = term.year_id
            if not (year.date_start and year.date_end and term.date_start and term.date_end):
                continue
            if term.date_start < year.date_start or term.date_end > year.date_end:
                raise ValidationError(
                    "Term '%s' must fall within its academic year (%s)." % (term.name, year.name)
                )