// 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.CallbackSemaphore;

import org.chromium.sdk.JsEvaluateContext;

import org.chromium.sdk.JsVariable;

import org.chromium.sdk.SyncCallback;

import org.chromium.sdk.internal.InternalContext.ContextDismissedCheckedException;

import org.chromium.sdk.internal.protocol.CommandResponse;

import org.chromium.sdk.internal.protocol.SuccessCommandResponse;

import org.chromium.sdk.internal.protocol.data.ValueHandle;

import org.chromium.sdk.internal.protocolparser.JsonProtocolParseException;

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

import org.chromium.sdk.internal.tools.v8.V8CommandProcessor;

import org.chromium.sdk.internal.tools.v8.V8Helper;

import org.chromium.sdk.internal.tools.v8.request.DebuggerMessage;

import org.chromium.sdk.internal.tools.v8.request.DebuggerMessageFactory;

/**

 * Generic implementation of {@link JsEvaluateContext}. The abstract class leaves unspecified

 * stack frame identifier (possibly null) and reference to {@link InternalContext}.

 */

abstract class JsEvaluateContextImpl implements JsEvaluateContext {

  public void evaluateSync(String expression, EvaluateCallback evaluateCallback)

      throws MethodIsBlockingException {

    CallbackSemaphore callbackSemaphore = new CallbackSemaphore();

    evaluateAsync(expression, evaluateCallback, callbackSemaphore);

    boolean res = callbackSemaphore.tryAcquireDefault();

    if (!res) {

      evaluateCallback.failure("Timeout");

    }

  }

  public void evaluateAsync(final String expression, final EvaluateCallback callback,

      SyncCallback syncCallback) {

    try {

      evaluateAsyncImpl(expression, callback, syncCallback);

    } catch (ContextDismissedCheckedException e) {

      getInternalContext().getDebugSession().maybeRethrowContextException(e);

      // or

      try {

        callback.failure(e.getMessage());

      } finally {

        syncCallback.callbackDone(null);

      }

    }

  }

  public void evaluateAsyncImpl(final String expression, final EvaluateCallback callback,

      SyncCallback syncCallback) throws ContextDismissedCheckedException {

    Integer frameIdentifier = getFrameIdentifier();

    Boolean isGlobal = frameIdentifier == null ? Boolean.TRUE : null;

    DebuggerMessage message =

        DebuggerMessageFactory.evaluate(expression, frameIdentifier, isGlobal, Boolean.TRUE);

    V8CommandProcessor.V8HandlerCallback commandCallback = callback == null

        ? null

        : new V8CommandProcessor.V8HandlerCallback() {

          public void messageReceived(CommandResponse response) {

            SuccessCommandResponse successResponse = response.asSuccess();

            if (successResponse != null) {

              ValueHandle body;

              try {

                body = successResponse.getBody().asEvaluateBody();

              } catch (JsonProtocolParseException e) {

                throw new RuntimeException(e);

              }

              JsVariable variable =

                  new JsVariableImpl(JsEvaluateContextImpl.this.getInternalContext(),

                      V8Helper.createMirrorFromLookup(body).getValueMirror(), expression);

              if (variable != null) {

                callback.success(variable);

              } else {

                callback.failure("Evaluation failed");

              }

            } else {

              callback.failure(response.asFailure().getMessage());

            }

          }

          public void failure(String message) {

            callback.failure(message);

          }

        };

    getInternalContext().sendV8CommandAsync(message, true, commandCallback,

        syncCallback);

  }

  /**

   * @return frame identifier or null if the context is not frame-related

   */

  protected abstract Integer getFrameIdentifier();

  protected abstract InternalContext getInternalContext();

}