/*
 * Copyright 2015, The Querydsl Team (http://www.querydsl.com/team)
 *
 * 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 com.querydsl.core.types;

import java.lang.reflect.AnnotatedElement;

import javax.annotation.Nullable;
import javax.annotation.concurrent.Immutable;

import com.querydsl.core.util.ReflectionUtils;

/**
 * {@code PathImpl} defines a default implementation of the {@link Path} interface
 *
 * @author tiwe
 *
 * @param <T>
 */
@Immutable
public class PathImpl<T> extends ExpressionBase<T> implements Path<T> {

    private static final long serialVersionUID = -2498447742798348162L;

    private final PathMetadata metadata;

    private final Path<?> root;

    @Nullable
    private transient AnnotatedElement annotatedElement;

    protected PathImpl(Class<? extends T> type, String variable) {
        this(type, PathMetadataFactory.forVariable(variable));
    }

    protected PathImpl(Class<? extends T> type, PathMetadata metadata) {
        super(type);
        this.metadata = metadata;
        this.root = metadata.getRootPath() != null ? metadata.getRootPath() : this;
    }

    protected PathImpl(Class<? extends T> type, Path<?> parent, String property) {
        this(type, PathMetadataFactory.forProperty(parent, property));
    }

    @Override
    public final boolean equals(Object o) {
        if (o == this) {
            return true;
        } else if (o instanceof Path<?>) {
            return ((Path<?>) o).getMetadata().equals(metadata);
        } else {
            return false;
        }
    }

    @Override
    public final PathMetadata getMetadata() {
        return metadata;
    }

    @Override
    public final Path<?> getRoot() {
        return root;
    }

    @Override
    public final AnnotatedElement getAnnotatedElement() {
        if (annotatedElement == null) {
            if (metadata.getPathType() == PathType.PROPERTY) {
                Class<?> beanClass = metadata.getParent().getType();
                String propertyName = metadata.getName();
                annotatedElement = ReflectionUtils.getAnnotatedElement(beanClass, propertyName, getType());

            } else {
                annotatedElement = getType();
            }
        }
        return annotatedElement;
    }

    @Override
    public final <R, C> R accept(Visitor<R, C> v, C context) {
        return v.visit(this, context);
    }

}