/**
 * Removes a stale `nonce` from EVM tx payloads planned ahead of signing so the
 * signer can fetch a fresh nonce at broadcast time (multi-step Yield / LiFi).
 */

function unwrapSingleKeyTransactionObject(
  obj: Record<string, unknown>,
): Record<string, unknown> {
  const keys = Object.keys(obj)
  if (keys.length !== 1) {
    return obj
  }
  
  const firstKey = keys[0]
  const inner = obj[firstKey]
  
  // Type guard: only unwrap if inner value is a plain object
  if (
    typeof inner === 'object' &&
    inner !== null &&
    !Array.isArray(inner)
  ) {
    return inner as Record<string, unknown>
  }
  
  return obj
}

/**
 * If the payload is JSON (object or JSON string), drop `nonce` from the inner tx object.
 * Otherwise returns the input unchanged.
 */
export function stripStalePlanningNonceIfJsonObject(
  unsigned: string | Record<string, unknown>,
): unknown {
  if (
    typeof unsigned === 'object' &&
    unsigned !== null &&
    !Array.isArray(unsigned)
  ) {
    const spread = { ...unsigned } as Record<string, unknown>
    const inner = unwrapSingleKeyTransactionObject(spread)
    const { nonce: _staleNonce, ...rest } = inner
    return rest
  }
  if (typeof unsigned === 'string') {
    try {
      const parsed = JSON.parse(unsigned) as unknown
      // Validate parsed result is a plain object
      if (
        typeof parsed === 'object' &&
        parsed !== null &&
        !Array.isArray(parsed)
      ) {
        const inner = unwrapSingleKeyTransactionObject(
          parsed as Record<string, unknown>,
        )
        const { nonce: _staleNonce, ...rest } = inner
        return rest
      }
    } catch {
      return unsigned
    }
  }
  return unsigned
}