plm-lottery/tests/unit/test_migrations.py

"""B-97 (DAT-75, DAT-56, ARC-62, ARC-64): the Alembic chain is executed, not assumed.

The two expression indexes that carry invariants — `ix_rounds_single_active` ("at
most one active round", B-09) and `ix_users_username_lower` ("usernames are
case-insensitive", B-57) — are invisible to autogenerate, and `batch_alter_table`
on SQLite rebuilds the table and drops them with only a warning. Every other test
builds its schema with `Base.metadata.create_all`, so a migration that lost one of
them would reach production unnoticed. This one runs `alembic upgrade head` on an
empty database, exactly as the container does at startup.

Alembic runs in a subprocess: env.py calls `asyncio.run` and `fileConfig`, neither of
which belongs inside the pytest process.
"""

import os
import re
import sqlite3
import subprocess
import sys
from pathlib import Path

import pytest

_ROOT = Path(__file__).resolve().parents[2]


@pytest.fixture(scope="module")
def migrated_db(tmp_path_factory) -> Path:
    db_path = tmp_path_factory.mktemp("migrations") / "migrated.db"
    env = {**os.environ, "DATABASE_URL": f"sqlite+aiosqlite:///{db_path}"}
    result = subprocess.run(
        [sys.executable, "-m", "alembic", "upgrade", "head"],
        cwd=_ROOT,
        env=env,
        capture_output=True,
        text=True,
        timeout=120,
    )
    assert result.returncode == 0, f"alembic upgrade head failed:\n{result.stderr[-3000:]}"
    return db_path


def _index_sql(db_path: Path, name: str) -> str | None:
    with sqlite3.connect(db_path) as conn:
        row = conn.execute("SELECT sql FROM sqlite_master WHERE type = 'index' AND name = ?", (name,)).fetchone()
    return re.sub(r"\s+", " ", row[0]).lower() if row else None


def test_the_expression_indexes_survive_the_whole_migration_chain(migrated_db):
    """DAT-75 / ARC-62 / B-97: both indexes exist, with their definition, at head."""
    single_active = _index_sql(migrated_db, "ix_rounds_single_active")
    assert single_active is not None, "ix_rounds_single_active was lost by a migration"
    assert "unique index" in single_active
    assert "on rounds ((1))" in single_active
    for status in ("open", "closing", "drawing", "paying_out"):
        assert f"'{status}'" in single_active

    username_lower = _index_sql(migrated_db, "ix_users_username_lower")
    assert username_lower is not None, "ix_users_username_lower was lost by a migration"
    assert "unique index" in username_lower
    assert "lower(username)" in username_lower


def test_the_migrated_database_still_enforces_both_invariants(migrated_db):
    """DAT-75 / B-97: a second active round and a case-variant username are refused."""
    with sqlite3.connect(migrated_db) as conn:
        conn.execute("INSERT INTO rounds (status, opened_at) VALUES ('open', '2026-01-01 00:00:00')")
        with pytest.raises(sqlite3.IntegrityError):
            conn.execute("INSERT INTO rounds (status, opened_at) VALUES ('closing', '2026-01-01 00:00:00')")
        # A closed round is not active, so any number of them may coexist.
        conn.execute("INSERT INTO rounds (status, opened_at) VALUES ('closed', '2026-01-01 00:00:00')")

        columns = "(username, password_hash, derivation_index, address, cached_balance_sats, token_version, created_at)"
        conn.execute(f"INSERT INTO users {columns} VALUES ('Alice', 'x', 0, 'plm1qa', 0, 0, '2026-01-01 00:00:00')")
        with pytest.raises(sqlite3.IntegrityError):
            conn.execute(f"INSERT INTO users {columns} VALUES ('aLICE', 'x', 1, 'plm1qb', 0, 0, '2026-01-01 00:00:00')")


def _alembic(db_path: Path, *args: str) -> None:
    env = {**os.environ, "DATABASE_URL": f"sqlite+aiosqlite:///{db_path}"}
    result = subprocess.run(
        [sys.executable, "-m", "alembic", *args], cwd=_ROOT, env=env, capture_output=True, text=True, timeout=120
    )
    assert result.returncode == 0, f"alembic {' '.join(args)} failed:\n{result.stderr[-3000:]}"


def test_pending_transaction_txids_table_matches_the_model(migrated_db):
    """B-77 (DAT-70): the migrated table has the model's columns, the unique txid and the
    index on the owning row."""
    from app.db.models import PendingTransactionTxid

    with sqlite3.connect(migrated_db) as conn:
        columns = {row[1]: row for row in conn.execute("PRAGMA table_info(pending_transaction_txids)")}
        sql = conn.execute("SELECT sql FROM sqlite_master WHERE name = 'pending_transaction_txids'").fetchone()[0]
        indexes = {row[1] for row in conn.execute("PRAGMA index_list(pending_transaction_txids)")}
    assert set(columns) == {c.name for c in PendingTransactionTxid.__table__.columns}
    assert "unique" in sql.lower()
    assert "ix_pending_transaction_txids_pending_transaction_id" in indexes


def test_existing_pending_transactions_are_backfilled_with_the_txids_they_remember(tmp_path):
    """B-77 (DAT-70): upgrading a database that already has rows records each one's
    current txid with its raw transaction, and the txid a bump replaced with an empty
    raw_hex — and the expression indexes survive the step."""
    db_path = tmp_path / "old.db"
    _alembic(db_path, "upgrade", "477bddae1a84")
    with sqlite3.connect(db_path) as conn:
        columns = (
            "(kind, current_txid, fee_rate_sat_vb, raw_tx_hex, broadcast_at, last_broadcast_at, status, "
            "replaced_by_txid, attempt_count, updated_at)"
        )
        stamp = "'2026-01-01 00:00:00'"
        conn.execute(
            f"INSERT INTO pending_transactions {columns} VALUES "
            f"('bet', 'cc', 2, 'rawcc', {stamp}, {stamp}, 'pending', 'bb', 2, {stamp})"
        )
        conn.execute(
            f"INSERT INTO pending_transactions {columns} VALUES "
            f"('withdrawal', 'dd', 1, 'rawdd', {stamp}, {stamp}, 'building', NULL, 1, {stamp})"
        )
    _alembic(db_path, "upgrade", "head")
    with sqlite3.connect(db_path) as conn:
        rows = sorted(conn.execute("SELECT pending_transaction_id, txid, raw_hex FROM pending_transaction_txids"))
    assert rows == [(1, "bb", ""), (1, "cc", "rawcc"), (2, "dd", "rawdd")]
    assert _index_sql(db_path, "ix_rounds_single_active") is not None
    assert _index_sql(db_path, "ix_users_username_lower") is not None