import {
  app,
  BrowserWindow,
  dialog,
  ipcMain,
  session,
  shell,
} from 'electron'
import type {
  DownloadItem,
  Event as ElectronEvent,
  IpcMainInvokeEvent,
  WebContents,
} from 'electron'
import { existsSync } from 'node:fs'
import path from 'node:path'
import type { ProcessOptions } from '../../src/shared/types'
import { IMAGE_INPUT_EXTENSIONS, ImageProcessor } from './image-processor'
import { LicenseManager } from './license-manager'

app.setName('正版情趣王')
app.enableSandbox()

const singleInstance = app.requestSingleInstanceLock()
if (!singleInstance) {
  app.quit()
}

let mainWindow: BrowserWindow | null = null
const imageProcessor = new ImageProcessor()
const licenseManager = new LicenseManager()
const UPDATE_INSTALLER_EXTENSIONS = new Set(['.exe', '.msi'])

function createWindow(): void {
  const preload = path.join(__dirname, '../preload/index.js')
  const windowOptions: Electron.BrowserWindowConstructorOptions = {
    width: 1360,
    height: 860,
    minWidth: 1120,
    minHeight: 720,
    show: false,
    backgroundColor: '#F4F7FB',
    title: '正版情趣王',
    titleBarStyle: 'hidden',
    webPreferences: {
      preload,
      contextIsolation: true,
      nodeIntegration: false,
      sandbox: true,
      webSecurity: true,
    },
  }
  if (process.platform !== 'darwin') {
    windowOptions.titleBarOverlay = {
      color: '#F7F9FC',
      symbolColor: '#596273',
      height: 48,
    }
  }
  mainWindow = new BrowserWindow(windowOptions)

  mainWindow.webContents.setWindowOpenHandler(() => ({ action: 'deny' }))
  mainWindow.webContents.on('will-navigate', (event, targetUrl) => {
    if (targetUrl !== mainWindow?.webContents.getURL()) {
      event.preventDefault()
    }
  })
  mainWindow.once('ready-to-show', () => mainWindow?.show())

  const devServerUrl = process.env.VITE_DEV_SERVER_URL
  if (devServerUrl) {
    void mainWindow.loadURL(devServerUrl)
  } else {
    void mainWindow.loadFile(path.join(__dirname, '../../../dist/index.html'))
  }
}

function registerIpcHandlers(): void {
  ipcMain.handle('app:info', (event) => {
    assertTrustedSender(event)
    return licenseManager.getAppInfo()
  })
  ipcMain.handle('license:state', (event) => {
    assertTrustedSender(event)
    return licenseManager.getState()
  })
  ipcMain.handle('license:activate', (event, activationCode: unknown) => {
    assertTrustedSender(event)
    if (typeof activationCode !== 'string' || activationCode.length > 64) {
      throw new Error('激活码格式不正确')
    }
    return licenseManager.activate(activationCode)
  })
  ipcMain.handle('license:validate', (event) => {
    assertTrustedSender(event)
    return licenseManager.validate()
  })
  ipcMain.handle('license:clear', (event) => {
    assertTrustedSender(event)
    return licenseManager.clear()
  })
  ipcMain.handle('license:check-version', (event) => {
    assertTrustedSender(event)
    return licenseManager.checkVersion()
  })
  ipcMain.handle('license:download-update', async (
    event,
    downloadUrl: unknown,
    latestVersion: unknown,
  ) => {
    assertTrustedSender(event)
    const url = validateUpdateUrl(downloadUrl)
    const savePath = await downloadUpdateInstaller(event.sender, url, latestVersion)
    const choice = await dialog.showMessageBox(mainWindow!, {
      type: 'info',
      title: '更新已下载',
      message: '新版安装包下载完成',
      detail: '安装包已保存到：\n' + savePath + '\n\n点击“立即安装”继续升级，安装程序可能会提示关闭当前软件。',
      buttons: ['立即安装', '打开文件夹', '稍后安装'],
      defaultId: 0,
      cancelId: 2,
      noLink: true,
    })
    if (choice.response === 0) {
      const openError = await shell.openPath(savePath)
      if (openError) {
        throw new Error('无法启动安装程序：' + openError)
      }
    } else if (choice.response === 1) {
      shell.showItemInFolder(savePath)
    }
  })
  ipcMain.handle('images:select-files', async (event) => {
    assertTrustedSender(event)
    const result = await dialog.showOpenDialog(mainWindow!, {
      title: '选择图片',
      properties: ['openFile', 'multiSelections'],
      filters: [{ name: '支持的图片', extensions: IMAGE_INPUT_EXTENSIONS }],
    })
    return result.canceled ? [] : result.filePaths
  })
  ipcMain.handle('images:select-folder', async (event) => {
    assertTrustedSender(event)
    const result = await dialog.showOpenDialog(mainWindow!, {
      title: '选择图片文件夹',
      properties: ['openDirectory'],
    })
    return result.canceled ? [] : result.filePaths
  })
  ipcMain.handle('images:select-output', async (event) => {
    assertTrustedSender(event)
    const result = await dialog.showOpenDialog(mainWindow!, {
      title: '选择输出目录',
      properties: ['openDirectory', 'createDirectory'],
    })
    return result.canceled ? null : result.filePaths[0]
  })
  ipcMain.handle('images:inspect', (event, paths: unknown) => {
    assertTrustedSender(event)
    return imageProcessor.inspect(validatePaths(paths))
  })
  ipcMain.handle('images:process', (event, options: ProcessOptions) => {
    assertTrustedSender(event)
    const validated: ProcessOptions = {
      ...options,
      paths: validatePaths(options?.paths),
    }
    return imageProcessor.process(validated, (progress) => {
      if (!event.sender.isDestroyed()) {
        event.sender.send('images:progress', progress)
      }
    })
  })
  ipcMain.handle('images:cancel', (event) => {
    assertTrustedSender(event)
    imageProcessor.cancel()
  })
  ipcMain.handle('images:reveal', (event, filePath: unknown) => {
    assertTrustedSender(event)
    if (typeof filePath !== 'string' || !path.isAbsolute(filePath)) {
      throw new Error('文件路径无效')
    }
    shell.showItemInFolder(filePath)
  })
}

function validateUpdateUrl(value: unknown): URL {
  if (typeof value !== 'string') {
    throw new Error('下载地址无效')
  }
  const url = new URL(value)
  if (url.protocol !== 'https:') {
    throw new Error('安装包必须通过 HTTPS 下载')
  }
  const extension = path.extname(decodeUrlPathname(url)).toLowerCase()
  if (!UPDATE_INSTALLER_EXTENSIONS.has(extension)) {
    throw new Error('下载地址不是受支持的 Windows 安装包')
  }
  return url
}

function decodeUrlPathname(url: URL): string {
  try {
    return decodeURIComponent(url.pathname)
  } catch {
    throw new Error('安装包下载地址格式不正确')
  }
}

function installerFilename(url: URL, latestVersion: unknown): string {
  const extension = path.extname(decodeUrlPathname(url)).toLowerCase()
  const version = typeof latestVersion === 'string'
    ? latestVersion.trim().replace(/^v/i, '').replace(/[^0-9A-Za-z._-]/g, '').slice(0, 32)
    : ''
  return version
    ? '正版情趣王-Setup-' + version + extension
    : '正版情趣王-Setup' + extension
}

function availableDownloadPath(filename: string): string {
  const downloadsDirectory = app.getPath('downloads')
  const extension = path.extname(filename)
  const basename = path.basename(filename, extension)
  let candidate = path.join(downloadsDirectory, filename)
  for (let index = 2; existsSync(candidate); index += 1) {
    candidate = path.join(downloadsDirectory, basename + '-' + index + extension)
  }
  return candidate
}

function downloadUpdateInstaller(
  sender: WebContents,
  url: URL,
  latestVersion: unknown,
): Promise<string> {
  const savePath = availableDownloadPath(installerFilename(url, latestVersion))
  const browserSession = sender.session

  return new Promise((resolve, reject) => {
    let downloadItem: DownloadItem | null = null
    let settled = false

    const cleanup = (): void => {
      clearTimeout(timeout)
      browserSession.removeListener('will-download', handleDownload)
    }
    const finish = (error?: Error): void => {
      if (settled) return
      settled = true
      cleanup()
      if (error) reject(error)
      else resolve(savePath)
    }
    const handleDownload = (
      _event: ElectronEvent,
      item: DownloadItem,
      source: WebContents,
    ): void => {
      if (source !== sender) return
      downloadItem = item
      browserSession.removeListener('will-download', handleDownload)
      item.setSavePath(savePath)
      item.once('done', (_doneEvent, state) => {
        if (state === 'completed') {
          finish()
        } else {
          finish(new Error(state === 'cancelled' ? '安装包下载已取消' : '安装包下载中断，请重试'))
        }
      })
    }
    const timeout = setTimeout(() => {
      downloadItem?.cancel()
      finish(new Error('安装包下载超时，请检查网络后重试'))
    }, 30 * 60 * 1000)

    browserSession.on('will-download', handleDownload)
    try {
      // 由 Electron 直接下载，避免依赖 Windows 的 HTTPS 默认应用关联。
      sender.downloadURL(url.toString())
    } catch (error) {
      finish(error instanceof Error ? error : new Error('无法开始下载安装包'))
    }
  })
}

function assertTrustedSender(event: IpcMainInvokeEvent): void {
  const senderUrl = event.senderFrame?.url || ''
  if (senderUrl.startsWith('file://')) {
    return
  }
  if (!app.isPackaged && senderUrl.startsWith('http://127.0.0.1:5173')) {
    return
  }
  throw new Error('拒绝来自非可信页面的请求')
}

function validatePaths(value: unknown): string[] {
  if (!Array.isArray(value) || value.length > 10_000) {
    throw new Error('文件列表无效')
  }
  return value.map((item) => {
    if (typeof item !== 'string' || !path.isAbsolute(item) || item.length > 4096) {
      throw new Error('文件路径无效')
    }
    return item
  })
}

if (singleInstance) {
  app.whenReady().then(() => {
    app.setAppUserModelId('com.jxxyk.genuineqingquwang')
    session.defaultSession.setPermissionRequestHandler((_webContents, _permission, callback) => {
      callback(false)
    })
    registerIpcHandlers()
    createWindow()
  })

  app.on('second-instance', () => {
    if (mainWindow) {
      if (mainWindow.isMinimized()) mainWindow.restore()
      mainWindow.focus()
    }
  })

  app.on('activate', () => {
    if (BrowserWindow.getAllWindows().length === 0) createWindow()
  })

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