mod ioctl;

use clap::Parser;
use std::fs::File;
use std::os::fd::AsRawFd;
use std::path::{Path, PathBuf};
use std::sync::Arc;
use log::LevelFilter;
use users::{get_current_gid, get_current_uid};
use aya::AyaFS;
use aya::block_device::BLOCK_SIZE;
use aya::block_device::disk::Disk;
use crate::ioctl::ioctl_blkgetsize64;

#[derive(Parser, Debug)]
#[command(author, version, about)]
struct Args {
    block_device: Option<PathBuf>,
    #[arg(short, long)]
    user_id: Option<u32>,
    #[arg(short, long)]
    group_id: Option<u32>,
    #[arg(short, action = clap::ArgAction::Count)]
    verbosity: u8,
}

fn get_device_size<T: AsRef<Path>>(path: T) -> u64 {
    let device = File::options()
        .write(true)
        .open(path.as_ref())
        .expect("Failed to open device.");
    let device_raw_fd = device.as_raw_fd();
    let mut device_size = 0u64;
    let device_size_ptr = &mut device_size as *mut u64;
    unsafe {
        ioctl_blkgetsize64(device_raw_fd, device_size_ptr)
            .expect("ioctl exceptions occur.");
    }
    device_size
}

fn main() {
    let args = Args::parse();
    let device_path = args.block_device
        .expect("Not device path specified.");
    let verbosity = args.verbosity;
    let uid = args.user_id.unwrap_or_else(get_current_uid);
    let gid = args.group_id.unwrap_or_else(get_current_gid);

    let log_level = match verbosity {
        0 => LevelFilter::Error,
        1 => LevelFilter::Warn,
        2 => LevelFilter::Info,
        3 => LevelFilter::Debug,
        _ => LevelFilter::Trace,
    };
    env_logger::builder().filter_level(log_level).init();
    let device_size = get_device_size(device_path.as_path());
    let disk = Arc::new(Disk::new(device_path));
    let mut fs = AyaFS::new(
        disk,
        device_size as usize / BLOCK_SIZE,
        uid,
        gid,
    );
    fs.write_back();
}