use std::error::Error;
use std::fmt;
use std::io;

use command_runner::CommandRunner;
use symbols::Symbol;

pub struct GitSubmodules<'a> {
  target: &'a str,
  command_runner: &'a CommandRunner
}

impl<'a> GitSubmodules<'a> {
  pub fn new(target: &'a str, command_runner: &'a CommandRunner) -> GitSubmodules<'a> {
    GitSubmodules {
      target: target,
      command_runner: command_runner
    }
  }
}

impl<'a> fmt::Display for GitSubmodules<'a> {
  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
    write!(f, "Submodules for {}", self.target)
  }
}

impl<'a> GitSubmodules<'a> {
  fn _run_in_target_repo(&self, args: &[&str]) -> Result<Vec<u8>, io::Error> {
    let mut new_args = vec!["-C", self.target];
    new_args.extend_from_slice(args);
    self.command_runner.run_with_args("git", &new_args).map(|res| res.stdout)
  }
}

impl<'a> Symbol for GitSubmodules<'a> {
  fn target_reached(&self) -> Result<bool, Box<Error>> {
    let output = try!(self._run_in_target_repo(&["submodule", "status"]));
    Ok(String::from_utf8(output).unwrap().lines().all(|line| line.len() == 0 || line.starts_with(' ')))
  }

  fn execute(&self) -> Result<(), Box<Error>> {
    try!(self._run_in_target_repo(&["submodule", "update", "--init"]));
    Ok(())
  }
}

#[cfg(test)]
mod test {
}