// Copyright (c) 2009 The Chromium Authors. All rights reserved.

// Use of this source code is governed by a BSD-style license that can be

// found in the LICENSE file.

package org.chromium.sdk.internal;

import java.util.Collections;

import java.util.Comparator;

import java.util.List;

import java.util.Map;

import java.util.SortedMap;

import java.util.TreeMap;

import org.chromium.sdk.JsArray;

import org.chromium.sdk.JsVariable;

import org.chromium.sdk.internal.tools.v8.MethodIsBlockingException;

/**

 * A generic implementation of the JsArray interface.

 */

class JsArrayImpl extends JsObjectImpl implements JsArray {

  /**

   * An indexed sparse array of elements. Keys are indices, values are elements.

   */

  private SortedMap<Integer, JsVariableImpl> indexToElementMap;

  /**

   * This constructor implies lazy resolution of object properties.

   *

   * @param context this array belongs in

   * @param parentFqn the fully qualified name of this array parent

   * @param valueState the mirror corresponding to this array

   */

  JsArrayImpl(InternalContext context, String parentFqn, ValueMirror valueState) {

    super(context, parentFqn, valueState);

  }

  private synchronized void ensureElementsMap() throws MethodIsBlockingException {

    if (indexToElementMap != null) {

      return;

    }

    SortedMap<Integer, JsVariableImpl> map =

      // TODO(peter.rybin): do we need this comparator at all?

        new TreeMap<Integer, JsVariableImpl>(new Comparator<Integer>() {

          public int compare(Integer o1, Integer o2) {

            return o1 - o2;

          }

        });

    for (JsVariableImpl prop : getProperties()) {

      String name = prop.getRawName();

      Integer index = getAsArrayIndex(name);

      if (index == null) {

        continue;

      }

      map.put(index, prop);

    }

    indexToElementMap = Collections.unmodifiableSortedMap(map);

  }

  public JsVariable get(int index) throws MethodIsBlockingException {

    ensureElementsMap();

    return indexToElementMap.get(index);

  }

  public SortedMap<Integer, ? extends JsVariable> toSparseArray() throws MethodIsBlockingException {

    ensureElementsMap();

    return indexToElementMap;

  }

  public int length() {

    // TODO(peter.rybin) optimize it: either read "length" from remote or count PropertyReference

    // rather than JsVariableImpl

    int lastIndex = -1;

    List<JsVariableImpl> properties = getSubpropertiesHelper().getPropertiesLazily();

    // TODO(peter.rybin): rename propRefs

    for (JsVariableImpl prop : properties) {

      String name = prop.getRawName();

      Integer index = getAsArrayIndex(name);

      if (index == null) {

        continue;

      }

      if (index > lastIndex) {

        lastIndex = index;

      }

    }

    return lastIndex + 1;

  }

  @Override

  public String toString() {

    SortedMap<Integer, ? extends JsVariable> elements;

    try {

      elements = toSparseArray();

    } catch (MethodIsBlockingException e) {

      return "[JsArray: Exception in retrieving data]";

    }

    StringBuilder result = new StringBuilder();

    result.append("[JsArray: length=").append(elements.size());

    for (Map.Entry<Integer, ? extends JsVariable> entry : elements.entrySet()) {

      result.append(',').append(entry.getKey()).append('=').append(entry.getValue());

    }

    result.append(']');

    return result.toString();

  }

  @Override

  public JsArrayImpl asArray() {

    return this;

  }

  @Override

  protected JsVariableImpl.NameDecorator getChildPropertyNameDecorator() {

    return ARRAY_ELEMENT_DECORATOR;

  }

  /**

   * @return integer representation of the index or null if it is not an integer

   */

  static Integer getAsArrayIndex(String varName) {

    if (!JsonUtil.isInteger(varName)) {

      return null;

    }

    try {

      int index = Integer.parseInt(varName);

      return index;

    } catch (NumberFormatException e) {

      return null;

    }

  }

  private final static JsVariableImpl.NameDecorator ARRAY_ELEMENT_DECORATOR =

      new JsVariableImpl.NameDecorator() {

    @Override

    String decorateVarName(String rawName) {

      Integer index = getAsArrayIndex(rawName);

      if (index == null) {

        return rawName;

      }

      // Fix array element indices

      return OPEN_BRACKET + rawName + CLOSE_BRACKET;

    }

    @Override

    String buildAccessSuffix(String rawName) {

      Integer index = getAsArrayIndex(rawName);

      if (index == null) {

        return NOOP.buildAccessSuffix(rawName);

      }

      return OPEN_BRACKET + rawName + CLOSE_BRACKET;

    }

    private static final String OPEN_BRACKET = "[";

    private static final String CLOSE_BRACKET = "]";

  };

}