#include "MIDI.h"

MIDI::MIDI()
{
  if (0 > snd_seq_open(&seq_handle, "default", SND_SEQ_OPEN_INPUT, SND_SEQ_NONBLOCK))
  {
    throw std::runtime_error("MIDI sequencer couldn't be opened");
  }

  if (0 > snd_seq_set_client_name(seq_handle, "Midi Listener"))
  {
    throw std::runtime_error("MIDI client name couldn't be set");
  }

  if (0 > ((in_port = snd_seq_create_simple_port(seq_handle, "24:0",
                    SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE | SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ,
                    SND_SEQ_PORT_TYPE_APPLICATION))))
  {
    throw std::runtime_error("MIDI port couldn't be opened");
  }

  debug_cout << "in_port: " << std::to_string(in_port) << std::endl;

  if (1) {
    snd_seq_addr_t sender, dest;
    snd_seq_port_subscribe_t *subs;
    sender.client = 24;
    sender.port = 0;
    dest.client = snd_seq_client_id(seq_handle);
    dest.port = in_port;
    snd_seq_port_subscribe_alloca(&subs);
    snd_seq_port_subscribe_set_sender(subs, &sender);
    snd_seq_port_subscribe_set_dest(subs, &dest);
    snd_seq_port_subscribe_set_queue(subs, 1);
    snd_seq_port_subscribe_set_time_update(subs, 1);
    snd_seq_port_subscribe_set_time_real(subs, 1);
    // TODO: fix timestamp (currently always 0)
    if (0 > snd_seq_subscribe_port(seq_handle, subs))
    {
      throw std::runtime_error("MIDI port couldn't be connected");
    }
  } else {
    if (0 > snd_seq_connect_from(seq_handle, in_port, 24, 0))
    {
      throw std::runtime_error("MIDI port couldn't be connected");
    }
  }

  npfd = snd_seq_poll_descriptors_count(seq_handle, POLLIN);
  if (npfd < 0) {
    throw std::runtime_error("snd_seq_poll_descriptors_count() failed");
  }
  pfd = (struct pollfd *)malloc(npfd * sizeof(struct pollfd));
  if (pfd == nullptr) {
    throw std::runtime_error("alloca() error for MIDI");
  }
  if (0 > snd_seq_poll_descriptors(seq_handle, pfd, npfd, POLLIN))
  {
    throw std::runtime_error("snd_seq_poll_descriptors() failure");
  }

  if (npfd != 1) {
    std::cout << "Warning: " << std::to_string(npfd) << " poll fds for MIDI" << std::endl;
  } else if (fd() <= 2) {
    std::cout << "Warning: Bad MIDI fd: " << std::to_string(fd()) << std::endl;
  }
}

MIDI::~MIDI()
{
  free(pfd);
}

int MIDI::fd()
{
  return pfd->fd;
}

bool MIDI::event_ready()
{
  int result = snd_seq_event_input_pending(seq_handle, 1);
  if (result < 0) {
    throw std::runtime_error("snd_seq_event_input_pending() failed");
  }

  return result > 0;
}

snd_seq_event_t* MIDI::read(void)
{
  snd_seq_event_t *ev = NULL;
  if (0 > snd_seq_event_input(seq_handle, &ev))
  {
   std::cerr << "snd_seq_event_input(): -EAGAIN" << std::endl;
  }

  return ev;
}

namespace {
uint64_t timestamp_from_event(const snd_seq_event_t *ev)
{
  return ((ev->flags & SND_SEQ_TIME_STAMP_MASK) == SND_SEQ_TIME_STAMP_REAL) ? ev->time.time.tv_sec : ev->time.tick;
}
}

// returns if click starts
void MIDI::process(snd_seq_event_t *ev)
{
  uint64_t timestamp = timestamp_from_event(ev); // original timestamp

  // TODO: fix timestamp to be set automatically
  struct timespec t;
  if (TIME_UTC != timespec_get(&t, TIME_UTC))
  {
    log_cout << "Error: timespec_get()" << std::endl;
  }
  else
  {
    ev->time.time.tv_sec = t.tv_sec;
    ev->time.time.tv_nsec = t.tv_nsec;
  }

  if ((ev->type == SND_SEQ_EVENT_NOTEON) ||(ev->type == SND_SEQ_EVENT_NOTEOFF)) {
    const char *type = (ev->type == SND_SEQ_EVENT_NOTEON) ? "on " : "off";
    debug_cout << fmt::format("[{}] Note {}: {:2x} vel({:2x}), ch {:2x}\n", timestamp,
                                            type,
                                            ev->data.note.note,
                                            ev->data.note.velocity,
                                            ev->data.control.channel);
    if (ev->type == SND_SEQ_EVENT_NOTEON) {
      signal_note(ev->data.control.channel, ev->data.note.note, timestamp);
    }
  }
  else if (ev->type == SND_SEQ_EVENT_CONTROLLER)
  {
    debug_cout << fmt::format("[{}] Control:  {:2x} val({:2x})\n", timestamp_from_event(ev),
                                             ev->data.control.param,
                                             ev->data.control.value);
  }
  else if (ev->type == SND_SEQ_EVENT_SENSING)
  {
    signal_active_sensing();
    debug_cout << fmt::format("[{}] Active Sensing", timestamp_from_event(ev)) << std::endl;
  }
  else if (ev->type == SND_SEQ_EVENT_CLOCK)
  {
    signal_clock();
    debug_cout << fmt::format("[{}] Clock\n", timestamp_from_event(ev)) << std::endl;
  }
  else
  {
    log_cout << fmt::format("[{}] Unknown MIDI event: {}", timestamp_from_event(ev), ev->type) << std::endl;
  }

  signal_count_events(snd_seq_event_length(ev));
  //log_cout << fmt::format("MIDI Bytes: {}", snd_seq_event_length(ev)) << std::endl;
}

void MIDI::flush()
{
  while (event_ready()) {
    (void) read();
  }
}

void MIDI::wait_for_event()
{
  int result = poll(pfd, npfd, 10000);
  if (result > 0)
  {
    // event
  }
  else if (result == 0) {
    // timeout
  } else {
    throw std::runtime_error("Poll unsuccessful");
  }
}