oolite/src/Core/Scripting/OOJavaScriptEngine.m

/*

OOJavaScriptEngine.h

JavaScript support for Oolite
Copyright (C) 2007 David Taylor and Jens Ayton.

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., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA.

*/

#import "OOJavaScriptEngine.h"
#import "OOJSScript.h"
#import "OOCollectionExtractors.h"
#import "Universe.h"
#import "PlanetEntity.h"
#import "NSStringOOExtensions.h"

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


extern NSString * const kOOLogDebugMessage;


static OOJavaScriptEngine *sSharedEngine = nil;
static JSObject *xglob, *universeObj, *systemObj, *playerObj, *missionObj;


extern OOJSScript *currentOOJSScript;


OOINLINE jsval BOOLToJSVal(BOOL b) INLINE_CONST_FUNC;
OOINLINE jsval BOOLToJSVal(BOOL b)
{
	return BOOLEAN_TO_JSVAL(b != NO);
}


// For _bool scripting methods which always return @"YES" or @"NO" and nothing else.
OOINLINE jsval BooleanStringToJSVal(NSString *string) INLINE_PURE_FUNC;
OOINLINE jsval BooleanStringToJSVal(NSString *string)
{
	return BOOLEAN_TO_JSVAL([string isEqualToString:@"YES"]);
}


#define JSValToNSString(cx, val) [NSString stringWithJavaScriptValue:val inContext:cx]


static void ReportJSError(JSContext *cx, const char *message, JSErrorReport *report);


//===========================================================================
// MissionVars class
//===========================================================================

static JSBool MissionVarsGetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp);
static JSBool MissionVarsSetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp);


static JSClass MissionVars_class =
{
	"MissionVariables",
	JSCLASS_HAS_PRIVATE,
	
	JS_PropertyStub,
	JS_PropertyStub,
	MissionVarsGetProperty,
	MissionVarsSetProperty,
	JS_EnumerateStub,
	JS_ResolveStub,
	JS_ConvertStub,
	JS_FinalizeStub
};


static JSBool MissionVarsGetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp)
{
	NSDictionary	*mission_variables = [[PlayerEntity sharedPlayer] mission_variables];
	
	if (JSVAL_IS_STRING(name))
	{
		NSString	*key = [@"mission_" stringByAppendingString:[NSString stringWithJavaScriptValue:name inContext:cx]];
		NSString	*value = [mission_variables objectForKey:key];
		
		if (value == nil)
		{
			*vp = JSVAL_VOID;
		}
		else
		{
			/*	The point of this code is to try and tell the JS interpreter to treat numeric strings
				as numbers where possible so that standard arithmetic works as you'd expect rather than
				1+1 == "11". So a JSVAL_DOUBLE is returned if possible, otherwise a JSVAL_STRING is returned.
			*/
			
			BOOL	isNumber = NO;
			double	dVal;
			
			dVal = [value doubleValue];
			if (dVal != 0) isNumber = YES;
			else
			{
				NSCharacterSet *notZeroSet = [[NSCharacterSet characterSetWithCharactersInString:@"-0. "] invertedSet];
				if ([value rangeOfCharacterFromSet:notZeroSet].location == NSNotFound) isNumber = YES;
			}
			if (isNumber)
			{
				jsdouble ds = [value doubleValue];
				JSBool ok = JS_NewDoubleValue(cx, ds, vp);
				if (!ok) *vp = JSVAL_VOID;
			}
			else *vp = [value javaScriptValueInContext:cx];
		}
	}
	return JS_TRUE;
}


static JSBool MissionVarsSetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp)
{
	NSDictionary *mission_variables = [[PlayerEntity sharedPlayer] mission_variables];

	if (JSVAL_IS_STRING(name))
	{
		NSString	*key = [@"mission_" stringByAppendingString:[NSString stringWithJavaScriptValue:name inContext:cx]];
		NSString	*value = [NSString stringWithJavaScriptValue:*vp inContext:cx];
		[mission_variables setValue:value forKey:key];
	}
	return JS_TRUE;
}

//===========================================================================
// Global object class
//===========================================================================

static JSBool GlobalGetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp);


static JSClass global_class =
{
	"Oolite",
	0,
	
	JS_PropertyStub,
	JS_PropertyStub,
	JS_PropertyStub,
	JS_PropertyStub,
	JS_EnumerateStub,
	JS_ResolveStub,
	JS_ConvertStub,
	JS_FinalizeStub
};


enum global_propertyIDs
{
	GLOBAL_GALAXY_NUMBER,
	GLOBAL_PLANET_NUMBER,
	GLOBAL_MISSION_VARS,
	GLOBAL_GUI_SCREEN
};


// TODO: most of these should be properties of Player class.
static JSPropertySpec Global_props[] =
{
	// JS name					ID							flags
	{ "galaxyNumber",			GLOBAL_GALAXY_NUMBER,		JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY, GlobalGetProperty },
	{ "planetNumber",			GLOBAL_PLANET_NUMBER,		JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY, GlobalGetProperty },
	{ "missionVariables",		GLOBAL_MISSION_VARS,		JSPROP_PERMANENT | JSPROP_ENUMERATE, GlobalGetProperty },
	{ "guiScreen",				GLOBAL_GUI_SCREEN,			JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY, GlobalGetProperty },
	{ 0 }
};


static JSBool GlobalLog(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool GlobalLogWithClass(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);


static JSFunctionSpec Global_funcs[] =
{
	{ "Log", GlobalLog, 1, 0 },
	{ "LogWithClass", GlobalLogWithClass, 2, 0 },
	{ 0 }
};


static JSBool GlobalLog(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	NSString *logString = [NSString concatenationOfStringsFromJavaScriptValues:argv count:argc separator:@", " inContext:cx];
	OOLog(kOOLogDebugMessage, logString);
	return JS_TRUE;
}


static JSBool GlobalLogWithClass(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	NSString *logString = [NSString concatenationOfStringsFromJavaScriptValues:argv + 1 count:argc - 1 separator:@", " inContext:cx];
	OOLog([NSString stringWithJavaScriptValue:argv[0] inContext:cx], logString);
	return JS_TRUE;
}


static JSBool GlobalGetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp)
{
	if (!JSVAL_IS_INT(name)) return JS_TRUE;
	
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	id<OOJavaScriptConversion> result = nil;
	
	switch (JSVAL_TO_INT(name))
	{
		case GLOBAL_GALAXY_NUMBER:
			result = [playerEntity galaxy_number];
			break;
		
		case GLOBAL_PLANET_NUMBER:
			result = [playerEntity planet_number];
			break;

		case GLOBAL_GUI_SCREEN:
			result = [playerEntity gui_screen_string];
			break;

		case GLOBAL_MISSION_VARS: {
			JSObject *mv = JS_DefineObject(cx, xglob, "missionVariables", &MissionVars_class, 0x00, JSPROP_ENUMERATE | JSPROP_READONLY | JSPROP_PERMANENT);
			*vp = OBJECT_TO_JSVAL(mv);
			break;
		}
	}
	
	if (result != nil) *vp = [result javaScriptValueInContext:cx];
	return JS_TRUE;
}


//===========================================================================
// Player proxy
//===========================================================================

static JSBool PlayerGetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp);
static JSBool PlayerSetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp);


static JSClass Player_class =
{
	"Player",
	JSCLASS_HAS_PRIVATE,
	
	JS_PropertyStub,
	JS_PropertyStub,
	PlayerGetProperty,
	PlayerSetProperty,
	JS_EnumerateStub,
	JS_ResolveStub,
	JS_ConvertStub,
	JS_FinalizeStub
};


enum Player_propertyIDs
{
	PE_SHIP_DESCRIPTION,
	PE_COMMANDER_NAME,
	PE_SCORE,
	PE_CREDITS,
	PE_LEGAL_STATUS,
	PE_FUEL_LEVEL,
	PE_FUEL_LEAK_RATE,
	PE_ALERT_CONDITION,
	PE_STATUS_STRING,
	PE_DOCKED_AT_MAIN_STATION,
	PE_DOCKED_STATION_NAME,
	
	// Special handling -- these correspond to ALERT_FLAG_FOO (PlayerEntity.h). 0x10 is shifted left by the low nybble to get the alert mask.
	PE_DOCKED					= 0xA0,
	PE_ALERT_MASS_LOCKED		= 0xA1,
	PE_ALERT_TEMPERATURE		= 0xA2,
	PE_ALERT_ALTITUTE			= 0xA3,
	PE_ALERT_ENERGY				= 0xA4,
	PE_ALERT_HOSTILES			= 0xA5
};


static JSPropertySpec Player_props[] =
{
	// JS name					ID							flags
	{ "shipDescription",		PE_SHIP_DESCRIPTION,		JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "name",					PE_COMMANDER_NAME,			JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "score",					PE_SCORE,					JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ "credits",				PE_CREDITS,					JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ "legalStatus",			PE_LEGAL_STATUS,			JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ "fuel",					PE_FUEL_LEVEL,				JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ "fuelLeakRate",			PE_FUEL_LEAK_RATE,			JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ "alertCondition",			PE_ALERT_CONDITION,			JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "docked",					PE_DOCKED,					JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "alertTemperature",		PE_ALERT_TEMPERATURE,		JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "alertMassLocked",		PE_ALERT_MASS_LOCKED,		JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "alertAltitude",			PE_ALERT_ALTITUTE,			JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "alertEnergy",			PE_ALERT_ENERGY,			JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "alertHostiles",			PE_ALERT_HOSTILES,			JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "status",					PE_STATUS_STRING,			JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "dockedAtMainStation",	PE_DOCKED_AT_MAIN_STATION,	JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "stationName",			PE_DOCKED_STATION_NAME,		JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ 0 }
};


static JSBool PlayerAwardEquipment(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool PlayerRemoveEquipment(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool PlayerHasEquipment(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool PlayerLaunch(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool PlayerCall(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool PlayerAwardCargo(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool PlayerRemoveAllCargo(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool PlayerUseSpecialCargo(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);


static JSFunctionSpec Player_funcs[] =
{
	// JS name					Function					min args
	{ "awardEquipment",			PlayerAwardEquipment,		1 },
	{ "removeEquipment",		PlayerRemoveEquipment,		1 },
	{ "hasEquipment",			PlayerHasEquipment,			1 },
	{ "launch",					PlayerLaunch,				0 },
	{ "call",					PlayerCall,					1 },
	{ "awardCargo",				PlayerAwardCargo,			2 },
	{ "removeAllCargo",			PlayerRemoveAllCargo,		0 },
	{ "useSpecialCargo",		PlayerUseSpecialCargo,		1 },
	{ 0 }
};


static JSBool PlayerAwardCargo(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	NSString *amount_type = [NSString stringWithFormat:@"%@ %@", JSValToNSString(cx, argv[1]), JSValToNSString(cx, argv[0])];
	[playerEntity awardCargo:amount_type];
	
	return JS_TRUE;
}

static JSBool PlayerRemoveAllCargo(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	[playerEntity removeAllCargo];
	return JS_TRUE;
}


static JSBool PlayerUseSpecialCargo(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	if (argc == 1) {
		PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
		[playerEntity useSpecialCargo:JSValToNSString(cx, argv[0])];
	}
	return JS_TRUE;
}

static JSBool PlayerAwardEquipment(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	if (argc > 0 && JSVAL_IS_STRING(argv[0])) {
		JSString *jskey = JS_ValueToString(cx, argv[0]);
		[playerEntity awardEquipment: [NSString stringWithCString:JS_GetStringBytes(jskey)]];
	}
	return JS_TRUE;
}


static JSBool PlayerRemoveEquipment(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	if (argc > 0 && JSVAL_IS_STRING(argv[0])) {
		JSString *jskey = JS_ValueToString(cx, argv[0]);
		[playerEntity removeEquipment: [NSString stringWithCString:JS_GetStringBytes(jskey)]];
	}
	return JS_TRUE;
}


static JSBool PlayerHasEquipment(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	if (argc > 0 && JSVAL_IS_STRING(argv[0]))
	{
		NSString *key = [NSString stringWithJavaScriptValue:argv[0] inContext:cx];
		*rval = BOOLToJSVal([playerEntity has_extra_equipment:key]);
	}
	return JS_TRUE;
}


static JSBool PlayerLaunch(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	[playerEntity launchFromStation];
	return JS_TRUE;
}


static JSBool PlayerCall(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity	*player = nil;
	NSString		*selectorString = nil;
	SEL				selector = NULL;
	NSString		*paramString = nil;
	BOOL			haveParameter = NO;
	
	player = [PlayerEntity sharedPlayer];
	selectorString = [NSString stringWithJavaScriptValue:argv[0] inContext:cx];
	
	// Join all parameters together with spaces.
	if (1 < argc && [selectorString hasSuffix:@":"])
	{
		haveParameter = YES;
		paramString = [NSString concatenationOfStringsFromJavaScriptValues:argv + 1 count:argc - 1 separator:@" " inContext:cx];
	}
	
	selector = NSSelectorFromString(selectorString);
	if ([player respondsToSelector:selector])
	{
		OOLog(@"script.trace.javaScript.call", @"Player.call: selector = %@, paramters = \"%@\"", selectorString, paramString);
		OOLogIndentIf(@"script.trace.javaScript.call");
		
		if (haveParameter)  [player performSelector:selector withObject:paramString];
		else  [player performSelector:selector];
		
		OOLogOutdentIf(@"script.trace.javaScript.call");
		return JS_TRUE;
	}
	else
	{
		OOLog(@"script.javaScript.call.badSelector", @"**** Error in script %@: Player does not respond to call(%@).", [currentOOJSScript displayName], selectorString);
		return JS_FALSE;
	}
}


static JSBool PlayerGetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp)
{

	if (!JSVAL_IS_INT(name))  return JS_TRUE;

	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	id<OOJavaScriptConversion> result = nil;
	
	uint8_t ID = JSVAL_TO_INT(name);
	switch (ID)
	{
		case PE_SHIP_DESCRIPTION:
			result = [playerEntity commanderShip_string];
			break;

		case PE_COMMANDER_NAME:
			result = [playerEntity commanderName_string];
			break;

		case PE_SCORE:
			result = [playerEntity score_number];
			break;

		case PE_LEGAL_STATUS:
			result = [playerEntity legalStatus_number];
			break;

		case PE_CREDITS:
			result = [playerEntity credits_number];
			break;

		case PE_FUEL_LEVEL:
			result = [playerEntity fuel_level_number];
			break;

		case PE_FUEL_LEAK_RATE:
			result = [playerEntity fuel_leak_rate_number];
			break;

		case PE_ALERT_CONDITION:
			*vp = INT_TO_JSVAL([playerEntity alert_condition]);
			break;
		
		case PE_DOCKED_AT_MAIN_STATION:
			*vp = BooleanStringToJSVal([playerEntity dockedAtMainStation_bool]);
			break;
		
		case PE_DOCKED_STATION_NAME:
			result = [playerEntity dockedStationName_string];
			break;

		case PE_STATUS_STRING:
			result = [playerEntity status_string];
			break;
		
		default:
			if ((ID & 0xF0) == 0xA0)
			{
				unsigned flags = [playerEntity alert_flags];
				unsigned mask = 0x10 << ((unsigned)ID & 0xF);
				*vp = BOOLToJSVal((flags & mask) != 0);
			}
	}
	
	if (result != nil) *vp = [result javaScriptValueInContext:cx];
	return JS_TRUE;
}


static JSBool PlayerSetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp)
{
	if (!JSVAL_IS_INT(name))  return JS_TRUE;
	
	PlayerEntity	*playerEntity = [PlayerEntity sharedPlayer];
	NSString		*value = [NSString stringWithJavaScriptValue:*vp inContext:cx];
	
	switch (JSVAL_TO_INT(name))
	{
		case PE_SCORE:
			[playerEntity setKills:[value intValue]];
			break;

		case PE_LEGAL_STATUS:
			[playerEntity setLegalStatus:value];
			break;
		
		case PE_CREDITS:
			[playerEntity setCredits:[value intValue]];
			break;

		case PE_FUEL_LEVEL:
			[playerEntity setCredits:(int)([value doubleValue] * 10.0)];
			break;

		case PE_FUEL_LEAK_RATE:
			[playerEntity setFuelLeak:value];
			break;
	}
	return JS_TRUE;
}


//===========================================================================
// Universe (solar system) proxy
//===========================================================================

static JSBool SystemGetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp);
static JSBool SystemSetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp);

static JSClass System_class =
{
	"Universe",
	JSCLASS_HAS_PRIVATE,
	
	JS_PropertyStub,
	JS_PropertyStub,
	SystemGetProperty,
	SystemSetProperty,
	JS_EnumerateStub,
	JS_ResolveStub,
	JS_ConvertStub,
	JS_FinalizeStub
};


enum System_propertyIDs
{
	SYS_ID,
	SYS_NAME,
	SYS_DESCRIPTION,
	SYS_GOING_NOVA,
	SYS_GONE_NOVA,
	SYS_GOVT_STR,
	SYS_GOVT_ID,
	SYS_ECONOMY_STR,
	SYS_ECONOMY_ID,
	SYS_TECH_LVL,
	SYS_POPULATION,
	SYS_PRODUCTIVITY,
	SYS_INHABITANTS
};


static JSPropertySpec System_props[] =
{
	// JS name					ID							flags
	{ "ID",						SYS_ID,						JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "name",					SYS_NAME,					JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ "description",			SYS_DESCRIPTION,			JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ "inhabitantsDescription",	SYS_INHABITANTS,			JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ "goingNova",				SYS_GOING_NOVA,				JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "goneNova",				SYS_GONE_NOVA,				JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "government",				SYS_GOVT_ID,				JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ "governmentDescription",	SYS_GOVT_STR,				JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "economy",				SYS_ECONOMY_ID,				JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ "economyDescription",		SYS_ECONOMY_STR,			JSPROP_PERMANENT | JSPROP_ENUMERATE | JSPROP_READONLY },
	{ "techLevel",				SYS_TECH_LVL,				JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ "population",				SYS_POPULATION,				JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ "productivity",			SYS_PRODUCTIVITY,			JSPROP_PERMANENT | JSPROP_ENUMERATE },
	{ 0 }
};


static JSBool SystemAddPlanet(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool SystemAddMoon(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool SystemSendAllShipsAway(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool SystemSetSunNova(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool SystemCountShipsWithRole(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool SystemAddShips(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool SystemAddSystemShips(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool SystemAddShipsAt(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool SystemAddShipsAtPrecisely(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool SystemAddShipsWithinRadius(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool SystemSpawn(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool SystemSpawnShip(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);


static JSFunctionSpec System_funcs[] =
{
	// JS name					Function					min args
	{ "addPlanet",				SystemAddPlanet,			1 },
	{ "addMoon",				SystemAddMoon,				1 },
	{ "sendAllShipsAway",		SystemSendAllShipsAway,		1 },
	{ "setSunNova",				SystemSetSunNova,			1 },
	{ "countShipsWithRole",		SystemCountShipsWithRole,	1, 0 },
	{ "legacy_addShips",		SystemAddShips,				2, 0 },
	{ "legacy_addSystemShips",	SystemAddSystemShips,		3, 0 },
	{ "legacy_addShipsAt",		SystemAddShipsAt,			6, 0 },
	{ "legacy_addShipsAtPrecisely", SystemAddShipsAtPrecisely, 6, 0 },
	{ "legacy_addShipsWithinRadius", SystemAddShipsWithinRadius, 7, 0 },
	{ "legacy_spawn",			SystemSpawn,				2, 0 },
	{ "legacy_spawnShip",		SystemSpawnShip,			1, 0 },
	{ 0 }
};


static JSBool SystemAddPlanet(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	if (argc > 0 && JSVAL_IS_STRING(argv[0])) {
		NSString *key = JSValToNSString(cx, argv[0]);
		[playerEntity addPlanet:key];
	}
	return JS_TRUE;
}


static JSBool SystemAddMoon(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	if (argc > 0 && JSVAL_IS_STRING(argv[0])) {
		NSString *key = JSValToNSString(cx, argv[0]);
		[playerEntity addMoon:key];
	}
	return JS_TRUE;
}


static JSBool SystemSendAllShipsAway(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	[playerEntity sendAllShipsAway];
	return JS_TRUE;
}


static JSBool SystemSetSunNova(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	if (argc > 0) {
		NSString *key = JSValToNSString(cx, argv[0]);
		[playerEntity setSunNovaIn:key];
	}
	return JS_TRUE;
}


static Random_Seed currentSystem;
static NSDictionary *planetinfo = nil;

static JSBool SystemGetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp)
{
	if (!JSVAL_IS_INT(name))  return JS_TRUE;

	PlayerEntity	*playerEntity = [PlayerEntity sharedPlayer];
	id<OOJavaScriptConversion> result = nil;
	
	if (!equal_seeds(currentSystem, playerEntity->system_seed))
	{
		currentSystem = playerEntity->system_seed;
		
		[planetinfo release];
		planetinfo = [[[Universe sharedUniverse] generateSystemData:currentSystem] retain];
	}

	switch (JSVAL_TO_INT(name))
	{
		case SYS_ID:
			result = [playerEntity planet_number];
			break;

		case SYS_NAME:
			if ([[Universe sharedUniverse] sun] != nil)
			{
				result = [planetinfo objectForKey:KEY_NAME];
				if (result == nil) result = @"None";	// TODO: should this return JSVAL_VOID instead? Other cases below. -- ahruman
			}
			else
			{
				// Witchspace. (Hmm, does a system that's gone nova have a sun? If not, -[PlayerEntity planet_number] is broken, too.
				result = @"Interstellar space";
			}
			break;

		case SYS_DESCRIPTION:
			result = [planetinfo objectForKey:KEY_DESCRIPTION];
			if (result == nil) result = @"None";
			break;

		case SYS_INHABITANTS:
			result = [planetinfo objectForKey:KEY_INHABITANTS];
			if (result == nil) result = @"None";
			break;
		
		case SYS_GOING_NOVA:
			*vp = BooleanStringToJSVal([playerEntity sunWillGoNova_bool]);
			break;

		case SYS_GONE_NOVA:
			*vp = BooleanStringToJSVal([playerEntity sunGoneNova_bool]);
			break;

		case SYS_GOVT_ID:
			result = [playerEntity systemGovernment_number];
			break;

		case SYS_GOVT_STR:
			result = [playerEntity systemGovernment_string];
			break;

		case SYS_ECONOMY_ID:
			result = [playerEntity systemEconomy_number];
			break;

		case SYS_ECONOMY_STR:
			result = [playerEntity systemEconomy_string];
			break;

		case SYS_TECH_LVL:
			result = [playerEntity systemTechLevel_number];
			break;

		case SYS_POPULATION:
			result = [playerEntity systemPopulation_number];
			break;

		case SYS_PRODUCTIVITY:
			result = [playerEntity systemProductivity_number];
			break;
	}
	
	if (result != nil) *vp = [result javaScriptValueInContext:cx];
	return JS_TRUE;
}


static JSBool SystemSetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp)
{
	if (!JSVAL_IS_INT(name))  return JS_TRUE;
	
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	if (!equal_seeds(currentSystem, playerEntity->system_seed))
	{
		currentSystem = playerEntity->system_seed;
		if (planetinfo)  [planetinfo release];

		planetinfo = [[[Universe sharedUniverse] generateSystemData:currentSystem] retain];
	}
	int gn = [[playerEntity galaxy_number] intValue];
	int pn = [[playerEntity planet_number] intValue];
	Universe *universe = [Universe sharedUniverse];
	
	switch (JSVAL_TO_INT(name))
	{
		case SYS_NAME:
			[universe setSystemDataForGalaxy:gn planet:pn key:KEY_NAME value:JSValToNSString(cx, *vp)];
			break;

			case SYS_DESCRIPTION:
			[universe setSystemDataForGalaxy:gn planet:pn key:KEY_DESCRIPTION value:JSValToNSString(cx, *vp)];
			break;

		case SYS_INHABITANTS:
			[universe setSystemDataForGalaxy:gn planet:pn key:KEY_INHABITANTS value:JSValToNSString(cx, *vp)];
			break;

		case SYS_GOING_NOVA:
			*vp = BOOLToJSVal([[universe sun] willGoNova]);
			break;

		case SYS_GONE_NOVA:
			*vp = BOOLToJSVal([[universe sun] goneNova]);
			break;

		case SYS_GOVT_ID:
			[universe setSystemDataForGalaxy:gn planet:pn key:KEY_GOVERNMENT value:[NSNumber numberWithInt:[JSValToNSString(cx, *vp) intValue]]];
			break;

		case SYS_ECONOMY_ID:
			[universe setSystemDataForGalaxy:gn planet:pn key:KEY_ECONOMY value:[NSNumber numberWithInt:[JSValToNSString(cx, *vp) intValue]]];
			break;

		case SYS_TECH_LVL:
			[universe setSystemDataForGalaxy:gn planet:pn key:KEY_TECHLEVEL value:[NSNumber numberWithInt:[JSValToNSString(cx, *vp) intValue]]];
			break;

		case SYS_POPULATION:
			[universe setSystemDataForGalaxy:gn planet:pn key:KEY_POPULATION value:[NSNumber numberWithInt:[JSValToNSString(cx, *vp) intValue]]];
			break;

		case SYS_PRODUCTIVITY:
			[universe setSystemDataForGalaxy:gn planet:pn key:KEY_PRODUCTIVITY value:[NSNumber numberWithInt:[JSValToNSString(cx, *vp) intValue]]];
			break;
	}
	return JS_TRUE;
}


static JSBool SystemCountShipsWithRole(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	if (argc == 1)
	{
		NSString *role = JSValToNSString(cx, argv[0]);
		int num = [[Universe sharedUniverse] countShipsWithRole:role];
		*rval = INT_TO_JSVAL(num);
	}
	return JS_TRUE;
}


static JSBool SystemAddShips(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	if (argc == 2)
	{
		NSString *role = JSValToNSString(cx, argv[0]);
		int num = JSVAL_TO_INT(argv[1]);

		while (num--)
			[[Universe sharedUniverse] witchspaceShipWithRole:role];
	}
	return JS_TRUE;
}


static JSBool SystemAddSystemShips(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	if (argc == 3)
	{
		jsdouble posn;
		NSString *role = JSValToNSString(cx, argv[0]);
		int num = JSVAL_TO_INT(argv[1]);
		JS_ValueToNumber(cx, argv[2], &posn);
		while (num--)
			[[Universe sharedUniverse] addShipWithRole:role nearRouteOneAt:posn];
	}
	return JS_TRUE;
}


static JSBool SystemAddShipsAt(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	if (argc == 6)
	{
		jsdouble x, y, z;
		PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
		NSString *role = JSValToNSString(cx, argv[0]);
		int num = JSVAL_TO_INT(argv[1]);
		NSString *coordScheme = JSValToNSString(cx, argv[2]);
		JS_ValueToNumber(cx, argv[3], &x);
		JS_ValueToNumber(cx, argv[4], &y);
		JS_ValueToNumber(cx, argv[5], &z);
		NSString *arg = [NSString stringWithFormat:@"%@ %d %@ %f %f %f", role, num, coordScheme, x, y, z];
		[playerEntity addShipsAt:arg];
	}
	return JS_TRUE;
}


static JSBool SystemAddShipsAtPrecisely(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	if (argc == 6)
	{
		jsdouble x, y, z;
		PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
		NSString *role = JSValToNSString(cx, argv[0]);
		int num = JSVAL_TO_INT(argv[1]);
		NSString *coordScheme = JSValToNSString(cx, argv[2]);
		JS_ValueToNumber(cx, argv[3], &x);
		JS_ValueToNumber(cx, argv[4], &y);
		JS_ValueToNumber(cx, argv[5], &z);
		NSString *arg = [NSString stringWithFormat:@"%@ %d %@ %f %f %f", role, num, coordScheme, x, y, z];
		[playerEntity addShipsAtPrecisely:arg];
	}
	return JS_TRUE;
}


static JSBool SystemAddShipsWithinRadius(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	if (argc == 7)
	{
		jsdouble x, y, z;
		PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
		NSString *role = JSValToNSString(cx, argv[0]);
		int num = JSVAL_TO_INT(argv[1]);
		NSString *coordScheme = JSValToNSString(cx, argv[2]);
		JS_ValueToNumber(cx, argv[3], &x);
		JS_ValueToNumber(cx, argv[4], &y);
		JS_ValueToNumber(cx, argv[5], &z);
		int rad = JSVAL_TO_INT(argv[6]);
		NSString *arg = [NSString stringWithFormat:@"%@ %d %@ %f %f %f %d", role, num, coordScheme, x, y, z, rad];
		[playerEntity addShipsAt:arg];
	}
	return JS_TRUE;
}


static JSBool SystemSpawn(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	if (argc == 2)
	{
		PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
		NSString *role = JSValToNSString(cx, argv[0]);
		int num = JSVAL_TO_INT(argv[1]);
		NSString *arg = [NSString stringWithFormat:@"%@ %d", role, num];
		[playerEntity spawn:arg];
	}
	return JS_TRUE;
}


static JSBool SystemSpawnShip(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	if (argc == 1)
	{
		PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
		[playerEntity spawnShip:JSValToNSString(cx, argv[0])];
	}
	return JS_TRUE;
}


//===========================================================================
// Mission class
//===========================================================================

static JSBool MissionGetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp);
static JSBool MissionSetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp);


static JSClass Mission_class =
{
	"Mission",
	JSCLASS_HAS_PRIVATE,
	
	JS_PropertyStub,
	JS_PropertyStub,
	MissionGetProperty,
	MissionSetProperty,
	JS_EnumerateStub,
	JS_ResolveStub,
	JS_ConvertStub,
	JS_FinalizeStub
};


enum Mission_propertyIDs
{
	MISSION_TEXT, MISSION_MUSIC, MISSION_IMAGE, MISSION_CHOICES, MISSION_CHOICE, MISSION_INSTRUCTIONS
};

static JSPropertySpec Mission_props[] =
{
	{ "missionScreenTextKey", MISSION_TEXT, JSPROP_ENUMERATE },
	{ "musicFileName", MISSION_MUSIC, JSPROP_ENUMERATE },
	{ "imageFileName", MISSION_IMAGE, JSPROP_ENUMERATE },
	{ "choicesKey", MISSION_CHOICES, JSPROP_ENUMERATE },
	{ "choice", MISSION_CHOICE, JSPROP_ENUMERATE },
	{ "instructionsKey", MISSION_INSTRUCTIONS, JSPROP_ENUMERATE },
	{ 0 }
};


static JSBool MissionShowMissionScreen(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool MissionShowShipModel(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool MissionResetMissionChoice(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool MissionMarkSystem(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool MissionUnmarkSystem(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);


static JSFunctionSpec Mission_funcs[] =
{
	{ "showMissionScreen", MissionShowMissionScreen, 0, 0 },
	{ "showShipModel", MissionShowShipModel, 1, 0 },
	{ "resetMissionChoice", MissionResetMissionChoice, 0, 0 },
	{ "markSystem", MissionMarkSystem, 1, 0 },
	{ "unmarkSystem", MissionUnmarkSystem, 1, 0 },
	{ 0 }
};


static JSBool MissionGetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp)
{
	if (!JSVAL_IS_INT(name))  return JS_TRUE;

	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	id<OOJavaScriptConversion> result = nil;

	switch (JSVAL_TO_INT(name))
	{
		case MISSION_CHOICE:
			result = [playerEntity missionChoice_string];
			if (result == nil) result = @"None";
			break;
	}
	
	if (result != nil) *vp = [result javaScriptValueInContext:cx];
	return JS_TRUE;
}


static JSBool MissionSetProperty(JSContext *cx, JSObject *obj, jsval name, jsval *vp)
{
	if (!JSVAL_IS_INT(name))  return JS_TRUE;

	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];

	switch (JSVAL_TO_INT(name)) {
		case MISSION_TEXT: {
			if (JSVAL_IS_STRING(*vp)) {
				JSString *jskey = JS_ValueToString(cx, *vp);
				[playerEntity addMissionText: [NSString stringWithCString:JS_GetStringBytes(jskey)]];
			}
			break;
		}
		case MISSION_MUSIC: {
			if (JSVAL_IS_STRING(*vp)) {
				JSString *jskey = JS_ValueToString(cx, *vp);
				[playerEntity setMissionMusic: [NSString stringWithCString:JS_GetStringBytes(jskey)]];
			}
			break;
		}
		case MISSION_IMAGE: {
			if (JSVAL_IS_STRING(*vp)) {
				NSString *str = JSValToNSString(cx, *vp);
				if ([str length] == 0)
					str = @"none";
				[playerEntity setMissionImage:str];
			}
			break;
		}
		case MISSION_CHOICES: {
			if (JSVAL_IS_STRING(*vp)) {
				JSString *jskey = JS_ValueToString(cx, *vp);
				[playerEntity setMissionChoices: [NSString stringWithCString:JS_GetStringBytes(jskey)]];
			}
			break;
		}
		case MISSION_INSTRUCTIONS: {
			if (JSVAL_IS_STRING(*vp)) {
				JSString *jskey = JS_ValueToString(cx, *vp);
				NSString *ins = [NSString stringWithCString:JS_GetStringBytes(jskey)];
				if ([ins length])
					[playerEntity setMissionDescription:ins forMission:[currentOOJSScript name]];
				else
					[playerEntity clearMissionDescriptionForMission:[currentOOJSScript name]];
			}
			break;
		}
	}
	return JS_TRUE;
}


static JSBool MissionShowMissionScreen(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	[playerEntity setGuiToMissionScreen];
	return JS_TRUE;
}


static JSBool MissionShowShipModel(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	if (argc > 0 && JSVAL_IS_STRING(argv[0])) {
		JSString *jskey = JS_ValueToString(cx, argv[0]);
		[playerEntity showShipModel: [NSString stringWithCString:JS_GetStringBytes(jskey)]];
	}
	return JS_TRUE;
}


static JSBool MissionResetMissionChoice(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity *playerEntity = [PlayerEntity sharedPlayer];
	[playerEntity resetMissionChoice];
	return JS_TRUE;
}


static JSBool MissionMarkSystem(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity	*playerEntity = [PlayerEntity sharedPlayer];
	NSString		*params = [NSString concatenationOfStringsFromJavaScriptValues:argv count:argc separator:@" " inContext:cx];
	
	[playerEntity addMissionDestination:params];
	return JS_TRUE;
}


static JSBool MissionUnmarkSystem(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
{
	PlayerEntity	*playerEntity = [PlayerEntity sharedPlayer];
	NSString		*params = [NSString concatenationOfStringsFromJavaScriptValues:argv count:argc separator:@" " inContext:cx];
	
	[playerEntity removeMissionDestination:params];
	return JS_TRUE;
}


static void ReportJSError(JSContext *cx, const char *message, JSErrorReport *report)
{
	NSString		*severity = nil;
	NSString		*messageText = nil;
	NSString		*lineBuf = nil;
	NSString		*messageClass = nil;
	
	// Type of problem: error, warning or exception? (Strict flag wilfully ignored.)
	if (report->flags & JSREPORT_EXCEPTION) severity = @"exception";
	else if (report->flags & JSREPORT_WARNING) severity = @"warning";
	else severity = @"error";
	
	// The error message itself
	messageText = [NSString stringWithUTF16String:report->ucmessage];
	
	// Get offending line, if present, and trim trailing line breaks
	lineBuf = [NSString stringWithUTF16String:report->uclinebuf];
	while ([lineBuf hasSuffix:@"\n"] || [lineBuf hasSuffix:@"\r"])  lineBuf = [lineBuf substringToIndex:[lineBuf length] - 1];
	
	// Log message class
	messageClass = [NSString stringWithFormat:@"script.javaScript.%@.%u", severity, report->errorNumber];
	
	// First line: problem description
	OOLog(messageClass, @"***** JavaScript %@: %@", severity, messageText);
	
	// Second line: where error occured, and line if provided. (The line is only provided for compile-time errors, not run-time errors.)
	if ([lineBuf length] != 0)
	{
		OOLog(messageClass, @"      %s, line %d: %@", report->filename, report->lineno, lineBuf);
	}
	else
	{
		OOLog(messageClass, @"      %s, line %d.", report->filename, report->lineno);
	}
}


//===========================================================================
// JavaScript engine initialisation and shutdown
//===========================================================================

@implementation OOJavaScriptEngine

+ (OOJavaScriptEngine *)sharedEngine
{
	if (sSharedEngine == nil) [[self alloc] init];
	
	return sSharedEngine;
}


- (id) init
{
	assert(sSharedEngine == nil);
	
	self = [super init];
	
	assert(sizeof(jschar) == sizeof(unichar));

	/*set up global JS variables, including global and custom objects */

	/* initialize the JS run time, and return result in rt */
	rt = JS_NewRuntime(8L * 1024L * 1024L);

	/* if rt does not have a value, end the program here */
	if (!rt)
	{
		OOLog(@"script.javaScript.init.error", @"FATAL ERROR: failed to create JavaScript %@.", @"runtime");
		exit(1);
	}

	/* create a context and associate it with the JS run time */
	cx = JS_NewContext(rt, 8192);
	
	/* if cx does not have a value, end the program here */
	if (!cx)
	{
		OOLog(@"script.javaScript.init.error", @"FATAL ERROR: failed to create JavaScript %@.", @"context");
		exit(1);
	}

	JS_SetErrorReporter(cx, ReportJSError);

	/* create the global object here */
	glob = JS_NewObject(cx, &global_class, NULL, NULL);
	xglob = glob;

	/* initialize the built-in JS objects and the global object */
	builtins = JS_InitStandardClasses(cx, glob);
	JS_DefineProperties(cx, glob, Global_props);
	JS_DefineFunctions(cx, glob, Global_funcs);

	universeObj = JS_DefineObject(cx, glob, "universe", &System_class, NULL, JSPROP_ENUMERATE);
	//JS_DefineProperties(cx, universeObj, System_props);
	JS_DefineFunctions(cx, universeObj, System_funcs);

	systemObj = JS_DefineObject(cx, glob, "system", &System_class, NULL, JSPROP_ENUMERATE);
	JS_DefineProperties(cx, systemObj, System_props);
	JS_DefineFunctions(cx, systemObj, System_funcs);

	playerObj = JS_DefineObject(cx, glob, "player", &Player_class, NULL, JSPROP_ENUMERATE);
	JS_DefineProperties(cx, playerObj, Player_props);
	JS_DefineFunctions(cx, playerObj, Player_funcs);

	missionObj = JS_DefineObject(cx, glob, "mission", &Mission_class, NULL, JSPROP_ENUMERATE);
	JS_DefineProperties(cx, missionObj, Mission_props);
	JS_DefineFunctions(cx, missionObj, Mission_funcs);
	
	OOLog(@"script.javaScript.init.success", @"Set up JavaScript context.");
	
	sSharedEngine = self;
	return self;
}


- (void) dealloc
{
	sSharedEngine = nil;
	
	JS_DestroyContext(cx);
	JS_DestroyRuntime(rt);
	
	[super dealloc];
}


- (JSContext *) context
{
	return cx;
}

@end


@implementation NSString (OOJavaScriptExtensions)

// Convert a JSString to an NSString.
+ (id)stringWithJavaScriptString:(JSString *)string
{
	jschar		*chars = NULL;
	size_t		length;
	
	chars = JS_GetStringChars(string);
	length = JS_GetStringLength(string);
	
	return [NSString stringWithCharacters:chars length:length];
}


+ (id)stringWithJavaScriptValue:(jsval)value inContext:(JSContext *)context
{
	JSString	*string = NULL;
	
	string = JS_ValueToString(context, value);	// Calls the value's convert method if needed.
	return [NSString stringWithJavaScriptString:string];
}


- (jsval)javaScriptValueInContext:(JSContext *)context
{
	size_t		length;
	unichar		*buffer = NULL;
	JSString	*string = NULL;
	
	length = [self length];
	buffer = malloc(length * sizeof *buffer);
	if (buffer == NULL) return JSVAL_VOID;
	
	[self getCharacters:buffer];
	
	string = JS_NewUCStringCopyN(context, buffer, length);
	free(buffer);
	
	return STRING_TO_JSVAL(string);
}


+ (id)concatenationOfStringsFromJavaScriptValues:(jsval *)values count:(size_t)count separator:(NSString *)separator inContext:(JSContext *)context
{
	size_t				i;
	NSMutableString		*result = nil;
	NSString			*element = nil;
	
	if (count < 1) return nil;
	if (values == NULL) return NULL;
	
	for (i = 0; i != count; ++i)
	{
		element = [NSString stringWithJavaScriptValue:values[i] inContext:context];
		if (result == nil) result = [element mutableCopy];
		else
		{
			if (separator != nil) [result appendString:separator];
			[result appendString:element];
		}
	}
	
	return result;
}

@end


@implementation NSNumber (OOJavaScriptExtensions)

- (jsval)javaScriptValueInContext:(JSContext *)context
{
	jsval		result;
	BOOL		isFloat = NO;
	const char	*type;
	long long	longLongValue;
	
	if (self == [NSNumber numberWithBool:YES])
	{
		/*	Under OS X, at least, numberWithBool: returns one of two singletons.
			There is no other way to reliably identify a boolean NSNumber.
			Fun, eh? */
		result = JSVAL_TRUE;
	}
	else if (self == [NSNumber numberWithBool:NO])
	{
		result = JSVAL_FALSE;
	}
	else
	{
		longLongValue = [self longLongValue];
		if (longLongValue < (long long)JSVAL_INT_MIN || (long long)JSVAL_INT_MAX < longLongValue)
		{
			// values outside JSVAL_INT range are returned as doubles.
			isFloat = YES;
		}
		else
		{
			// Check value type.
			type = [self objCType];
			if (type[0] == 'f' || type[0] == 'd') isFloat = YES;
		}
		
		if (isFloat)
		{
			if (!JS_NewDoubleValue(context, [self doubleValue], &result)) result = JSVAL_VOID;
		}
		else
		{
			result = INT_TO_JSVAL(longLongValue);
		}
	}
	
	return result;
}

@end


NSString *JSPropertyAsString(JSContext *context, JSObject *object, const char *name)
{
	JSBool			OK;
	jsval			returnValue;
	NSString		*result;
	
	if (context == NULL || object == NULL || name == NULL) return nil;
	
	OK = JS_GetProperty(context, object, name, &returnValue);
	if (OK && !JSVAL_IS_VOID(returnValue))
	{
		result = [NSString stringWithJavaScriptValue:returnValue inContext:context];
	}
	
	return result;
}