import { app, nativeImage, type NativeImage } from 'electron'
import { join } from 'path'
import { is } from '@electron-toolkit/utils'

/**
 * Resolves the directory holding the bundled binaries (yt-dlp.exe, ffmpeg.exe).
 *
 * In dev they live in the repo at resources/bin/.
 * In a packaged build, electron-builder's extraResources copies them to
 * <resources>/bin (see electron-builder.yml), reachable via process.resourcesPath.
 */
export function getBinDir(): string {
  return is.dev ? join(app.getAppPath(), 'resources', 'bin') : join(process.resourcesPath, 'bin')
}

/**
 * The app icon (.ico), for the system tray. In dev it's the repo's build/icon.ico;
 * in a packaged build, electron-builder's extraResources copies it to
 * <resources>/icon.ico (see electron-builder.yml).
 */
export function getAppIconPath(): string {
  return is.dev
    ? join(app.getAppPath(), 'build', 'icon.ico')
    : join(process.resourcesPath, 'icon.ico')
}

let appIconImage: NativeImage | null = null
/**
 * The app icon as a cached NativeImage, for OS notifications (W13/L127). Loaded
 * once from getAppIconPath(); a missing icon yields an empty image, which
 * Notification treats as "no icon" (the OS default) rather than erroring. This
 * gives completion/background toasts the real brand glyph — notably on the
 * portable build, which has no installed AUMID shortcut icon for Windows to use.
 */
export function getAppIconImage(): NativeImage {
  // Cache only a valid image so a transient read miss isn't latched forever; a
  // genuinely-missing icon just re-reads (cheap — notifications are infrequent).
  if (!appIconImage || appIconImage.isEmpty()) {
    appIconImage = nativeImage.createFromPath(getAppIconPath())
  }
  return appIconImage
}

/**
 * AeroFetch keeps its OWN writable copy of yt-dlp.exe under userData, separate
 * from the read-only bundled seed in resources/bin. The managed copy is what
 * actually gets spawned and self-updated (`--update-to`), so an app reinstall or
 * portable re-extraction — which only ever replace the bundled seed — can never
 * roll a freshly-updated yt-dlp back to a stale version. See ensureManagedYtdlp
 * in ytdlp.ts, which seeds this from getBundledYtdlpPath() on first run.
 *
 * ffmpeg/ffprobe/aria2c stay in getBinDir(): they're not self-updating and
 * yt-dlp finds them via `--ffmpeg-location <binDir>`.
 */
function getManagedBinDir(): string {
  return join(app.getPath('userData'), 'bin')
}

/** The bundled, read-only yt-dlp.exe seeded into the managed copy when missing. */
export function getBundledYtdlpPath(): string {
  return join(getBinDir(), 'yt-dlp.exe')
}

/** The managed (spawned + auto-updated) yt-dlp.exe under userData. */
export function getYtdlpPath(): string {
  return join(getManagedBinDir(), 'yt-dlp.exe')
}

export function getFfmpegPath(): string {
  return join(getBinDir(), 'ffmpeg.exe')
}

/**
 * yt-dlp finds ffprobe via --ffmpeg-location (the bin dir), so the app never
 * spawns it directly — but it must be present, or duration-aware post-processing
 * (SponsorBlock-remove, --force-keyframes-at-cuts, --split-chapters) fails. This
 * accessor exists so startDownload can assert its presence up front.
 */
export function getFfprobePath(): string {
  return join(getBinDir(), 'ffprobe.exe')
}

/** User-facing error shown by download/probe/index/update when yt-dlp.exe is missing. */
export const YTDLP_MISSING_MSG =
  'yt-dlp.exe is missing. Open Settings → Software update to re-download it.'

/** Optional bundled external downloader; absent unless dropped into resources/bin. */
export function getAria2cPath(): string {
  return join(getBinDir(), 'aria2c.exe')
}

/**
 * Absolute path to a Windows system executable (e.g. taskkill.exe, schtasks.exe).
 *
 * SECURITY (audit F3): system tools are resolved by full path under System32
 * rather than by bare name, so a same-named binary planted in the current
 * working directory or earlier on PATH can't be invoked in their place — a real
 * risk for the portable build, which runs from user-writable locations.
 */
export function getSystem32Path(exe: string): string {
  return join(process.env.SystemRoot || 'C:\\Windows', 'System32', exe)
}