// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/extensions/api/braille_display_private/braille_display_private_api.h"

#include <utility>

#include "base/lazy_instance.h"
#include "base/memory/raw_ptr.h"
#include "build/build_config.h"
#include "build/chromeos_buildflags.h"
#include "chrome/browser/extensions/api/braille_display_private/braille_controller.h"
#include "chrome/browser/profiles/profile.h"

#if BUILDFLAG(IS_CHROMEOS)
#include "chrome/browser/ash/accessibility/accessibility_manager.h"
#include "device/bluetooth/public/cpp/bluetooth_address.h"
#include "extensions/browser/extensions_browser_client.h"
#endif

namespace OnDisplayStateChanged =
    extensions::api::braille_display_private::OnDisplayStateChanged;
namespace OnKeyEvent = extensions::api::braille_display_private::OnKeyEvent;
namespace WriteDots = extensions::api::braille_display_private::WriteDots;
using extensions::api::braille_display_private::DisplayState;
using extensions::api::braille_display_private::KeyEvent;
using extensions::api::braille_display_private::BrailleController;

namespace extensions {

class BrailleDisplayPrivateAPI::DefaultEventDelegate
    : public BrailleDisplayPrivateAPI::EventDelegate {
 public:
  DefaultEventDelegate(EventRouter::Observer* observer, Profile* profile);
  ~DefaultEventDelegate() override;

  void BroadcastEvent(std::unique_ptr<Event> event) override;
  bool HasListener() override;

 private:
  raw_ptr<EventRouter::Observer> observer_;
  raw_ptr<Profile> profile_;
};

BrailleDisplayPrivateAPI::BrailleDisplayPrivateAPI(
    content::BrowserContext* context)
    : profile_(Profile::FromBrowserContext(context)),
      event_delegate_(new DefaultEventDelegate(this, profile_)) {}

BrailleDisplayPrivateAPI::~BrailleDisplayPrivateAPI() = default;

void BrailleDisplayPrivateAPI::Shutdown() {
  event_delegate_.reset();
}

static base::LazyInstance<
    BrowserContextKeyedAPIFactory<BrailleDisplayPrivateAPI>>::DestructorAtExit
    g_braille_display_private_api_factory = LAZY_INSTANCE_INITIALIZER;

// static
BrowserContextKeyedAPIFactory<BrailleDisplayPrivateAPI>*
BrailleDisplayPrivateAPI::GetFactoryInstance() {
  return g_braille_display_private_api_factory.Pointer();
}

void BrailleDisplayPrivateAPI::OnBrailleDisplayStateChanged(
    const DisplayState& display_state) {
  std::unique_ptr<Event> event(
      new Event(events::BRAILLE_DISPLAY_PRIVATE_ON_DISPLAY_STATE_CHANGED,
                OnDisplayStateChanged::kEventName,
                OnDisplayStateChanged::Create(display_state)));
  event_delegate_->BroadcastEvent(std::move(event));
}

void BrailleDisplayPrivateAPI::OnBrailleKeyEvent(const KeyEvent& key_event) {
  // Key events only go to extensions of the active profile.
  if (!IsProfileActive()) {
    return;
  }
  std::unique_ptr<Event> event(
      new Event(events::BRAILLE_DISPLAY_PRIVATE_ON_KEY_EVENT,
                OnKeyEvent::kEventName, OnKeyEvent::Create(key_event)));
  event_delegate_->BroadcastEvent(std::move(event));
}

bool BrailleDisplayPrivateAPI::IsProfileActive() {
#if BUILDFLAG(IS_CHROMEOS)
  return extensions::ExtensionsBrowserClient::Get()->IsActiveContext(profile_);
#else  // !BUILDFLAG(IS_CHROMEOS)
  return true;
#endif
}

void BrailleDisplayPrivateAPI::SetEventDelegateForTest(
    std::unique_ptr<EventDelegate> delegate) {
  event_delegate_ = std::move(delegate);
}

void BrailleDisplayPrivateAPI::OnListenerAdded(
    const EventListenerInfo& details) {
  BrailleController* braille_controller = BrailleController::GetInstance();
  if (!scoped_observation_.IsObservingSource(braille_controller)) {
    scoped_observation_.Observe(braille_controller);
  }
}

void BrailleDisplayPrivateAPI::OnListenerRemoved(
    const EventListenerInfo& details) {
  BrailleController* braille_controller = BrailleController::GetInstance();
  if (!event_delegate_->HasListener() &&
      scoped_observation_.IsObservingSource(braille_controller)) {
    scoped_observation_.Reset();
  }
}

BrailleDisplayPrivateAPI::DefaultEventDelegate::DefaultEventDelegate(
    EventRouter::Observer* observer, Profile* profile)
    : observer_(observer), profile_(profile) {
  EventRouter* event_router = EventRouter::Get(profile_);
  event_router->RegisterObserver(observer_, OnDisplayStateChanged::kEventName);
  event_router->RegisterObserver(observer_, OnKeyEvent::kEventName);
}

BrailleDisplayPrivateAPI::DefaultEventDelegate::~DefaultEventDelegate() {
  EventRouter::Get(profile_)->UnregisterObserver(observer_);
}

void BrailleDisplayPrivateAPI::DefaultEventDelegate::BroadcastEvent(
    std::unique_ptr<Event> event) {
  EventRouter::Get(profile_)->BroadcastEvent(std::move(event));
}

bool BrailleDisplayPrivateAPI::DefaultEventDelegate::HasListener() {
  EventRouter* event_router = EventRouter::Get(profile_);
  return (event_router->HasEventListener(OnDisplayStateChanged::kEventName) ||
          event_router->HasEventListener(OnKeyEvent::kEventName));
}

namespace api {

ExtensionFunction::ResponseAction
BrailleDisplayPrivateGetDisplayStateFunction::Run() {
  auto get_display_state_on_io = []() {
    return BrailleController::GetInstance()->GetDisplayState()->ToValue();
  };
  bool did_post_task =
      content::GetIOThreadTaskRunner({})->PostTaskAndReplyWithResult(
          FROM_HERE, base::BindOnce(get_display_state_on_io),
          base::BindOnce(
              &BrailleDisplayPrivateGetDisplayStateFunction::ReplyWithState,
              this));
  DCHECK(did_post_task);
  return RespondLater();
}

void BrailleDisplayPrivateGetDisplayStateFunction::ReplyWithState(
    base::DictValue state) {
  Respond(WithArguments(std::move(state)));
}

BrailleDisplayPrivateWriteDotsFunction::
    BrailleDisplayPrivateWriteDotsFunction() = default;

BrailleDisplayPrivateWriteDotsFunction::
    ~BrailleDisplayPrivateWriteDotsFunction() = default;

ExtensionFunction::ResponseAction
BrailleDisplayPrivateWriteDotsFunction::Run() {
  params_ = WriteDots::Params::Create(args());
  EXTENSION_FUNCTION_VALIDATE(params_);

  bool did_post_task = content::GetIOThreadTaskRunner({})->PostTaskAndReply(
      FROM_HERE,
      base::BindOnce(&BrailleDisplayPrivateWriteDotsFunction::WriteDotsOnIO,
                     this),
      base::BindOnce(&BrailleDisplayPrivateWriteDotsFunction::Respond, this,
                     NoArguments()));
  DCHECK(did_post_task);
  return RespondLater();
}

void BrailleDisplayPrivateWriteDotsFunction::WriteDotsOnIO() {
  BrailleController::GetInstance()->WriteDots(params_->cells, params_->columns,
                                              params_->rows);
}

ExtensionFunction::ResponseAction
BrailleDisplayPrivateUpdateBluetoothBrailleDisplayAddressFunction::Run() {
#if BUILDFLAG(IS_CHROMEOS)
  EXTENSION_FUNCTION_VALIDATE(args().size() >= 1);
  EXTENSION_FUNCTION_VALIDATE(args()[0].is_string());
  const std::string& address = args()[0].GetString();
  // Validate that the address is a well-formed Bluetooth MAC address.
  // CanonicalizeBluetoothAddress returns empty on invalid input.
  std::string canonical = device::CanonicalizeBluetoothAddress(address);
  if (canonical.empty()) {
    return RespondNow(Error("Invalid Bluetooth address"));
  }
  ash::AccessibilityManager::Get()->UpdateBluetoothBrailleDisplayAddress(
      canonical);
  return RespondNow(NoArguments());
#else
  NOTREACHED();
#endif
}

}  // namespace api
}  // namespace extensions