use std::error::Error;
use std::fmt;
use std::fs;
use std::os::unix::fs::MetadataExt;

use users::get_user_by_name;

use symbols::Symbol;
use symbols::dir::Dir;
use command_runner::CommandRunner;


pub struct DirFor<'a, D> where D: AsRef<str> + fmt::Display {
  dir: Dir<D>,
  path: D,
  user_name: &'a str,
  command_runner: &'a CommandRunner
}

impl<'a, D> DirFor<'a, D> where D: AsRef<str> + fmt::Display + Clone {
  pub fn new(path: D, user_name: &'a str, command_runner: &'a CommandRunner) -> Self {
    DirFor { dir: Dir::new(path.clone()), path: path, user_name: user_name, command_runner: command_runner }
  }
}

impl<'a, D> Symbol for DirFor<'a, D> where D: AsRef<str> + fmt::Display {
  fn target_reached(&self) -> Result<bool, Box<Error>> {
    match self.dir.target_reached() {
      Ok(true) => {
        let actual_uid = fs::metadata(self.path.as_ref()).unwrap().uid();
        let target_uid = get_user_by_name(self.user_name).unwrap().uid();
        Ok(actual_uid == target_uid)
      },
      res => res
    }
  }

  fn execute(&self) -> Result<(), Box<Error>> {
    try!(self.dir.execute());
    try!(self.command_runner.run_with_args("chown", &[self.user_name, self.path.as_ref()]));
    Ok(())
  }
}

impl<'a, D> fmt::Display for DirFor<'a, D> where D: AsRef<str> + fmt::Display {
  fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error>{
    write!(f, "Dir {} for {}", self.path, self.user_name)
  }
}