Function parsePDFPageRange

src/utils/pdfUtils.ts:16–50

(
  pages: string,
)

 * Pages are 1-indexed.
 */
export function parsePDFPageRange(
  pages: string,
): { firstPage: number; lastPage: number } | null {
  const trimmed = pages.trim()
  if (!trimmed) {
    return null
  }

  // "N-" open-ended range
  if (trimmed.endsWith('-')) {
    const first = parseInt(trimmed.slice(0, -1), 10)
    if (isNaN(first) || first < 1) {
      return null
    }
    return { firstPage: first, lastPage: Infinity }
  }

  const dashIndex = trimmed.indexOf('-')
  if (dashIndex === -1) {
    // Single page: "5"
    const page = parseInt(trimmed, 10)
    if (isNaN(page) || page < 1) {
      return null
    }
    return { firstPage: page, lastPage: page }
  }

  // Range: "1-10"
  const first = parseInt(trimmed.slice(0, dashIndex), 10)
  const last = parseInt(trimmed.slice(dashIndex + 1), 10)
  if (isNaN(first) || isNaN(last) || first < 1 || last < 1 || last < first) {
    return null
  }
  return { firstPage: first, lastPage: last }
}

/**
 * Check if PDF reading is supported with the current model.