#include <AudioToolbox/AudioToolbox.h>
#include <dlfcn.h>
#include <stdio.h>
#include <string.h>

static void check (OSStatus err, const char* what)
{
    if (err != noErr)
        printf ("FAIL: %s -> %d\n", what, (int) err);
    else
        printf ("PASS: %s\n", what);
}

int main (int argc, char** argv)
{
    if (argc < 2)
    {
        printf ("usage: %s <Pascalcompressor executable path>\n", argv[0]);
        return 2;
    }

    void* handle = dlopen (argv[1], RTLD_NOW | RTLD_LOCAL);
    if (!handle)
    {
        printf ("FAIL: dlopen -> %s\n", dlerror());
        return 1;
    }
    printf ("PASS: dlopen bundle\n");

    AudioComponentDescription desc;
    memset (&desc, 0, sizeof (desc));
    desc.componentType = kAudioUnitType_Effect;
    desc.componentSubType = 'Pscp';
    desc.componentManufacturer = 'PscC';
    desc.componentFlags = 0;
    desc.componentFlagsMask = 0;

    void* (*factory) (const AudioComponentDescription*) = dlsym (handle, "PascalcompressorAUFactory");
    if (!factory)
    {
        printf ("FAIL: dlsym factory -> %s\n", dlerror());
        return 1;
    }
    printf ("PASS: dlsym factory\n");

    AudioComponent comp = AudioComponentRegister (&desc,
                                                  CFSTR ("Pascal: Pascalcompressor"),
                                                  0x00010000,
                                                  (AudioComponentFactoryFunction) factory);
    if (!comp)
    {
        printf ("FAIL: AudioComponentRegister\n");
        return 1;
    }
    printf ("PASS: AudioComponentRegister\n");

    AudioUnit au = 0;
    check (AudioComponentInstanceNew (comp, &au), "AudioComponentInstanceNew");
    if (!au) return 1;
    printf ("      instance %p\n", (void*) au);

    AudioUnitParameterInfo info;
    memset (&info, 0, sizeof (info));
    UInt32 infoSz = sizeof (info);
    for (UInt32 pid = 0; pid < 7; ++pid)
    {
        if (AudioUnitGetProperty (au, kAudioUnitProperty_ParameterInfo,
                                  kAudioUnitScope_Global, pid, &info, &infoSz) == noErr)
            printf ("      parameter %u: default %.3f name='%s'\n", (unsigned) pid,
                    (double) info.defaultValue,
                    info.cfNameString ? CFStringGetCStringPtr (info.cfNameString, kCFStringEncodingUTF8) : "?");
    }

    AudioStreamBasicDescription fmt;
    memset (&fmt, 0, sizeof (fmt));
    fmt.mSampleRate = 44100.0;
    fmt.mFormatID = kAudioFormatLinearPCM;
    fmt.mFormatFlags = kAudioFormatFlagsNativeFloatPacked | kAudioFormatFlagIsNonInterleaved;
    fmt.mBytesPerPacket = 4;
    fmt.mFramesPerPacket = 1;
    fmt.mBytesPerFrame = 4;
    fmt.mChannelsPerFrame = 2;
    fmt.mBitsPerChannel = 32;

    check (AudioUnitSetProperty (au, kAudioUnitProperty_StreamFormat,
                                 kAudioUnitScope_Input, 0, &fmt, sizeof (fmt)),
           "Set input format");
    check (AudioUnitSetProperty (au, kAudioUnitProperty_StreamFormat,
                                 kAudioUnitScope_Output, 0, &fmt, sizeof (fmt)),
           "Set output format");

    check (AudioUnitInitialize (au), "AudioUnitInitialize");

    AudioUnitParameter p;
    memset (&p, 0, sizeof (p));
    p.mAudioUnit = au;
    for (int i = 0; i < 7; ++i)
    {
        p.mParameterID = (AudioUnitParameterID) i;
        p.mScope = kAudioUnitScope_Global;
        p.mElement = 0;
        AudioUnitParameterValue value = 0.0f;
        OSStatus err = AudioUnitGetParameter (au, p.mParameterID, p.mScope, p.mElement, &value);
        if (err == noErr)
            printf ("      parameter %d = %.3f\n", i, (double) value);
    }

    AudioUnitParameterValue setTo = 0.5f;
    check (AudioUnitSetParameter (au, 1, kAudioUnitScope_Global, 0, setTo, 0),
           "Set threshold parameter");

    const int numFrames = 512;
    AudioBufferList abl;
    abl.mNumberBuffers = 2;
    for (int c = 0; c < 2; ++c)
    {
        abl.mBuffers[c].mNumberChannels = 1;
        abl.mBuffers[c].mDataByteSize = numFrames * sizeof (float);
        abl.mBuffers[c].mData = malloc (abl.mBuffers[c].mDataByteSize);
        memset (abl.mBuffers[c].mData, 0, abl.mBuffers[c].mDataByteSize);
    }

    AudioTimeStamp ts;
    memset (&ts, 0, sizeof (ts));
    ts.mSampleTime = 0.0;
    ts.mFlags = kAudioTimeStampSampleTimeValid;

    check (AudioUnitRender (au, NULL, &ts, 0, numFrames, &abl), "AudioUnitRender (silence)");

    float* ch0 = (float*) abl.mBuffers[0].mData;
    float peak = 0.0f;
    for (int n = 0; n < numFrames; ++n)
        peak = peak > ch0[n] ? peak : ch0[n];
    printf ("      rendered peak: %.6f\n", (double) peak);

    for (int c = 0; c < 2; ++c) free (abl.mBuffers[c].mData);

    check (AudioComponentInstanceDispose (au), "AudioComponentInstanceDispose");
    dlclose (handle);
    return 0;
}