/**

 * $Id: dreamcast.c,v 1.15 2006-05-15 08:28:48 nkeynes Exp $

 * Central switchboard for the system. This pulls all the individual modules

 * together into some kind of coherent structure. This is also where you'd

 * add Naomi support, if I ever get a board to play with...

 *

 * Copyright (c) 2005 Nathan Keynes.

 *

 * 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.

 */

#include <errno.h>

#include <glib/gstrfuncs.h>

#include "dream.h"

#include "mem.h"

#include "aica/aica.h"

#include "asic.h"

#include "dreamcast.h"

#include "gdrom/ide.h"

#include "maple/maple.h"

/**

 * Current state of the DC virtual machine

 */

#define STATE_UNINIT 0

#define STATE_RUNNING 1

#define STATE_STOPPING 2

#define STATE_STOPPED 3 

static volatile int dreamcast_state = STATE_UNINIT;

static uint32_t timeslice_length = DEFAULT_TIMESLICE_LENGTH;

static char *dreamcast_config = "DEFAULT";

#define MAX_MODULES 32

static int num_modules = 0;

dreamcast_module_t modules[MAX_MODULES];

/**

 * The unknown module is used for logging files without an actual module

 * declaration

 */

struct dreamcast_module unknown_module = { "****", NULL, NULL, NULL, NULL, 

					   NULL, NULL, NULL };

/**

 * This function is responsible for defining how all the pieces of the

 * dreamcast actually fit together. 

 *

 * Note currently the locations of the various MMIO pages are hard coded in

 * the MMIO definitions - they should probably be moved here.

 */

void dreamcast_configure( )

{

    /* Register the memory framework */

    dreamcast_register_module( &mem_module );

    /* Setup standard memory map */

    mem_create_ram_region( 0x0C000000, 16 MB, MEM_REGION_MAIN );

    mem_create_ram_region( 0x00800000, 2 MB, MEM_REGION_AUDIO );

    mem_create_ram_region( 0x00703000, 8 KB, MEM_REGION_AUDIO_SCRATCH );

    mem_create_ram_region( 0x05000000, 8 MB, MEM_REGION_VIDEO );

    mem_load_rom( "dcboot.rom", 0x00000000, 0x00200000, 0x89f2b1a1 );

    mem_load_rom( "dcflash.rom",0x00200000, 0x00020000, 0x357c3568 );

    /* Load in the rest of the core modules */

    dreamcast_register_module( &sh4_module );

    dreamcast_register_module( &asic_module );

    dreamcast_register_module( &pvr2_module );

    dreamcast_register_module( &aica_module );

    dreamcast_register_module( &maple_module );

    dreamcast_register_module( &ide_module );

    /* Attach any default maple devices, ie a pair of controllers */

    /*

    maple_device_t controller1 = maple_new_device("Sega Controller");

    maple_device_t controller2 = maple_new_device("Sega Controller");

    maple_attach_device( controller1, 0, 0 );

    maple_attach_device( controller2, 1, 0 );

    */

}

/**

 * Constructs a system configuration for the AICA in standalone mode,

 * ie sound chip only.

 */

void dreamcast_configure_aica_only( )

{

    dreamcast_register_module( &mem_module );

    mem_create_ram_region( 0x00800000, 2 MB, MEM_REGION_AUDIO );

    mem_create_ram_region( 0x00703000, 8 KB, MEM_REGION_AUDIO_SCRATCH );

    dreamcast_register_module( &aica_module );

    aica_enable();

    dreamcast_state = STATE_STOPPED;

}

void dreamcast_register_module( dreamcast_module_t module ) 

{

    modules[num_modules++] = module;

    if( module->init != NULL )

	module->init();

}

void dreamcast_init( void )

{

    dreamcast_configure();

    dreamcast_state = STATE_STOPPED;

}

void dreamcast_reset( void )

{

    int i;

    for( i=0; i<num_modules; i++ ) {

	if( modules[i]->reset != NULL )

	    modules[i]->reset();

    }

}

void dreamcast_run( void )

{

    int i;

    if( dreamcast_state != STATE_RUNNING ) {

	for( i=0; i<num_modules; i++ ) {

	    if( modules[i]->start != NULL )

		modules[i]->start();

	}

    }

    dreamcast_state = STATE_RUNNING;

    while( dreamcast_state == STATE_RUNNING ) {

	int time_to_run = timeslice_length;

	for( i=0; i<num_modules; i++ ) {

	    if( modules[i]->run_time_slice != NULL )

		time_to_run = modules[i]->run_time_slice( time_to_run );

	}

    }

    for( i=0; i<num_modules; i++ ) {

	if( modules[i]->stop != NULL )

	    modules[i]->stop();

    }

    dreamcast_state = STATE_STOPPED;

}

void dreamcast_stop( void )

{

    if( dreamcast_state == STATE_RUNNING )

	dreamcast_state = STATE_STOPPING;

}

gboolean dreamcast_is_running( void )

{

    return dreamcast_state == STATE_RUNNING;

}

/***************************** User Configuration **************************/

static struct dreamcast_config_entry global_config[] =

    {{ "bios", CONFIG_TYPE_FILE, "dcboot.rom" },

     { "flash", CONFIG_TYPE_FILE, "dcflash.rom" },

     { "default path", CONFIG_TYPE_PATH, "." },

     { "save path", CONFIG_TYPE_PATH, "save" },

     { "bootstrap", CONFIG_TYPE_FILE, "IP.BIN" },

     { NULL, CONFIG_TYPE_NONE }};

static struct dreamcast_config_entry serial_config[] =

    {{ "device", CONFIG_TYPE_FILE, "/dev/ttyS1" },

     { NULL, CONFIG_TYPE_NONE }};

struct dreamcast_config_group dreamcast_config_root[] = 

    {{ "global", global_config },

     { "controllers", NULL },

     { "serial", serial_config },

     { NULL, CONFIG_TYPE_NONE }};

void dreamcast_set_default_config( )

{

    struct dreamcast_config_group *group = dreamcast_config_root;

    while( group->key != NULL ) {

	struct dreamcast_config_entry *param = group->params;

	if( param != NULL ) {

	    while( param->key != NULL ) {

		if( param->value != param->default_value ) {

		    if( param->value != NULL )

			free( param->value );

		    param->value = (gchar *)param->default_value;

		}

		param++;

	    }

	}

	group++;

    }

    maple_detach_all();

}

gboolean dreamcast_load_config( const gchar *filename )

{

    FILE *f = fopen(filename, "ro");

    gboolean result;

    if( f == NULL ) {

	ERROR( "Unable to open '%s': %s", filename, strerror(errno) );

	return FALSE;

    }

    result = dreamcast_load_config_stream( f );

    fclose(f);

    return result;

}

gboolean dreamcast_load_config_stream( FILE *f )

{

    char buf[512], *p;

    int maple_device = -1, maple_subdevice = -1;

    struct dreamcast_config_group devgroup;

    struct dreamcast_config_group *group = NULL;

    maple_device_t device = NULL;

    dreamcast_set_default_config();

    while( fgets( buf, sizeof(buf), f ) != NULL ) {

	g_strstrip(buf);

	if( buf[0] == '#' )

	    continue;

	if( *buf == '[' ) {

	    char *p = strchr(buf, ']');

	    if( p != NULL ) {

		struct dreamcast_config_group *tmp_group;

		maple_device = maple_subdevice = -1;

		*p = '\0';

		g_strstrip(buf+1);

		tmp_group = &dreamcast_config_root[0];

		while( tmp_group->key != NULL ) {

		    if( strcasecmp(tmp_group->key, buf+1) == 0 ) {

			group = tmp_group;

			break;

		    }

		    tmp_group++;

		}

	    }

	} else if( group != NULL ) {

	    char *value = strchr( buf, '=' );

	    if( value != NULL ) {

		struct dreamcast_config_entry *param = group->params;

		*value = '\0';

		value++;

		g_strstrip(buf);

		g_strstrip(value);

		if( strcmp(group->key,"controllers") == 0  ) {

		    if( g_strncasecmp( buf, "device ", 7 ) == 0 ) {

			maple_device = strtoul( buf+7, NULL, 0 );

			if( maple_device < 0 || maple_device > 3 ) {

			    ERROR( "Device number must be between 0..3 (not '%s')", buf+7);

			    continue;

			}

			maple_subdevice = 0;

			device = maple_new_device( value );

			if( device == NULL ) {

			    ERROR( "Unrecognized device '%s'", value );

			} else {

			    devgroup.key = "controllers";

			    devgroup.params = maple_get_device_config(device);

			    maple_attach_device( device, maple_device, maple_subdevice );

			    group = &devgroup;

			}

			continue;

		    } else if( g_strncasecmp( buf, "subdevice ", 10 ) == 0 ) {

			maple_subdevice = strtoul( buf+10, NULL, 0 );

			if( maple_device == -1 ) {

			    ERROR( "Subdevice not allowed without primary device" );

			} else if( maple_subdevice < 1 || maple_subdevice > 5 ) {

			    ERROR( "Subdevice must be between 1..5 (not '%s')", buf+10 );

			} else if( (device = maple_new_device(value)) == NULL ) {

			    ERROR( "Unrecognized subdevice '%s'", value );

			} else {

			    devgroup.key = "controllers";

			    devgroup.params = maple_get_device_config(device);

			    maple_attach_device( device, maple_device, maple_subdevice );

			    group = &devgroup;

			}

			continue;

		    }

		}

		while( param->key != NULL ) {

		    if( strcasecmp( param->key, buf ) == 0 ) {

			param->value = g_strdup(value);

			break;

		    }

		    param++;

		}

	    }

	}

    }

    return TRUE;

}

gboolean dreamcast_save_config( const gchar *filename )

{

    FILE *f = fopen(filename, "wo");

    gboolean result;

    if( f == NULL ) {

	ERROR( "Unable to open '%s': %s", filename, strerror(errno) );

	return FALSE;

    }

    result = dreamcast_save_config_stream(f);

    fclose(f);

}    

gboolean dreamcast_save_config_stream( FILE *f )

{

    struct dreamcast_config_group *group = &dreamcast_config_root[0];

    while( group->key != NULL ) {

	struct dreamcast_config_entry *entry = group->params;

	fprintf( f, "[%s]\n", group->key );

	if( entry != NULL ) {

	    while( entry->key != NULL ) {

		fprintf( f, "%s = %s\n", entry->key, entry->value );

		entry++;

	    }

	} else if( strcmp(group->key, "controllers") == 0 ) {

	    int i,j;

	    for( i=0; i<4; i++ ) {

		for( j=0; j<6; j++ ) {

		    maple_device_t dev = maple_get_device( i, j );

		    if( dev != NULL ) {

			if( j == 0 )

			    fprintf( f, "Device %d = %s\n", i, dev->device_class->name );

			else 

			    fprintf( f, "Subdevice %d = %s\n", j, dev->device_class->name );

			entry = dev->get_config(dev);

			while( entry->key != NULL ) {

			    fprintf( f, "%*c%s = %s\n", j==0?4:8, ' ',entry->key, entry->value );

			    entry++;

			}

		    }

		}

	    }

	}

	fprintf( f, "\n" );

	group++;

    }

    return TRUE;

}

/********************************* Save States *****************************/

#define DREAMCAST_SAVE_MAGIC "%!-DreamOn!Save\0"

#define DREAMCAST_SAVE_VERSION 0x00010000

struct save_state_header {

    char magic[16];

    uint32_t version;

    uint32_t module_count;

};

int dreamcast_load_state( const gchar *filename )

{

    int i,j;

    uint32_t count, len;

    int have_read[MAX_MODULES];

    char tmp[64];

    struct save_state_header header;

    FILE *f;

    f = fopen( filename, "r" );

    if( f == NULL ) return errno;

    fread( &header, sizeof(header), 1, f );

    if( strncmp( header.magic, DREAMCAST_SAVE_MAGIC, 16 ) != 0 ) {

	ERROR( "Not a DreamOn save state file" );

	return 1;

    }

    if( header.version != DREAMCAST_SAVE_VERSION ) {

	ERROR( "DreamOn save state version not supported" );

	return 1;

    }

    if( header.module_count > MAX_MODULES ) {

	ERROR( "DreamOn save state is corrupted (bad module count)" );

	return 1;

    }

    for( i=0; i<MAX_MODULES; i++ ) {

	have_read[i] = 0;

    }

    for( i=0; i<header.module_count; i++ ) {

	fread(tmp, 4, 1, f );

	if( strncmp(tmp, "BLCK", 4) != 0 ) {

	    ERROR( "DreamOn save state is corrupted (missing block header %d)", i );

	    return 2;

	}

	len = fread_string(tmp, sizeof(tmp), f );

	if( len > 64 || len < 1 ) {

	    ERROR( "DreamOn save state is corrupted (bad string)" );

	    return 2;

	}

	/* Find the matching module by name */

	for( j=0; j<num_modules; j++ ) {

	    if( strcmp(modules[j]->name,tmp) == 0 ) {

		have_read[j] = 1;

		if( modules[j]->load == NULL ) {

		    ERROR( "DreamOn save state is corrupted (no loader for %s)", modules[j]->name );

		    return 2;

		} else if( modules[j]->load(f) != 0 ) {

		    ERROR( "DreamOn save state is corrupted (%s failed)", modules[j]->name );

		    return 2;

		}

		break;

	    }

	}

	if( j == num_modules ) {

	    ERROR( "DreamOn save state contains unrecognized section" );

	    return 2;

	}

    }

    /* Any modules that we didn't load - reset to the default state.

     * (ie it's not an error to skip a module if you don't actually

     * care about its state).

     */

    for( j=0; j<num_modules; j++ ) {

	if( have_read[j] == 0 && modules[j]->reset != NULL ) {

	    modules[j]->reset();

	}

    }

    fclose(f);

    INFO( "Save state read from %s", filename );

}

int dreamcast_save_state( const gchar *filename )

{

    int i;

    FILE *f;

    struct save_state_header header;

    f = fopen( filename, "w" );

    if( f == NULL )

	return errno;

    strcpy( header.magic, DREAMCAST_SAVE_MAGIC );

    header.version = DREAMCAST_SAVE_VERSION;

    header.module_count = 0;

    for( i=0; i<num_modules; i++ ) {

	if( modules[i]->save != NULL )

	    header.module_count++;

    }

    fwrite( &header, sizeof(header), 1, f );

    for( i=0; i<num_modules; i++ ) {

	if( modules[i]->save != NULL ) {

	    fwrite( "BLCK", 4, 1, f );

	    fwrite_string( modules[i]->name, f );

	    modules[i]->save(f);

	}

    }

    fclose( f );

    INFO( "Save state written to %s", filename );

}