import { promises as fs } from "node:fs"
import * as path from "node:path"

async function ensureDir(dir: string): Promise<void> {
  await fs.mkdir(dir, { recursive: true })
}

async function copyDir(src: string, dest: string): Promise<void> {
  await ensureDir(dest)
  const entries = await fs.readdir(src, { withFileTypes: true })
  for (const entry of entries) {
    const srcPath = path.join(src, entry.name)
    const destPath = path.join(dest, entry.name)
    if (entry.isDirectory()) {
      await copyDir(srcPath, destPath)
    } else if (entry.isFile()) {
      await fs.copyFile(srcPath, destPath)
    }
    // Symlinks and others are ignored
  }
}

export async function copyFilesCLI(): Promise<void> {
  const args = process.argv.slice(2)
  const showHelp = args.includes("-h") || args.includes("--help")
  const sourceArg = args[0]
  const destArg = args[1]

  console.log("sourceArg:", sourceArg, "destArg:", destArg)
  if (showHelp || !sourceArg || !destArg) {
    console.error(
      [
        "Usage: tsx scripts/copyFiles.ts <source-path> <destination-path>",
        "",
        "Copies all files from <source-path> into <destination-path>.",
        "Examples:",
        "  tsx scripts/copyFiles.ts static/fonts dist/fonts",
      ].join("\n")
    )
    process.exit(showHelp ? 0 : 1)
  }

  const src = path.resolve(process.cwd(), sourceArg)
  const dest = path.resolve(process.cwd(), destArg)

  // Prevent copying into source or a parent of source
  const rel = path.relative(src, dest)
  if (!rel || !rel.startsWith("..")) {
    console.error("Destination must not be inside the source fonts directory.")
    process.exit(1)
  }

  await ensureDir(dest)
  await copyDir(src, dest)
  console.log(`Copied files from "${src}" to "${dest}".`)
}

// Run if invoked via CLI
if (require.main === module) {
  try {
    await copyFilesCLI()
  } catch (err) {
    console.error(err instanceof Error ? err.message : String(err))
    process.exit(1)
  }
}