use std::env;
use std::io::{Cursor, Seek, Read};
use std::path::{Components, Path, PathBuf};
use flate2::read::GzDecoder;
use tar::Archive;


use crate::system_dirs::get_local_data_directory;
use crate::ftp::{self, ftp_get_size};
use crate::util;

fn check_java(version: u8) -> bool {
    let dir = get_local_data_directory().join("java").join(format!("java-{}-{}", version, if env::consts::OS == "windows" { "win" } else {"lin"}));
    dir.exists()
}

pub fn install_java(version: u8) {
    if check_java(version) {
        return;
    }
    let ftp_dir = PathBuf::new().join("java").join(format!("java-{}-{}", version, if env::consts::OS == "windows" { "win.zip" } else {"lin.tar.gz"}));
    let mut buff = Cursor::new(vec![]);
    let mut total: usize = 0;
    let size = ftp_get_size(ftp_dir.clone()).unwrap();
    ftp::ftp_retr(ftp_dir, &mut buff, |data| util::download_callback(data, &mut total, size)).unwrap();

    std::fs::create_dir_all(get_local_data_directory().join("java").join(format!("java-{}-{}", version, if env::consts::OS == "windows" { "win" } else {"lin"}))).unwrap();
    buff.rewind().unwrap();
    if env::consts::OS != "windows" {
        let tar = GzDecoder::new(buff);
        let mut archive = Archive::new(tar);
        if !unpack_archive(archive, get_local_data_directory().join("java").join(format!("java-{}-lin", version))).is_ok() {
            std::fs::remove_dir_all(get_local_data_directory().join("java").join(format!("java-{}-lin", version))).unwrap();
        }
    } else {
        if !zip_extract::extract(buff, get_local_data_directory().join("java").join(format!("java-{}-win", version)).as_path(), true).is_ok() {
            std::fs::remove_dir_all(get_local_data_directory().join("java").join(format!("java-{}-win", version))).unwrap();
        }
    }

}

fn unpack_archive<T: Read>(mut archive: Archive<T>, dst: PathBuf) -> Result<(), Box<dyn std::error::Error>> {
    for file in archive.entries()? {
        let path = PathBuf::new().join(dst.clone());
        let mut file = file?;
        let file_path = file.path()?;
        let mut file_path = file_path.components();
        let _ = file_path.next();
        let file_path = file_path.as_path();
        file.unpack(path.join(file_path))?;
    }
    Ok(())
}