// Copyright 2019 Alexandros Frantzis
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.
//
// SPDX-License-Identifier: MPL-2.0
//! Email processing and filtering.
use std::io::Write;
use std::process::{Command, Output, Stdio};
use crate::{Email, Result};
impl Email {
/// Filters the contents of the email using an external command,
/// returning a new email with the filtered contents.
///
/// The command is expected to be provided as a `&str` array, with the
/// first element being the command name and the remaining elements the
/// command arguments.
///
/// # Example
///
/// ```no_run
/// use mda::Email;
/// let email = Email::from_stdin()?;
/// let email = email.filter(&["bogofilter", "-ep"])?;
/// # Ok::<(), Box<dyn std::error::Error>>(())
/// ```
pub fn filter(&self, cmd: &[&str]) -> Result<Email> {
Email::from_vec(self.process(cmd)?.stdout)
}
/// Process the contents of the email using an external command,
/// returning a `std::process::Output` for the executed command.
///
/// The command is expected to be provided as a `&str` array, with the
/// first element being the command name and the remaining elements the
/// command arguments.
///
/// # Example
///
/// ```no_run
/// use mda::Email;
/// let email = Email::from_stdin()?;
/// let output = email.process(&["bogofilter"])?;
/// if let Some(0) = output.status.code() {
/// email.deliver_to_maildir("/my/spam/path")?;
/// }
/// # Ok::<(), Box<dyn std::error::Error>>(())
/// ```
pub fn process(&self, cmd: &[&str]) -> Result<Output> {
let mut child =
Command::new(cmd[0])
.args(&cmd[1..])
.stdin(Stdio::piped())
.stdout(Stdio::piped())
.spawn()?;
child.stdin
.as_mut()
.ok_or("Failed to write to stdin")?
.write_all(&self.data)?;
Ok(child.wait_with_output()?)
}
/// Creates an `Email` by filtering the contents from stdin.
///
/// This can be more efficient than creating an `Email` from stdin and
/// filtering separately, since it can avoid an extra data copy.
///
/// The command is expected to be provided as a `&str` array, with the
/// first element being the command name and the remaining elements the
/// command arguments.
///
/// # Example
///
/// ```no_run
/// use mda::Email;
/// let email = Email::from_stdin_filtered(&["bogofilter", "-ep"])?;
/// # Ok::<(), Box<dyn std::error::Error>>(())
/// ```
pub fn from_stdin_filtered(cmd: &[&str]) -> Result<Self> {
let output =
Command::new(cmd[0])
.args(&cmd[1..])
.stdin(Stdio::inherit())
.output()?;
Email::from_vec(output.stdout)
}
}