/*
 * 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 "DesktopWidget.h"
#include "DirectoryView.h"
#include "FileUtils.h"
#include "PropertiesDialog.h"
#include <AK/LexicalPath.h>
#include <AK/StringBuilder.h>
#include <AK/URL.h>
#include <LibCore/ConfigFile.h>
#include <LibCore/MimeData.h>
#include <LibCore/StandardPaths.h>
#include <LibDesktop/Launcher.h>
#include <LibGUI/AboutDialog.h>
#include <LibGUI/Action.h>
#include <LibGUI/ActionGroup.h>
#include <LibGUI/Application.h>
#include <LibGUI/BoxLayout.h>
#include <LibGUI/BreadcrumbBar.h>
#include <LibGUI/Clipboard.h>
#include <LibGUI/Desktop.h>
#include <LibGUI/FileIconProvider.h>
#include <LibGUI/FileSystemModel.h>
#include <LibGUI/InputBox.h>
#include <LibGUI/Label.h>
#include <LibGUI/Menu.h>
#include <LibGUI/MenuBar.h>
#include <LibGUI/MessageBox.h>
#include <LibGUI/Painter.h>
#include <LibGUI/ProgressBar.h>
#include <LibGUI/Splitter.h>
#include <LibGUI/StatusBar.h>
#include <LibGUI/TextEditor.h>
#include <LibGUI/ToolBar.h>
#include <LibGUI/ToolBarContainer.h>
#include <LibGUI/TreeView.h>
#include <LibGUI/Widget.h>
#include <LibGUI/Window.h>
#include <LibGfx/Palette.h>
#include <pthread.h>
#include <serenity.h>
#include <signal.h>
#include <spawn.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

using namespace FileManager;

static int run_in_desktop_mode(RefPtr<Core::ConfigFile>);
static int run_in_windowed_mode(RefPtr<Core::ConfigFile>, String initial_location);
static void do_copy(const Vector<String>& selected_file_paths);
static void do_paste(const String& target_directory, GUI::Window* window);
static void show_properties(const String& container_dir_path, const String& path, const Vector<String>& selected, GUI::Window* window);

int main(int argc, char** argv)
{
    if (pledge("stdio thread shared_buffer accept unix cpath rpath wpath fattr proc exec sigaction", nullptr) < 0) {
        perror("pledge");
        return 1;
    }

    struct sigaction act;
    memset(&act, 0, sizeof(act));
    act.sa_flags = SA_NOCLDWAIT;
    act.sa_handler = SIG_IGN;
    int rc = sigaction(SIGCHLD, &act, nullptr);
    if (rc < 0) {
        perror("sigaction");
        return 1;
    }

    RefPtr<Core::ConfigFile> config = Core::ConfigFile::get_for_app("FileManager");

    auto app = GUI::Application::construct(argc, argv);

    if (pledge("stdio thread shared_buffer accept cpath rpath wpath fattr proc exec unix", nullptr) < 0) {
        perror("pledge");
        return 1;
    }

    if (app->args().contains_slow("--desktop") || app->args().contains_slow("-d"))
        return run_in_desktop_mode(move(config));

    // our initial location is defined as, in order of precedence:
    // 1. the first command-line argument (e.g. FileManager /bin)
    // 2. the user's home directory
    // 3. the root directory
    String initial_location;

    if (argc >= 2) {
        char* buffer = realpath(argv[1], nullptr);
        initial_location = buffer;
        free(buffer);
    }

    if (initial_location.is_empty())
        initial_location = Core::StandardPaths::home_directory();

    if (initial_location.is_empty())
        initial_location = "/";

    return run_in_windowed_mode(move(config), initial_location);
}

void do_copy(const Vector<String>& selected_file_paths)
{
    if (selected_file_paths.is_empty())
        ASSERT_NOT_REACHED();

    StringBuilder copy_text;
    for (auto& path : selected_file_paths) {
        auto url = URL::create_with_file_protocol(path);
        copy_text.appendff("{}\n", url);
    }
    GUI::Clipboard::the().set_data(copy_text.build().bytes(), "text/uri-list");
}

void do_paste(const String& target_directory, GUI::Window* window)
{
    auto data_and_type = GUI::Clipboard::the().data_and_type();
    if (data_and_type.mime_type != "text/uri-list") {
        dbgln("Cannot paste clipboard type {}", data_and_type.mime_type);
        return;
    }
    auto copied_lines = String::copy(data_and_type.data).split('\n');
    if (copied_lines.is_empty()) {
        dbgln("No files to paste");
        return;
    }

    for (auto& uri_as_string : copied_lines) {
        if (uri_as_string.is_empty())
            continue;
        URL url = uri_as_string;
        if (!url.is_valid() || url.protocol() != "file") {
            dbgln("Cannot paste URI {}", uri_as_string);
            continue;
        }

        auto new_path = String::formatted("{}/{}", target_directory, url.basename());
        if (!FileUtils::copy_file_or_directory(url.path(), new_path)) {
            auto error_message = String::formatted("Could not paste {}.", url.path());
            GUI::MessageBox::show(window, error_message, "File Manager", GUI::MessageBox::Type::Error);
        }
    }
}

void show_properties(const String& container_dir_path, const String& path, const Vector<String>& selected, GUI::Window* window)
{
    RefPtr<PropertiesDialog> properties;
    if (selected.is_empty()) {
        properties = window->add<PropertiesDialog>(path, true);
    } else {
        properties = window->add<PropertiesDialog>(selected.first(), access(container_dir_path.characters(), W_OK) != 0);
    }

    properties->exec();
}

int run_in_desktop_mode(RefPtr<Core::ConfigFile> config)
{
    static constexpr const char* process_name = "FileManager (Desktop)";
    set_process_name(process_name, strlen(process_name));
    pthread_setname_np(pthread_self(), process_name);

    (void)config;
    auto window = GUI::Window::construct();
    window->set_title("Desktop Manager");
    window->set_window_type(GUI::WindowType::Desktop);
    window->set_has_alpha_channel(true);

    auto& desktop_widget = window->set_main_widget<FileManager::DesktopWidget>();
    desktop_widget.set_layout<GUI::VerticalBoxLayout>();

    auto& directory_view = desktop_widget.add<DirectoryView>(DirectoryView::Mode::Desktop);
    (void)directory_view;

    auto copy_action = GUI::CommonActions::make_copy_action(
        [&](auto&) {
            auto paths = directory_view.selected_file_paths();

            if (paths.is_empty())
                ASSERT_NOT_REACHED();

            do_copy(paths);
        },
        window);
    copy_action->set_enabled(false);

    directory_view.on_selection_change = [&](const GUI::AbstractView& view) {
        copy_action->set_enabled(!view.selection().is_empty());
    };

    auto properties_action
        = GUI::Action::create(
            "Properties...", { Mod_Alt, Key_Return }, Gfx::Bitmap::load_from_file("/res/icons/16x16/properties.png"), [&](const GUI::Action&) {
                String path = directory_view.path();
                Vector<String> selected = directory_view.selected_file_paths();

                show_properties(path, path, selected, directory_view.window());
            },
            window);

    auto paste_action = GUI::CommonActions::make_paste_action(
        [&](const GUI::Action&) {
            do_paste(directory_view.path(), directory_view.window());
        },
        window);
    paste_action->set_enabled(GUI::Clipboard::the().mime_type() == "text/uri-list" && access(directory_view.path().characters(), W_OK) == 0);

    GUI::Clipboard::the().on_change = [&](const String& data_type) {
        paste_action->set_enabled(data_type == "text/uri-list" && access(directory_view.path().characters(), W_OK) == 0);
    };

    auto desktop_view_context_menu = GUI::Menu::construct("Directory View");

    auto file_manager_action = GUI::Action::create("Show in FileManager...", {}, Gfx::Bitmap::load_from_file("/res/icons/16x16/filetype-folder.png"), [&](const GUI::Action&) {
        Desktop::Launcher::open(URL::create_with_file_protocol(directory_view.path()));
    });

    auto display_properties_action = GUI::Action::create("Display settings...", {}, Gfx::Bitmap::load_from_file("/res/icons/16x16/app-display-settings.png"), [&](const GUI::Action&) {
        Desktop::Launcher::open(URL::create_with_file_protocol("/bin/DisplaySettings"));
    });

    desktop_view_context_menu->add_action(directory_view.mkdir_action());
    desktop_view_context_menu->add_action(directory_view.touch_action());
    desktop_view_context_menu->add_action(paste_action);
    desktop_view_context_menu->add_separator();
    desktop_view_context_menu->add_action(file_manager_action);
    desktop_view_context_menu->add_action(directory_view.open_terminal_action());
    desktop_view_context_menu->add_separator();
    desktop_view_context_menu->add_action(display_properties_action);

    auto desktop_context_menu = GUI::Menu::construct("Directory View Directory");
    desktop_context_menu->add_action(copy_action);
    desktop_context_menu->add_action(paste_action);
    desktop_context_menu->add_action(directory_view.delete_action());
    desktop_context_menu->add_separator();
    desktop_context_menu->add_action(properties_action);

    directory_view.on_context_menu_request = [&](const GUI::ModelIndex& index, const GUI::ContextMenuEvent& event) {
        if (!index.is_valid())
            desktop_view_context_menu->popup(event.screen_position());
        else
            desktop_context_menu->popup(event.screen_position());
    };

    auto wm_config = Core::ConfigFile::get_for_app("WindowManager");
    auto selected_wallpaper = wm_config->read_entry("Background", "Wallpaper", "");
    if (!selected_wallpaper.is_empty()) {
        GUI::Desktop::the().set_wallpaper(selected_wallpaper, false);
    }

    window->show();
    return GUI::Application::the()->exec();
}

int run_in_windowed_mode(RefPtr<Core::ConfigFile> config, String initial_location)
{
    auto window = GUI::Window::construct();
    window->set_title("File Manager");

    auto left = config->read_num_entry("Window", "Left", 150);
    auto top = config->read_num_entry("Window", "Top", 75);
    auto width = config->read_num_entry("Window", "Width", 640);
    auto height = config->read_num_entry("Window", "Height", 480);
    window->set_rect({ left, top, width, height });

    auto& widget = window->set_main_widget<GUI::Widget>();
    widget.set_layout<GUI::VerticalBoxLayout>();
    widget.set_fill_with_background_color(true);
    widget.layout()->set_spacing(2);

    auto& toolbar_container = widget.add<GUI::ToolBarContainer>();

    auto& main_toolbar = toolbar_container.add<GUI::ToolBar>();
    auto& location_toolbar = toolbar_container.add<GUI::ToolBar>();
    location_toolbar.layout()->set_margins({ 6, 3, 6, 3 });

    location_toolbar.set_visible(false);

    auto& location_label = location_toolbar.add<GUI::Label>("Location: ");
    location_label.size_to_fit();

    auto& location_textbox = location_toolbar.add<GUI::TextBox>();
    location_textbox.set_size_policy(GUI::SizePolicy::Fill, GUI::SizePolicy::Fixed);
    location_textbox.set_preferred_size(0, 22);

    auto& breadcrumb_toolbar = toolbar_container.add<GUI::ToolBar>(Gfx::Orientation::Horizontal, 16);
    breadcrumb_toolbar.layout()->set_margins({});
    auto& breadcrumb_bar = breadcrumb_toolbar.add<GUI::BreadcrumbBar>();

    location_textbox.on_focusout = [&] {
        location_toolbar.set_visible(false);
        breadcrumb_toolbar.set_visible(true);
    };

    auto& splitter = widget.add<GUI::HorizontalSplitter>();
    auto& tree_view = splitter.add<GUI::TreeView>();
    auto directories_model = GUI::FileSystemModel::create({}, GUI::FileSystemModel::Mode::DirectoriesOnly);
    tree_view.set_model(directories_model);
    tree_view.set_column_hidden(GUI::FileSystemModel::Column::Icon, true);
    tree_view.set_column_hidden(GUI::FileSystemModel::Column::Size, true);
    tree_view.set_column_hidden(GUI::FileSystemModel::Column::Owner, true);
    tree_view.set_column_hidden(GUI::FileSystemModel::Column::Group, true);
    tree_view.set_column_hidden(GUI::FileSystemModel::Column::Permissions, true);
    tree_view.set_column_hidden(GUI::FileSystemModel::Column::ModificationTime, true);
    tree_view.set_column_hidden(GUI::FileSystemModel::Column::Inode, true);
    tree_view.set_column_hidden(GUI::FileSystemModel::Column::SymlinkTarget, true);
    tree_view.set_size_policy(GUI::SizePolicy::Fixed, GUI::SizePolicy::Fill);
    tree_view.set_preferred_size(175, 0);
    bool is_reacting_to_tree_view_selection_change = false;

    auto& directory_view = splitter.add<DirectoryView>(DirectoryView::Mode::Normal);

    location_textbox.on_escape_pressed = [&] {
        directory_view.set_focus(true);
    };

    // Open the root directory. FIXME: This is awkward.
    tree_view.toggle_index(directories_model->index(0, 0, {}));

    auto& statusbar = widget.add<GUI::StatusBar>();

    auto& progressbar = statusbar.add<GUI::ProgressBar>();
    progressbar.set_caption("Generating thumbnails: ");
    progressbar.set_format(GUI::ProgressBar::Format::ValueSlashMax);
    progressbar.set_visible(false);
    progressbar.set_frame_shape(Gfx::FrameShape::Panel);
    progressbar.set_frame_shadow(Gfx::FrameShadow::Sunken);
    progressbar.set_frame_thickness(1);

    location_textbox.on_return_pressed = [&] {
        directory_view.open(location_textbox.text());
    };

    auto refresh_tree_view = [&] {
        directories_model->update();

        auto current_path = directory_view.path();

        struct stat st;
        // If the directory no longer exists, we find a parent that does.
        while (stat(current_path.characters(), &st) != 0) {
            directory_view.open_parent_directory();
            current_path = directory_view.path();
            if (current_path == directories_model->root_path()) {
                break;
            }
        }

        // Reselect the existing folder in the tree.
        auto new_index = directories_model->index(current_path, GUI::FileSystemModel::Column::Name);
        if (new_index.is_valid()) {
            tree_view.expand_all_parents_of(new_index);
            tree_view.set_cursor(new_index, GUI::AbstractView::SelectionUpdate::Set, true);
        }

        directory_view.refresh();
    };

    auto directory_context_menu = GUI::Menu::construct("Directory View Directory");
    auto directory_view_context_menu = GUI::Menu::construct("Directory View");
    auto tree_view_directory_context_menu = GUI::Menu::construct("Tree View Directory");
    auto tree_view_context_menu = GUI::Menu::construct("Tree View");

    auto open_parent_directory_action = GUI::Action::create("Open parent directory", { Mod_Alt, Key_Up }, Gfx::Bitmap::load_from_file("/res/icons/16x16/open-parent-directory.png"), [&](const GUI::Action&) {
        directory_view.open_parent_directory();
    });

    RefPtr<GUI::Action> view_as_table_action;
    RefPtr<GUI::Action> view_as_icons_action;
    RefPtr<GUI::Action> view_as_columns_action;

    view_as_icons_action = GUI::Action::create_checkable(
        "Icon view", { Mod_Ctrl, KeyCode::Key_1 }, Gfx::Bitmap::load_from_file("/res/icons/16x16/icon-view.png"), [&](const GUI::Action&) {
            directory_view.set_view_mode(DirectoryView::ViewMode::Icon);
            config->write_entry("DirectoryView", "ViewMode", "Icon");
            config->sync();
        },
        window);

    view_as_table_action = GUI::Action::create_checkable(
        "Table view", { Mod_Ctrl, KeyCode::Key_2 }, Gfx::Bitmap::load_from_file("/res/icons/16x16/table-view.png"), [&](const GUI::Action&) {
            directory_view.set_view_mode(DirectoryView::ViewMode::Table);
            config->write_entry("DirectoryView", "ViewMode", "Table");
            config->sync();
        },
        window);

    view_as_columns_action = GUI::Action::create_checkable(
        "Columns view", { Mod_Ctrl, KeyCode::Key_3 }, Gfx::Bitmap::load_from_file("/res/icons/16x16/columns-view.png"), [&](const GUI::Action&) {
            directory_view.set_view_mode(DirectoryView::ViewMode::Columns);
            config->write_entry("DirectoryView", "ViewMode", "Columns");
            config->sync();
        },
        window);

    auto view_type_action_group = make<GUI::ActionGroup>();
    view_type_action_group->set_exclusive(true);
    view_type_action_group->add_action(*view_as_icons_action);
    view_type_action_group->add_action(*view_as_table_action);
    view_type_action_group->add_action(*view_as_columns_action);

    auto tree_view_selected_file_paths = [&] {
        Vector<String> paths;
        auto& view = tree_view;
        view.selection().for_each_index([&](const GUI::ModelIndex& index) {
            paths.append(directories_model->full_path(index));
        });
        return paths;
    };

    auto select_all_action = GUI::Action::create("Select all", { Mod_Ctrl, KeyCode::Key_A }, [&](const GUI::Action&) {
        directory_view.current_view().select_all();
    });

    auto copy_action = GUI::CommonActions::make_copy_action(
        [&](auto&) {
            auto paths = directory_view.selected_file_paths();

            if (paths.is_empty())
                paths = tree_view_selected_file_paths();

            if (paths.is_empty())
                ASSERT_NOT_REACHED();

            do_copy(paths);
            refresh_tree_view();
        },
        window);
    copy_action->set_enabled(false);

    auto properties_action
        = GUI::Action::create(
            "Properties...", { Mod_Alt, Key_Return }, Gfx::Bitmap::load_from_file("/res/icons/16x16/properties.png"), [&](const GUI::Action& action) {
                String container_dir_path;
                String path;
                Vector<String> selected;
                if (action.activator() == directory_context_menu || directory_view.active_widget()->is_focused()) {
                    path = directory_view.path();
                    container_dir_path = path;
                    selected = directory_view.selected_file_paths();
                } else {
                    path = directories_model->full_path(tree_view.selection().first());
                    container_dir_path = LexicalPath(path).basename();
                    selected = tree_view_selected_file_paths();
                }

                show_properties(container_dir_path, path, selected, directory_view.window());
            },
            window);

    auto paste_action = GUI::CommonActions::make_paste_action(
        [&](const GUI::Action& action) {
            String target_directory;
            if (action.activator() == directory_context_menu)
                target_directory = directory_view.selected_file_paths()[0];
            else
                target_directory = directory_view.path();
            do_paste(target_directory, directory_view.window());
            refresh_tree_view();
        },
        window);

    auto folder_specific_paste_action = GUI::CommonActions::make_paste_action(
        [&](const GUI::Action& action) {
            String target_directory;
            if (action.activator() == directory_context_menu)
                target_directory = directory_view.selected_file_paths()[0];
            else
                target_directory = directory_view.path();
            do_paste(target_directory, directory_view.window());
            refresh_tree_view();
        },
        window);

    auto go_back_action = GUI::CommonActions::make_go_back_action(
        [&](auto&) {
            directory_view.open_previous_directory();
        },
        window);

    auto go_forward_action = GUI::CommonActions::make_go_forward_action(
        [&](auto&) {
            directory_view.open_next_directory();
        },
        window);

    auto go_home_action = GUI::CommonActions::make_go_home_action(
        [&](auto&) {
            directory_view.open(Core::StandardPaths::home_directory());
        },
        window);

    GUI::Clipboard::the().on_change = [&](const String& data_type) {
        auto current_location = directory_view.path();
        paste_action->set_enabled(data_type == "text/uri-list" && access(current_location.characters(), W_OK) == 0);
    };

    auto tree_view_delete_action = GUI::CommonActions::make_delete_action(
        [&](auto&) {
            FileUtils::delete_paths(tree_view_selected_file_paths(), true, window);
            refresh_tree_view();
        },
        &tree_view);

    // This is a little awkward. The menu action does something different depending on which view has focus.
    // It would be nice to find a good abstraction for this instead of creating a branching action like this.
    auto focus_dependent_delete_action = GUI::CommonActions::make_delete_action([&](auto&) {
        if (tree_view.is_focused())
            tree_view_delete_action->activate();
        else
            directory_view.delete_action().activate();
        refresh_tree_view();
    });
    focus_dependent_delete_action->set_enabled(false);

    auto mkdir_action = GUI::Action::create("New directory...", { Mod_Ctrl | Mod_Shift, Key_N }, Gfx::Bitmap::load_from_file("/res/icons/16x16/mkdir.png"), [&](const GUI::Action&) {
        directory_view.mkdir_action().activate();
        refresh_tree_view();
    });

    auto touch_action = GUI::Action::create("New file...", { Mod_Ctrl | Mod_Shift, Key_F }, Gfx::Bitmap::load_from_file("/res/icons/16x16/new.png"), [&](const GUI::Action&) {
        directory_view.touch_action().activate();
        refresh_tree_view();
    });

    auto menubar = GUI::MenuBar::construct();

    auto& app_menu = menubar->add_menu("File Manager");
    app_menu.add_action(mkdir_action);
    app_menu.add_action(touch_action);
    app_menu.add_action(copy_action);
    app_menu.add_action(paste_action);
    app_menu.add_action(focus_dependent_delete_action);
    app_menu.add_action(directory_view.open_terminal_action());
    app_menu.add_separator();
    app_menu.add_action(properties_action);
    app_menu.add_separator();
    app_menu.add_action(GUI::CommonActions::make_quit_action([](auto&) {
        GUI::Application::the()->quit();
    }));

    auto action_show_dotfiles = GUI::Action::create_checkable("Show dotfiles", { Mod_Ctrl, Key_H }, [&](auto& action) {
        directory_view.set_should_show_dotfiles(action.is_checked());
        refresh_tree_view();
    });

    auto& view_menu = menubar->add_menu("View");
    view_menu.add_action(*view_as_icons_action);
    view_menu.add_action(*view_as_table_action);
    view_menu.add_action(*view_as_columns_action);
    view_menu.add_separator();
    view_menu.add_action(action_show_dotfiles);

    auto& go_menu = menubar->add_menu("Go");
    go_menu.add_action(go_back_action);
    go_menu.add_action(go_forward_action);
    go_menu.add_action(open_parent_directory_action);
    go_menu.add_action(go_home_action);
    go_menu.add_action(GUI::Action::create(
        "Go to location...", { Mod_Ctrl, Key_L }, [&](auto&) {
            location_toolbar.set_visible(true);
            breadcrumb_toolbar.set_visible(false);
            location_textbox.select_all();
            location_textbox.set_focus(true);
        }));

    auto& help_menu = menubar->add_menu("Help");
    help_menu.add_action(GUI::Action::create("About", [&](auto&) {
        GUI::AboutDialog::show("File Manager", Gfx::Bitmap::load_from_file("/res/icons/32x32/filetype-folder.png"), window);
    }));

    GUI::Application::the()->set_menubar(move(menubar));

    main_toolbar.add_action(go_back_action);
    main_toolbar.add_action(go_forward_action);
    main_toolbar.add_action(open_parent_directory_action);
    main_toolbar.add_action(go_home_action);

    main_toolbar.add_separator();
    main_toolbar.add_action(mkdir_action);
    main_toolbar.add_action(touch_action);
    main_toolbar.add_action(copy_action);
    main_toolbar.add_action(paste_action);
    main_toolbar.add_action(focus_dependent_delete_action);
    main_toolbar.add_action(directory_view.open_terminal_action());

    main_toolbar.add_separator();
    main_toolbar.add_action(*view_as_icons_action);
    main_toolbar.add_action(*view_as_table_action);
    main_toolbar.add_action(*view_as_columns_action);

    directory_view.on_path_change = [&](const String& new_path, bool can_write_in_path) {
        auto icon = GUI::FileIconProvider::icon_for_path(new_path);
        auto* bitmap = icon.bitmap_for_size(16);
        window->set_icon(bitmap);
        location_textbox.set_icon(bitmap);

        window->set_title(String::formatted("{} - File Manager", new_path));
        location_textbox.set_text(new_path);

        {
            LexicalPath lexical_path(new_path);

            auto segment_index_of_new_path_in_breadcrumb_bar = [&]() -> Optional<size_t> {
                for (size_t i = 0; i < breadcrumb_bar.segment_count(); ++i) {
                    if (breadcrumb_bar.segment_data(i) == new_path)
                        return i;
                }
                return {};
            }();

            if (segment_index_of_new_path_in_breadcrumb_bar.has_value()) {
                breadcrumb_bar.set_selected_segment(segment_index_of_new_path_in_breadcrumb_bar.value());
            } else {
                breadcrumb_bar.clear_segments();

                breadcrumb_bar.append_segment("/", GUI::FileIconProvider::icon_for_path("/").bitmap_for_size(16), "/");
                StringBuilder builder;

                for (auto& part : lexical_path.parts()) {
                    // NOTE: We rebuild the path as we go, so we have something to pass to GUI::FileIconProvider.
                    builder.append('/');
                    builder.append(part);

                    breadcrumb_bar.append_segment(part, GUI::FileIconProvider::icon_for_path(builder.string_view()).bitmap_for_size(16), builder.string_view());
                }

                breadcrumb_bar.set_selected_segment(breadcrumb_bar.segment_count() - 1);

                breadcrumb_bar.on_segment_click = [&](size_t segment_index) {
                    directory_view.open(breadcrumb_bar.segment_data(segment_index));
                };
            }
        }

        if (!is_reacting_to_tree_view_selection_change) {
            auto new_index = directories_model->index(new_path, GUI::FileSystemModel::Column::Name);
            if (new_index.is_valid()) {
                tree_view.expand_all_parents_of(new_index);
                tree_view.set_cursor(new_index, GUI::AbstractView::SelectionUpdate::Set);
            }
        }

        struct stat st;
        if (lstat(new_path.characters(), &st)) {
            perror("stat");
            return;
        }

        paste_action->set_enabled(can_write_in_path && GUI::Clipboard::the().mime_type() == "text/uri-list");
        go_forward_action->set_enabled(directory_view.path_history_position() < directory_view.path_history_size() - 1);
        go_back_action->set_enabled(directory_view.path_history_position() > 0);
        open_parent_directory_action->set_enabled(new_path != "/");
    };

    directory_view.on_accepted_drop = [&]() {
        refresh_tree_view();
    };

    directory_view.on_status_message = [&](const StringView& message) {
        statusbar.set_text(message);
    };

    directory_view.on_thumbnail_progress = [&](int done, int total) {
        if (done == total) {
            progressbar.set_visible(false);
            return;
        }
        progressbar.set_range(0, total);
        progressbar.set_value(done);
        progressbar.set_visible(true);
    };

    directory_view.on_selection_change = [&](GUI::AbstractView& view) {
        auto& selection = view.selection();
        copy_action->set_enabled(!selection.is_empty());
        focus_dependent_delete_action->set_enabled((!tree_view.selection().is_empty() && tree_view.is_focused())
            || !directory_view.current_view().selection().is_empty());
    };

    directory_context_menu->add_action(copy_action);
    directory_context_menu->add_action(folder_specific_paste_action);
    directory_context_menu->add_action(directory_view.delete_action());
    directory_context_menu->add_separator();
    directory_context_menu->add_action(properties_action);

    directory_view_context_menu->add_action(mkdir_action);
    directory_view_context_menu->add_action(touch_action);
    directory_view_context_menu->add_action(paste_action);
    directory_view_context_menu->add_action(directory_view.open_terminal_action());
    directory_view_context_menu->add_separator();
    directory_view_context_menu->add_action(action_show_dotfiles);
    directory_view_context_menu->add_separator();
    directory_view_context_menu->add_action(properties_action);

    tree_view_directory_context_menu->add_action(copy_action);
    tree_view_directory_context_menu->add_action(paste_action);
    tree_view_directory_context_menu->add_action(tree_view_delete_action);
    tree_view_directory_context_menu->add_separator();
    tree_view_directory_context_menu->add_action(properties_action);
    tree_view_directory_context_menu->add_separator();
    tree_view_directory_context_menu->add_action(mkdir_action);
    tree_view_directory_context_menu->add_action(touch_action);

    RefPtr<GUI::Menu> file_context_menu;
    NonnullRefPtrVector<LauncherHandler> current_file_handlers;
    RefPtr<GUI::Action> file_context_menu_action_default_action;

    directory_view.on_context_menu_request = [&](const GUI::ModelIndex& index, const GUI::ContextMenuEvent& event) {
        if (index.is_valid()) {
            auto& node = directory_view.node(index);

            if (node.is_directory()) {
                auto should_get_enabled = access(node.full_path().characters(), W_OK) == 0 && GUI::Clipboard::the().mime_type() == "text/uri-list";
                folder_specific_paste_action->set_enabled(should_get_enabled);
                directory_context_menu->popup(event.screen_position());
            } else {
                auto full_path = node.full_path();
                current_file_handlers = directory_view.get_launch_handlers(full_path);

                file_context_menu = GUI::Menu::construct("Directory View File");
                file_context_menu->add_action(copy_action);
                file_context_menu->add_action(paste_action);
                file_context_menu->add_action(directory_view.delete_action());

                file_context_menu->add_separator();
                bool added_open_menu_items = false;
                auto default_file_handler = directory_view.get_default_launch_handler(current_file_handlers);
                if (default_file_handler) {
                    auto file_open_action = default_file_handler->create_launch_action([&, full_path = move(full_path)](auto& launcher_handler) {
                        directory_view.launch(URL::create_with_file_protocol(full_path), launcher_handler);
                    });
                    if (default_file_handler->details().launcher_type == Desktop::Launcher::LauncherType::Application)
                        file_open_action->set_text(String::formatted("Run {}", file_open_action->text()));
                    else
                        file_open_action->set_text(String::formatted("Open in {}", file_open_action->text()));

                    file_context_menu_action_default_action = file_open_action;

                    file_context_menu->add_action(move(file_open_action));
                    added_open_menu_items = true;
                } else {
                    file_context_menu_action_default_action.clear();
                }

                if (current_file_handlers.size() > 1) {
                    added_open_menu_items = true;
                    auto& file_open_with_menu = file_context_menu->add_submenu("Open with");
                    for (auto& handler : current_file_handlers) {
                        if (&handler == default_file_handler.ptr())
                            continue;
                        file_open_with_menu.add_action(handler.create_launch_action([&, full_path = move(full_path)](auto& launcher_handler) {
                            directory_view.launch(URL::create_with_file_protocol(full_path), launcher_handler);
                        }));
                    }
                }

                if (added_open_menu_items)
                    file_context_menu->add_separator();

                file_context_menu->add_action(properties_action);
                file_context_menu->popup(event.screen_position(), file_context_menu_action_default_action);
            }
        } else {
            directory_view_context_menu->popup(event.screen_position());
        }
    };

    tree_view.on_selection = [&](const GUI::ModelIndex& index) {
        if (directories_model->m_previously_selected_index.is_valid())
            directories_model->update_node_on_selection(directories_model->m_previously_selected_index, false);

        directories_model->update_node_on_selection(index, true);
        directories_model->m_previously_selected_index = index;
    };

    tree_view.on_selection_change = [&] {
        focus_dependent_delete_action->set_enabled((!tree_view.selection().is_empty() && tree_view.is_focused())
            || !directory_view.current_view().selection().is_empty());

        if (tree_view.selection().is_empty())
            return;
        auto path = directories_model->full_path(tree_view.selection().first());
        if (directory_view.path() == path)
            return;
        TemporaryChange change(is_reacting_to_tree_view_selection_change, true);
        directory_view.open(path);
        copy_action->set_enabled(!tree_view.selection().is_empty());
        directory_view.delete_action().set_enabled(!tree_view.selection().is_empty());
    };

    tree_view.on_focus_change = [&]([[maybe_unused]] const bool has_focus, [[maybe_unused]] const GUI::FocusSource source) {
        focus_dependent_delete_action->set_enabled((!tree_view.selection().is_empty() && has_focus)
            || !directory_view.current_view().selection().is_empty());
    };

    tree_view.on_context_menu_request = [&](const GUI::ModelIndex& index, const GUI::ContextMenuEvent& event) {
        if (index.is_valid()) {
            tree_view_directory_context_menu->popup(event.screen_position());
        }
    };

    tree_view.on_drop = [&](const GUI::ModelIndex& index, const GUI::DropEvent& event) {
        if (!event.mime_data().has_urls())
            return;
        auto urls = event.mime_data().urls();
        if (urls.is_empty()) {
            dbgln("No files to drop");
            return;
        }

        auto& target_node = directories_model->node(index);
        if (!target_node.is_directory())
            return;

        bool had_accepted_drop = false;
        for (auto& url_to_copy : urls) {
            if (!url_to_copy.is_valid() || url_to_copy.path() == target_node.full_path())
                continue;
            auto new_path = String::formatted("{}/{}", target_node.full_path(), LexicalPath(url_to_copy.path()).basename());
            if (url_to_copy.path() == new_path)
                continue;

            if (!FileUtils::copy_file_or_directory(url_to_copy.path(), new_path)) {
                auto error_message = String::formatted("Could not copy {} into {}.", url_to_copy.to_string(), new_path);
                GUI::MessageBox::show(window, error_message, "File Manager", GUI::MessageBox::Type::Error);
            } else {
                had_accepted_drop = true;
            }
        }
        if (had_accepted_drop)
            refresh_tree_view();
    };

    directory_view.open(initial_location);
    directory_view.set_focus(true);

    paste_action->set_enabled(GUI::Clipboard::the().mime_type() == "text/uri-list" && access(initial_location.characters(), W_OK) == 0);

    window->show();

    // Read directory read mode from config.
    auto dir_view_mode = config->read_entry("DirectoryView", "ViewMode", "Icon");

    if (dir_view_mode.contains("Table")) {
        directory_view.set_view_mode(DirectoryView::ViewMode::Table);
        view_as_table_action->set_checked(true);
    } else if (dir_view_mode.contains("Columns")) {
        directory_view.set_view_mode(DirectoryView::ViewMode::Columns);
        view_as_columns_action->set_checked(true);
    } else {
        directory_view.set_view_mode(DirectoryView::ViewMode::Icon);
        view_as_icons_action->set_checked(true);
    }

    // Write window position to config file on close request.
    window->on_close_request = [&] {
        config->write_num_entry("Window", "Left", window->x());
        config->write_num_entry("Window", "Top", window->y());
        config->write_num_entry("Window", "Width", window->width());
        config->write_num_entry("Window", "Height", window->height());
        config->sync();

        return GUI::Window::CloseRequestDecision::Close;
    };

    return GUI::Application::the()->exec();
}