#include "midi.h"
#include <stdio.h>
#include <poll.h>
#include <stdatomic.h>
#include <alloca.h>

extern atomic_int gRunning;

int midiInit(MidiState *m, Synth *synth)
{
    if (snd_seq_open(&m->seq, "default", SND_SEQ_OPEN_INPUT | SND_SEQ_NONBLOCK, 0) < 0) {
        fprintf(stderr, "Failed to open ALSA sequencer\n");
        return 0;
    }
    snd_seq_nonblock(m->seq, 1);
    snd_seq_set_client_name(m->seq, "soundThing");
    m->client = snd_seq_client_id(m->seq);
    m->port   = snd_seq_create_simple_port(m->seq, "MIDI In",
                                           SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE,
                                           SND_SEQ_PORT_TYPE_APPLICATION);
    m->synth  = synth;
    return 1;
}

void midiListInputs(MidiState *m)
{
    snd_seq_client_info_t *cinfo;
    snd_seq_port_info_t   *pinfo;
    snd_seq_client_info_alloca(&cinfo);
    snd_seq_port_info_alloca(&pinfo);

    printf("\nAvailable MIDI inputs:\n");
    snd_seq_client_info_set_client(cinfo, -1);
    while (snd_seq_query_next_client(m->seq, cinfo) >= 0) {
        int client = snd_seq_client_info_get_client(cinfo);
        if (client == m->client) continue;

        snd_seq_port_info_set_client(pinfo, client);
        snd_seq_port_info_set_port(pinfo, -1);
        while (snd_seq_query_next_port(m->seq, pinfo) >= 0) {
            unsigned int caps = snd_seq_port_info_get_capability(pinfo);
            if (caps & SND_SEQ_PORT_CAP_READ && caps & SND_SEQ_PORT_CAP_SUBS_READ) {
                printf("  [%d:%d] %s — %s\n",
                       client,
                       snd_seq_port_info_get_port(pinfo),
                       snd_seq_client_info_get_name(cinfo),
                       snd_seq_port_info_get_name(pinfo));
            }
        }
    }
}

void midiConnect(MidiState *m, int srcClient, int srcPort)
{
    snd_seq_port_subscribe_t *sub;
    snd_seq_addr_t sender, dest;

    sender.client = srcClient;
    sender.port   = srcPort;
    dest.client   = m->client;
    dest.port     = m->port;

    snd_seq_port_subscribe_alloca(&sub);
    snd_seq_port_subscribe_set_sender(sub, &sender);
    snd_seq_port_subscribe_set_dest(sub, &dest);
    snd_seq_subscribe_port(m->seq, sub);

    printf("Connected [%d:%d] to Cricket\n", srcClient, srcPort);
}

void midiClose(MidiState *m)
{
    snd_seq_close(m->seq);
}

void *midiThread(void *arg)
{
    MidiState      *m = (MidiState *)arg;
    struct pollfd   pfd;
    snd_seq_poll_descriptors(m->seq, &pfd, 1, POLLIN);

    while (gRunning) {
        int ready = poll(&pfd, 1, 50);
        if (ready <= 0) continue;

        snd_seq_event_t *ev = NULL;
        while (snd_seq_event_input(m->seq, &ev) >= 0 && ev) {
            switch (ev->type) {
                case SND_SEQ_EVENT_NOTEON:
                    if (ev->data.note.velocity == 0)
                        synthNoteOff(m->synth, ev->data.note.note);
                else
                    synthNoteOn(m->synth, ev->data.note.note);
                break;
                case SND_SEQ_EVENT_NOTEOFF:
                    synthNoteOff(m->synth, ev->data.note.note);
                    break;
                case SND_SEQ_EVENT_CONTROLLER:
                    if (ev->data.control.param == 70)
                        m->synth->waveform = ev->data.control.value % WAVE_COUNT;
                break;
                case SND_SEQ_EVENT_PITCHBEND:
                    m->synth->pitchBend = ev->data.control.value / 8191.0f;
                break;
            }
            snd_seq_free_event(ev);
            ev = NULL;
        }
    }
    return NULL;
}