package org.simantics.scl.compiler.constants;

import org.cojen.classfile.TypeDesc;
import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
import org.simantics.scl.compiler.internal.codegen.references.Val;
import org.simantics.scl.compiler.internal.codegen.types.JavaTypeTranslator;
import org.simantics.scl.compiler.internal.codegen.utils.ClassBuilder;
import org.simantics.scl.compiler.internal.codegen.utils.MethodBuilder;
import org.simantics.scl.compiler.top.SCLCompilerConfiguration;
import org.simantics.scl.compiler.types.TVar;
import org.simantics.scl.compiler.types.Type;
import org.simantics.scl.compiler.types.Types;

public class JavaStaticMethod extends FunctionValue {
    
    String className;
    String methodName;
    
    TypeDesc returnTypeDesc;
    TypeDesc[] parameterTypeDescs;
    
    public JavaStaticMethod(String className, String methodName, Type effect, TVar[] typeParameters, Type returnType, Type ... parameterTypes) {
        super(typeParameters, effect, returnType, parameterTypes);
        if(SCLCompilerConfiguration.DEBUG) {
            if(className.contains("/"))
                throw new InternalCompilerError();
        }
        ClassBuilder.checkClassName(className);
        this.className = className;
        this.methodName = methodName;
    }
    
    public JavaStaticMethod(String className, String methodName, Type effect, Type returnType, Type ... parameterTypes) {
        super(Types.freeVarsArray(Types.functionE(parameterTypes, effect, returnType)), effect, returnType, parameterTypes);
        if(SCLCompilerConfiguration.DEBUG) {
            if(className.contains("/"))
                throw new InternalCompilerError();
        }
        ClassBuilder.checkClassName(className);
        this.className = className;
        this.methodName = methodName;
    }
   
    public JavaStaticMethod(String className, String methodName, 
            Type effect,
            TypeDesc returnTypeDesc, TypeDesc[] parameterTypeDescs, 
            Type returnType, Type ... parameterTypes) {
        super(Types.freeVarsArray(Types.functionE(parameterTypes, effect, returnType)), effect, returnType, parameterTypes);
        if(SCLCompilerConfiguration.DEBUG) {
            if(className == null)
                throw new NullPointerException();
            if(methodName == null)
                throw new NullPointerException();
            if(parameterTypeDescs != null)
                for(TypeDesc td : parameterTypeDescs)
                    if(td.equals(TypeDesc.VOID))
                        throw new InternalCompilerError();
        }
        if( (returnTypeDesc == null) != (parameterTypeDescs == null) )
            throw new IllegalArgumentException("Either specify both returnTypeDesc and parameterTypeDescs or neither");
        ClassBuilder.checkClassName(className);
        this.className = className;
        this.methodName = methodName;
        this.returnTypeDesc = returnTypeDesc;
        this.parameterTypeDescs = parameterTypeDescs;
    }
    
    public JavaStaticMethod(String className, String methodName, 
            TypeDesc returnTypeDesc, TypeDesc[] parameterTypeDescs, 
            Type returnType, Type ... parameterTypes) {
        this(className, methodName, Types.NO_EFFECTS, 
                returnTypeDesc, parameterTypeDescs, 
                returnType, 
                parameterTypes);
    }
    
    @Override
    public Type applyExact(MethodBuilder mb, Val[] parameters) {
        if(returnTypeDesc == null || parameterTypeDescs == null) {
            // This method may be called from multiple threads at the same time when returnTypeDesc
            // and parameterTypeDescs are uninitialized. Double initialization is OK in this case,
            // but because there are two fields, we have to check that both are initialized.             
            JavaTypeTranslator tt = mb.getJavaTypeTranslator();
            returnTypeDesc = tt.toTypeDesc(returnType);
            parameterTypeDescs = JavaTypeTranslator.filterVoid(
                    tt.toTypeDescs(parameterTypes));
        }
        
        mb.push(parameters, getParameterTypes());
        mb.invokeStatic(className, methodName, 
                returnTypeDesc, 
                parameterTypeDescs);
        
        return getReturnType();
    }
    
    @Override
    public String toString() {
        return className + "#" + methodName;
    }

}