Implement REPL command to add current item to a m3u8 playlist

Cargo.lock

@@ -1161,6 +1161,7 @@ dependencies = [
  "clap 3.2.25",
  "console",
  "lazy_static 1.4.0",
+ "m3u8-rs",
  "muss-interpreter",
  "muss-player",
 ]

Cargo.toml

@@ -25,6 +25,9 @@ clap = { version = "3.0", features = ["derive"] }
 console = { version = "0.15" }
 lazy_static = { version = "1.4" }
 
+# cli add to playlist functionality
+m3u8-rs = { version = "^3.0.0" }
+
 [target.'cfg(not(target_os = "linux"))'.dependencies]
 muss-player = { version = "0.9.0", path = "./player", default-features = false, features = ["mpd"] }
 

src/help.rs

@@ -196,5 +196,8 @@ REPL-specific operations to help with writing Muss scripts: ?command
  pause
     Immediate song control actions to apply to the current item.
 
+ volume number
+    Set playback volume to number, in percent (starts at 100% when the cli parameter is not used).
+
  verbose
     Toggle verbose messages, like extra information on items in ?list and other goodies.";

src/main.rs

@@ -57,6 +57,7 @@ mod channel_io;
 mod cli;
 mod debug_state;
 mod help;
+mod playlists;
 mod repl;
 
 use std::io;

src/playlists.rs

@@ -0,0 +1,89 @@
+use std::io::Write;
+use std::path::Path;
+
+use m3u8_rs::{MediaSegment, MediaPlaylist};
+
+use muss_interpreter::Item;
+
+use crate::repl::{TERMINAL_WRITE_ERROR, ReplState};
+
+/// Add the currently-playing item to a m3u8 playlist, printing any error to the terminal
+pub fn add_to_playlist_cmd(cmd_args: &[&str], state: &mut ReplState) {
+    if let Some(&file_arg) = cmd_args.get(1) {
+        let mut playlist = match open_media_playlist(file_arg) {
+            Ok(playlist) => playlist,
+            Err(e) => {
+                writeln!(state.terminal, "Failed to open playlist {}: {}", file_arg, e).expect(TERMINAL_WRITE_ERROR);
+                return;
+            }
+        };
+        let current_item = match get_current_item(state) {
+            Some(item) => item,
+            None => {
+                writeln!(state.terminal, "Nothing playing").expect(TERMINAL_WRITE_ERROR);
+                return;
+            }
+        };
+        match item_to_media_segment(&current_item) {
+            Some(segment) => playlist.segments.push(segment),
+            None => {
+                writeln!(state.terminal, "Failed to convert item into playlist media segment").expect(TERMINAL_WRITE_ERROR);
+                return;
+            }
+        }
+        match save_media_playlist(file_arg, playlist) {
+            Ok(_) => {},
+            Err(e) => {
+                writeln!(state.terminal, "Failed to save playlist {}: {}", file_arg, e).expect(TERMINAL_WRITE_ERROR);
+                return;
+            }
+        }
+    } else {
+        writeln!(state.terminal, "Missing ?add-to parameter, usage: ?add-to <playlist file>").expect(TERMINAL_WRITE_ERROR);
+    }
+}
+
+fn open_media_playlist(path: impl AsRef<std::path::Path>) -> Result<MediaPlaylist, String> {
+    if path.as_ref().exists() {
+        let playlist_bytes = std::fs::read(path).map_err(|e| e.to_string())?;
+        m3u8_rs::parse_media_playlist_res(&playlist_bytes).map_err(|e| e.to_string())
+    } else {
+        Ok(MediaPlaylist::default())
+    }
+}
+
+fn save_media_playlist(path: impl AsRef<std::path::Path>, playlist: MediaPlaylist) -> std::io::Result<()> {
+    let mut playlist_file = std::io::BufWriter::new(std::fs::File::create(path)?);
+    playlist.write_to(&mut playlist_file)
+}
+
+fn item_to_media_segment(item: &Item) -> Option<m3u8_rs::MediaSegment> {
+    Some(MediaSegment {
+        uri: music_filename(item)?,
+        title: music_title(item),
+        ..Default::default()
+    })
+}
+
+fn music_title(item: &Item) -> Option<String> {
+    item.field("title").and_then(|x| x.to_owned().to_str())
+}
+
+fn music_filename(item: &Item) -> Option<String> {
+    if let Some(filename) = item.field("filename") {
+        let relative_path = if let Ok(cwd) = std::env::current_dir() {
+            let cwd: &Path = &cwd;
+            filename.as_str().replace(cwd.to_str().unwrap_or(""), "./")
+        } else {
+            filename.to_string()
+        };
+        Some(relative_path)
+    } else {
+        None
+    }
+}
+
+pub fn get_current_item(state: &mut ReplState) -> Option<muss_interpreter::Item> {
+    let data = state.controller_debug.read().expect("Failed to get read lock for debug player data");
+    data.now_playing.clone()
+}

src/repl.rs

@@ -22,13 +22,13 @@ lazy_static! {
     });
 }
 
-const TERMINAL_WRITE_ERROR: &str = "Failed to write to terminal output";
+pub const TERMINAL_WRITE_ERROR: &str = "Failed to write to terminal output";
 const INTERPRETER_WRITE_ERROR: &str = "Failed to write to interpreter";
 
 type DebugItem = Result<Item, String>;
 
-struct ReplState {
-    terminal: Term,
+pub struct ReplState {
+    pub terminal: Term,
     line_number: usize,
     statement_buf: Vec<char>,
     writer: ChannelWriter,
@@ -41,7 +41,7 @@ struct ReplState {
     cursor_rightward_position: usize,
     //debug: Arc<RwLock<DebugState>>,
     list_rx: Receiver<DebugItem>,
-    controller_debug: std::sync::Arc<std::sync::RwLock<crate::debug_state::DebugState>>,
+    pub controller_debug: std::sync::Arc<std::sync::RwLock<crate::debug_state::DebugState>>,
 }
 
 #[derive(Clone)]
@@ -753,13 +753,12 @@ fn repl_commands(command_str: &str, state: &mut ReplState, args: &CliArgs) {
             writeln!(state.terminal, "{}", super::help::REPL_COMMANDS).expect(TERMINAL_WRITE_ERROR)
         }
         "?now" => {
-            let data = state.controller_debug.read().expect("Failed to get read lock for debug player data");
-            if let Some(item) = &data.now_playing {
+            if let Some(item) = crate::playlists::get_current_item(state) {
                 let verbose = DEBUG_STATE
                     .read()
                     .expect("Failed to get read lock for debug state")
                     .verbose;
-                pretty_print_item(item, &mut state.terminal, args, verbose);
+                pretty_print_item(&item, &mut state.terminal, args, verbose);
             } else {
                 writeln!(state.terminal, "Nothing playing").expect(TERMINAL_WRITE_ERROR)
             }
@@ -809,19 +808,11 @@ fn repl_commands(command_str: &str, state: &mut ReplState, args: &CliArgs) {
                 .expect("Failed to send control action");
         }
         "?volume" => volume_cmd(&words, state),
-        "?add-to" => add_to_playlist_cmd(&words, state),
+        "?add-to" => crate::playlists::add_to_playlist_cmd(&words, state),
         _ => writeln!(state.terminal, "Unknown command, try ?help").expect(TERMINAL_WRITE_ERROR),
     }
 }
 
-fn add_to_playlist_cmd(cmd_args: &[&str], state: &mut ReplState) {
-    if let Some(file_arg) = cmd_args.get(1) {
-        writeln!(state.terminal, "Got ?add-to {}, doing nothing (this command is not implemented)", file_arg).expect(TERMINAL_WRITE_ERROR);
-    } else {
-        writeln!(state.terminal, "Missing ?add-to parameter, usage: ?add-to <playlist file>").expect(TERMINAL_WRITE_ERROR);
-    }
-}
-
 fn volume_cmd(cmd_args: &[&str], state: &mut ReplState) {
     if let Some(volume_arg) = cmd_args.get(1) {
         let volume_result: Result<f32, _> = volume_arg.parse();
@@ -835,9 +826,9 @@ fn volume_cmd(cmd_args: &[&str], state: &mut ReplState) {
                 .expect("Failed to get lock for control action sender")
                 .send(muss_player::ControlAction::SetVolume { ack: false, volume: (vol * 100.0).round() as _ })
                 .expect("Failed to send control action"),
-            Err(e) => writeln!(state.terminal, "Error parsing ?volume <float> parameter: {}", e).expect(TERMINAL_WRITE_ERROR)
+            Err(e) => writeln!(state.terminal, "Error parsing ?volume number parameter: {}", e).expect(TERMINAL_WRITE_ERROR)
         }
     } else {
-        writeln!(state.terminal, "Missing ?volume parameter, usage: ?volume <float>").expect(TERMINAL_WRITE_ERROR);
+        writeln!(state.terminal, "Missing ?volume parameter, usage: ?volume number").expect(TERMINAL_WRITE_ERROR);
     }
 }