import sqlite3

from ._source import load_symbols


def _migration_namespace():
    return load_symbols("SCHEMA_VERSION", "_column_names", "run_migrations")


def test_migration_is_idempotent_and_creates_operation_contract():
    db = sqlite3.connect(":memory:")
    db.execute("CREATE TABLE audit_log (id INTEGER PRIMARY KEY, detail TEXT)")
    ns = _migration_namespace()
    assert ns["run_migrations"](db) == 1
    assert ns["run_migrations"](db) == 1
    columns = {row[1] for row in db.execute("PRAGMA table_info(operations)")}
    assert {"id", "correlation_id", "kind", "state", "idempotency_key", "recovery_actions"} <= columns
    assert "correlation_id" in {row[1] for row in db.execute("PRAGMA table_info(audit_log)")}


def test_newer_schema_is_rejected_without_mutation():
    db = sqlite3.connect(":memory:")
    db.execute("CREATE TABLE schema_metadata (key TEXT PRIMARY KEY, value TEXT NOT NULL)")
    db.execute("INSERT INTO schema_metadata VALUES ('schema_version','999')")
    ns = _migration_namespace()
    try:
        ns["run_migrations"](db)
    except RuntimeError as exc:
        assert "newer than supported" in str(exc)
    else:
        raise AssertionError("newer schema was accepted")