use std::error::Error;
use std::fmt;
use std::fs::File as FsFile;
use std::io::Write;
use std::path::{Path, PathBuf};

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

pub struct AcmeCertChain<'a, D: AsRef<str>, R: AsRef<Path>, C: CommandRunner> {
  domain: D,
  command_runner: &'a C,
  root_cert: R,
}

impl<'a, D: AsRef<str>, R: AsRef<Path>, C: CommandRunner> AcmeCertChain<'a, D, R, C> {
  pub fn new(domain: D, command_runner: &'a C, root_cert: R) -> Self {
    AcmeCertChain {
      domain,
      command_runner,
      root_cert,
    }
  }

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

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

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

const DAYS_IN_SECONDS: u32 = 24 * 60 * 60;

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

    let stdout = self.command_runner.get_output(
      "openssl",
      args![
        "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_ref()
      )
      .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",
          args![
            "verify",
            "-untrusted",
            self.root_cert.as_ref(),
            self.get_cert_chain_path(),
          ],
        )
        .is_ok(),
    )
  }

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

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

  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 {}