"""Leichte In-Place-Migrationen für SQLite (kein Alembic).

Wird beim App-Start nach create_all() ausgeführt. Idempotent.
"""
from __future__ import annotations

import logging

from sqlalchemy import text
from sqlmodel import Session

from app.core.db import engine

log = logging.getLogger("voice-agent.migrate")


def _existing_columns(conn, table: str) -> set[str]:
    rows = conn.execute(text(f"PRAGMA table_info({table})")).all()
    return {r[1] for r in rows}  # row[1] = column name


def run_migrations() -> None:
    with engine.begin() as conn:
        # 1) Job.owner_id Spalte nachrüsten, falls die Tabelle aus alter Version kommt.
        cols = _existing_columns(conn, "job")
        if "owner_id" not in cols:
            log.info("Migration: füge job.owner_id hinzu")
            conn.execute(text("ALTER TABLE job ADD COLUMN owner_id INTEGER"))
            conn.execute(text("CREATE INDEX IF NOT EXISTS ix_job_owner_id ON job(owner_id)"))


def assign_orphan_jobs_to(user_id: int) -> int:
    """Weist alle Jobs ohne owner_id dem angegebenen User zu. Gibt Anzahl zurück."""
    with Session(engine) as session:
        result = session.execute(
            text("UPDATE job SET owner_id = :uid WHERE owner_id IS NULL"),
            {"uid": user_id},
        )
        session.commit()
        n = result.rowcount or 0
        if n:
            log.info("Migration: %d Bestand-Jobs an user_id=%d zugeordnet", n, user_id)
        return n