#include "midi.h"
#include <windows.h>
#include <mmsystem.h>
#include <stdatomic.h>
#include <stdio.h>

extern atomic_int gRunning;

static void CALLBACK midiCallbackWin32(HMIDIIN hIn, UINT msg, DWORD_PTR instance,
                                        DWORD_PTR param1, DWORD_PTR param2)
{
    (void)hIn; (void)param2;
    if (msg != MIM_DATA) return;

    MidiState *m = (MidiState *)instance;
    BYTE status  = (BYTE)( param1        & 0xFF);
    BYTE data1   = (BYTE)((param1 >>  8) & 0xFF);
    BYTE data2   = (BYTE)((param1 >> 16) & 0xFF);
    BYTE type    = status & 0xF0;

    if (type == 0x90 && data2 > 0) {
        synthNoteOn(m->synth, data1);
    } else if (type == 0x80 || (type == 0x90 && data2 == 0)) {
        synthNoteOff(m->synth, data1);
    } else if (type == 0xB0) {
        int cc = data1, val = data2;
        if (cc < 128) {
            if (atomic_load(&m->midiLearnMode))
                atomic_store(&m->midiLearnCC, cc);
            if (m->ccMappings[cc].active) {
                float t = (float)val / 127.0f;
                *m->ccMappings[cc].valuePtr =
                    m->ccMappings[cc].min + t * (m->ccMappings[cc].max - m->ccMappings[cc].min);
            }
        }
    } else if (type == 0xE0) {
        int pb = (data2 << 7) | data1;  // 0..16383, centre = 8192
        m->synth->pitchBend = (pb - 8192) / 8191.0f;
    }
}

int midiInit(MidiState *m, Synth *synth)
{
    m->synth           = synth;
    m->hMidiIn         = NULL;
    m->connectedClient = -1;
    m->connectedPort   = -1;
    m->inputCount      = 0;
    atomic_store(&m->midiLearnMode, 0);
    atomic_store(&m->midiLearnCC, -1);
    for (int i = 0; i < 128; i++) m->ccMappings[i].active = 0;
    return 1;
}

void midiScanInputs(MidiState *m)
{
    m->inputCount = 0;
    UINT n = midiInGetNumDevs();
    for (UINT i = 0; i < n && m->inputCount < MIDI_MAX_INPUTS; i++) {
        MIDIINCAPSA caps;
        if (midiInGetDevCapsA(i, &caps, sizeof(caps)) == MMSYSERR_NOERROR) {
            MidiInputInfo *info = &m->inputs[m->inputCount++];
            info->client = (int)i;
            info->port   = 0;
            snprintf(info->clientName, sizeof(info->clientName), "%s", caps.szPname);
            snprintf(info->portName,   sizeof(info->portName),   "%s", caps.szPname);
        }
    }
}

void midiDevDisconnect(MidiState *m)
{
    if (m->hMidiIn) {
        midiInStop((HMIDIIN)m->hMidiIn);
        midiInClose((HMIDIIN)m->hMidiIn);
        m->hMidiIn = NULL;
    }
    m->connectedClient = -1;
    m->connectedPort   = -1;
}

void midiDevConnect(MidiState *m, int srcClient, int srcPort)
{
    (void)srcPort;
    midiDevDisconnect(m);
    HMIDIIN hIn = NULL;
    if (midiInOpen(&hIn, (UINT)srcClient, (DWORD_PTR)midiCallbackWin32,
                   (DWORD_PTR)m, CALLBACK_FUNCTION) == MMSYSERR_NOERROR) {
        midiInStart(hIn);
        m->hMidiIn         = hIn;
        m->connectedClient = srcClient;
        m->connectedPort   = 0;
    }
}

void midiClose(MidiState *m)
{
    midiDevDisconnect(m);
}

void *midiThread(void *arg)
{
    // WinMM delivers MIDI events via midiCallbackWin32 on its own MM thread.
    // This function exists only to satisfy the pthread_create call in soundThing.c.
    (void)arg;
    while (gRunning) Sleep(50);
    return NULL;
}