import pytest

from database.init_db import _ensure_bind_session_card_columns, _ensure_cards_allow_multiple_per_device


class FakeScalarResult:
    def __init__(self, value):
        self.value = value

    def scalar(self):
        return self.value


class FakeConnection:
    def __init__(self):
        self.stat_counts = {
            "idx_device_bind_sessions_card_uuid": 0,
            "idx_cards_device_id": 0,
            "uq_cards_device_id": 1,
        }
        self.column_counts = {
            "bind_mode": 0,
            "card_uuid": 0,
        }
        self.sql = []

    async def execute(self, statement, params=None):
        sql = str(statement)
        self.sql.append(sql)

        if "INFORMATION_SCHEMA.COLUMNS" in sql:
            return FakeScalarResult(self.column_counts.get(params["column_name"], 0))

        if "INFORMATION_SCHEMA.STATISTICS" in sql:
            for index_name, count in self.stat_counts.items():
                if f"INDEX_NAME = '{index_name}'" in sql:
                    return FakeScalarResult(count)
            return FakeScalarResult(0)

        return FakeScalarResult(0)


@pytest.mark.asyncio
async def test_ensure_bind_session_card_columns_adds_missing_columns_and_index():
    conn = FakeConnection()

    await _ensure_bind_session_card_columns(conn)

    executed = "\n".join(conn.sql)
    assert "ALTER TABLE device_bind_sessions ADD COLUMN bind_mode TINYINT NOT NULL DEFAULT 1 AFTER status" in executed
    assert "ALTER TABLE device_bind_sessions ADD COLUMN card_uuid VARCHAR(64) NULL AFTER bind_mode" in executed
    assert "ALTER TABLE device_bind_sessions ADD INDEX idx_device_bind_sessions_card_uuid (card_uuid)" in executed


@pytest.mark.asyncio
async def test_ensure_cards_allow_multiple_per_device_replaces_unique_device_index():
    conn = FakeConnection()

    await _ensure_cards_allow_multiple_per_device(conn)

    executed = "\n".join(conn.sql)
    assert "ALTER TABLE cards ADD INDEX idx_cards_device_id (device_id)" in executed
    assert "ALTER TABLE cards DROP INDEX uq_cards_device_id" in executed
    assert executed.index("ALTER TABLE cards ADD INDEX idx_cards_device_id") < executed.index(
        "ALTER TABLE cards DROP INDEX uq_cards_device_id"
    )