/*
 * gs.c - Cartridge handling, GS cart.
 *
 * Written by
 *  Marco van den Heuvel <blackystardust68@yahoo.com>
 *
 * This file is part of VICE, the Versatile Commodore Emulator.
 * See README for copyright notice.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 *  02111-1307  USA.
 *
 */

/* #define DEBUGC64GS */

#include "vice.h"

#include <stdio.h>
#include <string.h>

#define CARTRIDGE_INCLUDE_SLOTMAIN_API
#include "c64cartsystem.h"
#undef CARTRIDGE_INCLUDE_SLOTMAIN_API
#include "cartio.h"
#include "cartridge.h"
#include "export.h"
#include "gs.h"
#include "log.h"
#include "monitor.h"
#include "snapshot.h"
#include "types.h"
#include "util.h"
#include "crt.h"

#ifdef DEBUGC64GS
#define DBG(x)  log_printf x
#else
#define DBG(x)
#endif

/*
    C64GS (C64 Game System/System 3) Cartridge

    - 512kb ROM (64*8k), (permanently) mapped to $8000 in 8k game config

    - on any access (read or write) to IO1, the lower 6 bits of the address will
      be latched and used as the bank number

    CAUTION: the above is confirmed to be correct from looking at the "C64GS 4in1"
    cartridge, whether the same is true for the System 3 cartridges is unknown yet.
*/

static int currbank = 0;
static uint8_t regval = 0;

static void gs_io1_store(uint16_t addr, uint8_t value)
{
    regval = value;
    currbank = addr & 0x3f;
    cart_romlbank_set_slotmain(currbank);
    cart_port_config_changed_slotmain();
    DBG(("C64GS: w addr: $de%02x bank: $%02x value: $%02x", addr, currbank, value));
}

static uint8_t gs_io1_read(uint16_t addr)
{
    currbank = addr & 0x3f;
    cart_romlbank_set_slotmain(currbank);
    cart_port_config_changed_slotmain();
    DBG(("C64GS: r addr: $de%02x bank: $%02x", addr, currbank));
    return 0;
}

static uint8_t gs_io1_peek(uint16_t addr)
{
    return regval;
}

static int gs_dump(void)
{
    mon_out("Bank: %d\n", currbank);
    return 0;
}

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

static io_source_t gs_device = {
    CARTRIDGE_NAME_GS,     /* name of the device */
    IO_DETACH_CART,        /* use cartridge ID to detach the device when involved in a read-collision */
    IO_DETACH_NO_RESOURCE, /* does not use a resource for detach */
    0xde00, 0xdeff, 0x3f,  /* range for the device, regs:$de00-$de3f, mirrors:$de40-$deff */
    0,                     /* read is never valid */
    gs_io1_store,          /* store function */
    NULL,                  /* NO poke function */
    gs_io1_read,           /* read function */
    gs_io1_peek,           /* peek function */
    gs_dump,               /* device state information dump function */
    CARTRIDGE_GS,          /* cartridge ID */
    IO_PRIO_NORMAL,        /* normal priority, device read needs to be checked for collisions */
    0,                     /* insertion order, gets filled in by the registration function */
    IO_MIRROR_NONE         /* NO mirroring */
};

static io_source_list_t *gs_list_item = NULL;

static const export_resource_t export_res = {
    CARTRIDGE_NAME_GS, 0, 1, &gs_device, NULL, CARTRIDGE_GS
};

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

void gs_config_init(void)
{
    /* 8k configuration */
    cart_config_changed_slotmain(CMODE_8KGAME, CMODE_8KGAME, CMODE_READ);
    gs_io1_store((uint16_t)0xde00, 0);
}

void gs_config_setup(uint8_t *rawcart)
{
    memcpy(roml_banks, rawcart, 0x2000 * 64);
    /* 8k configuration */
    cart_config_changed_slotmain(CMODE_8KGAME, CMODE_8KGAME, CMODE_READ);
}

/* ---------------------------------------------------------------------*/
static int gs_common_attach(void)
{
    if (export_add(&export_res) < 0) {
        return -1;
    }
    gs_list_item = io_source_register(&gs_device);
    return 0;
}

int gs_bin_attach(const char *filename, uint8_t *rawcart)
{
    if (util_file_load(filename, rawcart, 0x80000, UTIL_FILE_LOAD_SKIP_ADDRESS) < 0) {
        return -1;
    }
    return gs_common_attach();
}

int gs_crt_attach(FILE *fd, uint8_t *rawcart)
{
    crt_chip_header_t chip;

    while (1) {
        if (crt_read_chip_header(&chip, fd)) {
            break;
        }
        if (chip.bank > 63 || (chip.start != 0x8000) || chip.size != 0x2000) {
            return -1;
        }
        if (crt_read_chip(rawcart, chip.bank << 13, &chip, fd)) {
            return -1;
        }
    }
    return gs_common_attach();
}

void gs_detach(void)
{
    export_remove(&export_res);
    io_source_unregister(gs_list_item);
    gs_list_item = NULL;
}

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

#define CART_DUMP_VER_MAJOR   1
#define CART_DUMP_VER_MINOR   1
#define SNAP_MODULE_NAME  "CARTGS"

int gs_snapshot_write_module(snapshot_t *s)
{
    snapshot_module_t *m;

    m = snapshot_module_create(s, SNAP_MODULE_NAME,
                               CART_DUMP_VER_MAJOR, CART_DUMP_VER_MINOR);
    if (m == NULL) {
        return -1;
    }

    if (0
        || (SMW_B(m, regval) < 0)
        || (SMW_B(m, (uint8_t)currbank) < 0)
        || (SMW_BA(m, roml_banks, 0x2000 * 64) < 0)) {
        snapshot_module_close(m);
        return -1;
    }

    snapshot_module_close(m);
    return 0;
}

int gs_snapshot_read_module(snapshot_t *s)
{
    uint8_t vmajor, vminor;
    snapshot_module_t *m;

    m = snapshot_module_open(s, SNAP_MODULE_NAME, &vmajor, &vminor);
    if (m == NULL) {
        return -1;
    }

    if ((vmajor != CART_DUMP_VER_MAJOR) || (vminor != CART_DUMP_VER_MINOR)) {
        snapshot_module_close(m);
        return -1;
    }

    if (0
        || (SMR_B(m, &regval) < 0)
        || (SMR_B_INT(m, &currbank) < 0)
        || (SMR_BA(m, roml_banks, 0x2000 * 64) < 0)) {
        snapshot_module_close(m);
        return -1;
    }

    snapshot_module_close(m);

    return gs_common_attach();
}
