import pytest

from django.db import transaction
from django.db.utils import IntegrityError

from psqlextra.fields import HStoreField

from . import migrations
from .fake_model import get_fake_model


def test_hstore_unique_migration_create_drop_model():
    """Tests whether indexes are properly created and dropped when creating and
    dropping a model."""

    uniqueness = ["beer", "cookies"]

    test = migrations.create_drop_model(
        HStoreField(uniqueness=uniqueness), ["CREATE UNIQUE", "DROP INDEX"]
    )

    with test as calls:
        assert len(calls["CREATE UNIQUE"]) == len(uniqueness)
        assert len(calls["DROP INDEX"]) == len(uniqueness)


def test_hstore_unique_migration_alter_db_table():
    """Tests whether indexes are renamed properly when renaming the database
    table."""

    test = migrations.alter_db_table(
        HStoreField(uniqueness=["beer", "cookie"]),
        ["RENAME TO", "CREATE INDEX", "DROP INDEX"],
    )

    with test as calls:
        # 1 rename for table, 2 for hstore keys
        assert len(calls["RENAME TO"]) == 3
        assert len(calls.get("CREATE UNIQUE", [])) == 0
        assert len(calls.get("DROP INDEX", [])) == 0


def test_hstore_unique_add_field():
    """Tests whether adding a field properly creates the indexes."""

    test = migrations.add_field(
        HStoreField(uniqueness=["beer"]), ["CREATE UNIQUE", "DROP INDEX"]
    )

    with test as calls:
        assert len(calls.get("CREATE UNIQUE", [])) == 1
        assert len(calls.get("DROP INDEX", [])) == 0


def test_hstore_unique_remove_field():
    """Tests whether removing a field properly removes the index."""

    test = migrations.remove_field(
        HStoreField(uniqueness=["beer"]), ["CREATE UNIQUE", "DROP INDEX"]
    )

    with test as calls:
        assert len(calls.get("CREATE UNIQUE", [])) == 0
        assert len(calls.get("DROP INDEX", [])) == 1


def test_hstore_unique_alter_field_nothing():
    """Tests whether no indexes are dropped when not changing anything in the
    uniqueness."""

    test = migrations.alter_field(
        HStoreField(uniqueness=["beer"]),
        HStoreField(uniqueness=["beer"]),
        ["CREATE UNIQUE", "DROP INDEX"],
    )

    with test as calls:
        assert len(calls.get("CREATE UNIQUE", [])) == 0
        assert len(calls.get("DROP INDEX", [])) == 0


def test_hstore_unique_alter_field_add():
    """Tests whether only one index is created when adding another key to the
    uniqueness."""

    test = migrations.alter_field(
        HStoreField(uniqueness=["beer"]),
        HStoreField(uniqueness=["beer", "beer1"]),
        ["CREATE UNIQUE", "DROP INDEX"],
    )

    with test as calls:
        assert len(calls.get("CREATE UNIQUE", [])) == 1
        assert len(calls.get("DROP INDEX", [])) == 0


def test_hstore_unique_alter_field_remove():
    """Tests whether one index is dropped when removing a key from
    uniqueness."""

    test = migrations.alter_field(
        HStoreField(uniqueness=["beer"]),
        HStoreField(uniqueness=[]),
        ["CREATE UNIQUE", "DROP INDEX"],
    )

    with test as calls:
        assert len(calls.get("CREATE UNIQUE", [])) == 0
        assert len(calls.get("DROP INDEX", [])) == 1


def test_hstore_unique_alter_field_add_together():
    """Tests whether adding one index is created when adding a "unique
    together"."""

    test = migrations.alter_field(
        HStoreField(uniqueness=["beer"]),
        HStoreField(uniqueness=["beer", ("beer1", "beer2")]),
        ["CREATE UNIQUE", "DROP INDEX"],
    )

    with test as calls:
        assert len(calls.get("CREATE UNIQUE", [])) == 1
        assert len(calls.get("DROP INDEX", [])) == 0


def test_hstore_unique_alter_field_remove_together():
    """Tests whether adding one index is dropped when adding a "unique
    together"."""

    test = migrations.alter_field(
        HStoreField(uniqueness=[("beer1", "beer2")]),
        HStoreField(uniqueness=[]),
        ["CREATE UNIQUE", "DROP INDEX"],
    )

    with test as calls:
        assert len(calls.get("CREATE UNIQUE", [])) == 0
        assert len(calls.get("DROP INDEX", [])) == 1


def test_hstore_unique_rename_field():
    """Tests whether renaming a field doesn't cause the index to be re-
    created."""

    test = migrations.rename_field(
        HStoreField(uniqueness=["beer", "cookies"]),
        ["RENAME TO", "CREATE INDEX", "DROP INDEX"],
    )

    with test as calls:
        assert len(calls.get("RENAME TO", [])) == 2
        assert len(calls.get("CREATE UNIQUE", [])) == 0
        assert len(calls.get("DROP INDEX", [])) == 0


def test_hstore_unique_enforcement():
    """Tests whether the constraints are actually properly enforced."""
    model = get_fake_model({"title": HStoreField(uniqueness=["en"])})

    # should pass, table is empty and 'ar' does not have to be unique
    model.objects.create(title={"en": "unique", "ar": "notunique"})
    model.objects.create(title={"en": "elseunique", "ar": "notunique"})

    # this should fail, key 'en' must be unique
    with transaction.atomic():
        with pytest.raises(IntegrityError):
            model.objects.create(title={"en": "unique", "ar": "notunique"})


def test_hstore_unique_enforcement_together():
    """Tests whether unique_together style constraints are enforced
    properly."""

    model = get_fake_model({"title": HStoreField(uniqueness=[("en", "ar")])})

    model.objects.create(title={"en": "unique", "ar": "notunique"})

    with transaction.atomic():
        with pytest.raises(IntegrityError):
            model.objects.create(title={"en": "unique", "ar": "notunique"})

    model.objects.create(title={"en": "notunique", "ar": "unique"})