path: root/src/gamestate.cpp

#include "gamestate.h"

#include "game.h"

#include "astleaf.h"
#include "astleafliteral.h"

#include <bu/sio.h>
using namespace Bu;

GameState::GameState( Game *pGame ) :
	pGame( pGame )
{
}

GameState::~GameState()
{
}

void GameState::parse( class AstBranch *pAst )
{
	if( pAst->getType() != AstNode::tScope )
		throw Bu::ExceptionBase("Nope, nothing doing, you can't parse a non-scope AstBranch.");

	lsLocal.push( new Scope() );
	int iDepth = lsLocal.getSize();
	parse( pAst->getNodeList() );
	if( lsLocal.getSize() == iDepth )
		delete lsLocal.peekPop();
}

void GameState::init()
{
	Variable vStart = pGame->getParam("start");
	if( vStart.getType() != Variable::tSituation )
		throw Bu::ExceptionBase("game.start is not set to a situation name.");

	gotoSituation( vStart.getString() );
}

void GameState::gotoSituation( const Bu::String &sName )
{
	lStack.clear();
	for( ScopeList::iterator i = lsLocal.begin(); i; i++ )
		delete *i;
	lsLocal.clear();

	Situation *pSit = pGame->getSituation( sName );
	sCurSituation = sName;
	if( !hsSituation.has( sName ) )
	{
		hsSituation.insert( sName, new Scope() );
		pSit->exec( *this, Situation::modeSetup );
	}

	// This is here in case you use a goto in a setup mode
	if( bEscape )
		return;

	pSit->exec( *this, Situation::modeEnter );
}

void GameState::callFunction( const Bu::String &sName )
{
	pGame->getFunction( sName )->call( *this );
}

bool GameState::hasVariable( const Bu::String &sName, ScopeId id )
{
	switch( id )
	{
		case sidLocal:
			return lsLocal.peek()->has( sName );

		case sidGlobal:
			return sGlobal.has( sName );

		case sidPlayer:
			return sPlayer.has( sName );

		case sidSituation:
			return hsSituation.get( sCurSituation )->has( sName );
	}
	
	throw Bu::ExceptionBase("Really bad scopeid passed into getVariable");
}

void GameState::delVariable( const Bu::String &sName, ScopeId id )
{
	switch( id )
	{
		case sidLocal:
			return lsLocal.peek()->erase( sName );

		case sidGlobal:
			return sGlobal.erase( sName );

		case sidPlayer:
			return sPlayer.erase( sName );

		case sidSituation:
			return hsSituation.get( sCurSituation )->erase( sName );
	}
	
	throw Bu::ExceptionBase("Really bad scopeid passed into getVariable");
}

Variable GameState::getVariable( const Bu::String &sName, ScopeId id )
{
	try
	{
	switch( id )
	{
		case sidLocal:
			return lsLocal.peek()->get( sName );

		case sidGlobal:
			return sGlobal.get( sName );

		case sidPlayer:
			return sPlayer.get( sName );

		case sidSituation:
			return hsSituation.get( sCurSituation )->get( sName );
	}
	}
	catch( Bu::HashException &e )
	{
		throw Bu::ExceptionBase("No %d variable named %s found.",
				id,
				sName.getStr() );
	}

	throw Bu::ExceptionBase("Really bad scopeid passed into getVariable");
}

void GameState::setVariable( const Bu::String &sName, const Variable &v,
	ScopeId id )
{
	switch( id )
	{
		case sidLocal:
			lsLocal.peek()->insert( sName, v );
			return;

		case sidGlobal:
			sGlobal.insert( sName, v );
			return;

		case sidPlayer:
			sPlayer.insert( sName, v );
			return;

		case sidSituation:
			hsSituation.get( sCurSituation )->insert( sName, v );
			return;
	}

	throw Bu::ExceptionBase("Really bad scopeid passed into setVariable");
}

Variable GameState::deref( const Variable &src )
{
	if( src.getType() == Variable::tVariable )
	{
		VariableRef r = src.getVariableRef();
		return getVariable( r.sName, r.sid );
	}
	return src;
}

Variable GameState::popDeref()
{
	Variable v = lStack.peekPop();
	if( v.getType() == Variable::tVariable )
	{
		VariableRef r = v.getVariableRef();
		return getVariable( r.sName, r.sid );
	}
	return v;
}

void GameState::parse( const AstBranch::NodeList &lCode )
{
	bEscape = false;
	for( AstBranch::NodeList::const_iterator i = lCode.begin(); i; i++ )
	{
//		sio << "Stack: " << lStack << sio.nl;
//		sio << "exec: " << (*i)->getType() << sio.nl;
		switch( (*i)->getType() )
		{
		// tLeaf
		case AstNode::tNot:
			{
				Variable x = popDeref();
				if( x.getType() != Variable::tBool )
					throw Bu::ExceptionBase("Non-bool used with logical not operator.");
				push( Variable( !x.getBool() ) );
			}
			break;

		case AstNode::tComp:
			{
				push( popDeref() == popDeref() );
			}
			break;

		case AstNode::tCompGt:
			{
				Variable y = popDeref();
				Variable x = popDeref();
				push( x > y );
			}
			break;

		case AstNode::tCompLt:
			{
				Variable y = popDeref();
				Variable x = popDeref();
				push( x < y );
			}
			break;

		case AstNode::tCompGtEq:
			{
				Variable y = popDeref();
				Variable x = popDeref();
				push( x >= y );
			}
			break;

		case AstNode::tCompLtEq:
			{
				Variable y = popDeref();
				Variable x = popDeref();
				push( x <= y );
			}
			break;

		case AstNode::tStore:
			{
				Variable y = popDeref();
				Variable dst = pop();
				VariableRef r = dst.getVariableRef();
				setVariable( r.sName, y, r.sid );
			}
			break;

		case AstNode::tAnd:
			{
				Variable y = popDeref();
				Variable x = popDeref();
				if( x.getType() != Variable::tBool ||
					y.getType() != Variable::tBool )
				{
					throw Bu::ExceptionBase("Non-bool used in logical AND operator.");
				}
				lStack.push( Variable( x.getBool() && y.getBool() ) );
			}
			break;

		case AstNode::tOr:
			{
				Variable y = popDeref();
				Variable x = popDeref();
				if( x.getType() != Variable::tBool ||
					y.getType() != Variable::tBool )
				{
					throw Bu::ExceptionBase("Non-bool used in logical OR operator.");
				}
				lStack.push( Variable( x.getBool() || y.getBool() ) );
			}
			break;

		case AstNode::tPlus:
			{
				Variable y = popDeref();
				Variable x = popDeref();
				lStack.push( x + y );
			}
			break;

		case AstNode::tMinus:
			{
				Variable y = popDeref();
				Variable x = popDeref();
				lStack.push( x - y );
			}
			break;

		case AstNode::tDivide:
			{
				Variable y = popDeref();
				Variable x = popDeref();
				lStack.push( x / y );
			}
			break;

		case AstNode::tMultiply:
			{
				Variable y = popDeref();
				Variable x = popDeref();
				lStack.push( x * y );
			}
			break;

		case AstNode::tPlusStore:
			{
				Variable y = popDeref();
				Variable x = pop();
				VariableRef r = x.getVariableRef();
				setVariable( r.sName, getVariable( r.sName, r.sid ) + y, r.sid );
			}
			break;

		case AstNode::tMinusStore:
			{
				Variable y = popDeref();
				Variable x = pop();
				VariableRef r = x.getVariableRef();
				setVariable( r.sName, getVariable( r.sName, r.sid ) - y, r.sid );
			}
			break;

		case AstNode::tDivideStore:
			{
				Variable y = popDeref();
				Variable x = pop();
				VariableRef r = x.getVariableRef();
				setVariable( r.sName, getVariable( r.sName, r.sid ) / y, r.sid );
			}
			break;

		case AstNode::tMultiplyStore:
			{
				Variable y = popDeref();
				Variable x = pop();
				VariableRef r = x.getVariableRef();
				setVariable( r.sName, getVariable( r.sName, r.sid ) * y, r.sid );
			}
			break;

		case AstNode::tNegate:
			push( -popDeref() );
			break;

		case AstNode::tIn:
		case AstNode::tGoto:
			{
				Variable x = popDeref();
				if( x.getType() != Variable::tSituation )
					throw Bu::ExceptionBase("You cannot goto anything but a situation.");
				gotoSituation( x.getString() );
				bEscape = true;
				return;
			}
			break;

		case AstNode::tSwap:
			{
				Variable y = pop();
				Variable x = pop();
				push( y );
				push( x );
			}
			break;

		// tLeafLiteral
		case AstNode::tVarName:
		case AstNode::tLiteral:
			lStack.push( dynamic_cast<const AstLeafLiteral *>(*i)->getValue() );
			break;

		case AstNode::tFuncCall:
			callFunction(
				dynamic_cast<const AstLeafLiteral *>(*i)
					->getValue().getString()
				);
			break;

		// tBranch
		case AstNode::tScope:
		case AstNode::tIf:
			{
				AstBranch::NodeList lIf =
					dynamic_cast<const AstBranch *>(*i)->getNodeList();
				AstBranch::NodeList::const_iterator iIf = lIf.begin();
				parse( dynamic_cast<const AstBranch *>(*iIf)->getNodeList() );
				Variable v = popDeref();
				if( v.getType() != Variable::tBool )
					throw Bu::ExceptionBase("conditional did not evaluate to boolean.");
				iIf++;
				if( v.getBool() )
				{
					parse( dynamic_cast<const AstBranch *>(*iIf)->
						getNodeList() );
				}
				else
				{
					iIf++;
					if( iIf )
						parse( dynamic_cast<const AstBranch *>(*iIf)->
							getNodeList() );
				}
			}
			break;

		case AstNode::tForEach:

			break;

		case AstNode::tWhile:
			{
				AstBranch::NodeList lWhile =
					dynamic_cast<const AstBranch *>(*i)->getNodeList();
				AstBranch::NodeList::const_iterator iTest = lWhile.begin();
				AstBranch::NodeList::const_iterator iDo = iTest+1;

				for(;;)
				{
					parse( dynamic_cast<const AstBranch *>(*iTest)->
						getNodeList() );
					Variable v = popDeref();
					if( v.getType() != Variable::tBool )
						throw Bu::ExceptionBase("conditional did not evaluate to boolean.");
					if( !v.getBool() )
						break;

					parse( dynamic_cast<const AstBranch *>(*iDo)->
						getNodeList() );
				}
			}
			break;
		}

		if( bEscape )
		{
			return;
		}
	}
}