use core_foundation::base::OSStatus;

use coremidi_sys::{MIDIPortConnectSource, MIDIPortDisconnectSource, MIDIPortDispose, MIDISend};

use std::ops::Deref;
use std::ptr;

use crate::callback::BoxedCallback;
use crate::endpoints::destinations::Destination;
use crate::endpoints::sources::Source;
use crate::object::Object;
use crate::packets::PacketList;

/// A MIDI connection port owned by a client.
/// See [MIDIPortRef](https://developer.apple.com/reference/coremidi/midiportref).
///
/// Ports can't be instantiated directly, but through a client.
///
#[derive(Debug)]
pub struct Port {
    pub(crate) object: Object,
}

impl Deref for Port {
    type Target = Object;

    fn deref(&self) -> &Object {
        &self.object
    }
}

impl Drop for Port {
    fn drop(&mut self) {
        unsafe { MIDIPortDispose(self.object.0) };
    }
}

/// An output [MIDI port](https://developer.apple.com/reference/coremidi/midiportref) owned by a client.
///
/// A simple example to create an output port and send a MIDI event:
///
/// ```rust,no_run
/// let client = coremidi::Client::new("example-client").unwrap();
/// let output_port = client.output_port("example-port").unwrap();
/// let destination = coremidi::Destination::from_index(0).unwrap();
/// let packets = coremidi::PacketBuffer::new(0, &[0x90, 0x40, 0x7f]);
/// output_port.send(&destination, &packets).unwrap();
/// ```
#[derive(Debug)]
pub struct OutputPort {
    pub(crate) port: Port,
}

impl OutputPort {
    /// Send a list of packets to a destination.
    /// See [MIDISend](https://developer.apple.com/reference/coremidi/1495289-midisend).
    ///
    pub fn send(
        &self,
        destination: &Destination,
        packet_list: &PacketList,
    ) -> Result<(), OSStatus> {
        let status = unsafe {
            MIDISend(
                self.port.object.0,
                destination.endpoint.object.0,
                packet_list.as_ptr(),
            )
        };
        if status == 0 {
            Ok(())
        } else {
            Err(status)
        }
    }
}

impl Deref for OutputPort {
    type Target = Port;

    fn deref(&self) -> &Port {
        &self.port
    }
}

/// An input [MIDI port](https://developer.apple.com/reference/coremidi/midiportref) owned by a client.
///
/// A simple example to create an input port:
///
/// ```rust,no_run
/// let client = coremidi::Client::new("example-client").unwrap();
/// let input_port = client.input_port("example-port", |packet_list| println!("{}", packet_list)).unwrap();
/// let source = coremidi::Source::from_index(0).unwrap();
/// input_port.connect_source(&source);
/// ```
#[derive(Debug)]
pub struct InputPort {
    // Note: the order is important here, port needs to be dropped first
    pub(crate) port: Port,
    pub(crate) callback: BoxedCallback<PacketList>,
}

impl InputPort {
    pub fn connect_source(&self, source: &Source) -> Result<(), OSStatus> {
        let status =
            unsafe { MIDIPortConnectSource(self.object.0, source.object.0, ptr::null_mut()) };
        if status == 0 {
            Ok(())
        } else {
            Err(status)
        }
    }

    pub fn disconnect_source(&self, source: &Source) -> Result<(), OSStatus> {
        let status = unsafe { MIDIPortDisconnectSource(self.object.0, source.object.0) };
        if status == 0 {
            Ok(())
        } else {
            Err(status)
        }
    }
}

impl Deref for InputPort {
    type Target = Port;

    fn deref(&self) -> &Port {
        &self.port
    }
}