export function requireValue(args: string[], index: number, flag: string): string {
  const value = args[index]
  if (!value || value.startsWith("--")) {
    throw new Error(`Missing value for ${flag}`)
  }
  return value
}

export function splitPaths(value: string): string[] {
  return value
    .split(",")
    .map((part) => part.trim())
    .filter(Boolean)
}

export function dedupeNonEmpty(values: string[]): string[] {
  const seen = new Set<string>()
  const output: string[] = []
  for (const value of values) {
    const trimmed = value.trim()
    if (!trimmed || seen.has(trimmed)) continue
    seen.add(trimmed)
    output.push(trimmed)
  }
  return output
}

export function parsePositiveInteger(raw: string, flag: string): number {
  const value = Number(raw)
  if (!Number.isInteger(value) || value <= 0) {
    throw new Error(`${flag} must be a positive integer.`)
  }
  return value
}