import db

from .list_screens import list_screens


def move_screen(slug: str, screen_id: int, direction: int) -> None:
    """direction: -1 (monter, l'écran devient plus tôt dans l'enchaînement)
    ou +1 (descendre) — échange l'order_index avec l'écran voisin."""
    screens_ = list_screens(slug)
    idx = next((i for i, s in enumerate(screens_) if s["id"] == screen_id), None)
    if idx is None:
        return
    swap_idx = idx + direction
    if swap_idx < 0 or swap_idx >= len(screens_):
        return
    a, b = screens_[idx], screens_[swap_idx]
    conn = db.connect(slug)
    conn.execute("UPDATE _screens SET order_index = ? WHERE id = ?", (b["order_index"], a["id"]))
    conn.execute("UPDATE _screens SET order_index = ? WHERE id = ?", (a["order_index"], b["id"]))
    conn.commit()
    conn.close()