package org.simantics.scl.compiler.elaboration.modules;

import org.simantics.scl.compiler.common.exceptions.InternalCompilerError;
import org.simantics.scl.compiler.common.names.Name;
import org.simantics.scl.compiler.constants.Constant;
import org.simantics.scl.compiler.constants.JavaTypeClassMethod;
import org.simantics.scl.compiler.types.Type;
import org.simantics.scl.compiler.types.Types;
import org.simantics.scl.compiler.types.util.MultiFunction;

public class TypeClassMethod {
    
    TypeClass typeClass;
    String name;
    String javaName;
    Type baseType;
    int arity;
    Name defaultImplementation;
    public long location;
    
    public TypeClassMethod(TypeClass typeClass, String name, String javaName,
            Type baseType, int arity, long location) {
        if(typeClass == null) throw new NullPointerException();
        if(name == null) throw new NullPointerException();
        if(javaName == null) throw new NullPointerException();
        if(baseType == null) throw new NullPointerException();
        this.typeClass = typeClass;
        this.name = name;
        this.javaName = javaName;
        this.baseType = baseType;
        this.arity = arity;
        this.location = location;
    }

    public void setDefaultImplementation(Name defaultImplementation) {
        if(this.defaultImplementation != null)
            throw new InternalCompilerError("Default method implementation already defined");
        this.defaultImplementation = defaultImplementation;
    }
    
    public Name getDefaultImplementation() {
        return defaultImplementation;
    }
    
    public String getName() {
        return name;
    }
    
    public String getJavaName() {
        return javaName;
    }
    
    public Type getBaseType() {
        return baseType;
    }
    
    public int getArity() {
        return arity;
    }

    public Type getType() {
        return Types.closure(Types.constrained(
                typeClass.class_, 
                baseType));
    }
    
    public TypeClass getTypeClass() {
        return typeClass;
    }

    public SCLValue createValue() {
        String moduleName = typeClass.name.module;
        SCLValue value = new SCLValue(Name.create(moduleName, name));
        MultiFunction mfun = Types.matchFunction(baseType);
        Type[] parameterTypes = new Type[mfun.parameterTypes.length + 1];
        System.arraycopy(mfun.parameterTypes, 0, parameterTypes, 1, mfun.parameterTypes.length);
        parameterTypes[0] = typeClass.class_;
        // FIXME totally incorrect type for the method
        Constant constant = new JavaTypeClassMethod(
                this,
                typeClass.javaName, 
                javaName, 
                mfun.effect,
                mfun.returnType, 
                parameterTypes);
        value.setValue(constant);
        value.setType(getType());
        return value;
    }
    
}