// SPDX-License-Identifier: GPL-2.0-only
/*
 * Digital Voice Modem - MBE Vocoder
 * GPLv2 Open Source. Use is subject to license terms.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 *  Copyright (C) 2019-2021 Doug McLain
 *  Copyright (C) 2021 Bryan Biedenkapp, N2PLL
 *
 */
/**
 * @file MBEDecoder.h
 * @ingroup vocoder
 * @file MBEDecoder.cpp
 * @ingroup vocoder
 */
#if !defined(__MBE_DECODER_H__)
#define __MBE_DECODER_H__

extern "C" {
#include "mbe.h"
}

#include "Defines.h"

#include <stdlib.h>
#include <queue>

namespace vocoder
{
    // ---------------------------------------------------------------------------
    //  Structure Declaration
    // ---------------------------------------------------------------------------

    struct mbelibParms
    {
        mbe_parms* m_cur_mp;
        mbe_parms* m_prev_mp;
        mbe_parms* m_prev_mp_enhanced;

        /// <summary></summary>
        mbelibParms()
        {
            m_cur_mp = (mbe_parms*)malloc(sizeof(mbe_parms));
            m_prev_mp = (mbe_parms*)malloc(sizeof(mbe_parms));
            m_prev_mp_enhanced = (mbe_parms*)malloc(sizeof(mbe_parms));
        }

        /// <summary></summary>
        ~mbelibParms()
        {
            free(m_prev_mp_enhanced);
            free(m_prev_mp);
            free(m_cur_mp);
        }
    };

    // ---------------------------------------------------------------------------
    //  Constants
    // ---------------------------------------------------------------------------

    /**
     * @brief Vocoder Decoding Mode
     */
    enum MBE_DECODER_MODE : int {
        DECODE_DMR_AMBE = 0,    //! DMR AMBE
        DECODE_88BIT_IMBE = 1   //! 88-bit IMBE (P25)
    };

    // ---------------------------------------------------------------------------
    //  Class Declaration
    // ---------------------------------------------------------------------------

    /**
     * @brief Implements MBE audio decoding.
     */
    class HOST_SW_API MBEDecoder
    {
    public:
        /**
         * @brief Initializes a new instance of the MBEDecoder class.
         * @param mode Decoder mode.
         */
        MBEDecoder(MBE_DECODER_MODE mode);
        /**
         * @brief Finalizes a instance of the MBEDecoder class.
         */
        ~MBEDecoder();

        /**
         * @brief Decodes the given MBE codewords to deinterleaved MBE bits using the decoder mode.
         * @param[in] codeword MBE codeword.
         * @param[out] mbeBits 
         * @returns int32_t 
         */
        int32_t decodeBits(uint8_t* codeword, char* mbeBits);

        /**
         * @brief Decodes the given MBE codewords to PCM samples using the decoder mode.
         * @param[in] codeword MBE codeword.
         * @param[out] samples PCM Samples (in float format).
         * @returns int32_t 
         */
        int32_t decodeF(uint8_t* codeword, float samples[]);
        /**
         * @brief Decodes the given MBE codewords to PCM samples using the decoder mode.
         * @param[in] codeword MBE codeword.
         * @param[out] samples PCM Samples (in short format).
         * @returns int32_t 
         */
        int32_t decode(uint8_t* codeword, int16_t samples[]);

    private:
        mbelibParms* m_mbelibParms;

        MBE_DECODER_MODE m_mbeMode;

        static const int dW[72];
        static const int dX[72];
        static const int rW[36];
        static const int rX[36];
        static const int rY[36];
        static const int rZ[36];

        float gainMaxBuf[200];
        float* gainMaxBufPtr;
        int gainMaxIdx;

    public:
        /**
         * @brief Gain adjustment.
         */
        __PROPERTY(float, gainAdjust, GainAdjust);
        /**
         * @brief Flag indicating automatic gain adjustment is enabled.
         */
        __PROPERTY(bool, autoGain, AutoGain);
    };

    // Extern methods for C#/C++ interop
    extern "C" {
#ifdef _WIN32
        extern __declspec(dllexport) MBEDecoder* MBEDecoder_Create(MBE_DECODER_MODE mode);
        extern __declspec(dllexport) int32_t MBEDecoder_Decode(MBEDecoder* pDecoder, uint8_t* codeword, int16_t* samples);
        extern __declspec(dllexport) void MBEDecoder_Delete(MBEDecoder* pDecoder);
#else
        extern MBEDecoder* MBEDecoder_Create(MBE_DECODER_MODE mode);
        extern int32_t MBEDecoder_Decode(MBEDecoder* pDecoder, uint8_t* codeword, int16_t* samples);
        extern void MBEDecoder_Delete(MBEDecoder* pDecoder);
#endif
    }

} // namespace vocoder

#endif // __MBE_DECODER_H__