// Copyright 2018 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.

#include "chromecast/browser/cast_gesture_dispatcher.h"

#include "chromecast/base/chromecast_switches.h"

namespace chromecast {
namespace shell {

namespace {
constexpr int kDefaultBackGestureHorizontalThreshold = 80;
}  // namespace

CastGestureDispatcher::CastGestureDispatcher(
    CastContentWindow::Delegate* delegate,
    bool enable_top_drag_gesture)
    : enable_top_drag_gesture_(enable_top_drag_gesture),
      back_horizontal_threshold_(
          GetSwitchValueInt(switches::kBackGestureHorizontalThreshold,
                            kDefaultBackGestureHorizontalThreshold)),
      delegate_(delegate) {
  DCHECK(delegate_);
}

CastGestureDispatcher::CastGestureDispatcher(
    CastContentWindow::Delegate* delegate)
    : CastGestureDispatcher(
          delegate,
          GetSwitchValueBoolean(switches::kEnableTopDragGesture, false)) {}

bool CastGestureDispatcher::CanHandleSwipe(CastSideSwipeOrigin swipe_origin) {
  return delegate_->CanHandleGesture(GestureForSwipeOrigin(swipe_origin));
}

GestureType CastGestureDispatcher::GestureForSwipeOrigin(
    CastSideSwipeOrigin swipe_origin) {
  switch (swipe_origin) {
    case CastSideSwipeOrigin::LEFT:
      return GestureType::GO_BACK;
    case CastSideSwipeOrigin::TOP:
      return enable_top_drag_gesture_ ? GestureType::TOP_DRAG
                                      : GestureType::NO_GESTURE;
    default:
      return GestureType::NO_GESTURE;
  }
}

void CastGestureDispatcher::HandleSideSwipeBegin(
    CastSideSwipeOrigin swipe_origin,
    const gfx::Point& touch_location) {
  if (!CanHandleSwipe(swipe_origin)) {
    return;
  }

  current_swipe_time_ = base::ElapsedTimer();

  GestureType gesture_type = GestureForSwipeOrigin(swipe_origin);
  if (gesture_type == GestureType::GO_BACK) {
    VLOG(1) << "back swipe gesture begin";
  }
}

void CastGestureDispatcher::HandleSideSwipeContinue(
    CastSideSwipeOrigin swipe_origin,
    const gfx::Point& touch_location) {
  if (!CanHandleSwipe(swipe_origin)) {
    return;
  }

  GestureType gesture_type = GestureForSwipeOrigin(swipe_origin);

  delegate_->GestureProgress(gesture_type, touch_location);
  VLOG(1) << "swipe gesture continue, elapsed time: "
          << current_swipe_time_.Elapsed().InMilliseconds() << "ms";
}

void CastGestureDispatcher::HandleSideSwipeEnd(
    CastSideSwipeOrigin swipe_origin,
    const gfx::Point& touch_location) {
  if (!CanHandleSwipe(swipe_origin)) {
    return;
  }

  GestureType gesture_type = GestureForSwipeOrigin(swipe_origin);
  VLOG(1) << "swipe end, elapsed time: "
          << current_swipe_time_.Elapsed().InMilliseconds() << "ms";

  // If it's a back gesture, we have special handling to check for the
  // horizontal threshold. If the finger has lifted before the horizontal
  // gesture, cancel the back gesture and do not consume it.
  if (gesture_type == GestureType::GO_BACK &&
      touch_location.x() < back_horizontal_threshold_) {
    VLOG(1) << "swipe gesture cancelled";
    delegate_->CancelGesture(GestureType::GO_BACK, touch_location);
    return;
  }

  delegate_->ConsumeGesture(gesture_type);
  VLOG(1) << "gesture complete, elapsed time: "
          << current_swipe_time_.Elapsed().InMilliseconds() << "ms";
}

void CastGestureDispatcher::HandleTapDownGesture(
    const gfx::Point& touch_location) {
  if (!delegate_->CanHandleGesture(GestureType::TAP_DOWN)) {
    return;
  }
  delegate_->ConsumeGesture(GestureType::TAP_DOWN);
}

void CastGestureDispatcher::HandleTapGesture(const gfx::Point& touch_location) {
  if (!delegate_->CanHandleGesture(GestureType::TAP)) {
    return;
  }
  delegate_->ConsumeGesture(GestureType::TAP);
}

}  // namespace shell
}  // namespace chromecast