text: // @flow
  import { app, Menu, shell, BrowserWindow } from 'electron';
  
  export default class MenuBuilder {
    mainWindow: BrowserWindow;
  
    constructor(mainWindow: BrowserWindow) {
      this.mainWindow = mainWindow;
    }
  
    buildMenu() {
      if (
        process.env.NODE_ENV === 'development' ||
        process.env.DEBUG_PROD === 'true'
      ) {
        this.setupDevelopmentEnvironment();
      }
  
      const template =
        process.platform === 'darwin'
          ? this.buildDarwinTemplate()
          : this.buildDefaultTemplate();
  
      const menu = Menu.buildFromTemplate(template);
      Menu.setApplicationMenu(menu);
  
      return menu;
    }
  
    setupDevelopmentEnvironment() {
      this.mainWindow.openDevTools();
      this.mainWindow.webContents.on('context-menu', (e, props) => {
        const { x, y } = props;
  
        Menu.buildFromTemplate([
          {
            label: 'Inspect element',
            click: () => {
              this.mainWindow.inspectElement(x, y);
            }
          }
        ]).popup(this.mainWindow);
      });
    }
  
    buildDarwinTemplate() {
      const subMenuAbout = {
        label: 'Core GUI',
        submenu: [
          {
            label: 'About Core GUI',
            selector: 'orderFrontStandardAboutPanel:'
          },
          { type: 'separator' },
          { label: 'Services', submenu: [] },
          { type: 'separator' },
          {
            label: 'Hide Core GUI',
            accelerator: 'Command+H',
            selector: 'hide:'
          },
          {
            label: 'Hide Others',
            accelerator: 'Command+Shift+H',
            selector: 'hideOtherApplications:'
          },
          { label: 'Show All', selector: 'unhideAllApplications:' },
          { type: 'separator' },
          {
            label: 'Quit',
            accelerator: 'Command+Q',
            click: () => {
              app.quit();
            }
          }
        ]
      };
      const subMenuEdit = {
        label: 'Edit',
        submenu: [
          { label: 'Undo', accelerator: 'Command+Z', selector: 'undo:' },
          { label: 'Redo', accelerator: 'Shift+Command+Z', selector: 'redo:' },
          { type: 'separator' },
          { label: 'Cut', accelerator: 'Command+X', selector: 'cut:' },
          { label: 'Copy', accelerator: 'Command+C', selector: 'copy:' },
          { label: 'Paste', accelerator: 'Command+V', selector: 'paste:' },
          {
            label: 'Select All',
            accelerator: 'Command+A',
            selector: 'selectAll:'
          }
        ]
      };
      const subMenuViewDev = {
        label: 'View',
        submenu: [
          {
            label: 'Reload',
            accelerator: 'Command+R',
            click: () => {
              this.mainWindow.webContents.reload();
            }
          },
          {
            label: 'Toggle Full Screen',
            accelerator: 'Ctrl+Command+F',
            click: () => {
              this.mainWindow.setFullScreen(!this.mainWindow.isFullScreen());
            }
          },
          {
            label: 'Toggle Developer Tools',
            accelerator: 'Alt+Command+I',
            click: () => {
              this.mainWindow.toggleDevTools();
            }
          }
        ]
      };
      const subMenuViewProd = {
        label: 'View',
        submenu: [
          {
            label: 'Toggle Full Screen',
            accelerator: 'Ctrl+Command+F',
            click: () => {
              this.mainWindow.setFullScreen(!this.mainWindow.isFullScreen());
            }
          }
        ]
      };
      const subMenuWindow = {
        label: 'Window',
        submenu: [
          {
            label: 'Minimize',
            accelerator: 'Command+M',
            selector: 'performMiniaturize:'
          },
          { label: 'Close', accelerator: 'Command+W', selector: 'performClose:' },
          { type: 'separator' },
          { label: 'Bring All to Front', selector: 'arrangeInFront:' }
        ]
      };
      const subMenuHelp = {
        label: 'Help',
        submenu: [
          {
            label: 'Learn More',
            click() {
              shell.openExternal('http://electron.atom.io');
            }
          },
          {
            label: 'Documentation',
            click() {
              shell.openExternal(
                'https://github.com/atom/electron/tree/master/docs#readme'
              );
            }
          },
          {
            label: 'Community Discussions',
            click() {
              shell.openExternal('https://discuss.atom.io/c/electron');
            }
          },
          {
            label: 'Search Issues',
            click() {
              shell.openExternal('https://github.com/atom/electron/issues');
            }
          }
        ]
      };
  
      const subMenuView =
        process.env.NODE_ENV === 'development' ? subMenuViewDev : subMenuViewProd;
  
      return [subMenuAbout, subMenuEdit, subMenuView, subMenuWindow, subMenuHelp];
    }
  
    buildDefaultTemplate() {
      const templateDefault = [
        {
          label: '&File',
          submenu: [
            {
              label: '&Open',
              accelerator: 'Ctrl+O'
            },
            {
              label: '&Close',
              accelerator: 'Ctrl+W',
              click: () => {
                this.mainWindow.close();
              }
            }
          ]
        },
        {
          label: '&View',
          submenu:
            process.env.NODE_ENV === 'development'
              ? [
                  {
                    label: '&Reload',
                    accelerator: 'Ctrl+R',
                    click: () => {
                      this.mainWindow.webContents.reload();
                    }
                  },
                  {
                    label: 'Toggle &Full Screen',
                    accelerator: 'F11',
                    click: () => {
                      this.mainWindow.setFullScreen(
                        !this.mainWindow.isFullScreen()
                      );
                    }
                  },
                  {
                    label: 'Toggle &Developer Tools',
                    accelerator: 'Alt+Ctrl+I',
                    click: () => {
                      this.mainWindow.toggleDevTools();
                    }
                  }
                ]
              : [
                  {
                    label: 'Toggle &Full Screen',
                    accelerator: 'F11',
                    click: () => {
                      this.mainWindow.setFullScreen(
                        !this.mainWindow.isFullScreen()
                      );
                    }
                  }
                ]
        },
        {
          label: 'Help',
          submenu: [
            {
              label: 'Learn More',
              click() {
                shell.openExternal('http://electron.atom.io');
              }
            },
            {
              label: 'Documentation',
              click() {
                shell.openExternal(
                  'https://github.com/atom/electron/tree/master/docs#readme'
                );
              }
            },
            {
              label: 'Community Discussions',
              click() {
                shell.openExternal('https://discuss.atom.io/c/electron');
              }
            },
            {
              label: 'Search Issues',
              click() {
                shell.openExternal('https://github.com/atom/electron/issues');
              }
            }
          ]
        }
      ];
  
      return templateDefault;
    }
  }
  