// This work is based on the implementation by Nikhil Kshirsagar which
// can be found here:
//    https://github.com/nkshirsagar/thinpool_shrink/blob/split_ranges/thin_shrink.py

extern crate clap;
extern crate thinp;

use clap::{App, Arg};
use std::path::Path;
use std::process::exit;
use thinp::file_utils;

fn main() {
    let parser = App::new("thin_shrink")
        .version(thinp::version::tools_version())
        .about("Rewrite xml metadata and move data in an inactive pool.")
        .arg(
            Arg::with_name("INPUT")
                .help("Specify thinp metadata xml file")
                .required(true)
                .long("input")
                .value_name("INPUT")
                .takes_value(true),
        )
        .arg(
            Arg::with_name("OUTPUT")
                .help("Specify output xml file")
                .required(true)
                .long("output")
                .value_name("OUTPUT")
                .takes_value(true),
        )
        .arg(
            Arg::with_name("DATA")
                .help("Specify pool data device where data will be moved")
                .required(true)
                .long("data")
                .value_name("DATA")
                .takes_value(true),
        )
        .arg(
            Arg::with_name("NOCOPY")
                .help("Skip the copying of data, useful for benchmarking")
                .required(false)
                .long("no-copy")
                .value_name("NOCOPY")
                .takes_value(false),
        )
        .arg(
            Arg::with_name("SIZE")
                .help("Specify new size for the pool (in data blocks)")
                .required(true)
                .long("nr-blocks")
                .value_name("SIZE")
                .takes_value(true),
        );

    let matches = parser.get_matches();

    // FIXME: check these look like xml
    let input_file = Path::new(matches.value_of("INPUT").unwrap());
    let output_file = Path::new(matches.value_of("OUTPUT").unwrap());
    let size = matches.value_of("SIZE").unwrap().parse::<u64>().unwrap();
    let data_file = Path::new(matches.value_of("DATA").unwrap());
    let do_copy = !matches.is_present("NOCOPY");

    if !file_utils::file_exists(input_file) {
        eprintln!("Couldn't find input file '{}'.", input_file.display());
        exit(1);
    }

    if let Err(reason) =
        thinp::shrink::toplevel::shrink(&input_file, &output_file, &data_file, size, do_copy)
    {
        println!("Application error: {}\n", reason);
        exit(1);
    }
}