You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: init.rs
    path of file: ./repos/moonfire-nvr/server/src/cmds
    
    the code of the file until where you have to start completion: // This file is part of Moonfire NVR, a security camera network video recorder.
// Copyright (C) 2020 The Moonfire NVR Authors; see AUTHORS and LICENSE.txt.
// SPDX-License-Identifier: GPL-v3.0-or-later WITH GPL-3.0-linking-exception.

use base::Error;
use bpaf::Bpaf;
use std::path::PathBuf;
use tracing::info;

/// Initializes a database.
#[derive(Bpaf, Debug)]
#[bpaf(command("init"))]
pub struct Args {
    #[bpaf(external(crate::parse_db_dir))]
    db_dir: PathBuf,
}

pub fn run(args: Args) -> Result<i32, Error> {
    let (_db_dir, mut conn) = super::open_conn(&args.db_dir, super::OpenMode::Create)?;

    // Check if the database has already been initialized.
    
    
pub fn run(args: Args) -> Result<i32, Error> {
    let (_db_dir, mut conn) = super::open_conn(&args.db_dir, super::OpenMode::Create)?;

    // Check if the database has already been initialized.
    let cur_ver = db::get_schema_version(&conn)?;
    if let Some(v) = cur_ver {
        info!("Database is already initialized with schema version {}.", v);
        return Ok(0);
    }

    // Use WAL mode (which is the most efficient way to preserve database integrity) with a large
    // page size (so reading large recording_playback rows doesn't require as many seeks). Changing
    // the page size requires doing a vacuum in non-WAL mode. This will be cheap on an empty
    // database. https://www.sqlite.org/pragma.html#pragma_page_size
    conn.execute_batch(
        r#"
        pragma journal_mode = delete;
        pragma page_size = 16384;
        vacuum;
        pragma journal_mode = wal;
        "#,
    )?;
    db::init(&mut conn)?;
    info!("Database initialized.");
    Ok(0)
}