use std::{
    env,
    error::Error,
    sync::{atomic, Arc},
};

mod args;

use clap::Parser;
use mqi::{
    prelude::*,
    connect_options::ApplName,
    core::values::MQSO,
    get::GetWait,
    mqstr,
    open_options::ObjectString,
    sys,
    types::MessageFormat,
    QueueManager, Subscription,
};
use tracing::Level;

#[derive(Parser, Debug)]
struct Args {
    #[command(flatten)]
    connection: args::ConnectionArgs,

    #[arg(short, long)]
    topic: Option<String>,
}

const APP_NAME: ApplName = ApplName(mqstr!("subscribe_managed"));

fn main() -> Result<(), Box<dyn Error>> {
    let subscriber = tracing_subscriber::fmt().compact().with_max_level(Level::TRACE).finish();
    tracing::subscriber::set_global_default(subscriber)?;

    let args = Args::parse();

    let topic_str = args.topic.or_else(|| env::var("TOPIC").ok());
    let topic = topic_str.as_deref().map(ObjectString);

    let client_definition = args.connection.client_definition()?;
    let qm_name = args.connection.queue_manager_name()?;
    let creds = args.connection.credentials();

    // Connect to the queue manager using the supplied optional arguments. Fail on any warning.
    let qm = QueueManager::connect((APP_NAME, qm_name, creds, client_definition)).warn_as_error()?;

    // Create a managed, non-durable subscription to the topic. Fail on any warning.
    // The subscription will persist until `_subscription` is descoped.
    let (_subscription, queue) =
        Subscription::subscribe_managed(&qm, (MQSO(sys::MQSO_CREATE | sys::MQSO_NON_DURABLE), topic)).warn_as_error()?;

    let mut buffer: [u8; 20 * 1024] = [0; 20 * 1024]; // 20kb

    // Interrupt handler to stop the MQGET loop
    let running = Arc::new(atomic::AtomicBool::new(true));
    let running_check = running.clone();
    ctrlc::set_handler(move || running.store(false, atomic::Ordering::Relaxed))?;

    while running_check.load(atomic::Ordering::Relaxed) {
        if let Some((data, _format)) = queue
            .get_data_with::<MessageFormat, _>(GetWait::Wait(500), buffer.as_mut_slice())
            .warn_as_error()?
        {
            println!("{data:?}");
            // TODO: demonstrate some simple message handling
        }
    }

    Ok(())
}