text: /*
   * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "DevicesModel.h"
  #include "GraphWidget.h"
  #include "InterruptsWidget.h"
  #include "MemoryStatsWidget.h"
  #include "NetworkStatisticsWidget.h"
  #include "ProcessFileDescriptorMapWidget.h"
  #include "ProcessMemoryMapWidget.h"
  #include "ProcessModel.h"
  #include "ProcessUnveiledPathsWidget.h"
  #include "ThreadStackWidget.h"
  #include <AK/NumberFormat.h>
  #include <LibCore/ArgsParser.h>
  #include <LibCore/Timer.h>
  #include <LibGUI/Action.h>
  #include <LibGUI/ActionGroup.h>
  #include <LibGUI/Application.h>
  #include <LibGUI/BoxLayout.h>
  #include <LibGUI/GroupBox.h>
  #include <LibGUI/Icon.h>
  #include <LibGUI/JsonArrayModel.h>
  #include <LibGUI/Label.h>
  #include <LibGUI/LazyWidget.h>
  #include <LibGUI/Menu.h>
  #include <LibGUI/MenuBar.h>
  #include <LibGUI/Painter.h>
  #include <LibGUI/SortingProxyModel.h>
  #include <LibGUI/Splitter.h>
  #include <LibGUI/TabWidget.h>
  #include <LibGUI/TableView.h>
  #include <LibGUI/ToolBar.h>
  #include <LibGUI/Widget.h>
  #include <LibGUI/Window.h>
  #include <LibGfx/Palette.h>
  #include <LibPCIDB/Database.h>
  #include <serenity.h>
  #include <signal.h>
  #include <spawn.h>
  #include <stdio.h>
  #include <unistd.h>
  
  static NonnullRefPtr<GUI::Widget> build_file_systems_tab();
  static NonnullRefPtr<GUI::Widget> build_pci_devices_tab();
  static NonnullRefPtr<GUI::Widget> build_devices_tab();
  static NonnullRefPtr<GUI::Widget> build_graphs_tab();
  static NonnullRefPtr<GUI::Widget> build_processors_tab();
  
  class UnavailableProcessWidget final : public GUI::Frame {
      C_OBJECT(UnavailableProcessWidget)
  public:
      virtual ~UnavailableProcessWidget() override { }
  
      const String& text() const { return m_text; }
      void set_text(String text) { m_text = move(text); }
  
  private:
      UnavailableProcessWidget(String text)
          : m_text(move(text))
      {
      }
  
      virtual void paint_event(GUI::PaintEvent& event) override
      {
          Frame::paint_event(event);
          if (text().is_empty())
              return;
          GUI::Painter painter(*this);
          painter.add_clip_rect(event.rect());
          painter.draw_text(frame_inner_rect(), text(), Gfx::TextAlignment::Center, palette().window_text(), Gfx::TextElision::Right);
      }
  
      String m_text;
  };
  
  static bool can_access_pid(pid_t pid)
  {
      auto path = String::formatted("/proc/{}", pid);
      return access(path.characters(), X_OK) == 0;
  }
  
  int main(int argc, char** argv)
  {
      if (pledge("stdio proc sendfd shared_buffer accept rpath exec unix cpath fattr", nullptr) < 0) {
          perror("pledge");
          return 1;
      }
  
      auto app = GUI::Application::construct(argc, argv);
  
      if (pledge("stdio proc sendfd shared_buffer accept rpath exec", nullptr) < 0) {
          perror("pledge");
          return 1;
      }
  
      if (unveil("/etc/passwd", "r") < 0) {
          perror("unveil");
          return 1;
      }
  
      if (unveil("/res", "r") < 0) {
          perror("unveil");
          return 1;
      }
  
      if (unveil("/proc", "r") < 0) {
          perror("unveil");
          return 1;
      }
  
      if (unveil("/dev", "r") < 0) {
          perror("unveil");
          return 1;
      }
  
      if (unveil("/bin", "r") < 0) {
          perror("unveil");
          return 1;
      }
  
      if (unveil("/bin/Profiler", "rx") < 0) {
          perror("unveil");
          return 1;
      }
  
      if (unveil("/bin/Inspector", "rx") < 0) {
          perror("unveil");
          return 1;
      }
  
      unveil(nullptr, nullptr);
  
      const char* args_tab = "processes";
      Core::ArgsParser parser;
      parser.add_option(args_tab, "Tab, one of 'processes', 'graphs', 'fs', 'pci', 'devices', 'network', 'processors' or 'interrupts'", "open-tab", 't', "tab");
      parser.parse(argc, argv);
      StringView args_tab_view = args_tab;
  
      auto app_icon = GUI::Icon::default_icon("app-system-monitor");
  
      auto window = GUI::Window::construct();
      window->set_title("System Monitor");
      window->resize(680, 400);
  
      auto& keeper = window->set_main_widget<GUI::Widget>();
      keeper.set_layout<GUI::VerticalBoxLayout>();
      keeper.set_fill_with_background_color(true);
      keeper.layout()->set_margins({ 2, 2, 2, 2 });
  
      auto& tabwidget = keeper.add<GUI::TabWidget>();
  
      auto process_container_splitter = GUI::VerticalSplitter::construct();
      tabwidget.add_widget("Processes", process_container_splitter);
      process_container_splitter->layout()->set_margins({ 4, 4, 4, 4 });
  
      auto& process_table_container = process_container_splitter->add<GUI::Widget>();
  
      auto graphs_widget = build_graphs_tab();
      tabwidget.add_widget("Graphs", graphs_widget);
  
      auto file_systems_widget = build_file_systems_tab();
      tabwidget.add_widget("File systems", file_systems_widget);
  
      auto pci_devices_widget = build_pci_devices_tab();
      tabwidget.add_widget("PCI devices", pci_devices_widget);
  
      auto devices_widget = build_devices_tab();
      tabwidget.add_widget("Devices", devices_widget);
  
      auto network_stats_widget = NetworkStatisticsWidget::construct();
      tabwidget.add_widget("Network", network_stats_widget);
  
      auto processors_widget = build_processors_tab();
      tabwidget.add_widget("Processors", processors_widget);
  
      auto interrupts_widget = InterruptsWidget::construct();
      tabwidget.add_widget("Interrupts", interrupts_widget);
  
      process_table_container.set_layout<GUI::VerticalBoxLayout>();
      process_table_container.layout()->set_spacing(0);
  
      auto& process_table_view = process_table_container.add<GUI::TableView>();
      process_table_view.set_column_headers_visible(true);
      process_table_view.set_model(GUI::SortingProxyModel::create(ProcessModel::create()));
      process_table_view.set_key_column_and_sort_order(ProcessModel::Column::CPU, GUI::SortOrder::Descending);
      process_table_view.model()->update();
  
      auto& refresh_timer = window->add<Core::Timer>(
          3000, [&] {
              process_table_view.model()->update();
              if (auto* memory_stats_widget = MemoryStatsWidget::the())
                  memory_stats_widget->refresh();
          });
  
      auto selected_id = [&](ProcessModel::Column column) -> pid_t {
          if (process_table_view.selection().is_empty())
              return -1;
          auto pid_index = process_table_view.model()->index(process_table_view.selection().first().row(), column);
          return pid_index.data().to_i32();
      };
  
      auto kill_action = GUI::Action::create("Kill process", { Mod_Ctrl, Key_K }, Gfx::Bitmap::load_from_file("/res/icons/16x16/kill.png"), [&](const GUI::Action&) {
          pid_t pid = selected_id(ProcessModel::Column::PID);
          if (pid != -1)
              kill(pid, SIGKILL);
      });
  
      auto stop_action = GUI::Action::create("Stop process", { Mod_Ctrl, Key_S }, Gfx::Bitmap::load_from_file("/res/icons/16x16/stop-hand.png"), [&](const GUI::Action&) {
          pid_t pid = selected_id(ProcessModel::Column::PID);
          if (pid != -1)
              kill(pid, SIGSTOP);
      });
  
      auto continue_action = GUI::Action::create("Continue process", { Mod_Ctrl, Key_C }, Gfx::Bitmap::load_from_file("/res/icons/16x16/continue.png"), [&](const GUI::Action&) {
          pid_t pid = selected_id(ProcessModel::Column::PID);
          if (pid != -1)
              kill(pid, SIGCONT);
      });
  
      auto profile_action = GUI::Action::create("Profile process", { Mod_Ctrl, Key_P },
          Gfx::Bitmap::load_from_file("/res/icons/16x16/app-profiler.png"), [&](auto&) {
              pid_t pid = selected_id(ProcessModel::Column::PID);
              if (pid != -1) {
                  auto pid_string = String::format("%d", pid);
                  pid_t child;
                  const char* argv[] = { "/bin/Profiler", "--pid", pid_string.characters(), nullptr };
                  if ((errno = posix_spawn(&child, "/bin/Profiler", nullptr, nullptr, const_cast<char**>(argv), environ))) {
                      perror("posix_spawn");
                  } else {
                      if (disown(child) < 0)
                          perror("disown");
                  }
              }
          });
  
      auto inspect_action = GUI::Action::create("Inspect process", { Mod_Ctrl, Key_I },
          Gfx::Bitmap::load_from_file("/res/icons/16x16/app-inspector.png"), [&](auto&) {
              pid_t pid = selected_id(ProcessModel::Column::PID);
              if (pid != -1) {
                  auto pid_string = String::format("%d", pid);
                  pid_t child;
                  const char* argv[] = { "/bin/Inspector", pid_string.characters(), nullptr };
                  if ((errno = posix_spawn(&child, "/bin/Inspector", nullptr, nullptr, const_cast<char**>(argv), environ))) {
                      perror("posix_spawn");
                  } else {
                      if (disown(child) < 0)
                          perror("disown");
                  }
              }
          });
  
      auto menubar = GUI::MenuBar::construct();
      auto& app_menu = menubar->add_menu("System Monitor");
      app_menu.add_action(GUI::CommonActions::make_quit_action([](auto&) {
          GUI::Application::the()->quit();
          return;
      }));
  
      auto& process_menu = menubar->add_menu("Process");
      process_menu.add_action(kill_action);
      process_menu.add_action(stop_action);
      process_menu.add_action(continue_action);
      process_menu.add_separator();
      process_menu.add_action(profile_action);
      process_menu.add_action(inspect_action);
  
      auto process_context_menu = GUI::Menu::construct();
      process_context_menu->add_action(kill_action);
      process_context_menu->add_action(stop_action);
      process_context_menu->add_action(continue_action);
      process_context_menu->add_separator();
      process_context_menu->add_action(profile_action);
      process_context_menu->add_action(inspect_action);
      process_table_view.on_context_menu_request = [&]([[maybe_unused]] const GUI::ModelIndex& index, const GUI::ContextMenuEvent& event) {
          process_context_menu->popup(event.screen_position());
      };
  
      auto& frequency_menu = menubar->add_menu("Frequency");
      GUI::ActionGroup frequency_action_group;
      frequency_action_group.set_exclusive(true);
  
      auto make_frequency_action = [&](auto& title, int interval, bool checked = false) {
          auto action = GUI::Action::create_checkable(title, [&refresh_timer, interval](auto&) {
              refresh_timer.restart(interval);
          });
          action->set_checked(checked);
          frequency_action_group.add_action(*action);
          frequency_menu.add_action(*action);
      };
  
      make_frequency_action("1 sec", 1000);
      make_frequency_action("3 sec", 3000, true);
      make_frequency_action("5 sec", 5000);
  
      auto& help_menu = menubar->add_menu("Help");
      help_menu.add_action(GUI::CommonActions::make_about_action("System Monitor", app_icon, window));
  
      app->set_menubar(move(menubar));
  
      auto& process_tab_unused_widget = process_container_splitter->add<UnavailableProcessWidget>("No process selected");
      process_tab_unused_widget.set_visible(true);
  
      auto& process_tab_widget = process_container_splitter->add<GUI::TabWidget>();
      process_tab_widget.set_tab_position(GUI::TabWidget::TabPosition::Bottom);
      process_tab_widget.set_visible(false);
  
      auto& memory_map_widget = process_tab_widget.add_tab<ProcessMemoryMapWidget>("Memory map");
      auto& open_files_widget = process_tab_widget.add_tab<ProcessFileDescriptorMapWidget>("Open files");
      auto& unveiled_paths_widget = process_tab_widget.add_tab<ProcessUnveiledPathsWidget>("Unveiled paths");
      auto& stack_widget = process_tab_widget.add_tab<ThreadStackWidget>("Stack");
  
      process_table_view.on_selection = [&](auto&) {
          auto pid = selected_id(ProcessModel::Column::PID);
          auto tid = selected_id(ProcessModel::Column::TID);
          if (!can_access_pid(pid)) {
              process_tab_widget.set_visible(false);
              process_tab_unused_widget.set_text("Process cannot be accessed");
              process_tab_unused_widget.set_visible(true);
              return;
          }
  
          process_tab_widget.set_visible(true);
          process_tab_unused_widget.set_visible(false);
          open_files_widget.set_pid(pid);
          stack_widget.set_ids(pid, tid);
          memory_map_widget.set_pid(pid);
          unveiled_paths_widget.set_pid(pid);
      };
  
      window->show();
  
      window->set_icon(app_icon.bitmap_for_size(16));
  
      if (args_tab_view == "processes")
          tabwidget.set_active_widget(process_container_splitter);
      else if (args_tab_view == "graphs")
          tabwidget.set_active_widget(graphs_widget);
      else if (args_tab_view == "fs")
          tabwidget.set_active_widget(file_systems_widget);
      else if (args_tab_view == "pci")
          tabwidget.set_active_widget(pci_devices_widget);
      else if (args_tab_view == "devices")
          tabwidget.set_active_widget(devices_widget);
      else if (args_tab_view == "network")
          tabwidget.set_active_widget(network_stats_widget);
      else if (args_tab_view == "processors")
          tabwidget.set_active_widget(processors_widget);
      else if (args_tab_view == "interrupts")
          tabwidget.set_active_widget(interrupts_widget);
  
      return app->exec();
  }
  
  class ProgressBarPaintingDelegate final : public GUI::TableCellPaintingDelegate {
  public:
      virtual ~ProgressBarPaintingDelegate() override { }
  
      virtual void paint(GUI::Painter& painter, const Gfx::IntRect& a_rect, const Palette& palette, const GUI::ModelIndex& index) override
      {
          auto rect = a_rect.shrunken(2, 2);
          auto percentage = index.data(GUI::ModelRole::Custom).to_i32();
  
          auto data = index.data();
          String text;
          if (data.is_string())
              text = data.as_string();
          Gfx::StylePainter::paint_progress_bar(painter, rect, palette, 0, 100, percentage, text);
          painter.draw_rect(rect, Color::Black);
      }
  };
  
  NonnullRefPtr<GUI::Widget> build_file_systems_tab()
  {
      auto fs_widget = GUI::LazyWidget::construct();
  
      fs_widget->on_first_show = [](GUI::LazyWidget& self) {
          self.set_layout<GUI::VerticalBoxLayout>();
          self.layout()->set_margins({ 4, 4, 4, 4 });
          auto& fs_table_view = self.add<GUI::TableView>();
  
          Vector<GUI::JsonArrayModel::FieldSpec> df_fields;
          df_fields.empend("mount_point", "Mount point", Gfx::TextAlignment::CenterLeft);
          df_fields.empend("class_name", "Class", Gfx::TextAlignment::CenterLeft);
          df_fields.empend("source", "Source", Gfx::TextAlignment::CenterLeft);
          df_fields.empend(
              "Size", Gfx::TextAlignment::CenterRight,
              [](const JsonObject& object) {
                  StringBuilder size_builder;
                  size_builder.append(" ");
                  size_builder.append(human_readable_size(object.get("total_block_count").to_u32() * object.get("block_size").to_u32()));
                  size_builder.append(" ");
                  return size_builder.to_string();
              },
              [](const JsonObject& object) {
                  return object.get("total_block_count").to_u32() * object.get("block_size").to_u32();
              },
              [](const JsonObject& object) {
                  auto total_blocks = object.get("total_block_count").to_u32();
                  if (total_blocks == 0)
                      return 0;
                  auto free_blocks = object.get("free_block_count").to_u32();
                  auto used_blocks = total_blocks - free_blocks;
                  int percentage = (int)((float)used_blocks / (float)total_blocks * 100.0f);
                  return percentage;
              });
          df_fields.empend(
              "Used", Gfx::TextAlignment::CenterRight,
              [](const JsonObject& object) {
              auto total_blocks = object.get("total_block_count").to_u32();
              auto free_blocks = object.get("free_block_count").to_u32();
              auto used_blocks = total_blocks - free_blocks;
              return human_readable_size(used_blocks * object.get("block_size").to_u32()); },
              [](const JsonObject& object) {
                  auto total_blocks = object.get("total_block_count").to_u32();
                  auto free_blocks = object.get("free_block_count").to_u32();
                  auto used_blocks = total_blocks - free_blocks;
                  return used_blocks * object.get("block_size").to_u32();
              });
          df_fields.empend(
              "Available", Gfx::TextAlignment::CenterRight,
              [](const JsonObject& object) {
                  return human_readable_size(object.get("free_block_count").to_u32() * object.get("block_size").to_u32());
              },
              [](const JsonObject& object) {
                  return object.get("free_block_count").to_u32() * object.get("block_size").to_u32();
              });
          df_fields.empend("Access", Gfx::TextAlignment::CenterLeft, [](const JsonObject& object) {
              bool readonly = object.get("readonly").to_bool();
              int mount_flags = object.get("mount_flags").to_int();
              return readonly || (mount_flags & MS_RDONLY) ? "Read-only" : "Read/Write";
          });
          df_fields.empend("Mount flags", Gfx::TextAlignment::CenterLeft, [](const JsonObject& object) {
              int mount_flags = object.get("mount_flags").to_int();
              StringBuilder builder;
              bool first = true;
              auto check = [&](int flag, const char* name) {
                  if (!(mount_flags & flag))
                      return;
                  if (!first)
                      builder.append(',');
                  builder.append(name);
                  first = false;
              };
              check(MS_NODEV, "nodev");
              check(MS_NOEXEC, "noexec");
              check(MS_NOSUID, "nosuid");
              check(MS_BIND, "bind");
              check(MS_RDONLY, "ro");
              if (builder.string_view().is_empty())
                  return String("defaults");
              return builder.to_string();
          });
          df_fields.empend("free_block_count", "Free blocks", Gfx::TextAlignment::CenterRight);
          df_fields.empend("total_block_count", "Total blocks", Gfx::TextAlignment::CenterRight);
          df_fields.empend("free_inode_count", "Free inodes", Gfx::TextAlignment::CenterRight);
          df_fields.empend("total_inode_count", "Total inodes", Gfx::TextAlignment::CenterRight);
          df_fields.empend("block_size", "Block size", Gfx::TextAlignment::CenterRight);
          fs_table_view.set_model(GUI::SortingProxyModel::create(GUI::JsonArrayModel::create("/proc/df", move(df_fields))));
  
          fs_table_view.set_column_painting_delegate(3, make<ProgressBarPaintingDelegate>());
  
          fs_table_view.model()->update();
      };
      return fs_widget;
  }
  
  NonnullRefPtr<GUI::Widget> build_pci_devices_tab()
  {
      auto pci_widget = GUI::LazyWidget::construct();
  
      pci_widget->on_first_show = [](GUI::LazyWidget& self) {
          self.set_layout<GUI::VerticalBoxLayout>();
          self.layout()->set_margins({ 4, 4, 4, 4 });
          auto& pci_table_view = self.add<GUI::TableView>();
  
          auto db = PCIDB::Database::open();
  
          Vector<GUI::JsonArrayModel::FieldSpec> pci_fields;
          pci_fields.empend(
              "Address", Gfx::TextAlignment::CenterLeft,
              [](const JsonObject& object) {
                  auto seg = object.get("seg").to_u32();
                  auto bus = object.get("bus").to_u32();
                  auto slot = object.get("slot").to_u32();
                  auto function = object.get("function").to_u32();
                  return String::formatted("{:04x}:{:02x}:{:02x}.{}", seg, bus, slot, function);
              });
          pci_fields.empend(
              "Class", Gfx::TextAlignment::CenterLeft,
              [db](const JsonObject& object) {
                  auto class_id = object.get("class").to_u32();
                  String class_name = db->get_class(class_id);
                  return class_name == "" ? String::formatted("{:04x}", class_id) : class_name;
              });
          pci_fields.empend(
              "Vendor", Gfx::TextAlignment::CenterLeft,
              [db](const JsonObject& object) {
                  auto vendor_id = object.get("vendor_id").to_u32();
                  String vendor_name = db->get_vendor(vendor_id);
                  return vendor_name == "" ? String::formatted("{:02x}", vendor_id) : vendor_name;
              });
          pci_fields.empend(
              "Device", Gfx::TextAlignment::CenterLeft,
              [db](const JsonObject& object) {
                  auto vendor_id = object.get("vendor_id").to_u32();
                  auto device_id = object.get("device_id").to_u32();
                  String device_name = db->get_device(vendor_id, device_id);
                  return device_name == "" ? String::formatted("{:02x}", device_id) : device_name;
              });
          pci_fields.empend(
              "Revision", Gfx::TextAlignment::CenterRight,
              [](const JsonObject& object) {
                  auto revision_id = object.get("revision_id").to_u32();
                  return String::formatted("{:02x}", revision_id);
              });
  
          pci_table_view.set_model(GUI::SortingProxyModel::create(GUI::JsonArrayModel::create("/proc/pci", move(pci_fields))));
          pci_table_view.model()->update();
      };
  
      return pci_widget;
  }
  
  NonnullRefPtr<GUI::Widget> build_devices_tab()
  {
      auto devices_widget = GUI::LazyWidget::construct();
  
      devices_widget->on_first_show = [](GUI::LazyWidget& self) {
          self.set_layout<GUI::VerticalBoxLayout>();
          self.layout()->set_margins({ 4, 4, 4, 4 });
  
          auto& devices_table_view = self.add<GUI::TableView>();
          devices_table_view.set_model(GUI::SortingProxyModel::create(DevicesModel::create()));
          devices_table_view.model()->update();
      };
  
      return devices_widget;
  }
  
  NonnullRefPtr<GUI::Widget> build_graphs_tab()
  {
      auto graphs_container = GUI::LazyWidget::construct();
  
      graphs_container->on_first_show = [](GUI::LazyWidget& self) {
          self.set_fill_with_background_color(true);
          self.set_background_role(ColorRole::Button);
          self.set_layout<GUI::VerticalBoxLayout>();
          self.layout()->set_margins({ 4, 4, 4, 4 });
  
          auto& cpu_graph_group_box = self.add<GUI::GroupBox>("CPU usage");
          cpu_graph_group_box.set_layout<GUI::HorizontalBoxLayout>();
          cpu_graph_group_box.layout()->set_margins({ 6, 16, 6, 6 });
          cpu_graph_group_box.set_fixed_height(120);
          Vector<GraphWidget*> cpu_graphs;
          for (size_t i = 0; i < ProcessModel::the().cpus().size(); i++) {
              auto& cpu_graph = cpu_graph_group_box.add<GraphWidget>();
              cpu_graph.set_max(100);
              cpu_graph.set_background_color(Color::White);
              cpu_graph.set_value_format(0, {
                                                .line_color = Color::Blue,
                                                .background_color = Color::from_rgb(0xaaaaff),
                                                .text_formatter = [](int value) {
                                                    return String::formatted("Total: {}%", value);
                                                },
                                            });
              cpu_graph.set_value_format(1, {
                                                .line_color = Color::Red,
                                                .background_color = Color::from_rgb(0xffaaaa),
                                                .text_formatter = [](int value) {
                                                    return String::formatted("Kernel: {}%", value);
                                                },
                                            });
              cpu_graphs.append(&cpu_graph);
          }
          ProcessModel::the().on_cpu_info_change = [cpu_graphs](const NonnullOwnPtrVector<ProcessModel::CpuInfo>& cpus) {
              for (size_t i = 0; i < cpus.size(); i++)
                  cpu_graphs[i]->add_value({ (int)cpus[i].total_cpu_percent, (int)cpus[i].total_cpu_percent_kernel });
          };
  
          auto& memory_graph_group_box = self.add<GUI::GroupBox>("Memory usage");
          memory_graph_group_box.set_layout<GUI::VerticalBoxLayout>();
          memory_graph_group_box.layout()->set_margins({ 6, 16, 6, 6 });
          memory_graph_group_box.set_fixed_height(120);
          auto& memory_graph = memory_graph_group_box.add<GraphWidget>();
          memory_graph.set_background_color(Color::White);
          memory_graph.set_stack_values(true);
          memory_graph.set_value_format(0, {
                                               .line_color = Color::from_rgb(0x619910),
                                               .background_color = Color::from_rgb(0xbbffbb),
                                               .text_formatter = [&memory_graph](int value) {
                                                   return String::formatted("Committed: {} KiB", value);
                                               },
                                           });
          memory_graph.set_value_format(1, {
                                               .line_color = Color::Blue,
                                               .background_color = Color::from_rgb(0xaaaaff),
                                               .text_formatter = [&memory_graph](int value) {
                                                   return String::formatted("Allocated: {} KiB", value);
                                               },
                                           });
          memory_graph.set_value_format(2, {
                                               .line_color = Color::Red,
                                               .background_color = Color::from_rgb(0xffaaaa),
                                               .text_formatter = [&memory_graph](int value) {
                                                   return String::formatted("Kernel heap: {} KiB", value);
                                               },
                                           });
  
          self.add<MemoryStatsWidget>(memory_graph);
      };
      return graphs_container;
  }
  
  NonnullRefPtr<GUI::Widget> build_processors_tab()
  {
      auto processors_widget = GUI::LazyWidget::construct();
  
      processors_widget->on_first_show = [](GUI::LazyWidget& self) {
          self.set_layout<GUI::VerticalBoxLayout>();
          self.layout()->set_margins({ 4, 4, 4, 4 });
  
          Vector<GUI::JsonArrayModel::FieldSpec> processors_field;
          processors_field.empend("processor", "Processor", Gfx::TextAlignment::CenterRight);
          processors_field.empend("cpuid", "CPUID", Gfx::TextAlignment::CenterLeft);
          processors_field.empend("brandstr", "Brand", Gfx::TextAlignment::CenterLeft);
          processors_field.empend("Features", Gfx::TextAlignment::CenterLeft, [](auto& object) {
              StringBuilder builder;
              auto features = object.get("features").as_array();
              for (auto& feature : features.values()) {
                  builder.append(feature.to_string());
                  builder.append(' ');
              }
              return GUI::Variant(builder.to_string());
          });
          processors_field.empend("family", "Family", Gfx::TextAlignment::CenterRight);
          processors_field.empend("model", "Model", Gfx::TextAlignment::CenterRight);
          processors_field.empend("stepping", "Stepping", Gfx::TextAlignment::CenterRight);
          processors_field.empend("type", "Type", Gfx::TextAlignment::CenterRight);
  
          auto& processors_table_view = self.add<GUI::TableView>();
          processors_table_view.set_model(GUI::JsonArrayModel::create("/proc/cpuinfo", move(processors_field)));
          processors_table_view.model()->update();
      };
  
      return processors_widget;
  }
  