// 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 org.chromium.sdk.JsValue.Type;

/**

 * A representation of a datum (value) in the remote JavaScript VM. Must contain all the

 * data immutable, except for properties. Reference to properties is optional and may be set later.

 */

public class ValueMirror {

  public static PropertyHoldingValueMirror createScalar(String value, Type type, String className) {

    return new ValueMirror(value, type, className).getProperties();

  }

  public static PropertyHoldingValueMirror createObject(int refID,

      SubpropertiesMirror subpropertiesMirror, Type type, String className) {

    if (subpropertiesMirror == null) {

      throw new NullPointerException();

    }

    return new ValueMirror(refID, subpropertiesMirror, type, className).getProperties();

  }

  public static ValueMirror createObjectUnknownProperties(int refID, Type type, String className) {

    return new ValueMirror(refID, null, type, className);

  }

  private final int ref;

  private final Type type;

  private final String value;

  private final String className;

  private volatile PropertyHoldingValueMirror properties = null;

  private ValueMirror(String value, Type type, String className) {

    this.type = type;

    this.value = value;

    this.ref = -1;

    this.className = className;

    this.properties = new PropertyHoldingValueMirror(this);

  }

  private ValueMirror(int refID, SubpropertiesMirror subpropertiesMirror, Type type,

      String className) {

    this.type = type;

    this.className = className;

    this.ref = refID;

    PropertyHoldingValueMirror propertiesMirror;

    if (subpropertiesMirror == null) {

      propertiesMirror = null;

    } else {

      propertiesMirror = new PropertyHoldingValueMirror(this, subpropertiesMirror);

    }

    this.properties = propertiesMirror;

    this.value = null;

  }

  public Type getType() {

    return type;

  }

  public PropertyHoldingValueMirror getProperties() {

    return properties;

  }

  public int getRef() {

    return ref;

  }

  /**

   * @return the type representation as a String

   */

  public String getTypeAsString() {

    switch (type) {

      case TYPE_NUMBER:

      case TYPE_OBJECT:

      case TYPE_ARRAY:

      case TYPE_FUNCTION:

      case TYPE_DATE:

        return JsDataTypeUtil.getJsonString(type);

      case TYPE_STRING:

      default:

        return "text";

    }

  }

  @Override

  public String toString() {

    switch (type) {

      case TYPE_UNDEFINED:

      case TYPE_NULL:

      case TYPE_DATE:

      case TYPE_STRING:

      case TYPE_NUMBER:

      case TYPE_BOOLEAN:

      case TYPE_REGEXP:

        return value == null

            ? ""

            : value;

      case TYPE_OBJECT:

      case TYPE_ARRAY:

        return "[" + className + "]";

      case TYPE_FUNCTION:

        return "[Function]";

      default:

        return "";

    }

  }

  public String getClassName() {

    return className;

  }

  private static Type getObjectJsType(String className) {

    return JsDataTypeUtil.fromJsonTypeAndClassName("object", className);

  }

  void mergeFrom(ValueMirror alternative) {

    synchronized (MERGE_VALUE_MIRROR_MONITOR) {

      if (alternative.properties != null) {

        if (this.properties == null) {

          this.properties =

              new PropertyHoldingValueMirror(this, alternative.properties.getSubpropertiesMirror());

        } else {

          mergeProperties(this.properties, alternative.properties);

        }

      }

    }

  }

  private static final Object MERGE_VALUE_MIRROR_MONITOR = new Object();

  /**

   * Merge a record from data base with a new record just received. Theoretically

   * the new record may have something that base version lacks.

   * However,this method is more of symbolic use right now.

   *

   * @param baseProperties record version which is kept in database

   * @param altProperties record version that just has come from outside and may

   *        contain additional data

   */

  private static void mergeProperties(PropertyHoldingValueMirror baseProperties,

      PropertyHoldingValueMirror altProperties) {

  }

}