import { chdirSync, existsSync } from 'node:fs'
import { dirname, join, resolve } from 'node:path'

const NATIVE_WRAPPER_DLL = 'libNativeWrapper.dll'

function uniquePaths(paths) {
  const seen = new Set()
  const result = []

  for (const candidate of paths) {
    if (!candidate) {
      continue
    }

    const normalized = resolve(candidate)
    if (seen.has(normalized)) {
      continue
    }

    seen.add(normalized)
    result.push(normalized)
  }

  return result
}

function hasAppBinMarker(dir) {
  return (
    existsSync(join(dir, 'launcher.exe')) ||
    existsSync(join(dir, NATIVE_WRAPPER_DLL)) ||
    existsSync(join(dir, 'bun.exe')) ||
    existsSync(join(dir, '..', 'Resources', 'version.json'))
  )
}

export function resolveWindowsBinDir() {
  const roots = uniquePaths([
    dirname(process.argv0),
    dirname(process.execPath),
    process.cwd()
  ])

  const candidates = []
  for (const root of roots) {
    candidates.push(root, join(root, 'bin'))
  }

  for (const candidate of uniquePaths(candidates)) {
    if (hasAppBinMarker(candidate)) {
      return candidate
    }
  }

  return dirname(process.argv0 || process.execPath)
}

export function ensureWindowsWorkingDirectory() {
  if (process.platform !== 'win32') {
    return
  }

  const binDir = resolveWindowsBinDir()
  if (resolve(process.cwd()) === resolve(binDir)) {
    return
  }

  try {
    chdirSync(binDir)
  } catch {
    // Ignore if we cannot change directory.
  }
}