use super::*;

use std::process::{ExitStatus, Stdio};

/// Return a `Error::Signal` if the process was terminated by a signal,
/// otherwise return an `Error::UnknownFailure`
fn error_from_signal(recipe: &str, line_number: Option<usize>, exit_status: ExitStatus) -> Error {
  match Platform::signal_from_exit_status(exit_status) {
    Some(signal) => Error::Signal {
      recipe,
      line_number,
      signal,
    },
    None => Error::Unknown {
      recipe,
      line_number,
    },
  }
}

/// A recipe, e.g. `foo: bar baz`
#[derive(PartialEq, Debug, Clone, Serialize)]
pub(crate) struct Recipe<'src, D = Dependency<'src>> {
  pub(crate) attributes: BTreeSet<Attribute>,
  pub(crate) body: Vec<Line<'src>>,
  pub(crate) dependencies: Vec<D>,
  pub(crate) doc: Option<&'src str>,
  pub(crate) name: Name<'src>,
  pub(crate) parameters: Vec<Parameter<'src>>,
  pub(crate) priors: usize,
  pub(crate) private: bool,
  pub(crate) quiet: bool,
  pub(crate) shebang: bool,
}

impl<'src, D> Recipe<'src, D> {
  pub(crate) fn argument_range(&self) -> RangeInclusive<usize> {
    self.min_arguments()..=self.max_arguments()
  }

  pub(crate) fn min_arguments(&self) -> usize {
    self
      .parameters
      .iter()
      .filter(|p| p.default.is_none() && p.kind != ParameterKind::Star)
      .count()
  }

  pub(crate) fn max_arguments(&self) -> usize {
    if self.parameters.iter().any(|p| p.kind.is_variadic()) {
      usize::max_value() - 1
    } else {
      self.parameters.len()
    }
  }

  pub(crate) fn name(&self) -> &'src str {
    self.name.lexeme()
  }

  pub(crate) fn line_number(&self) -> usize {
    self.name.line
  }

  pub(crate) fn public(&self) -> bool {
    !self.private
  }

  pub(crate) fn enabled(&self) -> bool {
    let windows = self.attributes.contains(&Attribute::Windows);
    let linux = self.attributes.contains(&Attribute::Linux);
    let macos = self.attributes.contains(&Attribute::Macos);
    let unix = self.attributes.contains(&Attribute::Unix);

    (!windows && !linux && !macos && !unix)
      || (cfg!(target_os = "windows") && windows)
      || (cfg!(target_os = "linux") && (linux || unix))
      || (cfg!(target_os = "macos") && (macos || unix))
      || (cfg!(windows) && windows)
      || (cfg!(unix) && unix)
  }

  fn print_exit_message(&self) -> bool {
    !self.attributes.contains(&Attribute::NoExitMessage)
  }

  pub(crate) fn run<'run>(
    &self,
    context: &RecipeContext<'src, 'run>,
    dotenv: &BTreeMap<String, String>,
    scope: Scope<'src, 'run>,
    search: &'run Search,
    positional: &[String],
  ) -> RunResult<'src, ()> {
    let config = &context.config;

    if config.verbosity.loquacious() {
      let color = config.color.stderr().banner();
      eprintln!(
        "{}===> Running recipe `{}`...{}",
        color.prefix(),
        self.name,
        color.suffix()
      );
    }

    let evaluator =
      Evaluator::recipe_evaluator(context.config, dotenv, &scope, context.settings, search);

    if self.shebang {
      self.run_shebang(context, dotenv, &scope, positional, config, evaluator)
    } else {
      self.run_linewise(context, dotenv, &scope, positional, config, evaluator)
    }
  }

  fn run_linewise<'run>(
    &self,
    context: &RecipeContext<'src, 'run>,
    dotenv: &BTreeMap<String, String>,
    scope: &Scope<'src, 'run>,
    positional: &[String],
    config: &Config,
    mut evaluator: Evaluator<'src, 'run>,
  ) -> RunResult<'src, ()> {
    let mut lines = self.body.iter().peekable();
    let mut line_number = self.line_number() + 1;
    loop {
      if lines.peek().is_none() {
        return Ok(());
      }
      let mut evaluated = String::new();
      let mut continued = false;
      let quiet_command = lines.peek().map_or(false, |line| line.is_quiet());
      let infallible_command = lines.peek().map_or(false, |line| line.is_infallible());

      let comment_line =
        context.settings.ignore_comments && lines.peek().map_or(false, |line| line.is_comment());

      loop {
        if lines.peek().is_none() {
          break;
        }
        let line = lines.next().unwrap();
        line_number += 1;
        if !comment_line {
          evaluated += &evaluator.evaluate_line(line, continued)?;
        }
        if line.is_continuation() && !comment_line {
          continued = true;
          evaluated.pop();
        } else {
          break;
        }
      }

      if comment_line {
        continue;
      }

      let mut command = evaluated.as_str();

      if quiet_command {
        command = &command[1..];
      }

      if infallible_command {
        command = &command[1..];
      }

      if command.is_empty() {
        continue;
      }

      if config.dry_run
        || config.verbosity.loquacious()
        || !((quiet_command ^ self.quiet) || config.verbosity.quiet())
      {
        let color = if config.highlight {
          config.color.command()
        } else {
          config.color
        };
        eprintln!("{}", color.stderr().paint(command));
      }

      if config.dry_run {
        continue;
      }

      let mut cmd = context.settings.shell_command(config);

      cmd.current_dir(&context.search.working_directory);

      cmd.arg(command);

      if context.settings.positional_arguments {
        cmd.arg(self.name.lexeme());
        cmd.args(positional);
      }

      if config.verbosity.quiet() {
        cmd.stderr(Stdio::null());
        cmd.stdout(Stdio::null());
      }

      cmd.export(context.settings, dotenv, scope);

      match InterruptHandler::guard(|| cmd.status()) {
        Ok(exit_status) => {
          if let Some(code) = exit_status.code() {
            if code != 0 && !infallible_command {
              return Err(Error::Code {
                recipe: self.name(),
                line_number: Some(line_number),
                code,
                print_message: self.print_exit_message(),
              });
            }
          } else {
            return Err(error_from_signal(
              self.name(),
              Some(line_number),
              exit_status,
            ));
          }
        }
        Err(io_error) => {
          return Err(Error::Io {
            recipe: self.name(),
            io_error,
          });
        }
      };
    }
  }

  pub(crate) fn run_shebang<'run>(
    &self,
    context: &RecipeContext<'src, 'run>,
    dotenv: &BTreeMap<String, String>,
    scope: &Scope<'src, 'run>,
    positional: &[String],
    config: &Config,
    mut evaluator: Evaluator<'src, 'run>,
  ) -> RunResult<'src, ()> {
    let mut evaluated_lines = vec![];
    for line in &self.body {
      evaluated_lines.push(evaluator.evaluate_line(line, false)?);
    }

    if config.verbosity.loud() && (config.dry_run || self.quiet) {
      for line in &evaluated_lines {
        eprintln!("{}", line);
      }
    }

    if config.dry_run {
      return Ok(());
    }

    let shebang_line = evaluated_lines.first().ok_or_else(|| Error::Internal {
      message: "evaluated_lines was empty".to_owned(),
    })?;

    let shebang = Shebang::new(shebang_line).ok_or_else(|| Error::Internal {
      message: format!("bad shebang line: {}", shebang_line),
    })?;

    let mut tempdir_builder = tempfile::Builder::new();
    tempdir_builder.prefix("just");
    let tempdir = match &context.settings.tempdir {
      Some(tempdir) => tempdir_builder.tempdir_in(context.search.working_directory.join(tempdir)),
      None => tempdir_builder.tempdir(),
    }
    .map_err(|error| Error::TmpdirIo {
      recipe: self.name(),
      io_error: error,
    })?;
    let mut path = tempdir.path().to_path_buf();
    path.push(shebang.script_filename(self.name()));

    {
      let mut f = fs::File::create(&path).map_err(|error| Error::TmpdirIo {
        recipe: self.name(),
        io_error: error,
      })?;
      let mut text = String::new();

      if shebang.include_shebang_line() {
        text += &evaluated_lines[0];
      } else {
        text += "\n";
      }

      text += "\n";
      // add blank lines so that lines in the generated script have the same line
      // number as the corresponding lines in the justfile
      for _ in 1..(self.line_number() + 2) {
        text += "\n";
      }
      for line in &evaluated_lines[1..] {
        text += line;
        text += "\n";
      }

      if config.verbosity.grandiloquent() {
        eprintln!("{}", config.color.doc().stderr().paint(&text));
      }

      f.write_all(text.as_bytes())
        .map_err(|error| Error::TmpdirIo {
          recipe: self.name(),
          io_error: error,
        })?;
    }

    // make the script executable
    Platform::set_execute_permission(&path).map_err(|error| Error::TmpdirIo {
      recipe: self.name(),
      io_error: error,
    })?;

    // create a command to run the script
    let mut command =
      Platform::make_shebang_command(&path, &context.search.working_directory, shebang).map_err(
        |output_error| Error::Cygpath {
          recipe: self.name(),
          output_error,
        },
      )?;

    if context.settings.positional_arguments {
      command.args(positional);
    }

    command.export(context.settings, dotenv, scope);

    // run it!
    match InterruptHandler::guard(|| command.status()) {
      Ok(exit_status) => exit_status.code().map_or_else(
        || Err(error_from_signal(self.name(), None, exit_status)),
        |code| {
          if code == 0 {
            Ok(())
          } else {
            Err(Error::Code {
              recipe: self.name(),
              line_number: None,
              code,
              print_message: self.print_exit_message(),
            })
          }
        },
      ),
      Err(io_error) => Err(Error::Shebang {
        recipe: self.name(),
        command: shebang.interpreter.to_owned(),
        argument: shebang.argument.map(String::from),
        io_error,
      }),
    }
  }
}

impl<'src, D: Display> ColorDisplay for Recipe<'src, D> {
  fn fmt(&self, f: &mut Formatter, color: Color) -> Result<(), fmt::Error> {
    if let Some(doc) = self.doc {
      writeln!(f, "# {}", doc)?;
    }

    for attribute in &self.attributes {
      writeln!(f, "[{}]", attribute.to_str())?;
    }

    if self.quiet {
      write!(f, "@{}", self.name)?;
    } else {
      write!(f, "{}", self.name)?;
    }

    for parameter in &self.parameters {
      write!(f, " {}", parameter.color_display(color))?;
    }
    write!(f, ":")?;

    for (i, dependency) in self.dependencies.iter().enumerate() {
      if i == self.priors {
        write!(f, " &&")?;
      }

      write!(f, " {}", dependency)?;
    }

    for (i, line) in self.body.iter().enumerate() {
      if i == 0 {
        writeln!(f)?;
      }
      for (j, fragment) in line.fragments.iter().enumerate() {
        if j == 0 {
          write!(f, "    ")?;
        }
        match fragment {
          Fragment::Text { token } => write!(f, "{}", token.lexeme())?,
          Fragment::Interpolation { expression, .. } => write!(f, "{{{{ {} }}}}", expression)?,
        }
      }
      if i + 1 < self.body.len() {
        writeln!(f)?;
      }
    }
    Ok(())
  }
}

impl<'src, D> Keyed<'src> for Recipe<'src, D> {
  fn key(&self) -> &'src str {
    self.name.lexeme()
  }
}
