/*
 * zaxxon.c - Cartridge handling, Zaxxon cart.
 *
 * Written by
 *  Andreas Boose <viceteam@t-online.de>
 *  Markus Brenner <markus@brenner.de>
 *
 * 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.
 *
 */

#include "vice.h"

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

#define CARTRIDGE_INCLUDE_SLOTMAIN_API
#include "c64cartsystem.h"
#undef CARTRIDGE_INCLUDE_SLOTMAIN_API
#include "cartridge.h"
#include "export.h"
#include "snapshot.h"
#include "types.h"
#include "util.h"
#include "zaxxon.h"
#include "crt.h"

/*
    this cart uses 4Kb mapped in at $8000-$8FFF and mirrored at $9000-$9FFF
    and 2 banks of 8Kb mapped in at $A000-$BFFF.

    the banks at $A000-$BFFF are selected by a read access to either
    $8000-$8FFF (select bank 1 in $A000-$BFFF) or $9000-$9FFF (select bank 2
    at $A000-$BFFF)
 */

static const export_resource_t export_res = {
    CARTRIDGE_NAME_ZAXXON, 1, 1, NULL, NULL, CARTRIDGE_ZAXXON
};

uint8_t zaxxon_roml_read(uint16_t addr)
{
    cart_romhbank_set_slotmain((addr & 0x1000) ? 1 : 0);
    return roml_banks[(addr & 0x1fff) + (roml_bank << 13)];
}

int zaxxon_peek_mem(export_t *ex, uint16_t addr, uint8_t *value)
{
    if (addr >= 0x8000 && addr <= 0x9fff) {
        *value = roml_banks[(addr & 0x1fff) + (roml_bank << 13)];
        return CART_READ_VALID;
    }
    if (addr >= 0xa000 && addr <= 0xbfff) {
        *value = romh_banks[(addr & 0x1fff) + (romh_bank << 13)];
        return CART_READ_VALID;
    }
    return CART_READ_THROUGH;
}

void zaxxon_config_init(void)
{
    cart_config_changed_slotmain(CMODE_16KGAME, CMODE_16KGAME, CMODE_READ);
}

void zaxxon_config_setup(uint8_t *rawcart)
{
    memcpy(roml_banks, rawcart, 0x2000);
    memcpy(romh_banks, &rawcart[0x2000], 0x4000);
    cart_config_changed_slotmain(CMODE_16KGAME, CMODE_16KGAME, CMODE_READ);
}

static int zaxxon_common_attach(void)
{
    if (export_add(&export_res) < 0) {
        return -1;
    }

    return 0;
}

/* accept 20k (4k+16k) and 24k (8k+16k) binaries */
int zaxxon_bin_attach(const char *filename, uint8_t *rawcart)
{
    if (util_file_load(filename, rawcart, 0x6000, UTIL_FILE_LOAD_SKIP_ADDRESS) < 0) {
        if (util_file_load(filename, rawcart, 0x5000, UTIL_FILE_LOAD_SKIP_ADDRESS) < 0) {
            return -1;
        }
        memmove(&rawcart[0x1000], &rawcart[0x0000], 0x5000);
    }
    return zaxxon_common_attach();
}

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

    /* first CHIP header holds $8000-$a000 data */
    if (crt_read_chip_header(&chip, fd)) {
        return -1;
    }

    if (chip.start != 0x8000 || (chip.size != 0x1000 && chip.size != 0x2000)) {
        return -1;
    }

    if (crt_read_chip(rawcart, 0, &chip, fd)) {
        return -1;
    }

    /* 4kB ROM is mirrored to $9000 */
    if (chip.size == 0x1000) {
        memcpy(&rawcart[0x1000], &rawcart[0x0000], 0x1000);
    }

    /* second/third CHIP headers hold $a000-$c000 banked data */
    for (i = 0; i <= 1; i++) {
        if (crt_read_chip_header(&chip, fd)) {
            return -1;
        }

        if (chip.start != 0xa000 || chip.size != 0x2000 || chip.bank > 1) {
            return -1;
        }

        if (crt_read_chip(rawcart, 0x2000 + (chip.bank << 13), &chip, fd)) {
            return -1;
        }
    }

    return zaxxon_common_attach();
}

void zaxxon_detach(void)
{
    export_remove(&export_res);
}

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

/* CARTZAXXON snapshot module format:

   type  | name | description
   --------------------------
   ARRAY | ROML | 8192 BYTES of ROML data
   ARRAY | ROMH | 16384 BYTES of ROMH data
 */

static const char snap_module_name[] = "CARTZAXXON";
#define SNAP_MAJOR   0
#define SNAP_MINOR   0

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

    m = snapshot_module_create(s, snap_module_name, SNAP_MAJOR, SNAP_MINOR);

    if (m == NULL) {
        return -1;
    }

    if (0
        || SMW_BA(m, roml_banks, 0x2000) < 0
        || SMW_BA(m, romh_banks, 0x4000) < 0) {
        snapshot_module_close(m);
        return -1;
    }

    return snapshot_module_close(m);
}

int zaxxon_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;
    }

    /* Do not accept versions higher than current */
    if (snapshot_version_is_bigger(vmajor, vminor, SNAP_MAJOR, SNAP_MINOR)) {
        snapshot_set_error(SNAPSHOT_MODULE_HIGHER_VERSION);
        goto fail;
    }

    if (0
        || SMR_BA(m, roml_banks, 0x2000) < 0
        || SMR_BA(m, romh_banks, 0x4000) < 0) {
        goto fail;
    }

    snapshot_module_close(m);

    return zaxxon_common_attach();

fail:
    snapshot_module_close(m);
    return -1;
}