"""Idempotency contract for the Issue #26 strategy-catalog migration."""

from __future__ import annotations

import importlib.util
from pathlib import Path
from types import SimpleNamespace
from unittest.mock import patch


_MIGRATION_PATH = (
    Path(__file__).parents[1]
    / "app/db/alembic/versions/20260814_0029_strategy_catalog_v1.py"
)


def _load_migration():
    spec = importlib.util.spec_from_file_location("strategy_catalog_0029", _MIGRATION_PATH)
    assert spec is not None and spec.loader is not None
    module = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(module)
    return module


class _Bind:
    def __init__(self) -> None:
        self.executed: list[str] = []
        self.params: list[dict | None] = []

    def execute(self, statement, params=None):
        self.executed.append(str(statement))
        self.params.append(params)
        return SimpleNamespace()


class _Inspector:
    def __init__(self, columns: set[str]) -> None:
        self.columns = columns

    def get_table_names(self) -> list[str]:
        return ["strategy_sets"]

    def get_columns(self, table_name: str) -> list[dict[str, str]]:
        assert table_name == "strategy_sets"
        return [{"name": name} for name in sorted(self.columns)]


def test_upgrade_is_repeatable_and_uses_data_and_constraint_guards() -> None:
    migration = _load_migration()
    columns = {"id", "name", "config", "nick", "created_at"}
    inspector = _Inspector(columns)
    bind = _Bind()
    added: list[str] = []

    def add_column(table_name: str, column) -> None:
        assert table_name == "strategy_sets"
        columns.add(column.name)
        added.append(column.name)

    with (
        patch.object(migration.op, "get_bind", return_value=bind),
        patch.object(migration.op, "add_column", side_effect=add_column),
        patch.object(migration, "inspect", return_value=inspector),
    ):
        migration.upgrade()
        migration.upgrade()

    assert added == ["status", "revision", "updated_at"]
    sql = "\n".join(bind.executed)
    assert "WHERE NOT EXISTS" in sql
    assert "IF NOT EXISTS" in sql
    assert "ck_strategy_sets_status" in sql
    assert "ck_strategy_sets_revision_positive" in sql
    assert any(params and params.get("nick") == "target_value:bf21a9e8fbc5" for params in bind.params)