// Copyright (c) 2014 - 2026 kio@little-bat.de
// BSD-2-Clause license
// https://opensource.org/licenses/BSD-2-Clause

#pragma once
#include "zxsp_types.h"


namespace zxsp
{

class SP0256
{
	Machine* const machine;

	const float32 rc;			   // RC value (for both stages), e.g. RC = 33kΩ * 22nF
	const float32 ff;			   // filter factor per audio-out sample (for both filter stages)
	Time		  time_per_sample; // SP0256: time[seconds] per sample = 1.0 / (XTAL/312)
	Sample		  volume;
	Sample		  amplification; // volume setting (incl. all other factors)
	bool		  hifi;

	// coroutine state machine
	uint   sm_state;		// for coroutine macros
	Time   time;			// up to which time the state machine ran:
	Time   time_sample_end; // time when the currently rendered 10kHz sample ends
	Sample sample;
	Sample sample_at_c1; // current filtered output value at C1 (output of filter stage 1)
	Sample sample_at_c2; // current filtered output value at C2 (output of filter stage 2)

	void run_statemachine(Time);
	void output_filtered(Sample, Time);

	// 17 sound and filter registers:
	uint  current_opcode;
	uint  repeat;		  // 6 bit: ≥ 1
	uint8 pitch;		  // 8 bit: 0 -> white noise
	uint8 amplitude;	  // 8 bit: bit[7…5] = exponent, bit[4…0] = mantissa
	uint8 c[12];		  // 8 bit: filter coefficients b and f
	int8  pitch_incr;	  // Δ update value applied to pitch after each period
	int8  amplitude_incr; // Δ update value applied to amplitude after each period

	int	   _c[12];	  // int10:  filter coefficients b and f (bereits umgerechnet)
	int	   _z[12];	  // feedback values
	uint16 _shiftreg; // noise
	uint   _i;

	// microsequencer registers:
	uint mode; // 2 bit	from SETMODE
	// uint repeat_prefix;// 2 bit	from SETMODE	(already shifted left 4 bits)
	uint page;			  // 4 bit	(already bit-swapped and shifted left 12 bits)
	uint pc;			  // 16 bit
	uint stack;			  // 16 bit single level return "stack"
	uint command;		  // 8 bit current/next command
	uint current_command; // 8 bit current command

	bool stand_by;		// 1 = stand by (utterance completed)
	bool command_valid; // 1 = command valid == !LRQ (load request)

	// speech rom AL2:		((presumably "american language" vs.2))
	uint8 rom[2048];
	uint  byte; // current/last byte read from rom, remaining valid bits are right-aligned
	uint  bits; // number of valid bits remaining

public:
	// Statistics
	struct Stats
	{
		Sample max_sample;
		Sample max_sample_at_c1;
		Sample max_sample_at_c2;
		Stats() : max_sample(0), max_sample_at_c1(0), max_sample_at_c2(0) {}
	};
	Stats allophone_stats[64];
	Stats opcode_stats[16];

public:
	SP0256(Machine*, cstr romfilepath, bool bitswapped, float RC = 33e3f * 22e-9f);
	~SP0256();

	void powerOn(/*Time t=0,*/ Sample volume = 1.0f, Frequency xtal = 3.12e6);
	void setHifi(bool f) { hifi = f; }
	bool isHifi() { return hifi; }
	void setVolume(Time, Sample);
	void setClock(Time, Frequency);
	void writeCommand(Time, uint);
	bool isStandby(Time); // test stand_by
	bool isBusy(Time);	  // test command_valid
	bool audioBufferEnd(Time);
	void reset(Time, Sample volume, Frequency xtal);

private:
	void disassAllophones();

	void cmdSetPage(uint opcode); // or RTS
	void cmdLoadAll();
	void cmdLoad2C(uint instr);
	void cmdLoad2();
	void cmdSetMsb35A(uint instr);
	void cmdSetMsb3();
	void cmdLoad4();
	void cmdSetMsb5();
	void cmdSetMsb6();
	void cmdJmp(uint opcode);
	void cmdSetMode(uint opcode);
	void cmdDelta9();
	void cmdSetMsbA();
	void cmdJsr(uint opcode);
	void cmdLoadC();
	void cmdDeltaD();
	void cmdLoadE();
	void cmdPause();

	void logSetPage(uint opcode); // or RTS
	void logLoadAll();
	void logLoad2C(uint instr);
	void logLoad2();
	void logSetMsb35A(uint instr);
	void logSetMsb3();
	void logLoad4();
	void logSetMsb5();
	void logSetMsb6();
	void logJmp(uint opcode);
	void logSetMode(uint opcode);
	void logDelta9();
	void logSetMsbA();
	void logJsr(uint opcode);
	void logLoadC();
	void logDeltaD();
	void logLoadE();
	void logPause();

	uint8 next8();
	uint8 nextL(uint n);
	uint8 nextR(uint n);
	int8  nextSL(uint n);
	int8  nextSR(uint n);
	void  set_clock(Frequency);
	void  set_volume(Sample);
};

} // namespace zxsp