From c65ba48e1031e1450bc399122886b06c559a77bf Mon Sep 17 00:00:00 2001
From: Nils Andreas Svee <me@lochnair.net>
Date: Tue, 28 Apr 2026 23:06:33 +0700
Subject: [PATCH] feat(cli): implement main execution loop and network I/O
 logic

---
 crates/irtt-cli/src/main.rs | 118 +++++++++++++++++++++++++++++++++++-
 1 file changed, 117 insertions(+), 1 deletion(-)

diff --git a/crates/irtt-cli/src/main.rs b/crates/irtt-cli/src/main.rs
index f328e4d..73b0c35 100644
--- a/crates/irtt-cli/src/main.rs
+++ b/crates/irtt-cli/src/main.rs
@@ -1 +1,117 @@
-fn main() {}
+use std::{
+    io::{self, Write},
+    process::ExitCode,
+    thread,
+    time::{Duration, Instant},
+};
+
+use clap::Parser;
+use irtt_cli::{format_event, CliArgs};
+use irtt_client::{Client, ClientEvent, ClientTimestamp, OpenOutcome, RecvBudget};
+
+const RECV_BUDGET: RecvBudget = RecvBudget { max_packets: 16 };
+const FINAL_DRAIN: Duration = Duration::from_millis(100);
+const MAX_SLEEP: Duration = Duration::from_millis(20);
+
+fn main() -> ExitCode {
+    let args = CliArgs::parse();
+    match run(args) {
+        Ok(()) => ExitCode::SUCCESS,
+        Err(err) => {
+            eprintln!("irtt-rs: {err}");
+            ExitCode::FAILURE
+        }
+    }
+}
+
+fn run(args: CliArgs) -> Result<(), Box<dyn std::error::Error>> {
+    let mode = args.output;
+    let mut stdout = io::BufWriter::new(io::stdout().lock());
+    let mut client = Client::connect(args.to_client_config())?;
+
+    let open = client.open(ClientTimestamp::now())?;
+    print_event(open_event(&open), mode, &mut stdout)?;
+
+    while let Some(deadline) = client.next_send_deadline() {
+        let now = Instant::now();
+        if deadline <= now {
+            let events = client.send_probe()?;
+            print_events(&events, mode, &mut stdout)?;
+        }
+
+        let events = client.recv_available(RECV_BUDGET)?;
+        print_events(&events, mode, &mut stdout)?;
+
+        let events = client.poll_timeouts(ClientTimestamp::now())?;
+        print_events(&events, mode, &mut stdout)?;
+
+        sleep_until_next_send(client.next_send_deadline());
+    }
+
+    drain_final_replies(&mut client, mode, &mut stdout)?;
+
+    let events = client.poll_timeouts(ClientTimestamp::now())?;
+    print_events(&events, mode, &mut stdout)?;
+
+    let events = client.close(ClientTimestamp::now())?;
+    print_events(&events, mode, &mut stdout)?;
+    stdout.flush()?;
+    Ok(())
+}
+
+fn open_event(outcome: &OpenOutcome) -> &ClientEvent {
+    match outcome {
+        OpenOutcome::Started { event, .. } | OpenOutcome::NoTestCompleted { event, .. } => event,
+    }
+}
+
+fn drain_final_replies<W: Write>(
+    client: &mut Client,
+    mode: irtt_cli::OutputMode,
+    out: &mut W,
+) -> Result<(), Box<dyn std::error::Error>> {
+    let deadline = Instant::now() + FINAL_DRAIN;
+    while Instant::now() < deadline {
+        let events = client.recv_available(RECV_BUDGET)?;
+        if events.is_empty() {
+            thread::sleep(Duration::from_millis(5));
+        } else {
+            print_events(&events, mode, out)?;
+        }
+    }
+    Ok(())
+}
+
+fn sleep_until_next_send(deadline: Option<Instant>) {
+    let sleep_for = match deadline {
+        Some(deadline) => deadline
+            .saturating_duration_since(Instant::now())
+            .min(MAX_SLEEP),
+        None => Duration::from_millis(1),
+    };
+    if !sleep_for.is_zero() {
+        thread::sleep(sleep_for);
+    }
+}
+
+fn print_events<W: Write>(
+    events: &[ClientEvent],
+    mode: irtt_cli::OutputMode,
+    out: &mut W,
+) -> io::Result<()> {
+    for event in events {
+        print_event(event, mode, out)?;
+    }
+    Ok(())
+}
+
+fn print_event<W: Write>(
+    event: &ClientEvent,
+    mode: irtt_cli::OutputMode,
+    out: &mut W,
+) -> io::Result<()> {
+    if let Some(line) = format_event(event, mode) {
+        writeln!(out, "{line}")?;
+    }
+    Ok(())
+}