use std::borrow::Cow;
use std::error::Error;
use std::fmt;
use std::path::Path;

use command_runner::CommandRunner;
use resources::Resource;
use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};

pub struct AcmeAccountKey<'a, C: 'a + CommandRunner> {
  path: Cow<'a, Path>,
  command_runner: &'a C,
}

impl<'a, C: CommandRunner> AcmeAccountKey<'a, C> {
  pub fn new(path: Cow<'a, Path>, command_runner: &'a C) -> Self {
    AcmeAccountKey {
      path,
      command_runner,
    }
  }

  fn get_bytes(&self) -> u32 {
    4096
  }
}

impl<'a, C: CommandRunner> fmt::Display for AcmeAccountKey<'a, C> {
  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
    write!(f, "AcmeAccountKey {}", self.path.display())
  }
}

impl<'a, C: CommandRunner> Symbol for AcmeAccountKey<'a, C> {
  fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
    if !self.path.exists() {
      return Ok(false);
    }
    let stdout = try!(self.command_runner.get_output(
      "openssl",
      &[
        "rsa".as_ref(),
        "-in".as_ref(),
        self.path.as_os_str(),
        "-noout".as_ref(),
        "-check".as_ref(),
        "-text".as_ref()
      ]
    ));
    Ok(stdout.starts_with(&format!("Private-Key: ({} bit)\n", self.get_bytes()).as_bytes()))
  }

  fn execute(&self) -> Result<(), Box<dyn Error>> {
    self.command_runner.run_successfully(
      "openssl",
      &[
        "genrsa".as_ref(),
        "-out".as_ref(),
        self.path.as_os_str(),
        self.get_bytes().to_string().as_ref(),
      ],
    )
  }

  fn get_prerequisites(&self) -> Vec<Resource> {
    vec![Resource::new(
      "dir",
      self.path.parent().unwrap().to_string_lossy(),
    )]
  }

  fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
    Box::new(SymbolAction::new(runner, self))
  }

  fn into_action<'b>(self: Box<Self>, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b>
  where
    Self: 'b,
  {
    Box::new(OwnedSymbolAction::new(runner, *self))
  }
}

#[cfg(test)]
mod test {}