"""Migration runner + SQLite pragma sanity tests."""

from __future__ import annotations

import sqlite3
from pathlib import Path

import pytest

from cerbero_bite.state.db import (
    connect,
    current_version,
    list_migrations,
    run_migrations,
    transaction,
)


def test_list_migrations_is_ordered_and_starts_with_0001() -> None:
    migs = list_migrations()
    assert migs, "expected at least one migration file"
    versions = [m[0] for m in migs]
    assert versions == sorted(versions)
    assert versions[0] == 1


def test_run_migrations_creates_full_schema(tmp_path: Path) -> None:
    db_path = tmp_path / "state.sqlite"
    conn = connect(db_path)
    try:
        new_version = run_migrations(conn)
        assert new_version == max(m[0] for m in list_migrations())
        # Sanity: every documented table is present.
        existing = {
            row["name"]
            for row in conn.execute(
                "SELECT name FROM sqlite_master WHERE type='table'"
            ).fetchall()
        }
        assert {
            "positions",
            "instructions",
            "decisions",
            "dvol_history",
            "manual_actions",
            "system_state",
        } <= existing
    finally:
        conn.close()


def test_run_migrations_is_idempotent(tmp_path: Path) -> None:
    db_path = tmp_path / "state.sqlite"
    conn = connect(db_path)
    try:
        run_migrations(conn)
        first = current_version(conn)
        run_migrations(conn)  # second call must be a no-op
        assert current_version(conn) == first
    finally:
        conn.close()


def test_pragmas_applied(tmp_path: Path) -> None:
    db_path = tmp_path / "state.sqlite"
    conn = connect(db_path)
    try:
        run_migrations(conn)
        assert conn.execute("PRAGMA foreign_keys").fetchone()[0] == 1
        # WAL is sticky on the file: confirm via the journal_mode pragma.
        mode = conn.execute("PRAGMA journal_mode").fetchone()[0]
        assert mode.lower() == "wal"
    finally:
        conn.close()


def test_transaction_rolls_back_on_exception(tmp_path: Path) -> None:
    db_path = tmp_path / "state.sqlite"
    conn = connect(db_path)
    try:
        run_migrations(conn)
        with pytest.raises(RuntimeError, match="boom"), transaction(conn):
            conn.execute(
                "INSERT INTO system_state(id, last_health_check, "
                "config_version, started_at) VALUES (1, '2026-04-27', "
                "'1.0.0', '2026-04-27')"
            )
            raise RuntimeError("boom")
        # Row was rolled back.
        rows = conn.execute("SELECT COUNT(*) FROM system_state").fetchone()[0]
        assert rows == 0
    finally:
        conn.close()


def test_foreign_key_enforcement(tmp_path: Path) -> None:
    db_path = tmp_path / "state.sqlite"
    conn = connect(db_path)
    try:
        run_migrations(conn)
        # Inserting an instruction without a parent position must fail.
        with pytest.raises(sqlite3.IntegrityError):
            conn.execute(
                "INSERT INTO instructions(instruction_id, proposal_id, kind, "
                "payload_json, sent_at) VALUES (?, ?, ?, ?, ?)",
                ("i1", "missing", "open_combo", "{}", "2026-04-27"),
            )
    finally:
        conn.close()