/*
 * Copyright 2017 Red Hat, Inc.
 *
 *  All rights reserved. This program and the accompanying materials
 *  are made available under the terms of the Eclipse Public License v1.0
 *  and Apache License v2.0 which accompanies this distribution.
 *
 *  The Eclipse Public License is available at
 *  http://www.eclipse.org/legal/epl-v10.html
 *
 *  The Apache License v2.0 is available at
 *  http://www.opensource.org/licenses/apache2.0.php
 *
 *  You may elect to redistribute this code under either of these licenses.
 */

package io.vertx.ext.web.templ.handlebars.impl;

import java.util.Collections;
import java.util.Map.Entry;
import java.util.Set;

import com.github.jknack.handlebars.ValueResolver;

import io.vertx.core.json.JsonArray;

/**
 * @author <a href="https://github.com/Jotschi">Johannes Schüth</a>
 */
public class JsonArrayValueResolver implements ValueResolver {

  public static final ValueResolver INSTANCE = new JsonArrayValueResolver();

  @Override
  public Object resolve(final Object context) {
    if (context instanceof JsonArray) {
      return context;
    }
    return UNRESOLVED;
  }

  @Override
  public Object resolve(Object context, String name) {
    if (context instanceof JsonArray) {
      JsonArray jsonArray = ((JsonArray) context);
      if ("length".equals(name) || "size".equals(name)) {
        return jsonArray.size();
      }
      // NumberFormatException will bubble up and cause a HandlebarsException with line, row info
      Object value = jsonArray.getValue(Integer.valueOf(name));
      if (value != null) {
        return value;
      }
    }
    return UNRESOLVED;
  }

  @Override
  public Set<Entry<String, Object>> propertySet(final Object context) {
    return Collections.emptySet();
  }
}
