#include "lv2/core/lv2.h"

#include <iostream>

namespace {

const char * ACCELERATION_URI = "https://www.airwindows.com/acceleration";

enum PortIndex {
    ACCELERATION_LIMIT = 0,
    ACCELERATION_DRYWET = 1,
    ACCELERATION_IN = 2,
    ACCELERATION_OUT = 3
};

struct acceleration {
    const float * limit;
    const float * drywet;
    const float * in;
    float * out;
};

LV2_Handle instantiate(
        const LV2_Descriptor * d,
        double rate,
        const char * path,
        const LV2_Feature * const * features)
{
    return calloc(1, sizeof(acceleration));
}

void connect_port(
        LV2_Handle instance,
        uint32_t port,
        void * data)
{
    auto accel = (acceleration *) instance;

    switch (port) {
        case ACCELERATION_LIMIT:
            accel->limit = (const float *) data;
            break;

        case ACCELERATION_DRYWET:
            accel->limit = (const float *) data;
            break;

        case ACCELERATION_IN:
            accel->in = (const float *) data;
            break;

        case ACCELERATION_OUT:
            accel->out = (float *) data;
            break;

        default:
            std::cerr << "Invalid port " << port << ": ignoring." << std::endl;
    }
}

void activate(LV2_Handle instance)
{
}

void run(LV2_Handle instance, uint32_t num_samples)
{
    auto accel = (acceleration *) instance;
    for (auto i = 0u; i < num_samples; i++) {
        *accel->out++ = *accel->in++;
    }
}

void deactivate(LV2_Handle)
{
}

void destroy(LV2_Handle instance)
{
    free(instance);
}

const void * extension_data(const char * uri)
{
    return nullptr;
}

const LV2_Descriptor descriptor = {
    ACCELERATION_URI,
    instantiate,
    connect_port,
    activate,
    run,
    deactivate,
    destroy,
    extension_data
};

} // anon namespace

LV2_SYMBOL_EXPORT
const LV2_Descriptor * lv2_descriptor(uint32_t idx)
{
    if (idx == 0)
        return &descriptor;

    return nullptr;
}