"""Regression test for a schema-drift bug: a database created by an older
build of the app still had a `completed_here NOT NULL` column on `tasks`
that a later refactor dropped from the model. `create_all` never alters an
existing table, so every task insert on such a database failed with

    IntegrityError: null value in column "completed_here" ... violates
    not-null constraint

which, since task refresh runs from both the scheduler and `/api/tasks`
endpoints, looked like "everything 500s". `app.db.init_db` now reconciles
known-dead columns after `create_all`; this pins that behaviour down.
"""

from __future__ import annotations

from app.db import SessionLocal, engine, init_db
from app.models import TaskRecord
from sqlalchemy import text


def _simulate_pre_refactor_database() -> None:
    """Recreate the exact drift: today's `tasks` table, plus the long-gone
    `completed_here` column, `NOT NULL` and with no database-side default —
    just like a database that has been running since before the column was
    removed from the model.
    """
    with engine.begin() as conn:
        conn.execute(text("DROP TABLE IF EXISTS tasks"))
        conn.execute(
            text(
                """
                CREATE TABLE tasks (
                    id INTEGER PRIMARY KEY,
                    source VARCHAR(32) NOT NULL,
                    external_id VARCHAR(128) NOT NULL,
                    title TEXT NOT NULL,
                    description TEXT,
                    url TEXT,
                    project TEXT,
                    status VARCHAR(64),
                    priority VARCHAR(32),
                    due_date DATE,
                    start_date DATE,
                    labels JSON,
                    raw JSON,
                    is_done BOOLEAN NOT NULL DEFAULT 0,
                    completed_at DATETIME,
                    completed_date DATE,
                    completed_here BOOLEAN NOT NULL,
                    estimated_pomodoros INTEGER,
                    pinned BOOLEAN NOT NULL DEFAULT 0,
                    first_seen_at DATETIME NOT NULL,
                    last_seen_at DATETIME NOT NULL,
                    stale BOOLEAN NOT NULL DEFAULT 0
                )
                """
            )
        )


def test_init_db_drops_the_dead_not_null_column(session):
    _simulate_pre_refactor_database()

    init_db()

    db = SessionLocal()
    try:
        # This is exactly what `tasks_service._upsert` + `refresh_tasks` do on
        # a newly-seen task: insert a row without ever mentioning the column
        # the model no longer has.
        db.add(TaskRecord(source="jira", external_id="VPN-48", title="Renew VPN"))
        db.commit()  # pre-fix: IntegrityError (null value in "completed_here")

        stored = db.query(TaskRecord).filter_by(external_id="VPN-48").one()
        assert stored.title == "Renew VPN"
    finally:
        db.close()


def test_init_db_is_a_no_op_once_the_column_is_already_gone(session):
    """Running it twice (every boot does) must not blow up when there is
    nothing left to drop."""
    init_db()
    init_db()