//! Magnetic tape backup

use anyhow::{format_err, Error};

use proxmox::tools::fs::{
    create_path,
    CreateOptions,
};

pub mod file_formats;

mod tape_write;
pub use tape_write::*;

mod tape_read;
pub use tape_read::*;

mod helpers;
pub use helpers::*;

mod inventory;
pub use inventory::*;

mod changer;
pub use changer::*;

mod drive;
pub use drive::*;

mod media_state_database;
pub use media_state_database::*;

mod online_status_map;
pub use online_status_map::*;

mod media_pool;
pub use media_pool::*;

mod media_catalog;
pub use media_catalog::*;

mod chunk_archive;
pub use chunk_archive::*;

/// Directory path where we store all tape status information
pub const TAPE_STATUS_DIR: &str = "/var/lib/proxmox-backup/tape";

/// We limit chunk archive size, so that we can faster restore a
/// specific chunk (The catalog only store file numbers, so we
/// need to read the whole archive to restore a single chunk)
pub const MAX_CHUNK_ARCHIVE_SIZE: usize = 4*1024*1024*1024; // 4GB for now

/// To improve performance, we need to avoid tape drive buffer flush.
pub const COMMIT_BLOCK_SIZE: usize = 128*1024*1024*1024; // 128 GiB


/// Create tape status dir with correct permission
pub fn create_tape_status_dir() -> Result<(), Error> {
    let backup_user = crate::backup::backup_user()?;
    let mode = nix::sys::stat::Mode::from_bits_truncate(0o0640);
    let opts = CreateOptions::new()
        .perm(mode)
        .owner(backup_user.uid)
        .group(backup_user.gid);

    create_path(TAPE_STATUS_DIR, None, Some(opts))
        .map_err(|err: Error| format_err!("unable to create tape status dir - {}", err))?;

    Ok(())
}