Skip to main content

aether_midi/
engine.rs

1//! MIDI engine — manages hardware MIDI input via midir.
2
3use std::sync::{Arc, Mutex};
4use midir::{MidiInput, MidiInputConnection};
5use crate::{event::MidiEvent, router::MidiRouter};
6
7/// Manages MIDI hardware connections and routes events.
8pub struct MidiEngine {
9    router: Arc<Mutex<MidiRouter>>,
10    _connections: Vec<MidiInputConnection<()>>,
11    sample_counter: Arc<Mutex<u64>>,
12}
13
14impl MidiEngine {
15    /// Create a new MIDI engine.
16    pub fn new() -> Self {
17        Self {
18            router: Arc::new(Mutex::new(MidiRouter::new())),
19            _connections: Vec::new(),
20            sample_counter: Arc::new(Mutex::new(0)),
21        }
22    }
23
24    /// List available MIDI input port names.
25    pub fn list_ports() -> Vec<String> {
26        let midi_in = match MidiInput::new("aether-midi-list") {
27            Ok(m) => m,
28            Err(_) => return Vec::new(),
29        };
30        let ports = midi_in.ports();
31        ports.iter()
32            .filter_map(|p| midi_in.port_name(p).ok())
33            .collect()
34    }
35
36    /// Connect to a MIDI input port by index.
37    /// Returns Ok(()) if connected, Err with message if failed.
38    pub fn connect_port(&mut self, port_index: usize) -> Result<(), String> {
39        let midi_in = MidiInput::new("aether-midi-in")
40            .map_err(|e| format!("MIDI init error: {e}"))?;
41        let ports = midi_in.ports();
42        let port = ports.get(port_index)
43            .ok_or_else(|| format!("MIDI port {port_index} not found"))?;
44        let port_name = midi_in.port_name(port)
45            .unwrap_or_else(|_| format!("Port {port_index}"));
46
47        let router = Arc::clone(&self.router);
48        let counter = Arc::clone(&self.sample_counter);
49
50        let conn = midi_in.connect(
51            port,
52            "aether-midi-conn",
53            move |_timestamp_us, bytes, _| {
54                let ts = *counter.lock().unwrap();
55                if let Some(event) = MidiEvent::from_bytes(bytes, ts) {
56                    router.lock().unwrap().dispatch(&event);
57                }
58            },
59            (),
60        ).map_err(|e| format!("MIDI connect error: {e}"))?;
61
62        println!("MIDI: connected to '{port_name}'");
63        self._connections.push(conn);
64        Ok(())
65    }
66
67    /// Connect to the first available MIDI port.
68    pub fn connect_first(&mut self) -> Result<String, String> {
69        let ports = Self::list_ports();
70        if ports.is_empty() {
71            return Err("No MIDI input ports found".into());
72        }
73        self.connect_port(0)?;
74        Ok(ports[0].clone())
75    }
76
77    /// Get a reference to the router for registering handlers.
78    pub fn router(&self) -> Arc<Mutex<MidiRouter>> {
79        Arc::clone(&self.router)
80    }
81
82    /// Advance the sample counter (call once per audio buffer).
83    pub fn advance_samples(&self, samples: u64) {
84        *self.sample_counter.lock().unwrap() += samples;
85    }
86
87    /// Inject a MIDI event directly (for testing or virtual keyboard).
88    pub fn inject(&self, event: MidiEvent) {
89        self.router.lock().unwrap().dispatch(&event);
90    }
91}
92
93impl Default for MidiEngine {
94    fn default() -> Self { Self::new() }
95}