event LocationUpdate {
	lon : float
	lat : float
}

state s1 {
	LocationUpdate: lon = 20 -> s2
}

state s2 {
	LocationUpdate -> s1
}

grammar de.unisiegen.StatesLanguage with org.eclipse.xtext.common.Terminals

generate statesLanguage "http://www.eclipse.org/StatesLanguage"

StatesList :
    states += State* &
    actions += Action* &
    events += Event*
;

State:
    ('state'|'startstate') name = ID '{'
        actions += ActionInvocation* &
        transitions += StateTransition+ 
    '}'
;

StateTransition:
    EventInvocation '->' state = [State]
;

ActionInvocation:
    (percent = Number '%')? action = [Action] val += Value*
;
Action:
    'action' name = ID '{'
        params+= ParemeterDefinition*
    '}'
;

Event:
    'event' name = ID '{'
        params += ParemeterDefinition*
    '}'
;


ParemeterDefinition:
    name = ID ':' type = DATATYPE 
;

EventInvocation:
    eventName = [Event] (':' condition = Condition  (logicalOperators+= LOGICALBINARYOPERATOR conditions+= Condition)* )?
;

Condition:
    parameter = [ParemeterDefinition] 
    eqoperator = EQUALITYOPERATOR 
    val = Value 
;

Value:
    BOOL | STRING | Number 
;
Number:
    FLOAT | INT
;

enum DATATYPE:
    int|float|string|bool
;

terminal EQUALITYOPERATOR:
    "=" | ">" | "<" | ">=" | "<=" | "!=" 
;

enum LOGICALBINARYOPERATOR:
    and | or
;

terminal BOOL:
    "true"|"false"
;

terminal FLOAT:
    INT'.'INT
;

public class StatesLanguageScopeProvider extends AbstractDeclarativeScopeProvider {

	@Override
	public IScope getScope(EObject context, EReference reference) {
		
		if(context.eContainer() instanceof EventInvocationImpl){
			EventInvocationImpl eventInvocation = (EventInvocationImpl) context.eContainer();
			return Scopes.scopeFor(eventInvocation.getEventName().getParams());
		}
		IScope scope = super.getScope(context, reference);
		return scope;
	}
}