package bsh;

import java.io.*;
import java.util.*;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
	
	@author Pat Niemeyer (pat@pat.net)
*/
public class ClassGeneratorImpl extends ClassGenerator
{
	public Class generateClass( 
		String name, Modifiers modifiers, 
		Class [] interfaces, Class superClass, BSHBlock block, 
		boolean isInterface, CallStack callstack, Interpreter interpreter 
	)
		throws EvalError
	{
		// Delegate to the static method
		return generateClassImpl( name, modifiers, interfaces, superClass,
			block, isInterface, callstack, interpreter );
	}

	public Object invokeSuperclassMethod(
		BshClassManager bcm, Object instance, String methodName, Object [] args
	)
        throws UtilEvalError, ReflectError, InvocationTargetException
	{
		// Delegate to the static method
		return invokeSuperclassMethodImpl( bcm, instance, methodName, args );
	}

	/**
		Change the parent of the class instance namespace.
		This is currently used for inner class support.
		Note: This method will likely be removed in the future.
	*/
	// This could be static
	public void setInstanceNameSpaceParent( 
		Object instance, String className, NameSpace parent )
	{
		This ithis = 
			ClassGeneratorUtil.getClassInstanceThis( instance, className );
		ithis.getNameSpace().setParent( parent );
	}

	/**
		Parse the BSHBlock for for the class definition and generate the class
		using ClassGenerator.
	*/
	public static Class generateClassImpl( 
		String name, Modifiers modifiers, 
		Class [] interfaces, Class superClass, BSHBlock block, 
		boolean isInterface, CallStack callstack, Interpreter interpreter 
	)
		throws EvalError
	{
		// Scripting classes currently requires accessibility
		// This can be eliminated with a bit more work.
		Capabilities.setAccessibility( true );	
		if ( !Capabilities.haveAccessibility() )
			throw new InterpreterError(
				"Defining classes currently requires reflect Accessibility.");

		NameSpace enclosingNameSpace = callstack.top();
		String packageName = enclosingNameSpace.getPackage();
		String className =  enclosingNameSpace.isClass ?  
			( enclosingNameSpace.getName()+"$"+name ) : name;
		String fqClassName = 
			packageName == null ? className : packageName + "." + className;

		BshClassManager bcm = interpreter.getClassManager();
		// Race condition here...
		bcm.definingClass( fqClassName );

		// Create the class static namespace
		NameSpace classStaticNameSpace = 
			new NameSpace( enclosingNameSpace, className);
		classStaticNameSpace.isClass = true;

		callstack.push( classStaticNameSpace );

		// Evaluate any inner class class definitions in the block 
		// effectively recursively call this method for contained classes first
		block.evalBlock( 
			callstack, interpreter, true/*override*/, 
			ClassNodeFilter.CLASSCLASSES );

		// Generate the type for our class
		Variable [] variables = 
			getDeclaredVariables( block, callstack, interpreter, packageName );
		DelayedEvalBshMethod [] methods =
			getDeclaredMethods( block, callstack, interpreter, packageName );

		ClassGeneratorUtil classGenerator = new ClassGeneratorUtil( 
			modifiers, className, packageName, superClass, interfaces, 
			variables, methods, classStaticNameSpace, isInterface );
		byte [] code = classGenerator.generateClass();

		// if debug, write out the class file to debugClasses directory
		String dir = System.getProperty("debugClasses");
		if ( dir != null )
		try {
			FileOutputStream out= 
				new FileOutputStream( dir+"/"+className+".class" );
			out.write(code);
			out.close();
		} catch ( IOException e ) { }

		// Define the new class in the classloader
		Class genClass = bcm.defineClass( fqClassName, code );

//bcm.doneDefiningClass( fqClassName );

		// import the unq name into parent
		enclosingNameSpace.importClass( fqClassName.replace('$','.') );

		// Also cache the class so that no import resolution must occur
		// this avoids having to load our enclosing class which isn't
		// finished being generated yet... oy.

// caching is not correct and doesn't seem to help...
//	enclosingNameSpace.cacheClass( name, genClass );

// Also cache it in the static namespace...
//classStaticNameSpace.cacheClass( name, genClass );

//classStaticNameSpace.importClass( fqClassName.replace('$','.') );

		try {
			classStaticNameSpace.setLocalVariable( 
				ClassGeneratorUtil.BSHINIT, block, false/*strictJava*/ );
		} catch ( UtilEvalError e ) {
			throw new InterpreterError("unable to init static: "+e );
		}

		// Give the static space its class static import
		// important to do this after all classes are defined
		classStaticNameSpace.setClassStatic( genClass );

		// evaluate the static portion of the block in the static space
		block.evalBlock( 
			callstack, interpreter, true/*override*/, 
			ClassNodeFilter.CLASSSTATIC );

		callstack.pop();

		if ( !genClass.isInterface() )
		{
		// Set the static bsh This callback 
		String bshStaticFieldName = ClassGeneratorUtil.BSHSTATIC+className;
		try {
			LHS lhs = Reflect.getLHSStaticField( genClass, bshStaticFieldName );
			lhs.assign( 
				classStaticNameSpace.getThis( interpreter ), false/*strict*/ );
		} catch ( Exception e ) {
			throw new InterpreterError("Error in class gen setup: "+e );
		}
		}

		bcm.doneDefiningClass( fqClassName );
		return genClass;
	}

	static Variable [] getDeclaredVariables( 
		BSHBlock body, CallStack callstack, Interpreter interpreter, 
		String defaultPackage 
	) 
		throws EvalError
	{
		List vars = new ArrayList();
		for( int child=0; child