
package org.mule.modules.salesforce;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.WildcardType;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import org.mule.api.MuleContext;
import org.mule.api.MuleMessage;
import org.mule.api.expression.ExpressionManager;
import org.mule.api.transformer.DataType;
import org.mule.api.transformer.Transformer;
import org.mule.api.transformer.TransformerException;
import org.mule.transformer.types.DataTypeFactory;
import org.mule.util.TemplateParser;

public abstract class AbstractExpressionEvaluator {


    /**
     * Get all superclasses and interfaces recursively.
     * 
     * @param classes List of classes to which to add all found super classes and interfaces.
     * @param clazz   The class to start the search with.
     */
    protected void computeClassHierarchy(Class clazz, List classes) {
        for (Class current = clazz; (current!= null); current = current.getSuperclass()) {
            if (classes.contains(current)) {
                return ;
            }
            classes.add(current);
            for (Class currentInterface: current.getInterfaces()) {
                computeClassHierarchy(currentInterface, classes);
            }
        }
    }

    /**
     * Checks whether the specified class parameter is an instance of {@link List }
     * 
     * @param clazz <code>Class</code> to check.
     * @return
     */
    protected boolean isListClass(Class clazz) {
        List<Class> classes = new ArrayList<Class>();
        computeClassHierarchy(clazz, classes);
        return classes.contains(List.class);
    }

    /**
     * Checks whether the specified class parameter is an instance of {@link Map }
     * 
     * @param clazz <code>Class</code> to check.
     * @return
     */
    protected boolean isMapClass(Class clazz) {
        List<Class> classes = new ArrayList<Class>();
        computeClassHierarchy(clazz, classes);
        return classes.contains(Map.class);
    }

    protected boolean isList(Type type) {
        if ((type instanceof Class)&&isListClass(((Class) type))) {
            return true;
        }
        if (type instanceof ParameterizedType) {
            return isList(((ParameterizedType) type).getRawType());
        }
        if (type instanceof WildcardType) {
            Type[] upperBounds = ((WildcardType) type).getUpperBounds();
            return ((upperBounds.length!= 0)&&isList(upperBounds[ 0 ]));
        }
        return false;
    }

    protected boolean isMap(Type type) {
        if ((type instanceof Class)&&isMapClass(((Class) type))) {
            return true;
        }
        if (type instanceof ParameterizedType) {
            return isMap(((ParameterizedType) type).getRawType());
        }
        if (type instanceof WildcardType) {
            Type[] upperBounds = ((WildcardType) type).getUpperBounds();
            return ((upperBounds.length!= 0)&&isMap(upperBounds[ 0 ]));
        }
        return false;
    }

    protected boolean isAssignableFrom(Type expectedType, Class clazz) {
        if (expectedType instanceof Class) {
            if (((Class) expectedType).isPrimitive()) {
                if (((Class) expectedType).getName().equals("boolean")&&(clazz == Boolean.class)) {
                    return true;
                }
                if (((Class) expectedType).getName().equals("byte")&&(clazz == Byte.class)) {
                    return true;
                }
                if (((Class) expectedType).getName().equals("short")&&(clazz == Short.class)) {
                    return true;
                }
                if (((Class) expectedType).getName().equals("char")&&(clazz == Character.class)) {
                    return true;
                }
                if (((Class) expectedType).getName().equals("int")&&(clazz == Integer.class)) {
                    return true;
                }
                if (((Class) expectedType).getName().equals("float")&&(clazz == Float.class)) {
                    return true;
                }
                if (((Class) expectedType).getName().equals("long")&&(clazz == Long.class)) {
                    return true;
                }
                if (((Class) expectedType).getName().equals("double")&&(clazz == Double.class)) {
                    return true;
                }
                return false;
            } else {
                return ((Class) expectedType).isAssignableFrom(clazz);
            }
        }
        if (expectedType instanceof ParameterizedType) {
            return isAssignableFrom(((ParameterizedType) expectedType).getRawType(), clazz);
        }
        if (expectedType instanceof WildcardType) {
            Type[] upperBounds = ((WildcardType) expectedType).getUpperBounds();
            if (upperBounds.length!= 0) {
                return isAssignableFrom(upperBounds[ 0 ], clazz);
            }
        }
        return false;
    }

    protected Object evaluate(TemplateParser.PatternInfo patternInfo, ExpressionManager expressionManager, MuleMessage muleMessage, Object source) {
        if (source instanceof String) {
            String stringSource = ((String) source);
            if (stringSource.startsWith(patternInfo.getPrefix())&&stringSource.endsWith(patternInfo.getSuffix())) {
                return expressionManager.evaluate(stringSource, muleMessage);
            } else {
                return expressionManager.parse(stringSource, muleMessage);
            }
        }
        return source;
    }

    protected Object evaluateAndTransform(MuleContext muleContext, MuleMessage muleMessage, Type expectedType, String expectedMimeType, Object source)
        throws TransformerException
    {
        if (source == null) {
            return source;
        }
        Object target = null;
        if (isList(source.getClass())) {
            if (isList(expectedType)) {
                List newList = new ArrayList();
                Type valueType = ((ParameterizedType) expectedType).getActualTypeArguments()[ 0 ];
                ListIterator iterator = ((List) source).listIterator();
                while (iterator.hasNext()) {
                    Object subTarget = iterator.next();
                    newList.add(evaluateAndTransform(muleContext, muleMessage, valueType, expectedMimeType, subTarget));
                }
                target = newList;
            } else {
                target = source;
            }
        } else {
            if (isMap(source.getClass())) {
                if (isMap(expectedType)) {
                    Type keyType = Object.class;
                    Type valueType = Object.class;
                    if (expectedType instanceof ParameterizedType) {
                        keyType = ((ParameterizedType) expectedType).getActualTypeArguments()[ 0 ];
                        valueType = ((ParameterizedType) expectedType).getActualTypeArguments()[ 1 ];
                    }
                    Map map = ((Map) source);
                    Map newMap = new HashMap();
                    for (Object entryObj: map.entrySet()) {
                        {
                            Map.Entry entry = ((Map.Entry) entryObj);
                            Object newKey = evaluateAndTransform(muleContext, muleMessage, keyType, expectedMimeType, entry.getKey());
                            Object newValue = evaluateAndTransform(muleContext, muleMessage, valueType, expectedMimeType, entry.getValue());
                            newMap.put(newKey, newValue);
                        }
                    }
                    target = newMap;
                } else {
                    target = source;
                }
            } else {
                target = evaluate(TemplateParser.createMuleStyleParser().getStyle(), muleContext.getExpressionManager(), muleMessage, source);
            }
        }
        if ((target!= null)&&(!isAssignableFrom(expectedType, target.getClass()))) {
            DataType sourceDataType = DataTypeFactory.create(target.getClass());
            DataType targetDataType = null;
            if (expectedType instanceof ParameterizedType) {
                expectedType = ((ParameterizedType) expectedType).getRawType();
            }
            if (expectedMimeType!= null) {
                targetDataType = DataTypeFactory.create(((Class) expectedType), expectedMimeType);
            } else {
                targetDataType = DataTypeFactory.create(((Class) expectedType));
            }
            Transformer t = muleContext.getRegistry().lookupTransformer(sourceDataType, targetDataType);
            return t.transform(target);
        } else {
            return target;
        }
    }

    protected Object transform(MuleMessage muleMessage, Type expectedType, Object source)
        throws TransformerException
    {
        if (source == null) {
            return source;
        }
        Object target = null;
        if (isList(source.getClass())) {
            if (isList(expectedType)) {
                List newList = new ArrayList();
                Type valueType = ((ParameterizedType) expectedType).getActualTypeArguments()[ 0 ];
                ListIterator iterator = ((List) source).listIterator();
                while (iterator.hasNext()) {
                    Object subTarget = iterator.next();
                    newList.add(transform(muleMessage, valueType, subTarget));
                }
                target = newList;
            } else {
                target = source;
            }
        } else {
            if (isMap(source.getClass())) {
                if (isMap(expectedType)) {
                    Type keyType = Object.class;
                    Type valueType = Object.class;
                    if (expectedType instanceof ParameterizedType) {
                        keyType = ((ParameterizedType) expectedType).getActualTypeArguments()[ 0 ];
                        valueType = ((ParameterizedType) expectedType).getActualTypeArguments()[ 1 ];
                    }
                    Map map = ((Map) source);
                    Map newMap = new HashMap();
                    for (Object entryObj: map.entrySet()) {
                        {
                            Map.Entry entry = ((Map.Entry) entryObj);
                            Object newKey = transform(muleMessage, keyType, entry.getKey());
                            Object newValue = transform(muleMessage, valueType, entry.getValue());
                            newMap.put(newKey, newValue);
                        }
                    }
                    target = newMap;
                } else {
                    target = source;
                }
            } else {
                target = source;
            }
        }
        if ((target!= null)&&(!isAssignableFrom(expectedType, target.getClass()))) {
            DataType sourceDataType = DataTypeFactory.create(target.getClass());
            if (expectedType instanceof ParameterizedType) {
                expectedType = ((ParameterizedType) expectedType).getRawType();
            }
            DataType targetDataType = DataTypeFactory.create(((Class) expectedType));
            Transformer t = muleMessage.getMuleContext().getRegistry().lookupTransformer(sourceDataType, targetDataType);
            return t.transform(target);
        } else {
            return target;
        }
    }

}
