extern crate walkdir;
use std::fs;
use std::env;
use std::io;
use std::string::ToString;
use std::process::Command;
use std::path::Path;
use walkdir::WalkDir;

fn parse_dir(dir: &Path) {
  let paths = WalkDir::new(dir);
  for path in paths {
    let file = path.unwrap().path().display().to_string(); //convert std::path to string
    if file.contains(".mp4") {
      let new_file = file.clone() + ".encoded";
      encode(&file, &new_file);
    }
  }
}

fn encode(file: &str, new_file: &str) {
  let encoding = Command::new("ffmpeg").arg("-i").arg(file).arg("-f").arg("mp4").arg(new_file).output().unwrap_or_else(|e| {
    panic!("failed to execute process: {}", e);
  });
  println!("{}", String::from_utf8_lossy(&encoding.stdout));
  let new_name = file.clone().to_string() + ".old";
  rename_files(file, &new_name);
  rename_files(new_file, file);
}

fn rename_files(file: &str, new_name: &str) -> io::Result<()> {
  try!(fs::rename(file, new_name));
  Ok(())
}

fn check_dir(dir: &Path) -> io::Result<()> {
  if try!(fs::metadata(dir)).is_dir() {
    parse_dir(dir);
  }
  Ok(())
}

fn main() {
  let args: Vec<String> = env::args().collect();
  if args.len() > 1 {
    let dir = Path::new(&args[1]);
    check_dir(dir);
  }
}