#include "fuzz_data_producer.h"

struct FUZZ_dataProducer_s{

  const uint8_t *data;

  size_t size;

};

FUZZ_dataProducer_t* FUZZ_dataProducer_create(const uint8_t* data, size_t size) {

  FUZZ_dataProducer_t* const producer = malloc(sizeof(FUZZ_dataProducer_t));

  FUZZ_ASSERT(producer != NULL);

  producer->data = data;

  producer->size = size;

  return producer;

}

void FUZZ_dataProducer_free(FUZZ_dataProducer_t *producer) { free(producer); }

uint32_t FUZZ_dataProducer_retrieve32(FUZZ_dataProducer_t *producer) {

    const uint8_t* data = producer->data;

    const size_t size = producer->size;

    if (size == 0) {

        return 0;

    } else if (size < 4) {

        producer->size -= 1;

        return (uint32_t)data[size - 1];

    } else {

        const uint8_t* const p = data + size - 4;

        producer->size -= 4;

        return (uint32_t)p[0] | ((uint32_t)p[1] << 8)

            | ((uint32_t)p[2] << 16) | ((uint32_t)p[3] << 24);

    }

}

uint32_t FUZZ_getRange_from_uint32(uint32_t seed, uint32_t min, uint32_t max)

{

    uint32_t range = max - min;

    if (range == 0xffffffff) {

      return seed;

    }

    return min + seed % (range + 1);

}

uint32_t FUZZ_dataProducer_range32(FUZZ_dataProducer_t* producer,

    uint32_t min, uint32_t max)

{

    uint32_t const seed = FUZZ_dataProducer_retrieve32(producer);

    return FUZZ_getRange_from_uint32(seed, min, max);

}

LZ4F_frameInfo_t FUZZ_dataProducer_frameInfo(FUZZ_dataProducer_t* producer)

{

    LZ4F_frameInfo_t info = LZ4F_INIT_FRAMEINFO;

    info.blockSizeID = FUZZ_dataProducer_range32(producer, LZ4F_max64KB - 1, LZ4F_max4MB);

    if (info.blockSizeID < LZ4F_max64KB) {

        info.blockSizeID = LZ4F_default;

    }

    info.blockMode = FUZZ_dataProducer_range32(producer, LZ4F_blockLinked, LZ4F_blockIndependent);

    info.contentChecksumFlag = FUZZ_dataProducer_range32(producer, LZ4F_noContentChecksum,

                                           LZ4F_contentChecksumEnabled);

    info.blockChecksumFlag = FUZZ_dataProducer_range32(producer, LZ4F_noBlockChecksum,

                                         LZ4F_blockChecksumEnabled);

    return info;

}

LZ4F_preferences_t FUZZ_dataProducer_preferences(FUZZ_dataProducer_t* producer)

{

    LZ4F_preferences_t prefs = LZ4F_INIT_PREFERENCES;

    prefs.frameInfo = FUZZ_dataProducer_frameInfo(producer);

    prefs.compressionLevel = FUZZ_dataProducer_range32(producer, 0, LZ4HC_CLEVEL_MAX + 3) - 3;

    prefs.autoFlush = FUZZ_dataProducer_range32(producer, 0, 1);

    prefs.favorDecSpeed = FUZZ_dataProducer_range32(producer, 0, 1);

    return prefs;

}

size_t FUZZ_dataProducer_remainingBytes(FUZZ_dataProducer_t *producer){

  return producer->size;

}