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 "TextEditorWidget.h"
  #include <AK/Optional.h>
  #include <AK/StringBuilder.h>
  #include <AK/URL.h>
  #include <LibCore/File.h>
  #include <LibCore/MimeData.h>
  #include <LibGUI/AboutDialog.h>
  #include <LibGUI/Action.h>
  #include <LibGUI/ActionGroup.h>
  #include <LibGUI/BoxLayout.h>
  #include <LibGUI/Button.h>
  #include <LibGUI/CppSyntaxHighlighter.h>
  #include <LibGUI/FilePicker.h>
  #include <LibGUI/FontDatabase.h>
  #include <LibGUI/INISyntaxHighlighter.h>
  #include <LibGUI/JSSyntaxHighlighter.h>
  #include <LibGUI/Menu.h>
  #include <LibGUI/MenuBar.h>
  #include <LibGUI/MessageBox.h>
  #include <LibGUI/Splitter.h>
  #include <LibGUI/StatusBar.h>
  #include <LibGUI/TextBox.h>
  #include <LibGUI/TextEditor.h>
  #include <LibGUI/ToolBar.h>
  #include <LibGUI/ToolBarContainer.h>
  #include <LibGfx/Font.h>
  #include <LibMarkdown/Document.h>
  #include <LibWeb/HtmlView.h>
  #include <LibWeb/Parser/HTMLParser.h>
  #include <string.h>
  
  TextEditorWidget::TextEditorWidget()
  {
      set_fill_with_background_color(true);
      set_layout<GUI::VerticalBoxLayout>();
      layout()->set_spacing(2);
  
      auto& toolbar_container = add<GUI::ToolBarContainer>();
      auto& toolbar = toolbar_container.add<GUI::ToolBar>();
  
      auto& splitter = add<GUI::HorizontalSplitter>();
  
      m_editor = splitter.add<GUI::TextEditor>();
      m_editor->set_ruler_visible(true);
      m_editor->set_automatic_indentation_enabled(true);
      m_editor->set_line_wrapping_enabled(true);
  
      m_editor->on_change = [this] {
          if (m_markdown_preview_enabled)
              update_markdown_preview();
  
          // Do not mark as dirty on the first change (When document is first opened.)
          if (m_document_opening) {
              m_document_opening = false;
              return;
          }
  
          bool was_dirty = m_document_dirty;
          m_document_dirty = true;
          if (!was_dirty)
              update_title();
      };
  
      m_html_view = splitter.add<Web::HtmlView>();
      m_html_view->set_visible(false);
  
      m_find_replace_widget = add<GUI::Widget>();
      m_find_replace_widget->set_fill_with_background_color(true);
      m_find_replace_widget->set_size_policy(GUI::SizePolicy::Fill, GUI::SizePolicy::Fixed);
      m_find_replace_widget->set_preferred_size(0, 48);
      m_find_replace_widget->set_layout<GUI::VerticalBoxLayout>();
      m_find_replace_widget->layout()->set_margins({ 2, 2, 2, 4 });
      m_find_replace_widget->set_visible(false);
  
      m_find_widget = m_find_replace_widget->add<GUI::Widget>();
      m_find_widget->set_fill_with_background_color(true);
      m_find_widget->set_size_policy(GUI::SizePolicy::Fill, GUI::SizePolicy::Fixed);
      m_find_widget->set_preferred_size(0, 22);
      m_find_widget->set_layout<GUI::HorizontalBoxLayout>();
      m_find_widget->set_visible(false);
  
      m_replace_widget = m_find_replace_widget->add<GUI::Widget>();
      m_replace_widget->set_fill_with_background_color(true);
      m_replace_widget->set_size_policy(GUI::SizePolicy::Fill, GUI::SizePolicy::Fixed);
      m_replace_widget->set_preferred_size(0, 22);
      m_replace_widget->set_layout<GUI::HorizontalBoxLayout>();
      m_replace_widget->set_visible(false);
  
      m_find_textbox = m_find_widget->add<GUI::TextBox>();
      m_replace_textbox = m_replace_widget->add<GUI::TextBox>();
  
      m_find_next_action = GUI::Action::create("Find next", { Mod_Ctrl, Key_G }, Gfx::Bitmap::load_from_file("/res/icons/16x16/find-next.png"), [&](auto&) {
          auto needle = m_find_textbox->text();
          if (needle.is_empty()) {
              dbg() << "find_next(\"\")";
              return;
          }
          auto found_range = m_editor->document().find_next(needle, m_editor->normalized_selection().end());
          dbg() << "find_next(\"" << needle << "\") returned " << found_range;
          if (found_range.is_valid()) {
              m_editor->set_selection(found_range);
          } else {
              GUI::MessageBox::show(
                  String::format("Not found: \"%s\"", needle.characters()),
                  "Not found",
                  GUI::MessageBox::Type::Information,
                  GUI::MessageBox::InputType::OK, window());
          }
      });
  
      m_find_previous_action = GUI::Action::create("Find previous", { Mod_Ctrl | Mod_Shift, Key_G }, Gfx::Bitmap::load_from_file("/res/icons/16x16/find-previous.png"), [&](auto&) {
          auto needle = m_find_textbox->text();
          if (needle.is_empty()) {
              dbg() << "find_prev(\"\")";
              return;
          }
  
          auto selection_start = m_editor->normalized_selection().start();
          if (!selection_start.is_valid())
              selection_start = m_editor->normalized_selection().end();
  
          auto found_range = m_editor->document().find_previous(needle, selection_start);
  
          dbg() << "find_prev(\"" << needle << "\") returned " << found_range;
          if (found_range.is_valid()) {
              m_editor->set_selection(found_range);
          } else {
              GUI::MessageBox::show(
                  String::format("Not found: \"%s\"", needle.characters()),
                  "Not found",
                  GUI::MessageBox::Type::Information,
                  GUI::MessageBox::InputType::OK, window());
          }
      });
  
      m_replace_next_action = GUI::Action::create("Replace next", { Mod_Ctrl, Key_F1 }, [&](auto&) {
          auto needle = m_find_textbox->text();
          auto substitute = m_replace_textbox->text();
  
          if (needle.is_empty())
              return;
  
          auto selection_start = m_editor->normalized_selection().start();
          if (!selection_start.is_valid())
              selection_start = m_editor->normalized_selection().start();
  
          auto found_range = m_editor->document().find_next(needle, selection_start);
  
          if (found_range.is_valid()) {
              m_editor->set_selection(found_range);
              m_editor->insert_at_cursor_or_replace_selection(substitute);
          } else {
              GUI::MessageBox::show(
                  String::format("Not found: \"%s\"", needle.characters()),
                  "Not found",
                  GUI::MessageBox::Type::Information,
                  GUI::MessageBox::InputType::OK, window());
          }
      });
  
      m_replace_previous_action = GUI::Action::create("Replace previous", { Mod_Ctrl | Mod_Shift, Key_F1 }, [&](auto&) {
          auto needle = m_find_textbox->text();
          auto substitute = m_replace_textbox->text();
          if (needle.is_empty())
              return;
  
          auto selection_start = m_editor->normalized_selection().start();
          if (!selection_start.is_valid())
              selection_start = m_editor->normalized_selection().start();
  
          auto found_range = m_editor->document().find_previous(needle, selection_start);
  
          if (found_range.is_valid()) {
              m_editor->set_selection(found_range);
              m_editor->insert_at_cursor_or_replace_selection(substitute);
          } else {
              GUI::MessageBox::show(
                  String::format("Not found: \"%s\"", needle.characters()),
                  "Not found",
                  GUI::MessageBox::Type::Information,
                  GUI::MessageBox::InputType::OK, window());
          }
      });
  
      m_replace_all_action = GUI::Action::create("Replace all", { Mod_Ctrl, Key_F2 }, [&](auto&) {
          auto needle = m_find_textbox->text();
          auto substitute = m_replace_textbox->text();
          if (needle.is_empty())
              return;
  
          auto found_range = m_editor->document().find_next(needle);
          while (found_range.is_valid()) {
              m_editor->set_selection(found_range);
              m_editor->insert_at_cursor_or_replace_selection(substitute);
              found_range = m_editor->document().find_next(needle);
          }
      });
  
      m_find_previous_button = m_find_widget->add<GUI::Button>("Find previous");
      m_find_previous_button->set_size_policy(GUI::SizePolicy::Fixed, GUI::SizePolicy::Fill);
      m_find_previous_button->set_preferred_size(150, 0);
      m_find_previous_button->set_action(*m_find_previous_action);
  
      m_find_next_button = m_find_widget->add<GUI::Button>("Find next");
      m_find_next_button->set_size_policy(GUI::SizePolicy::Fixed, GUI::SizePolicy::Fill);
      m_find_next_button->set_preferred_size(150, 0);
      m_find_next_button->set_action(*m_find_next_action);
  
      m_find_textbox->on_return_pressed = [this] {
          m_find_next_button->click();
      };
  
      m_find_textbox->on_escape_pressed = [this] {
          m_find_replace_widget->set_visible(false);
          m_editor->set_focus(true);
      };
  
      m_replace_previous_button = m_replace_widget->add<GUI::Button>("Replace previous");
      m_replace_previous_button->set_size_policy(GUI::SizePolicy::Fixed, GUI::SizePolicy::Fill);
      m_replace_previous_button->set_preferred_size(100, 0);
      m_replace_previous_button->set_action(*m_replace_previous_action);
  
      m_replace_next_button = m_replace_widget->add<GUI::Button>("Replace next");
      m_replace_next_button->set_size_policy(GUI::SizePolicy::Fixed, GUI::SizePolicy::Fill);
      m_replace_next_button->set_preferred_size(100, 0);
      m_replace_next_button->set_action(*m_replace_next_action);
  
      m_replace_all_button = m_replace_widget->add<GUI::Button>("Replace all");
      m_replace_all_button->set_size_policy(GUI::SizePolicy::Fixed, GUI::SizePolicy::Fill);
      m_replace_all_button->set_preferred_size(100, 0);
      m_replace_all_button->set_action(*m_replace_all_action);
  
      m_replace_textbox->on_return_pressed = [this] {
          m_replace_next_button->click();
      };
  
      m_replace_textbox->on_escape_pressed = [this] {
          m_find_replace_widget->set_visible(false);
          m_editor->set_focus(true);
      };
  
      m_find_replace_action = GUI::Action::create("Find/Replace...", { Mod_Ctrl, Key_F }, Gfx::Bitmap::load_from_file("/res/icons/16x16/find.png"), [this](auto&) {
          m_find_replace_widget->set_visible(true);
          m_find_widget->set_visible(true);
          m_replace_widget->set_visible(true);
          m_find_textbox->set_focus(true);
  
          if (m_editor->has_selection()) {
              auto selected_text = m_editor->document().text_in_range(m_editor->normalized_selection());
              m_find_textbox->set_text(selected_text);
          }
          m_find_textbox->select_all();
      });
  
      m_editor->add_custom_context_menu_action(*m_find_replace_action);
      m_editor->add_custom_context_menu_action(*m_find_next_action);
      m_editor->add_custom_context_menu_action(*m_find_previous_action);
  
      m_statusbar = add<GUI::StatusBar>();
  
      m_editor->on_cursor_change = [this] {
          StringBuilder builder;
          builder.appendf("Line: %d, Column: %d", m_editor->cursor().line() + 1, m_editor->cursor().column());
          m_statusbar->set_text(builder.to_string());
      };
  
      m_new_action = GUI::Action::create("New", { Mod_Ctrl, Key_N }, Gfx::Bitmap::load_from_file("/res/icons/16x16/new.png"), [this](const GUI::Action&) {
          if (m_document_dirty) {
              auto save_document_first_result = GUI::MessageBox::show("Save Document First?", "Warning", GUI::MessageBox::Type::Warning, GUI::MessageBox::InputType::YesNoCancel);
              if (save_document_first_result == GUI::Dialog::ExecResult::ExecYes)
                  m_save_action->activate();
              if (save_document_first_result == GUI::Dialog::ExecResult::ExecCancel)
                  return;
          }
  
          m_document_dirty = false;
          m_editor->set_text(StringView());
          set_path(LexicalPath());
          update_title();
      });
  
      m_open_action = GUI::CommonActions::make_open_action([this](auto&) {
          Optional<String> open_path = GUI::FilePicker::get_open_filepath();
  
          if (!open_path.has_value())
              return;
  
          if (m_document_dirty) {
              auto save_document_first_result = GUI::MessageBox::show("Save Document First?", "Warning", GUI::MessageBox::Type::Warning, GUI::MessageBox::InputType::YesNoCancel, window());
              if (save_document_first_result == GUI::Dialog::ExecResult::ExecYes)
                  m_save_action->activate();
              if (save_document_first_result == GUI::Dialog::ExecResult::ExecCancel)
                  return;
          }
  
          open_sesame(open_path.value());
      });
  
      m_save_as_action = GUI::Action::create("Save as...", { Mod_Ctrl | Mod_Shift, Key_S }, Gfx::Bitmap::load_from_file("/res/icons/16x16/save.png"), [this](const GUI::Action&) {
          Optional<String> save_path = GUI::FilePicker::get_save_filepath(m_name.is_null() ? "Untitled" : m_name, m_extension.is_null() ? "txt" : m_extension);
          if (!save_path.has_value())
              return;
  
          if (!m_editor->write_to_file(save_path.value())) {
              GUI::MessageBox::show("Unable to save file.\n", "Error", GUI::MessageBox::Type::Error, GUI::MessageBox::InputType::OK, window());
              return;
          }
  
          m_document_dirty = false;
          set_path(LexicalPath(save_path.value()));
          dbg() << "Wrote document to " << save_path.value();
      });
  
      m_save_action = GUI::Action::create("Save", { Mod_Ctrl, Key_S }, Gfx::Bitmap::load_from_file("/res/icons/16x16/save.png"), [&](const GUI::Action&) {
          if (!m_path.is_empty()) {
              if (!m_editor->write_to_file(m_path)) {
                  GUI::MessageBox::show("Unable to save file.\n", "Error", GUI::MessageBox::Type::Error, GUI::MessageBox::InputType::OK, window());
              } else {
                  m_document_dirty = false;
                  update_title();
              }
              return;
          }
  
          m_save_as_action->activate();
      });
  
      m_line_wrapping_setting_action = GUI::Action::create_checkable("Line wrapping", [&](auto& action) {
          m_editor->set_line_wrapping_enabled(action.is_checked());
      });
      m_line_wrapping_setting_action->set_checked(m_editor->is_line_wrapping_enabled());
  
      auto menubar = GUI::MenuBar::construct();
      auto& app_menu = menubar->add_menu("Text Editor");
      app_menu.add_action(*m_new_action);
      app_menu.add_action(*m_open_action);
      app_menu.add_action(*m_save_action);
      app_menu.add_action(*m_save_as_action);
      app_menu.add_separator();
      app_menu.add_action(GUI::CommonActions::make_quit_action([this](auto&) {
          if (!request_close())
              return;
          GUI::Application::the().quit(0);
      }));
  
      auto& edit_menu = menubar->add_menu("Edit");
      edit_menu.add_action(m_editor->undo_action());
      edit_menu.add_action(m_editor->redo_action());
      edit_menu.add_separator();
      edit_menu.add_action(m_editor->cut_action());
      edit_menu.add_action(m_editor->copy_action());
      edit_menu.add_action(m_editor->paste_action());
      edit_menu.add_action(m_editor->delete_action());
      edit_menu.add_separator();
      edit_menu.add_action(*m_find_replace_action);
      edit_menu.add_action(*m_find_next_action);
      edit_menu.add_action(*m_find_previous_action);
      edit_menu.add_action(*m_replace_next_action);
      edit_menu.add_action(*m_replace_previous_action);
      edit_menu.add_action(*m_replace_all_action);
  
      m_markdown_preview_action = GUI::Action::create_checkable(
          "Markdown preview", [this](auto& action) {
              set_markdown_preview_enabled(action.is_checked());
          },
          this);
  
      auto& view_menu = menubar->add_menu("View");
      view_menu.add_action(*m_line_wrapping_setting_action);
      view_menu.add_separator();
      view_menu.add_action(*m_markdown_preview_action);
      view_menu.add_separator();
  
      auto& font_menu = view_menu.add_submenu("Font");
      GUI::FontDatabase::the().for_each_fixed_width_font([&](const StringView& font_name) {
          font_menu.add_action(GUI::Action::create(font_name, [this](const GUI::Action& action) {
              m_editor->set_font(GUI::FontDatabase::the().get_by_name(action.text()));
              m_editor->update();
          }));
      });
  
      syntax_actions.set_exclusive(true);
  
      auto& syntax_menu = view_menu.add_submenu("Syntax");
      m_plain_text_highlight = GUI::Action::create_checkable("Plain text", [&](auto&) {
          m_editor->set_syntax_highlighter(nullptr);
          m_editor->update();
      });
      m_plain_text_highlight->set_checked(true);
      syntax_actions.add_action(*m_plain_text_highlight);
      syntax_menu.add_action(*m_plain_text_highlight);
  
      m_cpp_highlight = GUI::Action::create_checkable("C++", [&](auto&) {
          m_editor->set_syntax_highlighter(make<GUI::CppSyntaxHighlighter>());
          m_editor->update();
      });
      syntax_actions.add_action(*m_cpp_highlight);
      syntax_menu.add_action(*m_cpp_highlight);
  
      m_js_highlight = GUI::Action::create_checkable("JavaScript", [&](auto&) {
          m_editor->set_syntax_highlighter(make<GUI::JSSyntaxHighlighter>());
          m_editor->update();
      });
      syntax_actions.add_action(*m_js_highlight);
      syntax_menu.add_action(*m_js_highlight);
  
      m_ini_highlight = GUI::Action::create_checkable("INI File", [&](auto&) {
          m_editor->set_syntax_highlighter(make<GUI::IniSyntaxHighlighter>());
          m_editor->update();
      });
      syntax_actions.add_action(*m_ini_highlight);
      syntax_menu.add_action(*m_ini_highlight);
  
      auto& help_menu = menubar->add_menu("Help");
      help_menu.add_action(GUI::Action::create("About", [&](auto&) {
          GUI::AboutDialog::show("Text Editor", Gfx::Bitmap::load_from_file("/res/icons/32x32/app-texteditor.png"), window());
      }));
  
      GUI::Application::the().set_menubar(move(menubar));
  
      toolbar.add_action(*m_new_action);
      toolbar.add_action(*m_open_action);
      toolbar.add_action(*m_save_action);
  
      toolbar.add_separator();
  
      toolbar.add_action(m_editor->cut_action());
      toolbar.add_action(m_editor->copy_action());
      toolbar.add_action(m_editor->paste_action());
      toolbar.add_action(m_editor->delete_action());
  
      toolbar.add_separator();
  
      toolbar.add_action(m_editor->undo_action());
      toolbar.add_action(m_editor->redo_action());
  }
  
  TextEditorWidget::~TextEditorWidget()
  {
  }
  
  void TextEditorWidget::set_path(const LexicalPath& lexical_path)
  {
      m_path = lexical_path.string();
      m_name = lexical_path.title();
      m_extension = lexical_path.extension();
  
      if (m_extension == "cpp" || m_extension == "h") {
          m_cpp_highlight->activate();
      } else if (m_extension == "js" || m_extension == "json") {
          m_js_highlight->activate();
      } else if (m_extension == "ini") {
          m_ini_highlight->activate();
      } else {
          m_plain_text_highlight->activate();
      }
  
      set_markdown_preview_enabled(m_extension == "md");
  
      update_title();
  }
  
  void TextEditorWidget::update_title()
  {
      StringBuilder builder;
      builder.append(m_path);
      if (m_document_dirty)
          builder.append(" (*)");
      builder.append(" - Text Editor");
      window()->set_title(builder.to_string());
  }
  
  void TextEditorWidget::open_sesame(const String& path)
  {
      auto file = Core::File::construct(path);
      if (!file->open(Core::IODevice::ReadOnly)) {
          GUI::MessageBox::show(String::format("Opening \"%s\" failed: %s", path.characters(), strerror(errno)), "Error", GUI::MessageBox::Type::Error, GUI::MessageBox::InputType::OK, window());
          return;
      }
  
      m_editor->set_text(file->read_all());
      m_document_dirty = false;
      m_document_opening = true;
  
      set_path(LexicalPath(path));
  
      m_editor->set_focus(true);
  }
  
  bool TextEditorWidget::request_close()
  {
      if (!m_document_dirty)
          return true;
      auto result = GUI::MessageBox::show("The document has been modified. Would you like to save?", "Unsaved changes", GUI::MessageBox::Type::Warning, GUI::MessageBox::InputType::YesNoCancel, window());
  
      if (result == GUI::MessageBox::ExecYes) {
          m_save_action->activate();
          return true;
      }
  
      if (result == GUI::MessageBox::ExecNo)
          return true;
  
      return false;
  }
  
  void TextEditorWidget::drop_event(GUI::DropEvent& event)
  {
      event.accept();
      window()->move_to_front();
  
      if (event.mime_data().has_urls()) {
          auto urls = event.mime_data().urls();
          if (urls.is_empty())
              return;
          if (urls.size() > 1) {
              GUI::MessageBox::show("TextEditor can only open one file at a time!", "One at a time please!", GUI::MessageBox::Type::Error, GUI::MessageBox::InputType::OK, window());
              return;
          }
          open_sesame(urls.first().path());
      }
  }
  
  void TextEditorWidget::set_markdown_preview_enabled(bool enabled)
  {
      if (m_markdown_preview_enabled == enabled)
          return;
      m_markdown_preview_enabled = enabled;
      m_markdown_preview_action->set_checked(enabled);
      m_html_view->set_visible(enabled);
      if (enabled)
          update_markdown_preview();
  }
  
  void TextEditorWidget::update_markdown_preview()
  {
      Markdown::Document document;
      if (document.parse(m_editor->text())) {
          auto html = document.render_to_html();
          auto html_document = Web::parse_html_document(html, URL::create_with_file_protocol(m_path));
          m_html_view->set_document(html_document);
      }
  }
  