mail4agent-messenger-shell 0.4.6

//! `m4a-send --as <nick> --to <nick> <text...>`: a bot answers through its
//! own messenger session.
//!
//! `--as` is the sending bot's own nick (the `to` of the wake it got),
//! `--to` the recipient nick (the wake's `from_nick`). The text is the
//! remaining arguments joined by spaces, or stdin when it is `-` or
//! missing. The running `m4a-web-client` sends it from the `--as` session
//! (encrypted DM, configured homeserver); with no client running this
//! process opens that one session itself. Settings come from the
//! environment and the env file (`M4A_ENV_FILE`, default
//! `~/.config/mail4agent/web-client.env`). Arguments carry no secrets and
//! the output is the room id and event id only.

use crate::{
    load_env_file, send_sock_path, send_via_socket, MachineClient, SendReply, SendRequest,
    MAX_SEND_BYTES, STORE_ROOT_ENV,
};
use std::io::Read;
use std::path::PathBuf;
use std::time::Duration;

const USAGE: &str =
    "usage: m4a-send --as <your nick> --to <nick> <text...>   (text '-' or none: read stdin)";

fn fail(code: i32, message: &str) -> ! {
    eprintln!("m4a-send: {message}");
    std::process::exit(code);
}

pub fn run(args: Vec<String>) {
    let mut as_nick = None;
    let mut to = None;
    let mut words: Vec<String> = Vec::new();
    let mut args = args.clone().into_iter();
    while let Some(arg) = args.next() {
        match arg.as_str() {
            "--as" => as_nick = args.next(),
            "--to" => to = args.next(),
            "-h" | "--help" => {
                println!("{USAGE}");
                return;
            }
            "--" => words.extend(args.by_ref()),
            _ => words.push(arg),
        }
    }
    let (Some(as_nick), Some(to)) = (as_nick, to) else {
        fail(2, USAGE);
    };
    let text = if words.is_empty() || words == ["-"] {
        let mut text = String::new();
        if std::io::stdin().read_to_string(&mut text).is_err() {
            fail(2, "stdin is not text");
        }
        text.trim_end_matches('\n').to_string()
    } else {
        words.join(" ")
    };
    if text.trim().is_empty() {
        fail(2, "text is empty");
    }
    if text.len() > MAX_SEND_BYTES {
        fail(2, &format!("text is longer than {MAX_SEND_BYTES} bytes"));
    }
    load_env_file();
    let get = |key: &str| std::env::var(key).ok().filter(|value| !value.is_empty());
    let Some(store_root) = get(STORE_ROOT_ENV).map(PathBuf::from) else {
        fail(1, "M4A_STORE_ROOT is not set (environment or env file)");
    };
    let request = SendRequest {
        as_nick: as_nick.clone(),
        to: to.clone(),
        text: text.clone(),
    };
    let sock = send_sock_path(get, &store_root);
    let reply = match send_via_socket(&sock, &request, Duration::from_secs(180)) {
        Ok(reply) => reply,
        Err(_) => {
            // No client answered: open the one session here.
            let mut client = match MachineClient::from_env_for(&as_nick) {
                Ok(client) => client,
                Err(err) => fail(
                    1,
                    &format!("no running client and opening {as_nick} failed: {err}"),
                ),
            };
            client.send_blocking(&as_nick, &to, &text, Duration::from_secs(120))
        }
    };
    print_reply(&reply);
}

fn print_reply(reply: &SendReply) {
    if reply.ok {
        println!(
            "sent room={} event={}",
            reply.room.as_deref().unwrap_or(""),
            reply.event_id.as_deref().unwrap_or("")
        );
    } else {
        fail(1, reply.error.as_deref().unwrap_or("send failed"));
    }
}