//
// Created by Melefo on 28/01/2020.
//

#ifndef COMSQUARE_DSP_HPP
#define COMSQUARE_DSP_HPP

#include <cstdint>
#include <array>
#include "../../Memory/AMemory.hpp"

namespace ComSquare::APU::DSP
{
    struct Master {
        //! @brief Main Volume register (MVOL)
        std::array<uint8_t, 2> volume;
        //! @brief Mutes all channel (6th bit FLG)
        bool mute : 1;
        //! @brief Soft reset DSP (7th bit FLG)
        bool reset : 1;
        //! @brief Current sound produced
        std::array<uint16_t, 2> output;
        //! @brief Not used register
        uint8_t unused;
    };

    struct Echo {
        //! @brief Echo Volume register (EVOL)
        std::array<uint8_t , 2> volume;
        //! @brief Echo feedback register (EFB)
        uint8_t feedback;
        //! @brief Echo FIR filter coefficients (COEF)
        std::array<uint8_t, 8> FIR;
        //! @brief Echo data start register (ESA)
        uint8_t data;
        //! @brief Echo delay size register (EDL)
        uint8_t delay;
        //! @brief Echo enabled (5th bit FLG)
        bool enabled = true;
        //! @brief Last sound produced for each voice in each channel
        std::array<std::array<int16_t, 8>, 2> history;
        //! @brief Current sound to echo
        std::array<uint16_t, 2> input;
        //! @brief Current sound echoed produced
        std::array<uint16_t, 2> output;
    };

    struct Noise {
        //! @brief Frequency of white noise (the first 4 bits FLG)
        uint8_t clock : 5;
        //! @brief Linear feedback shift register used to shift final output
        uint16_t lfsr = 0x4000;
    };

    struct BRR {
        //! @brief Offset pointing to sample directory in external RAM (DIR)
        uint8_t offset;
    };

    struct Latch {
        //! @brief Current voice's adsr1 in use
        uint8_t adsr1;
        //! @brief Envelope value register (ENVX)
        uint8_t envx;
        //! @brief Wave height register (OUTX)
        uint8_t outx;
        //! @brief Current voice's pitch in use
        uint16_t pitch;
        //! @brief Output currently being modified
        uint16_t output;
    };

    struct Voice {
        //! @brief Volume register (VOL)
        std::array<int8_t, 2> volume;
        //! @brief Pitch register (P)
        union {
            struct {
                //! @brief Lower 8 bits of pitch register
                uint8_t pitchL;
                //! @brief Higher 8 bits of pitch register
                uint8_t pitchH;
            };
            uint16_t pitch;
        };
        //! @brief Source number register (SRCN)
        uint8_t srcn;
        union {
            struct {
                //! @brief Envelope register (ADSR)
                uint8_t adsr1;
                //! @brief Envelope controllers register (ADSR)
                uint8_t adsr2;
            };
            uint16_t envelope;
        };
        //! @brief Gain register (GAIN)
        uint8_t gain;
        //! @brief envelope associated with this voice
        uint8_t envx;
        //! @brief Sample end register (ENDX)
        bool endx : 1;

        //! @brief Key On register (KON)
        bool kon : 1;
        //! @brief Key Off register (KOF)
        bool kof : 1;
        //! @brief Pitch modulation register (PMON)
        bool pmon : 1;
        //! @brief Noise enable register (NON)
        bool non : 1;
        //! @brief Echo enable register (EON)
        bool eon : 1;

        //! @brief Check if voice is in setup phase
        uint8_t konDelay;
        //! @brief Check if the output will be echoed
        bool echo;
        //! @brief Check if this voice will be looped
        bool loop;
    };

    //! @brief Current state of the DSP
    struct State
    {
        //! @brief Current voice modification to do
        uint8_t voice = 0;
        //! @brief Current buffer of samples
        int16_t *buffer;
        //! @brief Limit of the buffer
        int16_t *bufferEnd;
        //! @brief Beginning of the buffer
        int16_t *bufferStart;
    };
	/*//! @brief All the registers of the DSP
	struct Registers {
        //! @brief Main Volume register
	    std::array<uint8_t, 2> mVol; //master.volume

        //! @brief Echo Volume register
        std::array<uint8_t, 2> eVol; //echo.volume

		//! @brief Flags register
		union {
		    struct {
		        uint8_t noiseClock : 5; //noise.frequency
		        bool ecen : 1; //echo.readonly
		        bool mute : 1; //master.mute
		        bool reset : 1; //master.reset
		    };
            uint8_t flg;
        };

		//! @brief Echo feedback register
		uint8_t efb; //echo.feedback

		//! @brief Not used register
		uint8_t unused;

		//! @brief Source Directory offset register
		uint8_t dir; //brr.bank

		//! @brief Echo data start register
		uint8_t esa; //echo.bank
		//! @brief Echo delay size register
		uint8_t edl; //echo.delay
	};

    struct BRR {
        //! @brief BRR Header
        union {
            struct {
                //! @brief Shift value range
                unsigned range : 4;
                //! @brief Decompression filter
                unsigned filter : 2;
                //! @brief Flag if the sample loops
                bool loop : 1;
                //! @brief Stop the sample (or restart from loop point)
                bool end : 1;
            };
            uint8_t head;
        };
        //! @brief Sample data inside BRR
        uint64_t block;
    };

    struct Voice {
        //! @brief Volume register
        std::array<uint8_t, 2> volume; //voice.volume

		union {
			struct {
				//! @brief Lower 8 bits of pitch register
				uint8_t pitchL;
				//! @brief Higher 8 bits of pitch register
				uint8_t pitchH;
			};
			uint16_t pitch; //voice.pitch
		};

        //! @brief Source number register
        uint8_t srcn; //voice.source

        union {
            struct {
                //! @brief Envelope register
                uint8_t adsr1; //voice.adsr0
                //! @brief Envelope controllers register
                uint8_t adsr2; //voice.adsr1
            };
            uint16_t envelope;
        };

        //! @brief Gain register
        uint8_t gain; //voice.gain

        //! @brief Envelope value register
        uint8_t envx; //latch.envx
        //! @brief Wave height register
        uint8_t outx; //latch.outx

		//! @brief Key On register
		bool kon : 1; //voice.keyon
		//! @brief Key Off register
		bool kof : 1; //voice.keyoff
		bool keyLatch : 1; //voice._keylatch

		//! @brief Sample end register
		bool endx : 1; //voice._end
		//! @brief Noise enable register
		bool non : 1; //voice.noise
		//! @brief Echo enable register
		bool eon : 1; //voice.echo

		//! @brief Pitch modulation register
		bool pmon : 1; //voice.modulate

		//! @brief Echo FIR filter coefficients
		uint8_t coeff; //echo.fir

		bool latchEon : 1; //voice._echo
	};

    struct Latch
    {
        uint8_t adsr0;
        uint16_t pitch;
        uint16_t output;
    };*/

	class DSP : public Memory::AMemory {
	private:
		//! @brief Gaussian table used for making waves
		std::array<int16_t, 512> _gauss = {
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
            1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2,
            2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5,
            6, 6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 10,
            11, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 15, 16, 16, 17, 17,
            18, 19, 19, 20, 20, 21, 21, 22, 23, 23, 24, 24, 25, 26, 27, 27,
            28, 29, 29, 30, 31, 32, 32, 33, 34, 35, 36, 36, 37, 38, 39, 40,
            41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56,
            58, 59, 60, 61, 62, 64, 65, 66, 67, 69, 70, 71, 73, 74, 76, 77,
            78, 80, 81, 83, 84, 86, 87, 89, 90, 92, 94, 95, 97, 99, 100, 102,
            104, 106, 107, 109, 111, 113, 115, 117, 118, 120, 122, 124, 126, 128, 130, 132,
            134, 137, 139, 141, 143, 145, 147, 150, 152, 154, 156, 159, 161, 163, 166, 168,
            171, 173, 175, 178, 180, 183, 186, 188, 191, 193, 196, 199, 201, 204, 207, 210,
            212, 215, 218, 221, 224, 227, 230, 233, 236, 239, 242, 245, 248, 251, 254, 257,
            260, 263, 267, 270, 273, 276, 280, 283, 286, 290, 293, 297, 300, 304, 307, 311,
            314, 318, 321, 325, 328, 332, 336, 339, 343, 347, 351, 354, 358, 362, 366, 370,
            374, 378, 381, 385, 389, 393, 397, 401, 405, 410, 414, 418, 422, 426, 430, 434,
            439, 443, 447, 451, 456, 460, 464, 469, 473, 477, 482, 486, 491, 495, 499, 504,
            508, 513, 517, 522, 527, 531, 536, 540, 545, 550, 554, 559, 563, 568, 573, 577,
            582, 587, 592, 596, 601, 606, 611, 615, 620, 625, 630, 635, 640, 644, 649, 654,
            659, 664, 669, 674, 678, 683, 688, 693, 698, 703, 708, 713, 718, 723, 728, 732,
            737, 742, 747, 752, 757, 762, 767, 772, 777, 782, 787, 792, 797, 802, 806, 811,
            816, 821, 826, 831, 836, 841, 846, 851, 855, 860, 865, 870, 875, 880, 884, 889,
            894, 899, 904, 908, 913, 918, 923, 927, 932, 937, 941, 946, 951, 955, 960, 965,
            969, 974, 978, 983, 988, 992, 997, 1001, 1005, 1010, 1014, 1019, 1023, 1027, 1032, 1036,
            1040, 1045, 1049, 1053, 1057, 1061, 1066, 1070, 1074, 1078, 1082, 1086, 1090, 1094, 1098, 1102,
            1106, 1109, 1113, 1117, 1121, 1125, 1128, 1132, 1136, 1139, 1143, 1146, 1150, 1153, 1157, 1160,
            1164, 1167, 1170, 1174, 1177, 1180, 1183, 1186, 1190, 1193, 1196, 1199, 1202, 1205, 1207, 1210,
            1213, 1216, 1219, 1221, 1224, 1227, 1229, 1232, 1234, 1237, 1239, 1241, 1244, 1246, 1248, 1251,
            1253, 1255, 1257, 1259, 1261, 1263, 1265, 1267, 1269, 1270, 1272, 1274, 1275, 1277, 1279, 1280,
            1282, 1283, 1284, 1286, 1287, 1288, 1290, 1291, 1292, 1293, 1294, 1295, 1296, 1297, 1297, 1298,
            1299, 1300, 1300, 1301, 1302, 1302, 1303, 1303, 1303, 1304, 1304, 1304, 1304, 1304, 1305, 1305
        };

        //! @brief 8x voices of sample used to make sound
        std::array<Voice, 8> _voices {};
        Master _master {};
        Echo _echo {};
        Noise _noise {};
        BRR _brr {};
        Latch _latch {};
        State _state {};

        void voiceOutput(Voice &voice, bool channel);
        void voice1(Voice &voice);
        void voice2(Voice &voice);
        void voice3(Voice &voice);
        void voice3a(Voice &voice);
        void voice3b(Voice &voice);
        void voice3c(Voice &voice);
        void voice4(Voice &voice);
        void voice5(Voice &voice);
        void voice6(Voice &voice);
        void voice7(Voice &voice);
        void voice8(Voice &voice);
        void voice9(Voice &voice);
        void echo22();
        void echo23();
        void echo24();
        void echo25();
        void echo26();
        void echo27();
        void echo28();
        void echo29();
        void echo30();
        void misc27();
        void misc28();
        void misc29();
        void misc30();
	public:
		DSP(int16_t *buffer, int32_t size);
		DSP(const DSP &) = default;
		DSP &operator=(const DSP &) = default;
		~DSP() override = default;

		//! @brief Return all 8 voices from DSP
		const std::array<Voice, 8> &getVoices();
        const Master &getMaster();
        const Echo &getEcho();
        const Noise &getNoise();
        const BRR &getBrr();
        const Latch &getLatch();

		//! @brief Read from the internal DSP register.
		//! @param addr The address to read from. The address 0x0 should refer to the first byte of the register.
		//! @throw InvalidAddress will be thrown if the address is more than $7F (the number of register).
		//! @return Return the value of the register.
		uint8_t read(uint24_t addr) override;
		//! @brief Write data to the internal DSP register.
		//! @param addr The address to write to. The address 0x0 should refer to the first byte of register.
		//! @param data The new value of the register.
		//! @throw InvalidAddress will be thrown if the address is more than $7F (the number of register).
		void write(uint24_t addr, uint8_t data) override;

        //! @brief Execute current voice transformation
        void update();

        //! @brief Return the number of samples written
        int32_t getSamplesCount() const;

		//! @brief Get the name of this accessor (used for debug purpose)
		std::string getName() override;

		//! @brief Get the component of this accessor (used for debug purpose)
		Component getComponent() override;
	};
}

#endif //COMSQUARE_DSP_HPP