//
// Created by wolverindev on 07.02.20.
//

#include "SoundIO.h"
#include <algorithm>
#include "../../logger.h"

using namespace tc::audio;

SoundIORecord::SoundIORecord(struct ::SoundIoDevice *device) : device_handle{device} {
    soundio_device_ref(device);
}

SoundIORecord::~SoundIORecord() {
    soundio_device_unref(this->device_handle);
}

bool SoundIORecord::impl_start(std::string &error) {
    assert(this->device_handle);

    this->buffer = soundio_ring_buffer_create(nullptr, kChunkSize * sizeof(float) * 2); //2 Channels
    if(!buffer) {
        error = "failed to allocate the buffer";
        return false;
    }
    soundio_ring_buffer_clear(this->buffer);

    this->stream = soundio_instream_create(this->device_handle);
    if(!this->stream) {
        error = "out of memory";
        return false;
    }

    this->stream->userdata = this;
    this->stream->format = SoundIoFormatFloat32LE;
    this->stream->software_latency = 0.02;

    this->stream->overflow_callback = [](auto str) {
        auto handle = reinterpret_cast<SoundIORecord*>(str->userdata);
        log_info(category::audio, tr("Having an overflow on {}"), handle->device_handle->id);
    };

    this->stream->error_callback = [](auto str, int err) {
        auto handle = reinterpret_cast<SoundIORecord*>(str->userdata);
        log_info(category::audio, tr("Having an error on {}: {}. Aborting recording."), handle->device_handle->id, soundio_strerror(err));
        handle->stream_invalid = true;
    };

    this->stream->read_callback = [](struct SoundIoInStream *str, int frame_count_min, int frame_count_max) {
        auto handle = reinterpret_cast<SoundIORecord*>(str->userdata);
        handle->read_callback(frame_count_min, frame_count_max);
    };

    if(auto err = soundio_instream_open(this->stream); err) {
        error = soundio_strerror(err) + std::string{" (open)"};
        soundio_instream_destroy(this->stream);
        this->stream = nullptr;
        return false;
    }

    if(false && this->stream->layout_error) {
        error = std::string{"failed to set audio layout: "} + soundio_strerror(this->stream->layout_error);
        soundio_instream_destroy(this->stream);
        this->stream = nullptr;
        return false;
    }

    if(auto err = soundio_instream_start(this->stream); err) {
        error = soundio_strerror(err) + std::string{" (start)"};
        soundio_instream_destroy(this->stream);
        this->stream = nullptr;
        return false;
    }

    //TODO: Test for interleaved channel layout!

    return true;
}

void SoundIORecord::impl_stop() {
    if(!this->stream) return;

    soundio_instream_destroy(this->stream);
    this->stream = nullptr;

    soundio_ring_buffer_destroy(this->buffer);
    this->buffer = nullptr;
}

void SoundIORecord::read_callback(int frame_count_min, int frame_count_max) {
    const struct SoundIoChannelLayout *layout = &this->stream->layout;

    struct SoundIoChannelArea *areas;

    int frames_left{frame_count_max};
    int buffer_samples = soundio_ring_buffer_free_count(this->buffer) / (sizeof(float) * layout->channel_count);

    while(frames_left > 0) {
        int frame_count{frames_left};
        if(frame_count > buffer_samples)
            frame_count = buffer_samples;
        if(auto err = soundio_instream_begin_read(this->stream, &areas, &frame_count); err) {
            log_error(category::audio, tr("Failed to begin read from input stream buffer: {}"), soundio_strerror(err));
            return;
        }

        /* test for interleaved */
        {
            char* begin = areas[0].ptr - sizeof(float);
            for(size_t channel{0}; channel < layout->channel_count; channel++) {
                if((begin += sizeof(float)) != areas[channel].ptr) {
                    log_error(category::audio, tr("Expected interleaved buffer, which it isn't"));
                    return;
                }

                if(areas[channel].step != sizeof(float) * layout->channel_count) {
                    log_error(category::audio, tr("Invalid step size for channel {}"), channel);
                    return;
                }
            }
        }

        const auto length = sizeof(float) * layout->channel_count * frame_count;
        memcpy(soundio_ring_buffer_write_ptr(this->buffer), areas[0].ptr, length);
        soundio_ring_buffer_advance_write_ptr(this->buffer, length);
        buffer_samples -= frame_count;
        frames_left -= frame_count;

        if(buffer_samples == 0) {
            std::lock_guard consumer{this->consumer_lock};
            const auto byte_count = soundio_ring_buffer_fill_count(this->buffer);
            const auto frame_count = byte_count / (sizeof(float) * layout->channel_count);
            for(auto& consumer : this->_consumers)
                consumer->consume(soundio_ring_buffer_read_ptr(this->buffer), frame_count, layout->channel_count);
            soundio_ring_buffer_advance_read_ptr(this->buffer, byte_count);
            buffer_samples = frame_count;
        }

        if(auto err = soundio_instream_end_read(this->stream); err) {
            log_error(category::audio, tr("Failed to close input stream buffer: {}"), soundio_strerror(err));
            return;
        }
    }
}