piano-midi-monitor/src/main/index.ts

import { app, shell, BrowserWindow, ipcMain } from 'electron'
import { join } from 'path'
import { readFile, stat, writeFile } from 'fs/promises'
import { electronApp, optimizer, is } from '@electron-toolkit/utils'
import icon from '../../resources/icon.png?asset'
import { Config, defaultConfig } from '../common/config'

const configPath = './config.json'
const height = 160

const getNaturalKeys = (range: string): number => {
  const [startKeyRaw, endKeyRaw] = range.split('|')
  const startKey = Number(startKeyRaw)
  const endKey = Number(endKeyRaw)
  let naturalKeys = 0
  for (let i = startKey; i <= endKey; i += 1) {
    switch (i % 12) {
      case 0:
      case 2:
      case 4:
      case 5:
      case 7:
      case 9:
      case 11:
        naturalKeys += 1
        break
      default:
        break
    }
  }
  return naturalKeys
}

const createMainWindow = async (config: Config): Promise<BrowserWindow> => {
  // Create the browser window.
  const naturalKeys = getNaturalKeys(config.range)
  const width = naturalKeys * Number(config.naturalKeyWidth || 20) + Number(config.scaleFactor)
  const mainWindow = new BrowserWindow({
    width,
    height,
    show: false,
    autoHideMenuBar: true,
    ...(process.platform === 'linux' ? { icon } : {}),
    webPreferences: {
      preload: join(__dirname, '../preload/index.js'),
      sandbox: false,
      devTools: is.dev
    },
    maximizable: is.dev,
    minimizable: false,
    maxHeight: is.dev ? undefined : height,
    minHeight: is.dev ? undefined : height,
    minWidth: is.dev ? undefined : width,
    maxWidth: is.dev ? undefined : width,
    fullscreenable: false,
    resizable: is.dev,
    useContentSize: true
  })

  mainWindow.on('ready-to-show', () => {
    mainWindow.show()
  })

  mainWindow.webContents.setWindowOpenHandler((details) => {
    void shell.openExternal(details.url)
    return { action: 'deny' }
  })

  mainWindow.webContents.session.setPermissionRequestHandler(
    (_webContents, permission, callback) => {
      if (permission === 'midi') {
        callback(true)
        return
      }

      callback(false)
    }
  )

  let search: URLSearchParams
  if (is.dev && process.env['ELECTRON_RENDERER_URL']) {
    const url = new URL(process.env['ELECTRON_RENDERER_URL'])
    search = new URLSearchParams(url.searchParams)
    Object.entries(config).forEach(([key, value]) => {
      search.set(key, value)
    })
    search.set('window', 'main')
    url.search = search.toString()
    await mainWindow.loadURL(url.toString())
    return mainWindow
  }

  search = new URLSearchParams()
  Object.entries(config).forEach(([key, value]) => {
    search.set(key, value)
  })
  search.set('window', 'main')
  await mainWindow.loadFile(join(__dirname, '../renderer/index.html'), {
    search: search.toString()
  })
  return mainWindow
}

app.whenReady().then(async () => {
  const effectiveConfig = { ...defaultConfig }
  try {
    const theStat = await stat(configPath)
    if (theStat.isDirectory()) {
      return
    }
    const jsonRaw = await readFile(configPath, 'utf-8')
    const json = JSON.parse(jsonRaw)
    Object.entries(json).forEach(([key, value]) => {
      effectiveConfig[key] = value
    })
  } catch {
    await writeFile(configPath, JSON.stringify(defaultConfig))
  }

  electronApp.setAppUserModelId('sh.modal.pianomidimonitor')

  app.on('browser-window-created', (_, window) => {
    optimizer.watchWindowShortcuts(window)
  })

  const createSettingsWindow = async (
    parent: BrowserWindow,
    config: Config
  ): Promise<BrowserWindow> => {
    const settingsWindow = new BrowserWindow({
      width: 360,
      height: 640,
      show: false,
      autoHideMenuBar: true,
      ...(process.platform === 'linux' ? { icon } : {}),
      webPreferences: {
        preload: join(__dirname, '../preload/index.js'),
        sandbox: false,
        devTools: is.dev
      },
      maximizable: false,
      minimizable: false,
      fullscreenable: false,
      resizable: false,
      useContentSize: true,
      parent
    })

    settingsWindow.on('ready-to-show', () => {
      settingsWindow.show()
    })

    settingsWindow.webContents.setWindowOpenHandler((details) => {
      void shell.openExternal(details.url)
      return { action: 'deny' }
    })

    settingsWindow.webContents.session.setPermissionRequestHandler(
      (_webContents, permission, callback) => {
        if (permission === 'midi') {
          callback(true)
          return
        }

        callback(false)
      }
    )

    let search: URLSearchParams
    if (is.dev && process.env['ELECTRON_RENDERER_URL']) {
      const url = new URL(process.env['ELECTRON_RENDERER_URL'])
      search = new URLSearchParams(url.searchParams)
      Object.entries(config).forEach(([key, value]) => {
        search.set(key, value)
      })
      search.set('window', 'settings')
      url.search = search.toString()
      await settingsWindow.loadURL(url.toString())
      return settingsWindow
    }

    search = new URLSearchParams()
    Object.entries(config).forEach(([key, value]) => {
      search.set(key, value)
    })
    search.set('window', 'settings')
    await settingsWindow.loadFile(join(__dirname, '../renderer/index.html'), {
      search: search.toString()
    })

    return settingsWindow
  }

  ipcMain.on('action', async (event, value, formData) => {
    const webContents = event.sender
    const win = BrowserWindow.fromWebContents(webContents)
    if (!win) {
      return
    }
    switch (value) {
      case 'showSettings': {
        await createSettingsWindow(win, effectiveConfig)
        return
      }
      case 'cancelSaveConfig': {
        win.close()
        return
      }
      case 'resetConfig': {
        Object.entries(defaultConfig).forEach(([key, value]) => {
          effectiveConfig[key] = value
        })
        await writeFile(configPath, JSON.stringify(effectiveConfig))
        win.close()
        win.getParentWindow()?.close()
        await createMainWindow(effectiveConfig)
        return
      }
      case 'saveConfig': {
        Object.entries(formData).forEach(([key, value]) => {
          effectiveConfig[key] = value
        })
        await writeFile(configPath, JSON.stringify(effectiveConfig))
        win.close()
        win.getParentWindow()?.close()
        await createMainWindow(effectiveConfig)
        return
      }
    }
  })

  await createMainWindow(effectiveConfig)

  app.on('activate', async () => {
    if (BrowserWindow.getAllWindows().length === 0) {
      await createMainWindow(effectiveConfig)
    }
  })
})

app.on('window-all-closed', () => {
  if (process.platform !== 'darwin') {
    app.quit()
  }
})