// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_PUBLIC_BROWSER_BLUETOOTH_DELEGATE_H_
#define CONTENT_PUBLIC_BROWSER_BLUETOOTH_DELEGATE_H_

#include <string>
#include <vector>

#include "base/observer_list_types.h"
#include "base/scoped_observation_traits.h"
#include "build/build_config.h"
#include "content/common/content_export.h"
#include "content/public/browser/bluetooth_chooser.h"
#include "content/public/browser/bluetooth_scanning_prompt.h"
#include "third_party/blink/public/mojom/bluetooth/web_bluetooth.mojom-forward.h"
#include "url/origin.h"

// Some OS Bluetooth stacks (macOS and Android) automatically bond to a device
// when accessing a characteristic/descriptor which requires an authenticated
// client. For other platforms Chrome does the on-demand pairing.
#if BUILDFLAG(IS_WIN) || BUILDFLAG(IS_LINUX)
#define PAIR_BLUETOOTH_ON_DEMAND() true
#else
#define PAIR_BLUETOOTH_ON_DEMAND() false
#endif

namespace blink {
class WebBluetoothDeviceId;
}  // namespace blink

namespace device {
class BluetoothDevice;
class BluetoothUUID;
}  // namespace device

namespace content {

class RenderFrameHost;

// Provides an interface for managing device permissions for Web Bluetooth and
// Web Bluetooth Scanning API. An embedder may implement this to manage these
// permissions.
// TODO(https://crbug.com/1048325): There are several Bluetooth related methods
// in WebContentsDelegate and ContentBrowserClient that can be moved into this
// class.
class CONTENT_EXPORT BluetoothDelegate {
 public:
  // The result of the prompt when requesting device pairing
  // from the user.
  enum class PairPromptStatus {
    kSuccess,    // Result contains user credentials.
    kCancelled,  // User cancelled, or agent cancelled on their behalf.
  };

  // Based on the pairing kinds defined by Windows but it also applies to any
  // platform on which we support manual pairing through |PairingDelegate| Ref:
  // https://docs.microsoft.com/en-us/uwp/api/windows.devices.enumeration.devicepairingkinds?view=winrt-22621
  enum class PairingKind {
    kConfirmOnly,
    kConfirmPinMatch,
    kDisplayPin,
    kProvidePasswordCredential,
    kProvidePin
  };

  // Struct for pairing prompt result, include |pairing_kind| or |pin| or other
  // needed fields added in future all other fieds should be meaniningful only
  // if |result_code| is |kSuccess|
  struct PairPromptResult {
    PairPromptResult() = default;
    explicit PairPromptResult(PairPromptStatus code) : result_code(code) {}
    ~PairPromptResult() = default;

    PairPromptStatus result_code = PairPromptStatus::kCancelled;
    std::string pin;
  };

  using PairPromptCallback =
      base::OnceCallback<void(const PairPromptResult& result)>;

  // An observer used to track permission revocation events for a particular
  // RenderFrameHost.
  class CONTENT_EXPORT FramePermissionObserver : public base::CheckedObserver {
   public:
    // Notify observer that an object permission was revoked for |origin|.
    virtual void OnPermissionRevoked(const url::Origin& origin) = 0;

    // Returns the frame that the observer wishes to watch.
    virtual RenderFrameHost* GetRenderFrameHost() = 0;
  };
  virtual ~BluetoothDelegate() = default;

  // Shows a chooser for the user to select a nearby Bluetooth device. The
  // EventHandler should live at least as long as the returned chooser object.
  virtual std::unique_ptr<BluetoothChooser> RunBluetoothChooser(
      RenderFrameHost* frame,
      const BluetoothChooser::EventHandler& event_handler) = 0;

  // Shows a prompt for the user to allow/block Bluetooth scanning. The
  // EventHandler should live at least as long as the returned prompt object.
  virtual std::unique_ptr<BluetoothScanningPrompt> ShowBluetoothScanningPrompt(
      RenderFrameHost* frame,
      const BluetoothScanningPrompt::EventHandler& event_handler) = 0;

  // Prompt the user (via dialog, etc.) for pairing Bluetooth device
  // |device_identifier| is any string the caller wants to display
  // to the user to identify the device (MAC address, name, etc.). |callback|
  // will be called with the prompt result. |callback| may be called immediately
  // from this function, for example, if a credential prompt for the given
  // |frame| is already displayed.
  // |pairing_kind| is to determine which pairing kind of prompt to be created
  virtual void ShowDevicePairPrompt(
      RenderFrameHost* frame,
      const std::u16string& device_identifier,
      PairPromptCallback callback,
      PairingKind pairing_kind,
      const absl::optional<std::u16string>& pin) = 0;

  // This should return the WebBluetoothDeviceId that corresponds to the device
  // with |device_address| in the current |frame|. If there is not a
  // corresponding ID, then an invalid WebBluetoothDeviceId should be returned.
  virtual blink::WebBluetoothDeviceId GetWebBluetoothDeviceId(
      RenderFrameHost* frame,
      const std::string& device_address) = 0;

  // This should return the device address corresponding to a device with
  // |device_id| in the current |frame|. If there is not a corresponding
  // address, then an empty string should be returned.
  virtual std::string GetDeviceAddress(
      RenderFrameHost* frame,
      const blink::WebBluetoothDeviceId& device_id) = 0;

  // This should return the WebBluetoothDeviceId for |device_address| if the
  // device has been assigned an ID previously through AddScannedDevice() or
  // GrantServiceAccessPermission(). If not, a new ID should be generated for
  // |device_address| and stored in a temporary map of address to ID. Service
  // access should not be granted to these devices.
  virtual blink::WebBluetoothDeviceId AddScannedDevice(
      RenderFrameHost* frame,
      const std::string& device_address) = 0;

  // This should grant permission to the requesting and embedding origins
  // represented by |frame| to connect to the device with |device_address| and
  // access its |services|. Once permission is granted, a |WebBluetoothDeviceId|
  // should be generated for the device and returned.
  virtual blink::WebBluetoothDeviceId GrantServiceAccessPermission(
      RenderFrameHost* frame,
      const device::BluetoothDevice* device,
      const blink::mojom::WebBluetoothRequestDeviceOptions* options) = 0;

  // This should return true if |frame| has been granted permission to access
  // the device with |device_id| through GrantServiceAccessPermission().
  // |device_id|s generated with AddScannedDevices() should return false.
  virtual bool HasDevicePermission(
      RenderFrameHost* frame,
      const blink::WebBluetoothDeviceId& device_id) = 0;

  // Revokes |frame| access to the Bluetooth device ordered by website.
  virtual void RevokeDevicePermissionWebInitiated(
      RenderFrameHost* frame,
      const blink::WebBluetoothDeviceId& device_id) = 0;

  // This should return true if |frame| has permission to access |service| from
  // the device with |device_id|.
  virtual bool IsAllowedToAccessService(
      RenderFrameHost* frame,
      const blink::WebBluetoothDeviceId& device_id,
      const device::BluetoothUUID& service) = 0;

  // This should return true if |frame| can access at least one service from the
  // device with |device_id|.
  virtual bool IsAllowedToAccessAtLeastOneService(
      RenderFrameHost* frame,
      const blink::WebBluetoothDeviceId& device_id) = 0;

  // This should return true if |frame| has permission to access data associated
  // with |manufacturer_code| from advertisement packets from the device with
  // |device_id|.
  virtual bool IsAllowedToAccessManufacturerData(
      RenderFrameHost* frame,
      const blink::WebBluetoothDeviceId& device_id,
      uint16_t manufacturer_code) = 0;

  // This should return a list of devices that the origin in |frame| has been
  // allowed to access. Access permission is granted with
  // GrantServiceAccessPermission() and can be revoked by the user in the
  // embedder's UI. The list of devices returned should be PermittedDevice
  // objects, which contain the necessary fields to create the BluetoothDevice
  // JavaScript objects.
  virtual std::vector<blink::mojom::WebBluetoothDevicePtr> GetPermittedDevices(
      RenderFrameHost* frame) = 0;

  // Add a permission observer to allow observing permission revocation effects
  // for a particular frame.
  virtual void AddFramePermissionObserver(
      FramePermissionObserver* observer) = 0;

  // Remove a previously added permission observer.
  virtual void RemoveFramePermissionObserver(
      FramePermissionObserver* observer) = 0;
};

}  // namespace content

namespace base {

template <>
struct ScopedObservationTraits<
    content::BluetoothDelegate,
    content::BluetoothDelegate::FramePermissionObserver> {
  static void AddObserver(
      content::BluetoothDelegate* source,
      content::BluetoothDelegate::FramePermissionObserver* observer) {
    source->AddFramePermissionObserver(observer);
  }
  static void RemoveObserver(
      content::BluetoothDelegate* source,
      content::BluetoothDelegate::FramePermissionObserver* observer) {
    source->RemoveFramePermissionObserver(observer);
  }
};

}  // namespace base

#endif  // CONTENT_PUBLIC_BROWSER_BLUETOOTH_DELEGATE_H_