// license:BSD-3-Clause
// copyright-holders:Fabio Priuli,kmg
/***********************************************************************************************************


 NES/Famicom cartridge emulation for Nintendo NES-EVENT PCBs


 Here we emulate the following PCBs

 * Nintendo NES-EVENT [mapper 105]
 * Nintendo NES-EVENT2 [mapper 555]

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


#include "emu.h"
#include "event.h"


#ifdef NES_PCB_DEBUG
#define VERBOSE 1
#else
#define VERBOSE 0
#endif

#define LOG_MMC(x) do { if (VERBOSE) logerror x; } while (0)


//-------------------------------------------------
//  constructor
//-------------------------------------------------

DEFINE_DEVICE_TYPE(NES_EVENT,  nes_event_device,  "nes_event",  "NES Cart EVENT PCB")
DEFINE_DEVICE_TYPE(NES_EVENT2, nes_event2_device, "nes_event2", "NES Cart EVENT2 PCB")


nes_event_device::nes_event_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
	: nes_sxrom_device(mconfig, NES_EVENT, tag, owner, clock)
	, m_dsw(*this, "DIPSW")
	, m_nwc_init(0)
	, event_timer(nullptr)
	, m_timer_count(0)
	, m_timer_on(0)
	, m_timer_enabled(0)
{
}

nes_event2_device::nes_event2_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
	: nes_tqrom_device(mconfig, NES_EVENT2, tag, owner, clock)
	, m_dsw(*this, "DIPSW")
	, m_tqrom_mode(false)
	, event_timer(nullptr)
	, m_timer_count(0)
	, m_timer_enabled(0)
{
}


void nes_event_device::device_start()
{
	nes_sxrom_device::device_start();

	event_timer = timer_alloc(FUNC(nes_event_device::event_tick), this);
	event_timer->adjust(attotime::never);

	save_item(NAME(m_nwc_init));

	save_item(NAME(m_timer_count));
	save_item(NAME(m_timer_on));
	save_item(NAME(m_timer_enabled));
}

void nes_event_device::pcb_reset()
{
	nes_sxrom_device::pcb_reset();
	prg32(0);

	m_nwc_init = 2;

	m_timer_count = 0;
	m_timer_enabled = 0;
	m_timer_on = 0;
}

void nes_event2_device::device_start()
{
	mmc3_start();

	event_timer = timer_alloc(FUNC(nes_event2_device::event_tick), this);
	event_timer->adjust(attotime::zero, 0, clocks_to_attotime(1));

	save_item(NAME(m_tqrom_mode));

	save_item(NAME(m_timer_count));
	save_item(NAME(m_timer_enabled));
}

void nes_event2_device::pcb_reset()
{
	m_tqrom_mode = false;
	mmc3_common_initialize(0x07, 0x7f, 0);

	m_timer_count = 0;
	m_timer_enabled = 0;
}



/*-------------------------------------------------
 mapper specific handlers
 -------------------------------------------------*/

/*-------------------------------------------------

 EVENT PCB

 Games: Nintento World Championships 1990

 MMC1 variant with repurposed register at $a000 and a
 lot of discrete components

 iNES: mapper 105

 In MAME: Supported.

 -------------------------------------------------*/

void nes_event_device::set_chr()
{
	// no CHR switching, there are only 8KB VRAM from the cart
}

void nes_event_device::set_prg()
{
//  printf("enter with %d and reg1 0x%x - reg3 0x%x\n", m_nwc_init, m_reg[1], m_reg[3]);
	// reg[1] is different from base MMC1!
	// bit 0 is ignored, bit1/bit3 are used for PRG switch, bit4 is used for the timer
	// initially PRG is fixed, until bit4 of reg1 is set to 1 and then to 0
	switch (m_nwc_init)
	{
		case 2:
			if (BIT(m_reg[1], 4)) m_nwc_init--;
			return;
		case 1:
			if (!BIT(m_reg[1], 4)) m_nwc_init--;
			return;
	}

	// PRG mode 1 works similarly to base MMC1, but only acts on the higher 128KB (2nd PRG ROM)
	if (BIT(m_reg[1], 3))
		nes_sxrom_device::set_prg(0x08, 0x07);
	else
		prg32(BIT(m_reg[1], 1, 2));

	// after the init procedure above, bit4 of m_reg[1] is used to init IRQ, by setting and then clearing the bit
	// however, there are (bankswitch related?) writes with bit4 cleared before the one 'enabling' the timer, so
	// we need the additional m_timer_enabled variable, to avoid starting the timer before its time...
	if (BIT(m_reg[1], 4))
	{
		m_timer_count = 0;
		m_timer_enabled = 1;
		set_irq_line(CLEAR_LINE);
	}
	else if (!m_timer_on && m_timer_enabled)
	{
		event_timer->adjust(attotime::zero, 0, clocks_to_attotime(1));
		m_timer_on = 1;
	}
}

/*-------------------------------------------------

 EVENT2 PCB

 Games: Nintento Campus Challenge 1991

 Similar to the previous EVENT PCB, but based around
 the MMC3. Onboard 8K VRAM and 8K WRAM support Pinbot
 and SMB3, respectively, and an additional 2K WRAM at
 $5000 is used by the control routine. The board also
 featured an RJ11, used to transmit player names and
 scores to a display at the staged events.

 The present emulation is based on what is known via
 the reproduction board by RetroZone. That board is
 missing the RJ11, two DIP switches, and...?

 NES 2.0: mapper 555

 In MAME: Supported.

 -------------------------------------------------*/

u8 nes_event2_device::read_l(offs_t offset)
{
// LOG_MMC(("event2 read_l, offset: %04x\n", offset));
	offset += 0x100;
	if (offset >= 0x1800)
		return (m_timer_count >= (0x10 | m_dsw->read()) << 25) ? 0x80 : 0;
	else if (offset < 0x1000 || m_prgram.empty())
		return get_open_bus();
	else
		return m_prgram[(0x2000 + (offset & 0x7ff)) % m_prgram.size()];
}

u8 nes_event2_device::read_m(offs_t offset)
{
// LOG_MMC(("event2 read_m, offset: %04x\n", offset));
	if (m_prgram.empty())
		return get_open_bus();
	else
		return m_prgram[offset % m_prgram.size()];
}

void nes_event2_device::write_l(offs_t offset, u8 data)
{
	LOG_MMC(("event2 write_l, offset: %04x, data: %02x\n", offset, data));

	offset += 0x100;
	switch (offset & 0x1c00)
	{
		case 0x1000:
		case 0x1400:
			m_prgram[(0x2000 + (offset & 0x7ff)) % m_prgram.size()] = data;
			break;
		case 0x1800:
			m_tqrom_mode = (data & 0x06) == 0x02;

			m_prg_base = (data & 0x04) << 3;
			m_prg_mask = (data & 0x03) << 3 | 0x07;
			set_prg(m_prg_base, m_prg_mask);

			m_chr_base = m_prg_base << 2;
			set_chr(m_chr_source, m_chr_base, m_chr_mask);

			m_timer_enabled = BIT(data, 3);
			if (!m_timer_enabled)
				m_timer_count = 0;
			break;
	}
}

void nes_event2_device::write_m(offs_t offset, u8 data)
{
// LOG_MMC(("event2 write_m, offset: %04x, data: %02x\n", offset, data));
	if (!m_prgram.empty())
		m_prgram[offset % m_prgram.size()] = data;
}

void nes_event2_device::chr_cb(int start, int bank, int source)
{
	if (m_tqrom_mode)
		nes_tqrom_device::chr_cb(start, bank, source);
	else
		nes_txrom_device::chr_cb(start, bank, source);
}


//-------------------------------------------------
//  Dipswitch
//-------------------------------------------------

static INPUT_PORTS_START( nwc_dsw )
	PORT_START("DIPSW")
	PORT_DIPNAME( 0x0f, 0x04, "Timer" ) PORT_DIPLOCATION("SW:!1,!2,!3,!4")
	PORT_DIPSETTING( 0x00, "5:00.4" )
	PORT_DIPSETTING( 0x01, "5:19.2" )
	PORT_DIPSETTING( 0x02, "5:38.0" )
	PORT_DIPSETTING( 0x03, "5:56.7" )
	PORT_DIPSETTING( 0x04, "6:15.5" )
	PORT_DIPSETTING( 0x05, "6:34.3" )
	PORT_DIPSETTING( 0x06, "6:53.1" )
	PORT_DIPSETTING( 0x07, "7:11.9" )
	PORT_DIPSETTING( 0x08, "7:30.6" )
	PORT_DIPSETTING( 0x09, "7:49.4" )
	PORT_DIPSETTING( 0x0a, "8:08.2" )
	PORT_DIPSETTING( 0x0b, "8:27.0" )
	PORT_DIPSETTING( 0x0c, "8:45.8" )
	PORT_DIPSETTING( 0x0d, "9:04.5" )
	PORT_DIPSETTING( 0x0e, "9:23.3" )
	PORT_DIPSETTING( 0x0f, "9:42.1" )
INPUT_PORTS_END



ioport_constructor nes_event_device::device_input_ports() const
{
	return INPUT_PORTS_NAME( nwc_dsw );
}

ioport_constructor nes_event2_device::device_input_ports() const
{
	return INPUT_PORTS_NAME( nwc_dsw );
}


//-------------------------------------------------
//  event_tick - tick the event timer
//-------------------------------------------------

TIMER_CALLBACK_MEMBER(nes_event_device::event_tick)
{
	if (m_timer_on)
	{
		if (++m_timer_count >= (0x10 | m_dsw->read()) << 25)
		{
			set_irq_line(ASSERT_LINE);
			event_timer->reset();
		}
	}
}

TIMER_CALLBACK_MEMBER(nes_event2_device::event_tick)
{
	if (m_timer_enabled)
		m_timer_count++;
}
