from psycopg2 import IntegrityError

from odoo.exceptions import ValidationError
from odoo.tests.common import TransactionCase
from odoo.tools import mute_logger


class TestEnrollment(TransactionCase):

    @classmethod
    def setUpClass(cls):
        super().setUpClass()
        # Names/codes are deliberately distinct from demo data (see
        # demo/mc_program_demo.xml, demo/mc_academic_year_demo.xml) -
        # these tests must pass whether or not demo data is loaded.
        cls.year = cls.env["mc.academic.year"].create({
            "name": "TEST-2026-27",
            "date_start": "2026-06-01",
            "date_end": "2027-04-30",
        })
        cls.other_year = cls.env["mc.academic.year"].create({
            "name": "TEST-2027-28",
            "date_start": "2027-06-01",
            "date_end": "2028-04-30",
        })
        cls.program = cls.env["mc.program"].create({
            "name": "Test Grade 8 CBSE", "code": "TEST-G8", "sequence_no": 8,
            "display_label": "Test Grade 8",
        })
        cls.batch_a = cls.env["mc.batch"].create({
            "name": "Grade 8-A", "program_id": cls.program.id, "year_id": cls.year.id,
        })
        cls.batch_b = cls.env["mc.batch"].create({
            "name": "Grade 8-B", "program_id": cls.program.id, "year_id": cls.year.id,
        })
        partner = cls.env["res.partner"].create({"name": "Test Student"})
        cls.student = cls.env["mc.student"].create({
            "partner_id": partner.id, "name": "Test Student",
        })

    def _enroll(self, batch, year, state="active", roll_no="1"):
        return self.env["mc.enrollment"].create({
            "student_id": self.student.id,
            "program_id": self.program.id,
            "batch_id": batch.id,
            "year_id": year.id,
            "state": state,
            "roll_no": roll_no,
        })

    def test_admission_no_auto_generated(self):
        self.assertTrue(self.student.admission_no)
        self.assertIn("ADM", self.student.admission_no)

    def test_second_active_enrollment_same_year_rejected(self):
        self._enroll(self.batch_a, self.year)
        with self.assertRaises(ValidationError):
            self._enroll(self.batch_b, self.year)

    @mute_logger("odoo.sql_db")
    def test_db_index_backs_the_rule_even_if_orm_check_is_bypassed(self):
        # The @api.constrains gives a friendly message; the partial unique
        # index is what actually guarantees the rule. Prove the index is
        # there by writing around the ORM check.
        self._enroll(self.batch_a, self.year)
        with self.assertRaises(IntegrityError):
            with self.cr.savepoint():
                self.env.cr.execute(
                    "INSERT INTO mc_enrollment "
                    "(student_id, program_id, batch_id, year_id, state, create_uid, write_uid, create_date, write_date) "
                    "VALUES (%s, %s, %s, %s, 'active', %s, %s, now(), now())",
                    (self.student.id, self.program.id, self.batch_b.id, self.year.id,
                     self.env.uid, self.env.uid),
                )

    def test_active_enrollment_allowed_in_different_year(self):
        self._enroll(self.batch_a, self.year)
        # Should not raise: different academic year, no conflict.
        self._enroll(self.batch_a, self.other_year)

    def test_withdrawing_then_re_enrolling_active_is_allowed(self):
        first = self._enroll(self.batch_a, self.year)
        first.state = "withdrawn"
        # Should not raise: the only active row for this student+year was
        # just withdrawn, so a new active enrollment is legitimate.
        self._enroll(self.batch_b, self.year)