// 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 "ash/events/keyboard_driven_event_rewriter.h"

#include "ash/keyboard/keyboard_util.h"
#include "ash/session/session_controller_impl.h"
#include "ash/shell.h"
#include "base/types/cxx23_to_underlying.h"
#include "ui/events/ash/event_rewriter_ash.h"
#include "ui/events/event.h"
#include "ui/events/event_utils.h"

namespace ash {

KeyboardDrivenEventRewriter::KeyboardDrivenEventRewriter() = default;

KeyboardDrivenEventRewriter::~KeyboardDrivenEventRewriter() = default;

ui::EventDispatchDetails KeyboardDrivenEventRewriter::RewriteForTesting(
    const ui::Event& event,
    const Continuation continuation) {
  return Rewrite(event, continuation);
}

ui::EventDispatchDetails KeyboardDrivenEventRewriter::RewriteEvent(
    const ui::Event& event,
    const Continuation continuation) {
  if (!enabled_ ||
      Shell::Get()->session_controller()->IsActiveUserSessionStarted()) {
    return SendEvent(continuation, &event);
  }

  return Rewrite(event, continuation);
}

ui::EventDispatchDetails KeyboardDrivenEventRewriter::Rewrite(
    const ui::Event& event,
    const Continuation continuation) {
  int flags = event.flags();
  const int kModifierMask = ui::EF_SHIFT_DOWN;
  if ((flags & kModifierMask) != kModifierMask)
    return SendEvent(continuation, &event);

  DCHECK(event.type() == ui::EventType::kKeyPressed ||
         event.type() == ui::EventType::kKeyReleased)
      << "Unexpected event type " << base::to_underlying(event.type());
  const ui::KeyEvent& key_event = static_cast<const ui::KeyEvent&>(event);
  ui::KeyboardCode key_code = key_event.key_code();

  if (!keyboard_util::IsArrowKeyCode(key_code) && key_code != ui::VKEY_RETURN &&
      key_code != ui::VKEY_F6) {
    return SendEvent(continuation, &event);
  }

  ui::EventRewriterAsh::MutableKeyState state = {
      flags & ~(ui::EF_CONTROL_DOWN | ui::EF_ALT_DOWN | ui::EF_SHIFT_DOWN),
      key_event.code(), key_event.GetDomKey(), key_event.key_code()};

  if (arrow_to_tab_rewriting_enabled_) {
    if (keyboard_util::IsArrowKeyCode(key_code)) {
      const ui::KeyEvent tab_event(ui::EventType::kKeyPressed, ui::VKEY_TAB,
                                   ui::EF_NONE);
      state.code = tab_event.code();
      state.key = tab_event.GetDomKey();
      state.key_code = tab_event.key_code();
      if (key_code == ui::VKEY_LEFT || key_code == ui::VKEY_UP)
        state.flags |= ui::EF_SHIFT_DOWN;
    }
  }

  std::unique_ptr<ui::Event> rewritten_event;
  ui::EventRewriterAsh::BuildRewrittenKeyEvent(key_event, state,
                                               &rewritten_event);
  return SendEventFinally(continuation, rewritten_event.get());
}

}  // namespace ash