/*
 * plus4memcsory256k.c - CSORY 256K EXPANSION emulation.
 *
 * 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.
 *
 */

#include "vice.h"

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

#include "cartio.h"
#include "lib.h"
#include "log.h"
#include "machine.h"
#include "mem.h"
#include "monitor.h"
#include "plus4mem.h"
#include "plus4memcsory256k.h"
#include "plus4memhannes256k.h"
#include "resources.h"
#include "snapshot.h"
#include "types.h"
#include "uiapi.h"


static log_t cs256k_log = LOG_DEFAULT;

static int cs256k_activate(void);
static int cs256k_deactivate(void);

int cs256k_enabled = 0;

static int cs256k_block = 0xf;
static int cs256k_segment = 3;

uint8_t *cs256k_ram = NULL;

/* Some prototypes */
static uint8_t cs256k_reg_read(uint16_t addr);
static void cs256k_reg_store(uint16_t addr, uint8_t value);
static int cs256k_dump(void);

static io_source_t cs256k_device = {
    "CSORY",              /* name of the device */
    IO_DETACH_RESOURCE,   /* use resource to detach the device when involved in a read-collision */
    "MemoryHack",         /* resource to set to '0' */
    0xfd15, 0xfd15, 0x00, /* range for the device, reg:$fd15 */
    1,                    /* read is always valid */
    cs256k_reg_store,     /* store function */
    NULL,                 /* NO poke function */
    cs256k_reg_read,      /* read function */
    NULL,                 /* TODO: peek function */
    cs256k_dump,          /* chip state information dump function */
    IO_CART_ID_NONE,      /* not a cartridge */
    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 *cs256k_list_item = NULL;

int set_cs256k_enabled(int value)
{
    int val = value ? 1 : 0;

    if (val == cs256k_enabled) {
        return 0;
    }

    if (!val) {
        if (cs256k_enabled) {
            if (cs256k_deactivate() < 0) {
                return -1;
            }
        }
        cs256k_enabled = 0;
        io_source_unregister(cs256k_list_item);
        cs256k_list_item = NULL;
        plus4_pio1_init(-1);
    } else {
        if (!cs256k_enabled) {
            if (cs256k_activate() < 0) {
                return -1;
            }
        }
        cs256k_enabled = 1;
        cs256k_list_item = io_source_register(&cs256k_device);
        plus4_pio1_init(1);
    }
    return 0;
}

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

void cs256k_init(void)
{
    cs256k_log = log_open("CS256K");
}

void cs256k_reset(void)
{
    cs256k_block = 0xf;
    cs256k_segment = 3;
}

static int cs256k_activate(void)
{
    cs256k_ram = lib_realloc((void *)cs256k_ram, (size_t)0x40000);

    log_message(cs256k_log, "CSORY 256KiB expansion installed.");

    cs256k_reset();
    return 0;
}

static int cs256k_deactivate(void)
{
    lib_free(cs256k_ram);
    cs256k_ram = NULL;
    return 0;
}

void cs256k_shutdown(void)
{
    if (cs256k_enabled) {
        cs256k_deactivate();
    }
}

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

static uint8_t cs256k_reg_read(uint16_t addr)
{
    return 0xff;
}

static void cs256k_reg_store(uint16_t addr, uint8_t value)
{
    cs256k_block = (value & 0xf);
    cs256k_segment = (value & 0xc0) >> 6;
}

void cs256k_store(uint16_t addr, uint8_t value)
{
    if (addr >= (cs256k_segment * 0x4000) && addr < ((cs256k_segment + 1) * 0x4000)) {
        cs256k_ram[(cs256k_block * 0x4000) + (addr & 0x3fff)] = value;
    } else {
        mem_ram[addr] = value;
    }
}

uint8_t cs256k_read(uint16_t addr)
{
    if (addr >= (cs256k_segment * 0x4000) && addr < ((cs256k_segment + 1) * 0x4000)) {
        return cs256k_ram[(cs256k_block * 0x4000) + (addr & 0x3fff)];
    } else {
        return mem_ram[addr];
    }
}


void cs256k_ram_inject(uint16_t addr, uint8_t value)
{
    cs256k_store(addr, value);
}

static int cs256k_dump(void)
{
    mon_out("Segment: %d ($%04X-$%04X), block: %d\n",
            cs256k_segment, cs256k_segment * 0x4000U,
            (cs256k_segment * 0x4000U) + 0x3fffU, cs256k_block);

    return 0;
}
