use std::process::Command;
use std::fs::symlink_metadata;
use std::path::PathBuf;
use dirs::home_dir;
use crate::config::Dot;
use symlink::{symlink_auto, remove_symlink_auto};


fn prepare_dots(dots: Vec<Dot>, dots_dir: PathBuf, no_hostname_check: bool) -> Vec<Dot> {
    let mut hostname = "*".to_string();
    if !no_hostname_check {
        // Deeply saddened there is no better way to do this :(
        let hostname_cmd = Command::new("hostname").output().expect("failed to get hostname: command \"hostname\" failed");
        let hostname_stdout = hostname_cmd.stdout;
        let mut new_hostname = String::from_utf8(hostname_stdout.clone()).expect("failed to get hostname: unknown hostname encoding");
        new_hostname.pop(); // stdout contains a newline
        hostname = new_hostname;
    }

    let prepared_dots = dots.iter().filter(|dot| if no_hostname_check { true } else { dot.host == "*" || dot.host == hostname }).map(|m|
        Dot {
            source: dots_dir.join(&m.source),
            destination: if m.destination.is_absolute() { m.destination.clone() } else { prepend_user_dir(&m.destination) },
            host: m.host.clone()
        }
    );

    prepared_dots.collect()
}

pub fn deploy_dots(dots: Vec<Dot>, dots_dir: PathBuf, no_hostname_check: bool) {
   for dot in prepare_dots(dots, dots_dir, no_hostname_check) {
        println!("linking from {} to {}", dot.source.display(), dot.destination.display());
        let _ = symlink_auto(&dot.source, &dot.destination).map_err(|err|
            eprintln!("failed to symlink: {}", err.to_string())
        );
    }
}

pub fn unlink_dots(dots: Vec<Dot>, dots_dir: PathBuf, no_hostname_check: bool) {
    for dot in prepare_dots(dots, dots_dir, no_hostname_check) {
       println!("unlinking  {}", dot.destination.display());
        let metadata = symlink_metadata(dot.destination.clone());
        if metadata.is_err() {
            eprintln!("failed to query metadata for {}: {}", dot.destination.display(), metadata.err().unwrap());
            continue
        }
        if metadata.ok().unwrap().is_symlink() {
            let _ = remove_symlink_auto(dot.destination).map_err(|err|
                eprintln!("failed to remove symlink: {}", err)
            );
        }
    }
}

fn prepend_user_dir(path: &PathBuf) -> PathBuf {
    home_dir().unwrap().join(path)
}