Cagire/src/midi.rs

use parking_lot::Mutex;
use std::sync::Arc;

use crate::model::CcAccess;

pub const MAX_MIDI_OUTPUTS: usize = 4;
pub const MAX_MIDI_INPUTS: usize = 4;
pub const MAX_MIDI_DEVICES: usize = 4;

/// Raw CC memory storage type
type CcMemoryInner = Arc<Mutex<[[[u8; 128]; 16]; MAX_MIDI_DEVICES]>>;

/// CC memory storage: [device][channel][cc_number] -> value
/// Wrapped in a newtype to implement CcAccess (orphan rule)
#[derive(Clone)]
pub struct CcMemory(CcMemoryInner);

impl CcMemory {
    pub fn new() -> Self {
        Self(Arc::new(Mutex::new([[[0u8; 128]; 16]; MAX_MIDI_DEVICES])))
    }

    #[cfg(feature = "cli")]
    fn inner(&self) -> &CcMemoryInner {
        &self.0
    }

    #[allow(dead_code)] // used by integration tests
    pub fn set_cc(&self, device: usize, channel: usize, cc: usize, value: u8) {
        let mut mem = self.0.lock();
        mem[device.min(MAX_MIDI_DEVICES - 1)][channel.min(15)][cc.min(127)] = value;
    }
}

impl Default for CcMemory {
    fn default() -> Self {
        Self::new()
    }
}

impl CcAccess for CcMemory {
    fn get_cc(&self, device: usize, channel: usize, cc: usize) -> u8 {
        let mem = self.0.lock();
        mem[device.min(MAX_MIDI_DEVICES - 1)][channel.min(15)][cc.min(127)]
    }
}

#[derive(Clone, Debug)]
pub struct MidiDeviceInfo {
    pub name: String,
}

#[cfg(feature = "cli")]
pub fn list_midi_outputs() -> Vec<MidiDeviceInfo> {
    let Ok(midi_out) = midir::MidiOutput::new("cagire-probe") else {
        return Vec::new();
    };
    midi_out
        .ports()
        .iter()
        .filter_map(|port| {
            midi_out
                .port_name(port)
                .ok()
                .map(|name| MidiDeviceInfo { name })
        })
        .collect()
}

#[cfg(not(feature = "cli"))]
pub fn list_midi_outputs() -> Vec<MidiDeviceInfo> {
    Vec::new()
}

#[cfg(feature = "cli")]
pub fn list_midi_inputs() -> Vec<MidiDeviceInfo> {
    let Ok(midi_in) = midir::MidiInput::new("cagire-probe") else {
        return Vec::new();
    };
    midi_in
        .ports()
        .iter()
        .filter_map(|port| {
            midi_in
                .port_name(port)
                .ok()
                .map(|name| MidiDeviceInfo { name })
        })
        .collect()
}

#[cfg(not(feature = "cli"))]
pub fn list_midi_inputs() -> Vec<MidiDeviceInfo> {
    Vec::new()
}

pub struct MidiState {
    #[cfg(feature = "cli")]
    output_conns: [Option<midir::MidiOutputConnection>; MAX_MIDI_OUTPUTS],
    #[cfg(feature = "cli")]
    input_conns: [Option<midir::MidiInputConnection<(CcMemoryInner, usize)>>; MAX_MIDI_INPUTS],
    pub selected_outputs: [Option<usize>; MAX_MIDI_OUTPUTS],
    pub selected_inputs: [Option<usize>; MAX_MIDI_INPUTS],
    pub cc_memory: CcMemory,
}

impl Default for MidiState {
    fn default() -> Self {
        Self::new()
    }
}

impl MidiState {
    pub fn new() -> Self {
        Self {
            #[cfg(feature = "cli")]
            output_conns: [None, None, None, None],
            #[cfg(feature = "cli")]
            input_conns: [None, None, None, None],
            selected_outputs: [None; MAX_MIDI_OUTPUTS],
            selected_inputs: [None; MAX_MIDI_INPUTS],
            cc_memory: CcMemory::new(),
        }
    }

    #[cfg(feature = "cli")]
    pub fn connect_output(&mut self, slot: usize, port_index: usize) -> Result<(), String> {
        if slot >= MAX_MIDI_OUTPUTS {
            return Err("Invalid output slot".to_string());
        }
        let midi_out =
            midir::MidiOutput::new(&format!("cagire-out-{slot}")).map_err(|e| e.to_string())?;
        let ports = midi_out.ports();
        let port = ports.get(port_index).ok_or("MIDI output port not found")?;
        let conn = midi_out
            .connect(port, &format!("cagire-midi-out-{slot}"))
            .map_err(|e| e.to_string())?;
        self.output_conns[slot] = Some(conn);
        self.selected_outputs[slot] = Some(port_index);
        Ok(())
    }

    #[cfg(not(feature = "cli"))]
    pub fn connect_output(&mut self, _slot: usize, _port_index: usize) -> Result<(), String> {
        Ok(())
    }

    #[cfg(feature = "cli")]
    pub fn disconnect_output(&mut self, slot: usize) {
        if slot < MAX_MIDI_OUTPUTS {
            self.output_conns[slot] = None;
            self.selected_outputs[slot] = None;
        }
    }

    #[cfg(not(feature = "cli"))]
    pub fn disconnect_output(&mut self, slot: usize) {
        if slot < MAX_MIDI_OUTPUTS {
            self.selected_outputs[slot] = None;
        }
    }

    #[cfg(feature = "cli")]
    pub fn connect_input(&mut self, slot: usize, port_index: usize) -> Result<(), String> {
        if slot >= MAX_MIDI_INPUTS {
            return Err("Invalid input slot".to_string());
        }
        let midi_in =
            midir::MidiInput::new(&format!("cagire-in-{slot}")).map_err(|e| e.to_string())?;
        let ports = midi_in.ports();
        let port = ports.get(port_index).ok_or("MIDI input port not found")?;

        let cc_mem = Arc::clone(self.cc_memory.inner());
        let conn = midi_in
            .connect(
                port,
                &format!("cagire-midi-in-{slot}"),
                move |_timestamp, message, (cc_mem, slot)| {
                    if message.len() >= 3 {
                        let status = message[0];
                        let data1 = message[1] as usize;
                        let data2 = message[2];
                        if (status & 0xF0) == 0xB0 && data1 < 128 {
                            let channel = (status & 0x0F) as usize;
                            let mut mem = cc_mem.lock();
                            mem[*slot][channel][data1] = data2;
                        }
                    }
                },
                (cc_mem, slot),
            )
            .map_err(|e| e.to_string())?;

        self.input_conns[slot] = Some(conn);
        self.selected_inputs[slot] = Some(port_index);
        Ok(())
    }

    #[cfg(not(feature = "cli"))]
    pub fn connect_input(&mut self, _slot: usize, _port_index: usize) -> Result<(), String> {
        Ok(())
    }

    #[cfg(feature = "cli")]
    pub fn disconnect_input(&mut self, slot: usize) {
        if slot < MAX_MIDI_INPUTS {
            self.input_conns[slot] = None;
            self.selected_inputs[slot] = None;
        }
    }

    #[cfg(not(feature = "cli"))]
    pub fn disconnect_input(&mut self, slot: usize) {
        if slot < MAX_MIDI_INPUTS {
            self.selected_inputs[slot] = None;
        }
    }

    #[cfg(feature = "cli")]
    fn send_message(&mut self, device: u8, message: &[u8]) {
        let slot = (device as usize).min(MAX_MIDI_OUTPUTS - 1);
        if let Some(conn) = &mut self.output_conns[slot] {
            let _ = conn.send(message);
        }
    }

    #[cfg(not(feature = "cli"))]
    fn send_message(&mut self, _device: u8, _message: &[u8]) {}

    pub fn send_note_on(&mut self, device: u8, channel: u8, note: u8, velocity: u8) {
        let status = 0x90 | (channel & 0x0F);
        self.send_message(device, &[status, note & 0x7F, velocity & 0x7F]);
    }

    pub fn send_note_off(&mut self, device: u8, channel: u8, note: u8) {
        let status = 0x80 | (channel & 0x0F);
        self.send_message(device, &[status, note & 0x7F, 0]);
    }

    pub fn send_cc(&mut self, device: u8, channel: u8, cc: u8, value: u8) {
        let status = 0xB0 | (channel & 0x0F);
        self.send_message(device, &[status, cc & 0x7F, value & 0x7F]);
    }

    pub fn send_pitch_bend(&mut self, device: u8, channel: u8, value: u16) {
        let status = 0xE0 | (channel & 0x0F);
        let lsb = (value & 0x7F) as u8;
        let msb = ((value >> 7) & 0x7F) as u8;
        self.send_message(device, &[status, lsb, msb]);
    }

    pub fn send_pressure(&mut self, device: u8, channel: u8, value: u8) {
        let status = 0xD0 | (channel & 0x0F);
        self.send_message(device, &[status, value & 0x7F]);
    }

    pub fn send_program_change(&mut self, device: u8, channel: u8, program: u8) {
        let status = 0xC0 | (channel & 0x0F);
        self.send_message(device, &[status, program & 0x7F]);
    }

    pub fn send_realtime(&mut self, device: u8, msg: u8) {
        self.send_message(device, &[msg]);
    }
}