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


class DanceAttendance(models.Model):
    _name = "dance.attendance"
    _description = "Dance Attendance"
    _order = "session_id desc, student_id"

    student_id = fields.Many2one(
        "res.partner",
        required=True,
        domain="[('is_student', '=', True)]",
        ondelete="restrict",
    )
    session_id = fields.Many2one(
        "dance.session",
        required=True,
        ondelete="cascade",
    )
    batch_id = fields.Many2one(
        related="session_id.batch_id",
        store=True,
        readonly=True,
    )
    date = fields.Date(related="session_id.date", store=True, readonly=True)
    status = fields.Selection(
        [
            ("present", "Present"),
            ("absent", "Absent"),
            ("late", "Late"),
        ],
        default="present",
        required=True,
    )
    attendance_percent = fields.Float(
        string="Attendance %",
        compute="_compute_report_measures",
        store=True,
        group_operator="avg",
    )
    present_count = fields.Integer(
        string="Present/Late",
        compute="_compute_report_measures",
        store=True,
    )
    absent_count = fields.Integer(
        string="Absentees",
        compute="_compute_report_measures",
        store=True,
    )
    total_count = fields.Integer(
        string="Sessions",
        compute="_compute_report_measures",
        store=True,
    )
    remarks = fields.Text()

    _sql_constraints = [
        (
            "unique_attendance",
            "unique(student_id, session_id)",
            "Attendance is already marked for this student in this session.",
        ),
    ]

    @api.depends("status")
    def _compute_report_measures(self):
        for attendance in self:
            is_absent = attendance.status == "absent"
            attendance.attendance_percent = 0.0 if is_absent else 100.0
            attendance.present_count = 0 if is_absent else 1
            attendance.absent_count = 1 if is_absent else 0
            attendance.total_count = 1

    @api.constrains("student_id", "session_id")
    def _check_student_in_batch(self):
        for attendance in self:
            if not attendance.student_id or not attendance.session_id:
                continue
            enrollment = self.env["dance.enrollment"].search(
                [
                    ("student_id", "=", attendance.student_id.id),
                    ("batch_id", "=", attendance.session_id.batch_id.id),
                    ("status", "=", "active"),
                ],
                limit=1,
            )
            if not enrollment:
                raise ValidationError(
                    "Attendance can only be marked for active students in this batch."
                )