use std::borrow::Cow;
use std::error::Error;
use std::fmt;
use std::fs::File as FsFile;
use std::io::Write;
use std::path::Path;

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

pub struct AcmeCertChain<'a, C: 'a + CommandRunner> {
  domain: Cow<'a, str>,
  command_runner: &'a C
}

impl<'a, C: CommandRunner> AcmeCertChain<'a, C> {
  pub fn new(domain: Cow<'a, str>, command_runner: &'a C) -> Self {
    AcmeCertChain { domain, command_runner }
  }

  fn get_single_cert_path(&self) -> String {
    format!("/etc/ssl/local_certs/{}.crt", self.domain)
  }

  fn get_cert_chain_path(&self) -> String {
    format!("/etc/ssl/local_certs/{}.chained.crt", self.domain)
  }
}

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

const DAYS_IN_SECONDS: u32 = 24*60*60;

impl<'a, C: CommandRunner> Symbol for AcmeCertChain<'a, C> {
  fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
    if !Path::new(&self.get_cert_chain_path()).exists() {
      return Ok(false);
    }

    let stdout = try!(self.command_runner.get_output("openssl", &["x509", "-in", &self.get_cert_chain_path(), "-noout", "-subject", "-checkend", &(30*DAYS_IN_SECONDS).to_string()]));
    if stdout != format!("subject=CN = {}\nCertificate will not expire\n", self.domain).as_bytes() {
      return Ok(false);
    }
    // FIXME: From my understanding, the -untrusted *.pem parameter shouldn't be necessary, but is necessary with openssl 1.1.0f-3
    Ok(self.command_runner.run_successfully("openssl", &["verify", "-untrusted", "/home/acme/lets_encrypt_x3_cross_signed.pem", &self.get_cert_chain_path()]).is_ok())
  }

  fn execute(&self) -> Result<(), Box<dyn Error>> {
    let output = try!(self.command_runner.get_output("cat", &[self.get_single_cert_path().as_ref(), "/home/acme/lets_encrypt_x3_cross_signed.pem"]));
    let mut file = try!(FsFile::create(self.get_cert_chain_path()));
    try!(file.write_all(&output));
    Ok(())
  }

  fn get_prerequisites(&self) -> Vec<Resource> {
    vec![ Resource::new("file", self.get_single_cert_path()) ]
  }

  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 {
}