/*
 * Copyright 2005-2010 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.wamblee.system.adapters;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.wamblee.collections.CollectionFilter;
import org.wamblee.conditions.Condition;
import org.wamblee.reflection.ReflectionUtils;
import org.wamblee.system.core.RequiredInterface;
import org.wamblee.system.core.Scope;
import org.wamblee.system.core.SystemAssemblyException;

/**
 * Represents the configuration for exposing the setters of a class as required
 * interfaces.
 * 
 * @author Erik Brakkee
 */
public class SetterConfiguration {
    private Class clazz;

    private boolean publicOnly;

    private Map<Method, ParameterValues> setters;

    /**
     * Constructs the setter configuration. By default no setters are added.
     * 
     * @param aClass
     *            Class which is being configured.
     */
    public SetterConfiguration(Class aClass) {
        clazz = aClass;
        publicOnly = true;
        setters = new HashMap<Method, ParameterValues>();
    }

    /**
     * Makes sure that all available setters are used.
     * 
     */
    public SetterConfiguration initAllSetters() {
        setters.clear();

        for (Method method : getAllSetters(clazz, publicOnly)) {
            setters.put(method, createParameterValues(method));
        }

        return this;
    }

    /**
     * Called to set whether non-public setters are also used. By default only
     * public setters are used. The currently selected setters remain chosen.
     * 
     * @param aIsNonPublic
     *            Non public flag.
     * 
     */
    public SetterConfiguration setNonPublic(boolean aIsNonPublic) {
        publicOnly = !aIsNonPublic;

        return this;
    }

    /**
     * Removes all setters.
     * 
     * @return Reference to the current object to allow call chaining.
     */
    public SetterConfiguration clear() {
        setters.clear();

        return this;
    }

    /**
     * Removes a setter from the set of methods.
     * 
     * @param aName
     *            Name of the setter to remove.
     * 
     * @return Reference to the current object to allow call chaining.
     * 
     */
    public SetterConfiguration remove(String aName) {
        for (Method method : setters.keySet()) {
            if (method.getName().equals(aName)) {
                setters.remove(method);

                return this;
            }
        }

        throw new IllegalArgumentException(
            "No method configured by the name of '" + aName + "'");
    }

    /**
     * Removes the method from the set of methods.
     * 
     * @param aMethod
     *            Method to remove.
     * 
     * @return
     * 
     */
    public SetterConfiguration remove(Method aMethod) {
        if (!aMethod.getDeclaringClass().isAssignableFrom(clazz)) {
            throw new RuntimeException("Method " + aMethod +
                " not found in class " + clazz + " or its superclasses");
        }

        for (Method method : setters.keySet()) {
            if (method.equals(aMethod)) {
                setters.remove(method);

                return this;
            }
        }

        throw new IllegalArgumentException("Method '" + aMethod +
            "' was not configured. ");
    }

    /**
     * Adds a given setter name to the setters.
     * 
     * @param aName
     *            Name of a setter method.
     * 
     * @return Reference to the current object to allow call chaining.
     * 
     */
    public SetterConfiguration add(final String aName) {
        List<Method> methods = new ArrayList<Method>();
        CollectionFilter.filter(getAllSetters(clazz, publicOnly), methods,
            new Condition<Method>() {
                @Override
                public boolean matches(Method aObject) {
                    return aObject.getName().equals(aName);
                }
            });

        if (methods.size() == 0) {
            throw new IllegalArgumentException("Method '" + aName +
                "' not found in " + clazz.getName());
        }

        // TODO is it possible to get more than one setter here in case the
        // subclass overrides
        // the baseclass method?
        setters.put(methods.get(0), createParameterValues(methods.get(0)));

        return this;
    }

    /**
     * Adds a given setter identified by the type it accepts to the list of
     * setters.N
     * 
     * @param aType
     *            Type to look for. Note that this must be the exact type as
     *            autoboxing and autounboxing is not used.
     * 
     * @return Reference to the current object to allow call chaining.
     * 
     * @throws IllegalArgumentException
     *             In case no setter is found or multiple setters are found.
     */
    public SetterConfiguration addSetter(final Class aType) {
        List<Method> result = new ArrayList<Method>();
        CollectionFilter.filter(getAllSetters(clazz, publicOnly), result,
            new Condition<Method>() {
                @Override
                public boolean matches(Method aObject) {
                    Class type = aObject.getParameterTypes()[0];

                    return type.equals(aType);
                }
            });

        if (result.size() == 0) {
            throw new IllegalArgumentException("No setter found in class '" +
                clazz.getName() + "' that has a setter with argument type '" +
                aType.getName() + "'");
        }

        if (result.size() > 1) {
            StringBuffer settersString = new StringBuffer();

            for (Method method : result) {
                settersString.append((method.getName() + " "));
            }

            throw new IllegalArgumentException(
                "Multiple setters found in class '" + clazz.getName() +
                    " that accept type '" + aType.getName() + "': " +
                    settersString);
        }

        Method method = result.get(0);
        setters.put(method, createParameterValues(method));

        return this;
    }

    /**
     * Gets all setters for the current class.
     * 
     * 
     * @return List of all setters.
     */
    public static List<Method> getAllSetters(Class aClass, boolean aPublicOnly) {
        List<Method> result = new ArrayList<Method>();

        for (Method method : getAllMethods(aClass)) {
            if (!aPublicOnly || Modifier.isPublic(method.getModifiers())) {
                if (method.getName().startsWith("set") &&
                    (method.getParameterTypes().length == 1)) {
                    method.setAccessible(true);
                    result.add(method);
                }
            }
        }

        return result;
    }

    private static ParameterValues createParameterValues(Method aMethod) {
        Class[] paramTypes = aMethod.getParameterTypes();
        String[] paramNames = new String[paramTypes.length];

        for (int i = 0; i < paramTypes.length; i++) {
            paramNames[i] = aMethod.getName() + "." + i;
        }

        return new ParameterValues(paramNames, paramTypes);
    }

    private static final List<Method> getAllMethods(Class aClass) {
        return ReflectionUtils.getAllMethods(aClass);
    }

    /**
     * Gets the required interfaces based on the configured setteres.
     * 
     * @return List of required interfaces.
     */
    public List<RequiredInterface> getRequiredInterfaces() {
        List<RequiredInterface> result = new ArrayList<RequiredInterface>();

        for (Method method : setters.keySet()) {
            result.addAll(setters.get(method).getRequiredInterfaces());
        }

        return result;
    }

    /**
     * Invokes all configured setters with the appropriate values.
     * 
     * @param aScope
     *            Scope within which invocation takes place.
     * @param aObject
     *            Object on which the invocation takes place.
     * 
     */
    public void inject(Scope aScope, Object aObject) {
        if (!clazz.isInstance(aObject)) {
            throw new IllegalArgumentException("Object '" + aObject +
                "' is not an instance of " + clazz.getName());
        }

        for (Method method : setters.keySet()) {
            ParameterValues values = setters.get(method);

            try {
                method.invoke(aObject, values.values(aScope));
            } catch (IllegalAccessException e) {
                throw new SystemAssemblyException("Problem invoking " + method +
                    " with " + values, e);
            } catch (InvocationTargetException e) {
                throw new SystemAssemblyException("Problem invoking " + method +
                    " with " + values, e);
            }
        }
    }

    /**
     * Returns the parameter values for allowing detailed configuration of how
     * parameter values are set.
     * 
     * @param aMethod
     *            Setter name without the "set" prefix with the first character
     *            converted to lower case.
     * 
     * @return Parameter values.
     * 
     */
    public ParameterValues values(String aMethod) {
        for (Method method : setters.keySet()) {
            if (method.getName().equals(aMethod)) {
                return setters.get(method);
            }
        }

        throw new IllegalArgumentException("No setter method '" + aMethod +
            "' found");
    }

    public List<Method> getSetters() {
        return new ArrayList<Method>(setters.keySet());
    }
}