/*
 * Copyright 2008 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.awt.CompositeContext;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.wamblee.collections.CollectionFilter;
import org.wamblee.conditions.Condition;
import org.wamblee.conditions.FixedCondition;
import org.wamblee.general.Pair;
import org.wamblee.system.core.DefaultProvidedInterface;
import org.wamblee.system.core.DefaultRequiredInterface;
import org.wamblee.system.core.ProvidedInterface;
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 _class;
	private boolean _publicOnly;

	private List<Pair<Method, ParameterValues>> _setters;

	/**
	 * Constructs the setter configuration. By default all setters are added.
	 * 
	 * @param aClass
	 *            Class which is being configured.
	 */
	public SetterConfiguration(Class aClass) {
		_class = aClass;
		_publicOnly = true;
		_setters = getAllSetters(_class, _publicOnly);
	}

	/**
	 * Called to set whether non-public setters are also used. By default only
	 * public setters are used.
	 * 
	 * @param aIsNonPublic
	 *            Non public flag.
	 */
	public void setNonPublic(boolean aIsNonPublic) {
		_publicOnly = !aIsNonPublic;
		_setters = getAllSetters(_class, _publicOnly);
	}

	/**
	 * 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 (without the "set" prefix).
	 * @return Reference to the current object to allow call chaining.
	 */
	public SetterConfiguration remove(String aName) {
		final String name = createSetterName(aName);
		List<Pair<Method, ParameterValues>> setters = new ArrayList<Pair<Method, ParameterValues>>();
		CollectionFilter.filter(_setters, setters,
				new Condition<Pair<Method, ParameterValues>>() {
					@Override
					public boolean matches(Pair<Method, ParameterValues> aObject) {
						return !aObject.getFirst().getName().equals(name);
					}

				});
		if (_setters.size() == setters.size()) {
			throw new IllegalArgumentException(
					"No setter configured by the name of '" + aName + "'");
		}
		_setters = setters;
		return this;
	}

	/**
	 * Creates the name of a setter based on the name of the setter without the
	 * "set" prefix.
	 * 
	 * @param aName
	 *            Setter name.
	 * @return Setter name.
	 */
	private String createSetterName(String aName) {
		return "set" + aName.substring(0, 1).toUpperCase() + aName.substring(1);
	}

	/**
	 * Adds a given setter name to the setters.
	 * 
	 * @param aName
	 * @return Reference to the current object to allow call chaining.
	 */
	public SetterConfiguration add(String aName) {
		final String name = createSetterName(aName);
		int oldlen = _setters.size();
		CollectionFilter.filter(getAllSetters(_class, false), _setters,
				new Condition<Pair<Method, ParameterValues>>() {
					@Override
					public boolean matches(Pair<Method, ParameterValues> aObject) {
						return aObject.getFirst().getName().equals(name);
					}

				});
		if (_setters.size() == oldlen) {
			throw new IllegalArgumentException("No setter found for '" + aName
					+ "' in " + _class.getName());
		}
		return this;
	}

	/**
	 * Gets all setters for the current class.
	 * 
	 * @return List of all setters.
	 */
	private static List<Pair<Method, ParameterValues>> getAllSetters(
			Class aClass, boolean aPublicOnly) {
		List<Pair<Method, ParameterValues>> result = new ArrayList<Pair<Method, ParameterValues>>();
		for (Method method : getAllMethods(aClass)) {
			if (!aPublicOnly || Modifier.isPublic(method.getModifiers())) {
				if (method.getName().startsWith("set")
						&& method.getParameterTypes().length == 1) {
					method.setAccessible(true);
					String name = getSetterName(method);
					result
							.add(new Pair<Method, ParameterValues>(method,
									new ParameterValues(new String[] { name },
											new Class[] { method
													.getParameterTypes()[0] })));
				}
			}
		}
		return result;
	}

	private static final List<Method> getAllMethods(Class aClass) {
    	List<Method> result = new ArrayList<Method>();
    	result.addAll(Arrays.asList(aClass.getDeclaredMethods()));
    	Class superClass = aClass.getSuperclass();
    	if ( superClass != null ) { 
    		result.addAll(getAllMethods(superClass));
    	}
    	return result; 
    }

	/**
	 * 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 (Pair<Method, ParameterValues> method : _setters) {
			result.addAll(method.getSecond().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 (!_class.isInstance(aObject)) {
			throw new IllegalArgumentException("Object '" + aObject
					+ "' is not an instance of " + _class.getName());
		}
		for (Pair<Method, ParameterValues> setter : _setters) {
			Method method = setter.getFirst();
			ParameterValues values = setter.getSecond();

			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 aSetter
	 *            Setter name without the "set" prefix with the first character
	 *            converted to lower case.
	 * @return Parameter values.
	 */
	public ParameterValues values(String aMethod) {
		String name = createSetterName(aMethod);
		for (Pair<Method, ParameterValues> method : _setters) {
			if (method.getFirst().getName().equals(name)) {
				return method.getSecond();
			}
		}
		throw new IllegalArgumentException("No setter method '" + name
				+ "' found");
	}

	/**
	 * Gets the setter name for a given setter method. This is the name of the
	 * setter without the "set" prefix and with the first character converted to
	 * lowercase.
	 * 
	 * @param aMethod
	 *            Method.
	 * @return Setter name.
	 */
	private static String getSetterName(Method aMethod) {
		String result = aMethod.getName().substring(3);
		return result.substring(0, 1).toLowerCase() + result.substring(1);
	}

}