"""Test the ORM's `Pixel` model."""

import pytest
import sqlalchemy as sqla
from sqlalchemy import exc as sa_exc

from urban_meal_delivery import db


class TestSpecialMethods:
    """Test special methods in `Pixel`."""

    def test_create_pixel(self, pixel):
        """Test instantiation of a new `Pixel` object."""
        assert pixel is not None

    def test_text_representation(self, pixel):
        """`Pixel` has a non-literal text representation."""
        result = repr(pixel)

        assert result == f'<Pixel: ({pixel.n_x}, {pixel.n_y})>'


@pytest.mark.db
@pytest.mark.no_cover
class TestConstraints:
    """Test the database constraints defined in `Pixel`."""

    def test_insert_into_database(self, db_session, pixel):
        """Insert an instance into the (empty) database."""
        assert db_session.query(db.Pixel).count() == 0

        db_session.add(pixel)
        db_session.commit()

        assert db_session.query(db.Pixel).count() == 1

    def test_delete_a_referenced_grid(self, db_session, pixel):
        """Remove a record that is referenced with a FK."""
        db_session.add(pixel)
        db_session.commit()

        # Must delete without ORM as otherwise an UPDATE statement is emitted.
        stmt = sqla.delete(db.Grid).where(db.Grid.id == pixel.grid.id)

        with pytest.raises(
            sa_exc.IntegrityError, match='fk_pixels_to_grids_via_grid_id',
        ):
            db_session.execute(stmt)

    def test_negative_n_x(self, db_session, pixel):
        """Insert an instance with invalid data."""
        pixel.n_x = -1
        db_session.add(pixel)

        with pytest.raises(sa_exc.IntegrityError, match='n_x_is_positive'):
            db_session.commit()

    def test_negative_n_y(self, db_session, pixel):
        """Insert an instance with invalid data."""
        pixel.n_y = -1
        db_session.add(pixel)

        with pytest.raises(sa_exc.IntegrityError, match='n_y_is_positive'):
            db_session.commit()

    def test_non_unique_coordinates_within_a_grid(self, db_session, pixel):
        """Insert an instance with invalid data."""
        another_pixel = db.Pixel(grid=pixel.grid, n_x=pixel.n_x, n_y=pixel.n_y)
        db_session.add(another_pixel)

        with pytest.raises(sa_exc.IntegrityError, match='duplicate key value'):
            db_session.commit()


class TestProperties:
    """Test properties in `Pixel`."""

    def test_side_length(self, pixel):
        """Test `Pixel.side_length` property."""
        result = pixel.side_length

        assert result == 1_000

    def test_area(self, pixel):
        """Test `Pixel.area` property."""
        result = pixel.area

        assert result == 1.0