feat: q to quit and p to pause on CLI

Author: fraidev

Cargo.lock

@@ -20,3 +20,5 @@ console-subscriber = { workspace = true, optional = true }
 tracing.workspace = true
 tracing-subscriber.workspace = true
 flume.workspace = true
+crossterm = "0.27"
+tokio-util = "0.7"

crates/cli/Cargo.toml

@@ -1,17 +1,33 @@
+use crossterm::{
+    event::{self, Event, KeyCode, KeyModifiers},
+    terminal::{self},
+};
 use indicatif::{ProgressBar, ProgressState, ProgressStyle};
 use std::{
     collections::HashMap,
     fmt::Write,
     io::SeekFrom,
     sync::{atomic::AtomicU64, Arc},
+    time::Duration,
 };
 use tokio::{
     fs::{create_dir_all, File},
     io::{AsyncSeekExt, AsyncWriteExt},
+    signal,
 };
+use tokio_util::sync::CancellationToken;
 use tracing::trace;
 
-use bit_rev::{session::Session, utils};
+use bit_rev::{
+    session::{DownloadState, PieceResult, Session},
+    utils,
+};
+
+fn graceful_shutdown() {
+    let _ = terminal::disable_raw_mode();
+    println!("\n\nShutting down gracefully...");
+    std::process::exit(0);
+}
 
 #[tokio::main]
 async fn main() {
@@ -25,12 +41,14 @@ async fn main() {
     let output = std::env::args().nth(2);
 
     if let Err(err) = download_file(&filename, output).await {
+        let _ = terminal::disable_raw_mode();
         eprintln!("Error: {:?}", err);
     }
 }
 
 pub async fn download_file(filename: &str, out_file: Option<String>) -> anyhow::Result<()> {
-    let session = Session::new();
+    let session = Arc::new(Session::new());
+    let shutdown_token = CancellationToken::new();
 
     let add_torrent_result = session.add_torrent(filename.into()).await?;
     let torrent = add_torrent_result.torrent.clone();
@@ -85,56 +103,199 @@ pub async fn download_file(filename: &str, out_file: Option<String>) -> anyhow::
 
     let total_downloaded = Arc::new(AtomicU64::new(0));
     let total_downloaded_clone = total_downloaded.clone();
+    let session_clone = session.clone();
 
+    // Spawn progress update task
     tokio::spawn(async move {
         loop {
             let new = total_downloaded_clone.load(std::sync::atomic::Ordering::Relaxed);
             pb.set_position(new);
-            pb.set_message("Downloading");
+            let status = match session_clone.get_download_state() {
+                DownloadState::Init => "Initializing",
+                DownloadState::Downloading => "Downloading",
+                DownloadState::Paused => "Paused",
+            };
+            pb.set_message(status);
             tokio::time::sleep(std::time::Duration::from_millis(100)).await;
         }
     });
 
-    let mut hashset = std::collections::HashSet::new();
-    while hashset.len() < torrent.piece_hashes.len() {
-        let pr = add_torrent_result.pr_rx.recv_async().await?;
+    // Enable raw mode for single keypress detection
+    terminal::enable_raw_mode().expect("Failed to enable raw mode");
 
-        hashset.insert(pr.index);
+    // Set up Ctrl+C signal handler
+    let _shutdown_token_signal = shutdown_token.clone();
+    tokio::spawn(async move {
+        let mut sigint = signal::unix::signal(signal::unix::SignalKind::interrupt())
+            .expect("Failed to install SIGINT handler");
 
-        // Map piece to files and write data accordingly
-        let file_mappings = utils::map_piece_to_files(&torrent, pr.index as usize);
-        let mut piece_offset = 0;
+        sigint.recv().await;
+        graceful_shutdown();
+    });
 
-        for mapping in file_mappings {
-            let file = file_handles.get_mut(&mapping.file_index).ok_or_else(|| {
-                anyhow::anyhow!("File handle not found for index {}", mapping.file_index)
-            })?;
+    // Spawn keyboard input handler
+    // println!("Press 'p' to pause/resume, 'q' to quit (no Enter needed)");
+    let session_input = session.clone();
+    let shutdown_token_input = shutdown_token.clone();
+    tokio::spawn(async move {
+        loop {
+            // Check for cancellation
+            if shutdown_token_input.is_cancelled() {
+                break;
+            }
+
+            if event::poll(Duration::from_millis(100)).unwrap_or(false) {
+                if let Ok(Event::Key(key_event)) = event::read() {
+                    match key_event.code {
+                        KeyCode::Char('p') | KeyCode::Char('P') => {
+                            match session_input.get_download_state() {
+                                DownloadState::Paused => {
+                                    session_input.resume();
+                                }
+                                DownloadState::Downloading => {
+                                    session_input.pause();
+                                }
+                                DownloadState::Init => {
+                                    println!("\r\nCannot pause during initialization");
+                                }
+                            }
+                        }
+                        KeyCode::Char('q') | KeyCode::Char('Q') => {
+                            graceful_shutdown();
+                        }
+                        KeyCode::Char('c')
+                            if key_event.modifiers.contains(KeyModifiers::CONTROL) =>
+                        {
+                            graceful_shutdown();
+                        }
+                        _ => {}
+                    }
+                }
+            }
+            tokio::time::sleep(Duration::from_millis(50)).await;
+        }
+    });
 
-            // Seek to correct position in file
-            file.seek(SeekFrom::Start(mapping.file_offset as u64))
+    let mut hashset = std::collections::HashSet::new();
+    let mut pending_pieces: Vec<_> = Vec::new(); // Queue for pieces received while paused
+
+    while hashset.len() < torrent.piece_hashes.len() {
+        // Check for shutdown signal
+        if shutdown_token.is_cancelled() {
+            break;
+        }
+        // Process any pending pieces first if we're now downloading
+        if session.get_download_state() == DownloadState::Downloading && !pending_pieces.is_empty()
+        {
+            let pieces_to_process = std::mem::take(&mut pending_pieces);
+            for pr in pieces_to_process {
+                process_piece(
+                    &pr,
+                    &torrent,
+                    &mut file_handles,
+                    &mut hashset,
+                    &total_downloaded,
+                )
                 .await?;
+            }
+        }
 
-            // Write the portion of the piece that belongs to this file
-            let piece_data = &pr.buf[piece_offset..piece_offset + mapping.length];
-            file.write_all(piece_data).await?;
+        // Use a timeout to periodically check if we should process pending pieces
+        let pr_result = tokio::time::timeout(
+            Duration::from_millis(100),
+            add_torrent_result.pr_rx.recv_async(),
+        )
+        .await;
 
-            piece_offset += mapping.length;
+        match pr_result {
+            Ok(Ok(pr)) => {
+                // If paused, queue the piece but don't process it yet
+                if session.get_download_state() != DownloadState::Downloading {
+                    pending_pieces.push(pr);
+                    continue;
+                }
 
-            trace!(
-                "Wrote {} bytes to file {} at offset {}",
-                mapping.length,
-                mapping.file_index,
-                mapping.file_offset
-            );
+                // Process piece immediately if downloading
+                process_piece(
+                    &pr,
+                    &torrent,
+                    &mut file_handles,
+                    &mut hashset,
+                    &total_downloaded,
+                )
+                .await?;
+            }
+            Ok(Err(_)) => {
+                // Channel closed
+                break;
+            }
+            Err(_) => {
+                // Timeout - continue loop to check pending pieces
+                continue;
+            }
         }
+    }
 
-        total_downloaded.fetch_add(pr.length as u64, std::sync::atomic::Ordering::Relaxed);
+    // Process any remaining pending pieces at the end
+    for pr in pending_pieces {
+        process_piece(
+            &pr,
+            &torrent,
+            &mut file_handles,
+            &mut hashset,
+            &total_downloaded,
+        )
+        .await?;
     }
 
     // Sync all files
     for (_, file) in file_handles {
         file.sync_all().await?;
     }
 
+    // Restore terminal on completion
+    let _ = terminal::disable_raw_mode();
+    println!("\nDownload completed!");
+
     Ok(())
 }
+
+async fn process_piece(
+    pr: &PieceResult,
+    torrent: &bit_rev::torrent::Torrent,
+    file_handles: &mut HashMap<usize, File>,
+    hashset: &mut std::collections::HashSet<u32>,
+    total_downloaded: &Arc<AtomicU64>,
+) -> anyhow::Result<bool> {
+    hashset.insert(pr.index);
+
+    // Map piece to files and write data accordingly
+    let file_mappings = utils::map_piece_to_files(torrent, pr.index as usize);
+    let mut piece_offset = 0;
+
+    for mapping in file_mappings {
+        let file = file_handles.get_mut(&mapping.file_index).ok_or_else(|| {
+            anyhow::anyhow!("File handle not found for index {}", mapping.file_index)
+        })?;
+
+        // Seek to correct position in file
+        file.seek(SeekFrom::Start(mapping.file_offset as u64))
+            .await?;
+
+        // Write the portion of the piece that belongs to this file
+        let piece_data = &pr.buf[piece_offset..piece_offset + mapping.length];
+        file.write_all(piece_data).await?;
+
+        piece_offset += mapping.length;
+
+        trace!(
+            "Wrote {} bytes to file {} at offset {}",
+            mapping.length,
+            mapping.file_index,
+            mapping.file_offset
+        );
+    }
+
+    total_downloaded.fetch_add(pr.length as u64, std::sync::atomic::Ordering::Relaxed);
+    Ok(true)
+}