use ariadne::Fmt;
use yansi::Color;

use crate::{
  libsh::error::{ShErr, ShErrKind, ShResult, next_color},
  parse::{NdRule, Node, execute::prepare_argv},
  prelude::*,
  state::{self},
};

pub fn cd(node: Node) -> ShResult<()> {
  let span = node.get_span();
  let NdRule::Command {
    assignments: _,
    argv,
  } = node.class
  else {
    unreachable!()
  };
  let cd_span = argv.first().unwrap().span.clone();

  let mut argv = prepare_argv(argv)?;
  if !argv.is_empty() {
    argv.remove(0);
  }

  let (new_dir, arg_span) = if let Some((arg, span)) = argv.into_iter().next() {
    (PathBuf::from(arg), Some(span))
  } else {
    (PathBuf::from(env::var("HOME").unwrap()), None)
  };

  if !new_dir.exists() {
    let mut err = ShErr::new(ShErrKind::ExecFail, span.clone())
      .labeled(cd_span.clone(), "Failed to change directory");
    if let Some(span) = arg_span {
      err = err.labeled(
        span,
        format!(
          "No such file or directory '{}'",
          new_dir.display().fg(next_color())
        ),
      );
    }
    return Err(err);
  }

  if !new_dir.is_dir() {
    return Err(ShErr::new(ShErrKind::ExecFail, span.clone()).labeled(
      cd_span.clone(),
      format!(
        "cd: Not a directory '{}'",
        new_dir.display().fg(next_color())
      ),
    ));
  }

  if let Err(e) = state::change_dir(new_dir) {
    return Err(ShErr::new(ShErrKind::ExecFail, span.clone()).labeled(
      cd_span.clone(),
      format!("cd: Failed to change directory: '{}'", e.fg(Color::Red)),
    ));
  }
  let new_dir = env::current_dir().map_err(|e| {
    ShErr::new(ShErrKind::ExecFail, span.clone()).labeled(
      cd_span.clone(),
      format!(
        "cd: Failed to get current directory: '{}'",
        e.fg(Color::Red)
      ),
    )
  })?;
  unsafe { env::set_var("PWD", new_dir) };

  state::set_status(0);
  Ok(())
}