use imdl::infohash::Infohash;
use imdl::input::Input;
use imdl::input_target::InputTarget;
use imdl::magnet_link::MagnetLink;
use imdl::metainfo::Metainfo;
use imdl::torrent_summary::TorrentSummary;

use std::path::Path;

/// Helper method for imdl functions which expect an imdl::Input type
pub fn input_path<T: AsRef<Path>>(path: T) -> Result<Input, std::io::Error> {
    let path = path.as_ref();
    let absolute = path.canonicalize()?;
    let data = std::fs::read(absolute)?;
    Ok(Input::new(
        InputTarget::Path(path.to_path_buf()),
        data
    ))
}

/// Extracts the infohash of a magnet link
pub fn magnet_hash<T: AsRef<str>>(magnet: T) -> String {
    let magnet = MagnetLink::parse(magnet.as_ref()).expect("Parsing magnet failed");
    //Ok(magnet.name.expect("Magnet link has no name!"))
    //Ok(String::from_utf8_lossy(&magnet.infohash.inner.bytes).to_string())
    let bytes = magnet.infohash.inner.bytes.clone();
    let mut s = String::new();
    for byte in bytes {
        s.push_str(&format!("{:02x}", byte));
    }
    s
}

/// Extracts the name of a magnet link
pub fn magnet_name<T: AsRef<str>>(magnet: T) -> String {
    let magnet = MagnetLink::parse(magnet.as_ref()).expect("Parsing magnet failed");
    magnet.name.expect("Magnet link has no name!")
}

/// Extracts the infohash of a torrent file
pub fn torrent_hash<T: AsRef<Path>>(torrent: T) -> String {
    let input = input_path(torrent).unwrap();
    TorrentSummary::from_input(&input).expect("Parsing torrent file failed").torrent_summary_data().info_hash
}

/// Extracts the name of a torrent file
pub fn torrent_name<T: AsRef<Path>>(torrent: T) -> String {
    let input = input_path(torrent).unwrap();
    TorrentSummary::from_input(&input).expect("Parsing torrent file failed").torrent_summary_data().name
}

/// Turns a torrent file into a magnet link
pub fn torrent_to_magnet<T: AsRef<Path>>(torrent: T) -> String {
    let input = input_path(torrent).expect("Failed to read torrent file");
    let infohash = Infohash::from_input(&input).expect("Failed to parse infohash");
    let metainfo = Metainfo::from_input(&input).expect("Failed to parse meta info");

    let mut link = MagnetLink::with_infohash(infohash);

    link.set_name(&metainfo.info.name);

    for result in metainfo.trackers() {
      link.add_tracker(result.expect("failed tracker in metainfo"));
    }

    link.to_url().to_string()

}