// Copyright 2014 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 EXTENSIONS_BROWSER_SCRIPT_EXECUTOR_H_
#define EXTENSIONS_BROWSER_SCRIPT_EXECUTOR_H_

#include <map>
#include <set>
#include <string>
#include <vector>

#include "base/callback.h"
#include "base/values.h"
#include "extensions/common/constants.h"
#include "extensions/common/mojom/code_injection.mojom.h"
#include "extensions/common/mojom/css_origin.mojom-shared.h"
#include "extensions/common/mojom/host_id.mojom-forward.h"
#include "extensions/common/mojom/run_location.mojom-shared.h"
#include "extensions/common/user_script.h"

class GURL;

namespace content {
class WebContents;
}

namespace extensions {

// Contains all extensions that are executing scripts, mapped to the paths for
// those scripts. The paths may be an empty set if the script has no path
// associated with it (e.g. in the case of tabs.executeScript), but there will
// still be an entry for the extension.
using ExecutingScriptsMap = std::map<std::string, std::set<std::string>>;

// Callback that ScriptExecutor uses to notify when content scripts and/or
// tabs.executeScript calls run on a page.
using ScriptsExecutedNotification = base::RepeatingCallback<
    void(content::WebContents*, const ExecutingScriptsMap&, const GURL&)>;

// Interface for executing extension content scripts (e.g. executeScript) as
// described by the mojom::ExecuteCodeParams IPC, and notifying the
// caller when responded with ExecuteCodeCallback.
class ScriptExecutor {
 public:
  explicit ScriptExecutor(content::WebContents* web_contents);
  ~ScriptExecutor();

  // The scope of the script injection across the frames.
  enum FrameScope {
    SPECIFIED_FRAMES,
    INCLUDE_SUB_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 process the target is.
  enum ProcessType {
    DEFAULT_PROCESS,
    WEB_VIEW_PROCESS,
  };

  struct FrameResult {
    FrameResult();
    FrameResult(FrameResult&&);
    FrameResult& operator=(FrameResult&&);

    // The ID of the frame of the injection.
    int frame_id = -1;
    // The error associated with the injection, if any. Empty if the injection
    // succeeded.
    std::string error;
    // The URL of the frame from the injection. Only set if the frame exists.
    GURL url;
    // The result value from the injection, or null if the injection failed (or
    // had no result).
    base::Value value;
    // Whether the frame responded to the attempted injection (which can fail if
    // the frame was removed or never existed). Note this doesn't necessarily
    // mean the injection succeeded, since it could fail due to other reasons
    // (like permissions).
    bool frame_responded = false;
  };

  using ScriptFinishedCallback =
      base::OnceCallback<void(std::vector<FrameResult> frame_results)>;

  // Generates an injection key based on the host ID and either the file URL, if
  // available, or the code string. The format of the key is
  // "<type><host_id><digest>", where <type> is one of "F" (file) and "C"
  // (code), <host_id> is the host ID, and <digest> is an unspecified hash
  // digest of the file URL or the code string, respectively.
  static std::string GenerateInjectionKey(const mojom::HostID& host_id,
                                          const GURL& script_url,
                                          const std::string& code);

  // Executes a script. The arguments match mojom::ExecuteCodeParams in
  // frame.mojom (request_id is populated automatically).
  //
  // The script will be executed in the frames identified by |frame_ids| (which
  // are extension API frame IDs). If |frame_scope| is INCLUDE_SUB_FRAMES,
  // then the script will also be executed in all descendants of the specified
  // frames.
  //
  // |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 mojom::HostID& host_id,
                     mojom::CodeInjectionPtr injection,
                     FrameScope frame_scope,
                     const std::set<int>& frame_ids,
                     MatchAboutBlank match_about_blank,
                     mojom::RunLocation run_at,
                     ProcessType process_type,
                     const GURL& webview_src,
                     ScriptFinishedCallback callback);

  // Set the observer for ScriptsExecutedNotification callbacks.
  void set_observer(ScriptsExecutedNotification observer) {
    observer_ = std::move(observer);
  }

 private:
  content::WebContents* web_contents_;

  ScriptsExecutedNotification observer_;

  DISALLOW_COPY_AND_ASSIGN(ScriptExecutor);
};

}  // namespace extensions

#endif  // EXTENSIONS_BROWSER_SCRIPT_EXECUTOR_H_