// Copyright (c) 2012 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.

#ifndef CHROME_BROWSER_EXTENSIONS_SCRIPT_EXECUTOR_H_
#define CHROME_BROWSER_EXTENSIONS_SCRIPT_EXECUTOR_H_

#include <string>

#include "base/callback_forward.h"
#include "base/observer_list.h"
#include "chrome/browser/extensions/tab_helper.h"
#include "extensions/common/user_script.h"

class GURL;
struct ExtensionMsg_ExecuteCode_Params;

namespace base {
class ListValue;
}  // namespace base

namespace content {
class WebContents;
}

namespace extensions {

// Interface for executing extension content scripts (e.g. executeScript) as
// described by the ExtensionMsg_ExecuteCode_Params IPC, and notifying the
// caller when responded with ExtensionHostMsg_ExecuteCodeFinished.
class ScriptExecutor {
 public:
  ScriptExecutor(
      content::WebContents* web_contents,
      // |script_observers| is assumed to be owned by |this|'s owner, and in
      // such a way that |this| is destroyed first.
      ObserverList<TabHelper::ScriptExecutionObserver>* script_observers);

  ~ScriptExecutor();

  // The type of script being injected.
  enum ScriptType {
    JAVASCRIPT,
    CSS,
  };

  // The scope of the script injection across the frames.
  enum FrameScope {
    TOP_FRAME,
    ALL_FRAMES,
  };

  // Whether to insert the script in about: frames when its origin matches
  // the extension's host permissions.
  enum MatchAboutBlank {
    DONT_MATCH_ABOUT_BLANK,
    MATCH_ABOUT_BLANK,
  };

  // The type of world to inject into (main world, or its own isolated world).
  enum WorldType {
    MAIN_WORLD,
    ISOLATED_WORLD,
  };

  // The type of process the target is.
  enum ProcessType {
    DEFAULT_PROCESS,
    WEB_VIEW_PROCESS,
  };

  // The type of result the caller is interested in.
  enum ResultType {
    NO_RESULT,
    JSON_SERIALIZED_RESULT,
  };

  // Callback from ExecuteScript. The arguments are (error, on_page_id, on_url,
  // result). Success is implied by an empty error.
  typedef base::Callback<void(const std::string&, int32, const GURL&,
                              const base::ListValue&)>
      ExecuteScriptCallback;

  // Executes a script. The arguments match ExtensionMsg_ExecuteCode_Params in
  // extension_messages.h (request_id is populated automatically).
  //
  // |callback| will always be called even if the IPC'd renderer is destroyed
  // before a response is received (in this case the callback will be with a
  // failure and appropriate error message).
  void ExecuteScript(const std::string& extension_id,
                     ScriptType script_type,
                     const std::string& code,
                     FrameScope frame_scope,
                     MatchAboutBlank match_about_blank,
                     UserScript::RunLocation run_at,
                     WorldType world_type,
                     ProcessType process_type,
                     const GURL& webview_src,
                     const GURL& file_url,
                     bool user_gesture,
                     ResultType result_type,
                     const ExecuteScriptCallback& callback);

 private:
  // Called upon a request being given to execute the script.
  void ExecuteScriptHelper(scoped_ptr<ExtensionMsg_ExecuteCode_Params> params,
                           const ExecuteScriptCallback& callback);

  // The next value to use for request_id in ExtensionMsg_ExecuteCode_Params.
  int next_request_id_;

  content::WebContents* web_contents_;

  ObserverList<TabHelper::ScriptExecutionObserver>* script_observers_;
};

}  // namespace extensions

#endif  // CHROME_BROWSER_EXTENSIONS_SCRIPT_EXECUTOR_H_