import { app, BrowserWindow, dialog, ipcMain, Menu, screen, shell } from 'electron'
import type { BrowserWindow as BrowserWindowInstance, Event, IpcMainInvokeEvent, MenuItemConstructorOptions } from 'electron'
import { randomUUID } from 'node:crypto'
import path from 'node:path'
import { fileURLToPath } from 'node:url'
import { renderMp4Job } from './renderWorker.cjs'

const { validateRenderRequest } = require('../shared/renderValidation.cjs') as {
  validateRenderRequest(scene: unknown, options: unknown): RenderValidation
}

const isDev = !app.isPackaged
const isE2E = process.env.RUWIO_E2E === '1'
const devServerUrl = process.env.VITE_DEV_SERVER_URL ?? 'http://localhost:5200'
const devServerOrigin = new URL(devServerUrl).origin
const appIconPath = isDev
  ? path.join(process.cwd(), 'build', 'icon.png')
  : path.join(process.resourcesPath, 'build', 'icon.png')

let mainWindow: BrowserWindowInstance | null = null
const renderJobs = new Map<string, AbortController>()
// Serialize desktop renders: one active export at a time, mirroring the
// standalone server's MAX_ACTIVE_JOBS=1 (finding #6). The UI also guards this,
// but IPC is directly invokable, so enforce it in main too.
let renderActive = false

interface RenderValidation {
  ok: boolean
  error?: string
  scene?: Parameters<typeof renderMp4Job>[0]['scene']
  options?: Parameters<typeof renderMp4Job>[0]['options']
}

interface RenderMp4Payload {
  scene?: unknown
  fps?: unknown
  crf?: unknown
  preset?: unknown
  suggestedName?: unknown
}

function sendAppCommand(command: string): void {
  if (!mainWindow || mainWindow.isDestroyed()) return
  mainWindow.webContents.send('ruwio:menu-command', command)
}

declare global {
  // Playwright's Electron runner can evaluate in the main process and call this
  // env-gated hook without expanding the preload bridge surface.
  var __ruwioTestMenuCommand: ((command: string) => void) | undefined
}

function sendRenderProgress(
  target: Electron.WebContents,
  event: { jobId: string; progress: number; done: boolean; error?: string },
): void {
  if (!target.isDestroyed()) target.send('ruwio:render-progress', event)
}

function sanitizeMp4Name(value: unknown): string {
  const raw = typeof value === 'string' && value.trim() ? value.trim() : 'animation.mp4'
  const noPath = raw.replace(/[\\/]+/g, '-')
  const safe = noPath.replace(/[^a-z0-9äöüß._-]+/gi, '-').replace(/^-+|-+$/g, '')
  const named = safe || 'animation.mp4'
  return named.toLowerCase().endsWith('.mp4') ? named : `${named}.mp4`
}

async function handleRenderMp4(event: IpcMainInvokeEvent, payload: RenderMp4Payload): Promise<{ path: string } | null> {
  if (renderActive) {
    throw new Error('A render is already in progress')
  }
  renderActive = true
  try {
    return await runRenderMp4(event, payload)
  } finally {
    renderActive = false
  }
}

async function runRenderMp4(event: IpcMainInvokeEvent, payload: RenderMp4Payload): Promise<{ path: string } | null> {
  const validation = validateRenderRequest(payload?.scene, {
    fps: payload?.fps,
    crf: payload?.crf,
    preset: payload?.preset,
  })
  if (!validation.ok || !validation.scene || !validation.options) {
    throw new Error(validation.error || 'invalid render request')
  }

  // The desktop path captures a hidden, on-screen BrowserWindow, which Chromium
  // can't composite/capture beyond the physical display bounds — a canvas larger
  // than the screen would silently yield truncated frames. Fail fast with a clear
  // message instead (finding #11). The web/server path uses a headless viewport
  // and has no such limit, so this is desktop-only.
  const { width: canvasWidth, height: canvasHeight } = validation.scene.canvas
  const { width: displayWidth, height: displayHeight } = screen.getPrimaryDisplay().size
  if (canvasWidth > displayWidth || canvasHeight > displayHeight) {
    throw new Error(
      `Canvas ${canvasWidth}×${canvasHeight} is larger than this display ` +
        `(${displayWidth}×${displayHeight}). Desktop export can't capture a canvas ` +
        `bigger than the screen — reduce the canvas size and try again.`,
    )
  }

  const window = BrowserWindow.fromWebContents(event.sender)
  const saveOptions = {
    title: 'Export MP4',
    defaultPath: sanitizeMp4Name(payload?.suggestedName),
    filters: [{ name: 'MP4 Video', extensions: ['mp4'] }],
  }
  const e2eSavePath = isE2E
    ? process.env.RUWIO_E2E_SAVE_PATH || path.join(app.getPath('temp'), saveOptions.defaultPath)
    : ''
  const saveResult = e2eSavePath
    ? { canceled: false, filePath: e2eSavePath }
    : window
      ? await dialog.showSaveDialog(window, saveOptions)
      : await dialog.showSaveDialog(saveOptions)
  if (saveResult.canceled || !saveResult.filePath) return null

  const jobId = randomUUID()
  const controller = new AbortController()
  renderJobs.set(jobId, controller)
  sendRenderProgress(event.sender, { jobId, progress: 0, done: false })

  try {
    await renderMp4Job({
      jobId,
      scene: validation.scene,
      options: validation.options,
      outputPath: saveResult.filePath,
      signal: controller.signal,
      onProgress: (progress) => {
        sendRenderProgress(event.sender, { jobId, progress, done: false })
      },
    })
    sendRenderProgress(event.sender, { jobId, progress: 1, done: true })
    return { path: saveResult.filePath }
  } catch (err) {
    const message = (err as Error).message || String(err)
    sendRenderProgress(event.sender, { jobId, progress: 0, done: true, error: message })
    throw err
  } finally {
    renderJobs.delete(jobId)
  }
}

async function handleRenderCancel(_event: IpcMainInvokeEvent, jobId: unknown): Promise<void> {
  if (typeof jobId !== 'string' || !jobId) return
  renderJobs.get(jobId)?.abort()
}

function parseUrl(raw: string): URL | null {
  try {
    return new URL(raw)
  } catch {
    return null
  }
}

function isAllowedAppNavigation(raw: string): boolean {
  const url = parseUrl(raw)
  if (!url) return false
  if (isDev) return url.origin === devServerOrigin
  if (url.protocol !== 'file:') return false
  const appEntry = path.join(app.getAppPath(), 'dist', 'index.html')
  return path.normalize(fileURLToPath(url)) === path.normalize(appEntry)
}

function isAllowedExternalUrl(raw: string): boolean {
  const url = parseUrl(raw)
  return url?.protocol === 'https:'
}

function createMainWindow(): void {
  mainWindow = new BrowserWindow({
    width: 1280,
    height: 860,
    minWidth: 1024,
    minHeight: 700,
    title: 'RUWIO',
    icon: appIconPath,
    show: false,
    backgroundColor: '#14171f',
    webPreferences: {
      preload: path.join(__dirname, 'preload.cjs'),
      contextIsolation: true,
      nodeIntegration: false,
      sandbox: true,
    },
  })

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

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

  mainWindow.webContents.on('will-navigate', (event: Event, url: string) => {
    if (!isAllowedAppNavigation(url)) {
      event.preventDefault()
    }
  })

  if (isDev) {
    void mainWindow.loadURL(devServerUrl)
    mainWindow.webContents.openDevTools({ mode: 'detach' })
  } else {
    void mainWindow.loadFile(path.join(app.getAppPath(), 'dist', 'index.html'))
  }
}

function createMenu(): void {
  const template: MenuItemConstructorOptions[] = [
    {
      label: 'File',
      submenu: [
        {
          label: 'New Project',
          accelerator: 'CmdOrCtrl+N',
          click: () => sendAppCommand('new-project'),
        },
        {
          label: 'Open...',
          accelerator: 'CmdOrCtrl+O',
          click: () => sendAppCommand('open-project'),
        },
        {
          label: 'Recent Projects',
          accelerator: 'CmdOrCtrl+Shift+O',
          click: () => sendAppCommand('recent-projects'),
        },
        { type: 'separator' },
        {
          label: 'Save',
          accelerator: 'CmdOrCtrl+S',
          click: () => sendAppCommand('save-project'),
        },
        {
          label: 'Save As...',
          accelerator: 'CmdOrCtrl+Shift+S',
          click: () => sendAppCommand('save-project-as'),
        },
        { type: 'separator' },
        {
          label: 'Export...',
          accelerator: 'CmdOrCtrl+E',
          click: () => sendAppCommand('export-project'),
        },
        { type: 'separator' },
        process.platform === 'darwin' ? { role: 'close' } : { role: 'quit' },
      ],
    },
    {
      label: 'Edit',
      submenu: [
        {
          label: 'Undo',
          accelerator: 'CmdOrCtrl+Z',
          click: () => sendAppCommand('undo'),
        },
        {
          label: 'Redo',
          accelerator: 'CmdOrCtrl+Shift+Z',
          click: () => sendAppCommand('redo'),
        },
        { type: 'separator' },
        { role: 'cut' },
        { role: 'copy' },
        { role: 'paste' },
        { role: 'selectAll' },
        { type: 'separator' },
        {
          label: 'Copy Current Frame',
          accelerator: 'CmdOrCtrl+Alt+C',
          click: () => sendAppCommand('copy-current-frame'),
        },
      ],
    },
    {
      label: 'View',
      submenu: [
        { role: 'reload' },
        { role: 'forceReload' },
        { role: 'toggleDevTools' },
        { type: 'separator' },
        {
          label: 'Play / Pause',
          accelerator: 'Space',
          click: () => sendAppCommand('toggle-playback'),
        },
        {
          label: 'Stop',
          accelerator: 'Escape',
          click: () => sendAppCommand('stop-playback'),
        },
        {
          label: 'Jump to Start',
          accelerator: 'R',
          click: () => sendAppCommand('rewind'),
        },
        {
          label: 'Fullscreen Preview',
          accelerator: 'Shift+Space',
          click: () => sendAppCommand('fullscreen-preview'),
        },
        { type: 'separator' },
        {
          label: 'Toggle Side Panels',
          accelerator: 'Tab',
          click: () => sendAppCommand('toggle-panels'),
        },
        {
          label: 'Media Library',
          accelerator: 'CmdOrCtrl+M',
          click: () => sendAppCommand('media-library'),
        },
        {
          label: 'Document Settings',
          accelerator: 'CmdOrCtrl+,',
          click: () => sendAppCommand('document-settings'),
        },
        { type: 'separator' },
        { role: 'resetZoom' },
        { role: 'zoomIn' },
        { role: 'zoomOut' },
        { type: 'separator' },
        { role: 'togglefullscreen' },
      ],
    },
    {
      label: 'Window',
      submenu: [
        { role: 'minimize' },
        { role: 'zoom' },
      ],
    },
    {
      label: 'Help',
      submenu: [
        {
          label: 'RUWIO Help',
          accelerator: 'F1',
          click: () => sendAppCommand('help'),
        },
        {
          label: 'About RUWIO',
          click: () => sendAppCommand('about'),
        },
        { type: 'separator' },
        {
          label: 'Open Test Runner',
          accelerator: 'CmdOrCtrl+Shift+Alt+T',
          click: () => sendAppCommand('test-runner'),
        },
      ],
    },
  ]

  if (process.platform === 'darwin') {
    template.unshift({
      label: app.name,
      submenu: [
        { role: 'about' },
        { type: 'separator' },
        { role: 'services' },
        { type: 'separator' },
        { role: 'hide' },
        { role: 'hideOthers' },
        { role: 'unhide' },
        { type: 'separator' },
        { role: 'quit' },
      ],
    })
  }

  Menu.setApplicationMenu(Menu.buildFromTemplate(template))
}

app.setName('RUWIO')

app.whenReady().then(() => {
  ipcMain.handle('ruwio:render-mp4', handleRenderMp4)
  ipcMain.handle('ruwio:render-cancel', handleRenderCancel)
  if (isE2E) {
    globalThis.__ruwioTestMenuCommand = (command: string) => sendAppCommand(command)
  }
  createMenu()
  createMainWindow()

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

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