// license:LGPL-2.1+
// copyright-holders:Angelo Salese
/*******************************************************************************************************************

Nichibutsu 1414M4 device emulation

Written by Angelo Salese, based on researches by Tomasz Slanina with Legion

This is some fancy MCU / blitter that copies text strings in various Nihon Bussan games;

TODO:
- where is the condition that makes "insert coin" text to properly blink?
- first byte meaning is completely unknown;
- Ninja Emaki triggers unknown commands 0x8000 & 0xff20;
- Ninja Emaki continue screen is corrupt;
- How to NOT draw the params?

Notes:
- Just before any string in the "MCU" rom, there's a control byte, this meaning is as follows:
  0?-- ---- ---- ---- interpret as data?
  10-- ---- ---- ---- single string transfer
  11-- ---- ---- ---- src -> dst copy, if destination != 0 fixed src, otherwise do a src -> dst
  --xx xxxx xxxx xxxx destination offset in the VRAM tilemap

- I'm sure that this is a shared device, that shares everything. All of the known differences are due of not
  understood features of the chip (some bytes in the ROM etc.)

********************************************************************************************************************/

#include "emu.h"
#include "includes/nb1414m4.h"

const device_type NB1414M4 = &device_creator<nb1414m4_device>;

nb1414m4_device::nb1414m4_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
	: device_t(mconfig, NB1414M4, "NB1414M4 Mahjong Custom", tag, owner, clock, "nb1414m4", __FILE__),
	device_video_interface(mconfig, *this),
	m_data(*this, DEVICE_SELF)
{
}


//-------------------------------------------------
//  device_start - device-specific startup
//-------------------------------------------------

void nb1414m4_device::device_start()
{
}

//-------------------------------------------------
//  device_reset - device-specific startup
//-------------------------------------------------

void nb1414m4_device::device_reset()
{
}

/*****************************************************************************
    DEVICE HANDLERS
*****************************************************************************/

void nb1414m4_device::dma(UINT16 src, UINT16 dst, UINT16 size, UINT8 condition, UINT8 *vram)
{
	int i;

	for(i=0;i<size;i++)
	{
		if(i+dst+0x000 < 18) //avoid param overwrite
			continue;

		vram[i+dst+0x000] = (condition) ? (m_data[i+(0)+src] & 0xff) : 0x20;

		vram[i+dst+0x400] = m_data[i+(size)+src] & 0xff;
	}
}

void nb1414m4_device::fill(UINT16 dst, UINT8 tile, UINT8 pal, UINT8 *vram)
{
	int i;

	for(i=0;i<0x400;i++)
	{
		if(i+dst+0x000 < 18) //avoid param overwrite
			continue;

		vram[i+dst+0x000] = tile;
		vram[i+dst+0x400] = pal;
	}
}

void nb1414m4_device::insert_coin_msg(UINT8 *vram)
{
	int credit_count = (vram[0xf] & 0xff);
	UINT8 fl_cond = m_screen->frame_number() & 0x10; /* for insert coin "flickering" */
	UINT16 dst;

	if(credit_count == 0)
	{
		dst = (m_data[0x01]<<8|m_data[0x02]) & 0x3fff;

		dma(0x0003,dst,0x10,fl_cond,vram);
	}
	else
	{
		dst = (m_data[0x49]<<8|m_data[0x4a]) & 0x3fff;

		dma(0x004b,dst,0x18,1,vram);
	}
}

void nb1414m4_device::credit_msg(UINT8 *vram)
{
	int credit_count = (vram[0xf] & 0xff);
	UINT8 fl_cond = m_screen->frame_number() & 0x10; /* for insert coin "flickering" */
	UINT16 dst;

	dst = ((m_data[0x023]<<8)|(m_data[0x024]&0xff)) & 0x3fff;
	dma(0x0025,dst,0x10,1,vram); /* credit */

	dst = ((m_data[0x045]<<8)|(m_data[0x046]&0xff)) & 0x3fff;
	dst++; // m_data is 0x5e, needs to be 0x5f ...
	vram[dst+0x000] = (credit_count + 0x30); /* credit num */
	vram[dst+0x400] = (m_data[0x48]);

	if(credit_count == 1) /* ONE PLAYER ONLY */
	{
		dst = ((m_data[0x07b]<<8)|(m_data[0x07c]&0xff)) & 0x3fff;
		dma(0x007d,dst,0x18,fl_cond,vram);
	}
	else if(credit_count > 1) /* ONE OR TWO PLAYERS */
	{
		dst = ((m_data[0x0ad]<<8)|(m_data[0x0ae]&0xff)) & 0x3fff;
		dma(0x00af,dst,0x18,fl_cond,vram);
	}
}

void nb1414m4_device::kozure_score_msg(UINT16 dst, UINT8 src_base, UINT8 *vram)
{
	int i;
	UINT8 first_digit;
	UINT8 res;

	first_digit = 0;

	for(i=0;i<6;i++)
	{
		res = ((vram[(i/2)+5+src_base*3] >> (!(i & 1) * 4)) & 0xf);

		if(first_digit || res)
		{
			vram[i+dst+0x0000] = res + 0x30;
			first_digit = 1;
		}
		else
			vram[i+dst+0x0000] = 0x20;

		vram[i+dst+0x0400] = m_data[0x10f+(src_base*0x1c)+i];
	}

	vram[6+dst+0x0000] = 0x30;
	vram[6+dst+0x0400] = m_data[0x10f+(src_base*0x1c)+6];
	vram[7+dst+0x0000] = 0x30;
	vram[7+dst+0x0400] = m_data[0x10f+(src_base*0x1c)+7];

}

void nb1414m4_device::_0200(UINT16 mcu_cmd, UINT8 *vram)
{
	UINT16 dst;

	dst = (m_data[0x330+((mcu_cmd & 0xf)*2)]<<8)|(m_data[0x331+((mcu_cmd & 0xf)*2)]&0xff);

	dst &= 0x3fff;

	if(dst & 0x7ff) // fill
		fill(0x0000,m_data[dst & 0x3fff],m_data[dst+1],vram);
	else // src -> dst
		dma(dst & 0x3fff,0x0000,0x400,1,vram);
}

/*
[0x02] & 0x01 p1 up
[0x02] & 0x02 p1 down
[0x02] & 0x04 p1 left
[0x02] & 0x08 p1 right
[0x02] & 0x10 p1 button 1
[0x02] & 0x20 p1 button 2
[0x02] & 0x40 p1 button 3
[0x03] & 0x01 p2 up
[0x03] & 0x02 p2 down
[0x03] & 0x04 p2 left
[0x03] & 0x08 p2 right
[0x03] & 0x10 p2 button 1
[0x03] & 0x20 p2 button 2
[0x03] & 0x40 p2 button 3
[0x04] & 0x10 service
[0x04] & 0x04 coin A
[0x04] & 0x08 coin B
[0x04] & 0x01 start 1
[0x04] & 0x02 start 2
[0x05] DSW1
[0x06] DSW2
[0x07] & 0x40 demo sounds ON / OFF
[0x07] & 0x7 lives setting
[0x07] & 0x80 cabinet (upright / table)
[0x07] & 0x30 difficulty (easy / normal / hard / hardest)
[0x0f] coinage A
[0x10] coinage B
[0x11] sound test num
*/
void nb1414m4_device::_0600(UINT8 is2p, UINT8 *vram)
{
	UINT16 dst;
	int i;

	dst = ((m_data[0x1f5]<<8)|(m_data[0x1f6]&0xff)) & 0x3fff;
	vram[dst] = (vram[7] & 0x7) + 0x30;//m_data[0x1f7];

	dst = ((m_data[0x1f8]<<8)|(m_data[0x1f9]&0xff)) & 0x3fff;
	dma(0x1fa + (((vram[7] & 0x30) >> 4) * 0x18),dst,12,1,vram);

	// 0x25a - 0x261 unknown meaning

	dst = ((m_data[0x262]<<8)|(m_data[0x263]&0xff)) & 0x3fff;
	dma(0x264 + (((vram[7] & 0x80) >> 7) * 0x18),dst,12,1,vram);

	dst = ((m_data[0x294]<<8)|(m_data[0x295]&0xff)) & 0x3fff;
	dma(0x296 + (((vram[7] & 0x40) >> 6) * 0x18),dst,12,1,vram);

	dst = ((m_data[0x2c6]<<8)|(m_data[0x2c7]&0xff)) & 0x3fff;
	vram[dst] = ((vram[0xf] & 0xf0) >> 4) + 0x30;//m_data[0x2c8];

	dst = ((m_data[0x2c9]<<8)|(m_data[0x2ca]&0xff)) & 0x3fff;
	vram[dst] = ((vram[0xf] & 0x0f) >> 0) + 0x30;//m_data[0x2cb];

	dst = ((m_data[0x2cc]<<8)|(m_data[0x2cd]&0xff)) & 0x3fff;
	vram[dst] = ((vram[0x10] & 0xf0) >> 4) + 0x30;//m_data[0x2ce];

	dst = ((m_data[0x2cf]<<8)|(m_data[0x2d0]&0xff)) & 0x3fff;
	vram[dst] = ((vram[0x10] & 0x0f) >> 0) + 0x30;//m_data[0x2d1];

	dst = ((m_data[0x2d2]<<8)|(m_data[0x2d3]&0xff)) & 0x3fff;
	vram[dst+0] = ((vram[0x11] & 0xf0) >> 4) + 0x30;//m_data[0x2d4];
	vram[dst+1] = (vram[0x11] & 0x0f) + 0x30;//m_data[0x2d5];

	dst = ((m_data[0x2d6]<<8)|(m_data[0x2d7]&0xff)) & 0x3fff;
	dma(0x2d8 + (is2p * 0x18),dst,12,1,vram); // 1p / 2p string

	dst = ((m_data[0x308]<<8)|(m_data[0x309]&0xff)) & 0x3fff;
	for(i=0;i<5;i++) /* system inputs */
		dma(0x310 + (((vram[0x04] >> (4-i)) & 1) * 6),dst + (i * 0x20),0x3,1,vram);

	dst = ((m_data[0x30a]<<8)|(m_data[0x30b]&0xff)) & 0x3fff;
	for(i=0;i<7;i++) /* 1p / 2p inputs */
		dma(0x310 + (((vram[0x02 + is2p] >> (6-i)) & 1) * 6),dst + (i * 0x20),0x3,1,vram);

	dst = ((m_data[0x30c]<<8)|(m_data[0x30d]&0xff)) & 0x3fff;
	for(i=0;i<8;i++) /* dips */
		dma(0x310 + (((vram[0x05] >> (7-i)) & 1) * 6),dst + (i * 0x20),0x3,1,vram);

	dst = ((m_data[0x30e]<<8)|(m_data[0x30f]&0xff)) & 0x3fff;
	for(i=0;i<8;i++) /* dips */
		dma(0x310 + (((vram[0x06] >> (7-i)) & 1) * 6),dst + (i * 0x20),0x3,1,vram);
}

void nb1414m4_device::_0e00(UINT16 mcu_cmd, UINT8 *vram)
{
	UINT16 dst;

	dst = ((m_data[0xdf]<<8)|(m_data[0xe0]&0xff)) & 0x3fff;
	dma(0x00e1,dst,8,1,vram); /* hi-score */

	if(mcu_cmd & 0x04)
	{
		dst = ((m_data[0xfb]<<8)|(m_data[0xfc]&0xff)) & 0x3fff;
		dma(0x00fd,dst,8,!(mcu_cmd & 1),vram); /* 1p-msg */
		dst = ((m_data[0x10d]<<8)|(m_data[0x10e]&0xff)) & 0x3fff;
		kozure_score_msg(dst,0,vram); /* 1p score */
		if(mcu_cmd & 0x80)
		{
			dst = ((m_data[0x117]<<8)|(m_data[0x118]&0xff)) & 0x3fff;
			dma(0x0119,dst,8,!(mcu_cmd & 2),vram); /* 2p-msg */
			dst = ((m_data[0x129]<<8)|(m_data[0x12a]&0xff)) & 0x3fff;
			kozure_score_msg(dst,1,vram); /* 2p score */
		}
	}
	else
	{
		dst = ((m_data[0x133]<<8)|(m_data[0x134]&0xff)) & 0x3fff;
		dma(0x0135,dst,0x10,!(mcu_cmd & 1),vram); /* game over */
		insert_coin_msg(vram);
		if((mcu_cmd & 0x18) == 0) // TODO: either one of these two disables credit display
			credit_msg(vram);
	}
}

void nb1414m4_device::exec(UINT16 mcu_cmd, UINT8 *vram, UINT16 &scrollx, UINT16 &scrolly, tilemap_t *tilemap)
{
	/* latch fg scroll values */
	scrollx = (vram[0x0d] & 0xff) | ((vram[0x0e] & 0xff) << 8);
	scrolly = (vram[0x0b] & 0xff) | ((vram[0x0c] & 0xff) << 8);

	/* process the command */
	switch(mcu_cmd & 0xff00)
	{
		/* title screen / continue screens */
		case 0x0000: insert_coin_msg(vram); credit_msg(vram); break;

		/* direct DMA'ing / fill */
		case 0x0200: _0200(mcu_cmd & 0x87,vram); break;

		/* service mode */
		case 0x0600: _0600(mcu_cmd & 1,vram); break;

		/* gameplay */
		case 0x0e00: _0e00(mcu_cmd & 0xff,vram); break;

		case 0x8000: break; //Ninja Emaki, attract mode
		case 0xff00: break; //Ninja Emaki POST, presumably invalid
		default:
			popmessage("NB 1414M4 executes %04x command, contact MAMEdev\n",mcu_cmd);
			break;
	}

	/* mark tiles dirty */
	tilemap->mark_all_dirty();
}
