export type DirectSearchTarget =
  | { kind: 'address'; href: string; label: string }
  | { kind: 'transaction'; href: string; label: string }
  | { kind: 'block'; href: string; label: string }

const addressPattern = /^0x[a-f0-9]{40}$/i
const transactionHashPattern = /^0x[a-f0-9]{64}$/i
const blockNumberPattern = /^\d+$/

export function inferDirectSearchTarget(query: string): DirectSearchTarget | null {
  const trimmed = query.trim()
  if (!trimmed) {
    return null
  }

  if (addressPattern.test(trimmed)) {
    return {
      kind: 'address',
      href: `/addresses/0x${trimmed.slice(2)}`,
      label: 'Open address',
    }
  }

  if (transactionHashPattern.test(trimmed)) {
    return {
      kind: 'transaction',
      href: `/transactions/0x${trimmed.slice(2)}`,
      label: 'Open transaction',
    }
  }

  if (blockNumberPattern.test(trimmed)) {
    return {
      kind: 'block',
      href: `/blocks/${trimmed}`,
      label: 'Open block',
    }
  }

  return null
}