"""migration.py structural sanity: MIGRATIONS is well-formed, a fresh
install lands on the latest schema version with frame #1 + server
settings seeded, and re-running run_migrations() is a true no-op (it's
called unconditionally at every app.main import -- see main.py -- so it
has to tolerate being invoked against an already-current database)."""

from __future__ import annotations

from sqlalchemy import inspect, text

from app import db as db_module
from app.migration import MIGRATIONS, run_migrations
from app.models import Frame, ServerSettings


def test_migrations_list_is_sequential_and_unique():
    versions = [v for v, _ in MIGRATIONS]
    assert versions == sorted(versions)
    assert len(versions) == len(set(versions))
    assert versions == list(range(1, len(versions) + 1))


def test_fresh_install_lands_on_latest_version(db_session):
    with db_module.engine.connect() as conn:
        row = conn.execute(text("SELECT version FROM schema_version")).fetchone()
    assert row is not None
    assert row[0] == MIGRATIONS[-1][0]


def test_fresh_install_seeds_frame_one_and_server_settings(db_session):
    frame = db_session.get(Frame, 1)
    assert frame is not None
    assert frame.name

    settings = db_session.get(ServerSettings, 1)
    assert settings is not None


def test_rerunning_migrations_is_a_no_op(db_session):
    frame_count_before = len(db_session.query(Frame).all())
    run_migrations()
    run_migrations()
    frame_count_after = len(db_session.query(Frame).all())
    assert frame_count_before == frame_count_after == 1


def test_expected_columns_exist_on_current_schema():
    """A light spot-check, not exhaustive -- one column from a handful of
    the more recent migrations, to catch an ALTER that silently didn't
    apply (e.g. a typo'd table/column name in a migration function)."""
    inspector = inspect(db_module.engine)
    user_columns = {c["name"] for c in inspector.get_columns("users")}
    frame_columns = {c["name"] for c in inspector.get_columns("frames")}

    assert "webdav_base_url" in user_columns  # migration 15
    assert "webdav_username" in user_columns  # migration 14
    assert "calendar_caldav_url" in user_columns
    assert "whiteboard_cached_image" in frame_columns  # migration 14
    assert "calendar_week_start_offset" in frame_columns