/*
 * The JastAdd Extensible Java Compiler (http://jastadd.org) is covered
 * by the modified BSD License. You should have received a copy of the
 * modified BSD license with this compiler.
 * 
 * Copyright (c) 2005-2008, Torbjorn Ekman
 * All rights reserved.
 */

aspect GenericTypeVariables {
  
  // The bounds of a type variable should be resolved to type names
  eq TypeVariable.getTypeBound().nameType() = NameType.TYPE_NAME;

  rewrite TypeVariable {
		when (getNumTypeBound() == 0)
    to TypeVariable {
			addTypeBound(
        new TypeAccess(
          "java.lang",
          "Object"
        )
      );
			return this;
		}
	}    

  public void TypeVariable.nameCheck() {
    if(extractSingleType(lookupType(name())) != this)
      error("*** Semantic Error: type variable " + name() + " is multiply declared");
  }

  syn TypeDecl TypeVariable.lowerBound() = getTypeBound(0).type();
  
}

aspect GenericTypeVariablesMembers {
  eq TypeVariable.memberMethods(String name) {
    Collection list = new HashSet();
    for(int i = 0; i < getNumTypeBound(); i++) {
      for(Iterator iter = getTypeBound(i).type().memberMethods(name).iterator(); iter.hasNext(); ) {
        MethodDecl decl = (MethodDecl)iter.next();
        //if(decl.accessibleFrom(hostType()))
          list.add(decl);
      }
    }
    return list;
  }
  
  eq TypeVariable.memberFields(String name) {
    SimpleSet set = SimpleSet.emptySet;
    for(int i = 0; i < getNumTypeBound(); i++) {
      for(Iterator iter = getTypeBound(i).type().memberFields(name).iterator(); iter.hasNext(); ) {
        FieldDeclaration decl = (FieldDeclaration)iter.next();
        //if(decl.accessibleFrom(hostType()))
          set = set.add(decl);
      }
    }
    return set;
  }

}

aspect GenricTypeVariablesTypeAnalysis {

  public void TypeVariable.typeCheck() {
    if(!getTypeBound(0).type().isTypeVariable() && !getTypeBound(0).type().isClassDecl() && !getTypeBound(0).type().isInterfaceDecl()) {
      error("the first type bound must be either a type variable, or a class or interface type which " + 
        getTypeBound(0).type().fullName() + " is not");
    }
    for(int i = 1; i < getNumTypeBound(); i++) {
      if(!getTypeBound(i).type().isInterfaceDecl()) {
        error("type bound " + i + " must be an interface type which " + 
          getTypeBound(i).type().fullName() + " is not");
      }
    }
    HashSet typeSet = new HashSet();
    for(int i = 0; i < getNumTypeBound(); i++) {
      TypeDecl type = getTypeBound(i).type();
      TypeDecl erasure = type.erasure();
      if(typeSet.contains(erasure)) {
        if(type != erasure) {
          error("the erasure " + erasure.fullName() + " of typebound " + getTypeBound(i) + " is multiply declared in " + this);
        }
        else {
          error(type.fullName() + " is multiply declared");
        }
      }
      typeSet.add(erasure);
    }

    for(int i = 0; i < getNumTypeBound(); i++) {
      TypeDecl type = getTypeBound(i).type();
      for(Iterator iter = type.methodsIterator(); iter.hasNext(); ) {
        MethodDecl m = (MethodDecl)iter.next();
        for(int j = i+1; j < getNumTypeBound(); j++) {
          TypeDecl destType = getTypeBound(j).type();
          for(Iterator destIter = destType.memberMethods(m.name()).iterator(); destIter.hasNext(); ) {
            MethodDecl n = (MethodDecl)destIter.next();
            if(m.sameSignature(n) && m.type() != n.type()) {
              error("the two bounds, " + type.name() + " and " + destType.name() + ", in type variable " + name() + 
                " have a method " + m.signature() + " with conflicting return types " + m.type().name() + " and " + n.type().name());
            }
          }
        }
      }
    }

    
  }
  
  
}