#include "stdio.h"
#include "string.h"
#include "hardware.h"
#include "fpga_io.h"
#include "menu.h"
#include "archie.h"
#include "debug.h"
#include "user_io.h"

#define MAX_FLOPPY  4

#define CONFIG_FILENAME  "ARCHIE.CFG"

typedef struct
{
	unsigned long system_ctrl;     // system control word
	char rom_img[1024];              // rom image file name
} archie_config_t;

static archie_config_t config;

fileTYPE floppy[MAX_FLOPPY] = { 0 };

#define ARCHIE_FILE_TX         0x53
#define ARCHIE_FILE_TX_DAT     0x54
#define ARCHIE_FDC_GET_STATUS  0x55
#define ARCHIE_FDC_TX_DATA     0x56
#define ARCHIE_FDC_SET_STATUS  0x57

#define archie_debugf(a, ...) printf("\033[1;31mARCHIE: " a "\033[0m\n", ##__VA_ARGS__)
// #define archie_debugf(a, ...)
#define archie_x_debugf(a, ...) printf("\033[1;32mARCHIE: " a "\033[0m\n", ##__VA_ARGS__)

enum state {
	STATE_HRST, STATE_RAK1, STATE_RAK2, STATE_IDLE,
	STATE_WAIT4ACK1, STATE_WAIT4ACK2, STATE_HOLD_OFF
} kbd_state;

// archie keyboard controller commands
#define HRST    0xff
#define RAK1    0xfe
#define RAK2    0xfd
#define RQPD    0x40         // mask 0xf0
#define PDAT    0xe0         // mask 0xf0
#define RQID    0x20
#define KBID    0x80         // mask 0xc0
#define KDDA    0xc0         // new key down data, mask 0xf0
#define KUDA    0xd0         // new key up data, mask 0xf0
#define RQMP    0x22         // request mouse data
#define MDAT    0x00         // mouse data, mask 0x80
#define BACK    0x3f
#define NACK    0x30         // disable kbd scan, disable mouse
#define SACK    0x31         // enable kbd scan, disable mouse
#define MACK    0x32         // disable kbd scan, enable mouse
#define SMAK    0x33         // enable kbd scan, enable mouse
#define LEDS    0x00         // mask 0xf8
#define PRST    0x21         // nop

#define QUEUE_LEN 8
static unsigned char tx_queue[QUEUE_LEN][2];
static unsigned char tx_queue_rptr, tx_queue_wptr;
#define QUEUE_NEXT(a)  ((a+1)&(QUEUE_LEN-1))

static unsigned long ack_timeout;
static short mouse_x, mouse_y;

#define FLAG_SCAN_ENABLED  0x01
#define FLAG_MOUSE_ENABLED 0x02
static unsigned char flags;

// #define HOLD_OFF_TIME 2
#ifdef HOLD_OFF_TIME
static unsigned long hold_off_timer;
#endif

static uint8_t sector_buffer[1024];

const char *archie_get_rom_name(void)
{
	char *p = strrchr(config.rom_img, '/');
	if (!p) p = config.rom_img; else p++;

	return p;
}

const char *archie_get_floppy_name(char i)
{
	if (!floppy[i].size)  return "* no disk *";

	char *p = strrchr(floppy[i].name, '/');
	if (!p) p = floppy[i].name; else p++;

	return p;
}

void archie_set_ar(char i)
{
	if (i) config.system_ctrl |= 1;
	else config.system_ctrl &= ~1;
	user_io_8bit_set_status((i ? -1 : 0), 2);
}

char archie_get_ar()
{
	return config.system_ctrl & 1;
}

void archie_set_amix(char i)
{
	config.system_ctrl = (config.system_ctrl & ~0b110) | ((i & 3)<<1);
	user_io_8bit_set_status(config.system_ctrl << 1, 0b1100);
}

char archie_get_amix()
{
	return (config.system_ctrl>>1) & 3;
}

void archie_save_config(void)
{
	FileSaveConfig(CONFIG_FILENAME, &config, sizeof(config));
}

void archie_send_file(unsigned char id, char *name)
{
	archie_debugf("Sending file with id %d", id);

	fileTYPE file = { 0 };
	if (!FileOpen(&file, name)) return;

	// prepare transmission of new file
	EnableFpga();
	spi8(ARCHIE_FILE_TX);
	spi8(id);
	DisableFpga();

	unsigned long time = GetTimer(0);

	printf("[");

	unsigned short i, blocks = file.size / 512;
	for (i = 0; i<blocks; i++) {
		if (!(i & 127)) printf("*");

		DISKLED_ON;
		FileRead(&file, sector_buffer);
		DISKLED_OFF;

		EnableFpga();
		spi8(ARCHIE_FILE_TX_DAT);
		spi_block_write(sector_buffer, 1);
		DisableFpga();

		// still bytes to send? read next sector
		if (i != blocks - 1) FileNextSector(&file);
	}

	FileClose(&file);
	printf("]\n");

	time = GetTimer(0) - time;
	archie_debugf("Uploaded in %lu ms", time >> 20);

	// signal end of transmission
	EnableFpga();
	spi8(ARCHIE_FILE_TX);
	spi8(0x00);
	DisableFpga();
}

void archie_fdc_set_status(void)
{
	int i;

	// send status bytes for all four possible floppies
	EnableFpga();
	spi8(ARCHIE_FDC_SET_STATUS);
	for (i = 0; i<MAX_FLOPPY; i++)
	{
		unsigned char floppy_status = 0x00;
		if (floppy[i].size) floppy_status |= 1;
		spi8(floppy_status);
	}
	DisableFpga();
}

void archie_set_floppy(char i, char *name)
{
	if (!name)
	{
		archie_debugf("Floppy %d eject", i);
		FileClose(&floppy[i]);
		floppy[i].size = 0;
	}
	else
	{
		archie_debugf("Floppy %d insert %s", i, name);
		FileOpen(&floppy[i], name);
	}

	// update floppy status in fpga
	archie_fdc_set_status();
}

char archie_floppy_is_inserted(char i)
{
	return(floppy[i].size != 0);
}

void archie_set_rom(char *name)
{
	if (!name) return;
	
	printf("archie_set_rom(%s)\n", name);

	// save file name
	strcpy(config.rom_img, name);

	archie_send_file(0x01, name);
}

static void archie_kbd_enqueue(unsigned char state, unsigned char byte)
{
	if (QUEUE_NEXT(tx_queue_wptr) == tx_queue_rptr)
	{
		archie_debugf("KBD tx queue overflow");
		return;
	}

	//archie_debugf("KBD ENQUEUE %x (%x)", byte, state);
	tx_queue[tx_queue_wptr][0] = state;
	tx_queue[tx_queue_wptr][1] = byte;
	tx_queue_wptr = QUEUE_NEXT(tx_queue_wptr);
}

static void archie_kbd_tx(unsigned char state, unsigned char byte)
{
	//archie_debugf("KBD TX %x (%x)", byte, state);
	spi_uio_cmd_cont(0x05);
	spi8(byte);
	DisableIO();

	kbd_state = (enum state)state;
	ack_timeout = GetTimer(10);  // 10ms timeout
}

static void archie_kbd_send(unsigned char state, unsigned char byte)
{
	// don't send if we are waiting for an ack
	if ((kbd_state != STATE_WAIT4ACK1) && (kbd_state != STATE_WAIT4ACK2))
		archie_kbd_tx(state, byte);
	else
		archie_kbd_enqueue(state, byte);
}

static void archie_kbd_reset(void)
{
	archie_debugf("KBD reset");
	tx_queue_rptr = tx_queue_wptr = 0;
	kbd_state = STATE_HRST;
	mouse_x = mouse_y = 0;
	flags = 0;
}

void archie_init(void)
{
	char i;

	archie_debugf("init");

	// set config defaults
	config.system_ctrl = 0;
	strcpy(config.rom_img, "Archie/RISCOS.ROM");

	// try to load config from card
	int size = FileLoadConfig(CONFIG_FILENAME, 0, 0);
	if (size>0)
	{
		if (size == sizeof(archie_config_t))
		{
			FileLoadConfig(CONFIG_FILENAME, &config, sizeof(archie_config_t));
		}
		else
			archie_debugf("Unexpected config size %d != %d", size, sizeof(archie_config_t));
	}
	else
		archie_debugf("No %s config found", CONFIG_FILENAME);

	archie_set_ar(archie_get_ar());
	archie_set_amix(archie_get_amix());

	// upload rom file
	archie_set_rom(config.rom_img);

	// upload ext file
	//archie_send_file(0x02, "RISCOS.EXT");

	// try to open default floppies
	for (i = 0; i<MAX_FLOPPY; i++)
	{
		char fdc_name[] = "Archie/FLOPPY0.ADF";
		fdc_name[13] = '0' + i;
		if (FileOpen(&floppy[i], fdc_name))
			archie_debugf("Inserted floppy %d with %d bytes", i, floppy[i].size);
		else
			floppy[i].size = 0;
	}
	// update floppy status in fpga
	archie_fdc_set_status();

	archie_kbd_send(STATE_RAK1, HRST);
	ack_timeout = GetTimer(20);  // give archie 20ms to reply
}

void archie_kbd(unsigned short code)
{
	//archie_debugf("KBD key code %x", code);

	// don't send anything yet if we are still in reset state
	if (kbd_state <= STATE_RAK2)
	{
		archie_debugf("KBD still in reset");
		return;
	}

	// ignore any key event if key scanning is disabled
	if (!(flags & FLAG_SCAN_ENABLED))
	{
		archie_debugf("KBD keyboard scan is disabled!");
		return;
	}

	// select prefix for up or down event
	unsigned char prefix = (code & 0x8000) ? KUDA : KDDA;

	archie_kbd_send(STATE_WAIT4ACK1, prefix | (code >> 4));
	archie_kbd_send(STATE_WAIT4ACK2, prefix | (code & 0x0f));
}

void archie_mouse(unsigned char b, int16_t x, int16_t y)
{
	//archie_debugf("KBD MOUSE X:%d Y:%d B:%d", x, y, b);

	// max values -64 .. 63
	mouse_x += x;
	if (mouse_x >  63) mouse_x = 63;
	if (mouse_x < -64) mouse_x = -64;

	mouse_y -= y;
	if (mouse_y >  63) mouse_y = 63;
	if (mouse_y < -64) mouse_y = -64;

	// don't send anything yet if we are still in reset state
	if (kbd_state <= STATE_RAK2)
	{
		archie_debugf("KBD still in reset");
		return;
	}

	// ignore any mouse movement if mouse is disabled or if nothing to report
	if ((flags & FLAG_MOUSE_ENABLED) && (mouse_x || mouse_y))
	{
		// send asap if no pending byte
		if (kbd_state == STATE_IDLE) {
			archie_kbd_send(STATE_WAIT4ACK1, mouse_x & 0x7f);
			archie_kbd_send(STATE_WAIT4ACK2, mouse_y & 0x7f);
			mouse_x = mouse_y = 0;
		}
	}

	// ignore mouse buttons if key scanning is disabled
	if (flags & FLAG_SCAN_ENABLED)
	{
		static const uint8_t remap[] = { 0, 2, 1 };
		static unsigned char buts = 0;
		uint8_t s;

		// map all three buttons
		for (s = 0; s<3; s++)
		{
			uint8_t mask = (1 << s);
			if ((b&mask) != (buts&mask))
			{
				unsigned char prefix = (b&mask) ? KDDA : KUDA;
				archie_kbd_send(STATE_WAIT4ACK1, prefix | 0x07);
				archie_kbd_send(STATE_WAIT4ACK2, prefix | remap[s]);
			}
		}
		buts = b;
	}
}

static void archie_check_queue(void)
{
	if (tx_queue_rptr == tx_queue_wptr)
		return;

	archie_kbd_tx(tx_queue[tx_queue_rptr][0], tx_queue[tx_queue_rptr][1]);
	tx_queue_rptr = QUEUE_NEXT(tx_queue_rptr);
}

void archie_handle_kbd(void)
{
#ifdef HOLD_OFF_TIME
	if ((kbd_state == STATE_HOLD_OFF) && CheckTimer(hold_off_timer)) {
		archie_debugf("KBD resume after hold off");
		kbd_state = STATE_IDLE;
		archie_check_queue();
	}
#endif

	// timeout waiting for ack?
	if ((kbd_state == STATE_WAIT4ACK1) || (kbd_state == STATE_WAIT4ACK2)) {
		if (CheckTimer(ack_timeout)) {
			if (kbd_state == STATE_WAIT4ACK1)
				archie_debugf(">>>> KBD ACK TIMEOUT 1ST BYTE <<<<");
			if (kbd_state == STATE_WAIT4ACK2)
				archie_debugf(">>>> KBD ACK TIMEOUT 2ND BYTE <<<<");

			kbd_state = STATE_IDLE;
		}
	}

	// timeout in reset sequence?
	if (kbd_state <= STATE_RAK2)
	{
		if (CheckTimer(ack_timeout))
		{
			//archie_debugf("KBD timeout in reset state");

			archie_kbd_send(STATE_RAK1, HRST);
			ack_timeout = GetTimer(20);  // 20ms timeout
		}
	}

	spi_uio_cmd_cont(0x04);
	if (spi_in() == 0xa1)
	{
		unsigned char data = spi_in();
		DisableIO();

		//archie_debugf("KBD RX %x", data);

		switch (data) {
			// arm requests reset
		case HRST:
			archie_kbd_reset();
			archie_kbd_send(STATE_RAK1, HRST);
			ack_timeout = GetTimer(20);  // 20ms timeout
			break;

			// arm sends reset ack 1
		case RAK1:
			if (kbd_state == STATE_RAK1) {
				archie_kbd_send(STATE_RAK2, RAK1);
				ack_timeout = GetTimer(20);  // 20ms timeout
			}
			else
				kbd_state = STATE_HRST;
			break;

			// arm sends reset ack 2
		case RAK2:
			if (kbd_state == STATE_RAK2) {
				archie_kbd_send(STATE_IDLE, RAK2);
				ack_timeout = GetTimer(20);  // 20ms timeout
			}
			else
				kbd_state = STATE_HRST;
			break;

			// arm request keyboard id
		case RQID:
			archie_kbd_send(STATE_IDLE, KBID | 1);
			break;

			// arm acks first byte
		case BACK:
			if (kbd_state != STATE_WAIT4ACK1)
				archie_debugf("KBD unexpected BACK");

#ifdef HOLD_OFF_TIME
			// wait some time before sending next byte
			archie_debugf("KBD starting hold off");
			kbd_state = STATE_HOLD_OFF;
			hold_off_timer = GetTimer(10);
#else
			kbd_state = STATE_IDLE;
			archie_check_queue();
#endif
			break;

			// arm acks second byte
		case NACK:
		case SACK:
		case MACK:
		case SMAK:

			if (((data == SACK) || (data == SMAK)) && !(flags & FLAG_SCAN_ENABLED)) {
				archie_debugf("KBD Enabling key scanning");
				flags |= FLAG_SCAN_ENABLED;
			}

			if (((data == NACK) || (data == MACK)) && (flags & FLAG_SCAN_ENABLED)) {
				archie_debugf("KBD Disabling key scanning");
				flags &= ~FLAG_SCAN_ENABLED;
			}

			if (((data == MACK) || (data == SMAK)) && !(flags & FLAG_MOUSE_ENABLED)) {
				archie_debugf("KBD Enabling mouse");
				flags |= FLAG_MOUSE_ENABLED;
			}

			if (((data == NACK) || (data == SACK)) && (flags & FLAG_MOUSE_ENABLED)) {
				archie_debugf("KBD Disabling mouse");
				flags &= ~FLAG_MOUSE_ENABLED;
			}

			// wait another 10ms before sending next byte
#ifdef HOLD_OFF_TIME
			archie_debugf("KBD starting hold off");
			kbd_state = STATE_HOLD_OFF;
			hold_off_timer = GetTimer(10);
#else
			kbd_state = STATE_IDLE;
			archie_check_queue();
#endif
			break;
		}
	}
	else
		DisableIO();
}

void archie_handle_fdc(void)
{
	static uint8_t buffer[1024];
	static unsigned char old_status[4] = { 0,0,0,0 };
	unsigned char status[4];

	// read status
	EnableFpga();
	spi8(ARCHIE_FDC_GET_STATUS);
	status[0] = spi_in();
	status[1] = spi_in();
	status[2] = spi_in();
	status[3] = spi_in();
	DisableFpga();

	if (memcmp(status, old_status, 4) != 0)
	{
		//archie_x_debugf("status changed to %x %x %x %x", status[0], status[1], status[2], status[3]);
		memcpy(old_status, status, 4);

		// top four bits must be magic marker 1010
		if (((status[0] & 0xf0) == 0xa0) && (status[0] & 1))
		{
			//archie_x_debugf("status changed to %x %x %x %x", status[0], status[1], status[2], status[3]);
			//archie_x_debugf("DIO: BUSY with commmand %lx", status[1]);

			// check for read sector command
			if ((status[1] & 0xe0) == 0x80)
			{
				if (status[0] & 2)
				{
					int floppy_map = status[3] >> 4;
					int side = (status[2] & 0x80) ? 0 : 1;
					int track = status[2] & 0x7f;
					int sector = status[3] & 0x0f;
					unsigned long lba = 2 * (10 * track + 5 * side + sector);
					int floppy_index = -1;

					// allow only single floppy drives to be selected
					int i;
					for (i = 0; i<MAX_FLOPPY; i++)
						if (floppy_map == (0x0f ^ (1 << i)))
							floppy_index = i;

					if (floppy_index < 0)
						archie_x_debugf("DIO: unexpected floppy_map %x", floppy_map);
					else
					{
						fileTYPE *f = &floppy[floppy_index];

						archie_x_debugf("DIO: floppy %d sector read SD%d T%d S%d -> %ld",
							floppy_index, side, track, sector, lba);

						if (!f->size)
							archie_x_debugf("DIO: floppy not inserted. Core should not do this!!");
						else {
							DISKLED_ON;
							// read two consecutive sectors 
							FileSeekLBA(f, lba);
							FileReadAdv(f, buffer, 1024);
							DISKLED_OFF;

							EnableFpga();
							spi8(ARCHIE_FDC_TX_DATA);
							spi_write(buffer, 1024, 0);
							DisableFpga();
						}
					}
				}
			}
		}
	}
}

void archie_poll(void)
{
	archie_handle_kbd();
	archie_handle_fdc();
}