byreal-trade-copy/src/lib/copier/jupiter-client.ts

import { HTTPError } from 'ky'
import { config } from '../config'

/**
 * Returns Jupiter API authentication headers.
 * Shared across all Jupiter API callers (swap, price, etc.).
 * Ref: https://dev.jup.ag/portal/setup.md
 */
export function getJupiterHeaders(): Record<string, string> {
  const headers: Record<string, string> = {
    Accept: 'application/json',
  }
  if (config.jupiterApiKey) {
    headers['x-api-key'] = config.jupiterApiKey
  }
  return headers
}

/**
 * Retry wrapper with exponential backoff + jitter for Jupiter API calls.
 * Only retries on HTTP 429 (rate limited); all other errors propagate immediately.
 * Formula: delay = min(baseDelayMs * 2^attempt + jitter(0..500ms), maxDelayMs)
 * Ref: https://dev.jup.ag/portal/rate-limit.md
 */
export async function withRetry<T>(
  fn: () => Promise<T>,
  maxAttempts = 3,
  baseDelayMs = 1000,
  maxDelayMs = 10000,
): Promise<T> {
  let lastError: unknown
  for (let attempt = 0; attempt < maxAttempts; attempt++) {
    try {
      return await fn()
    } catch (error) {
      lastError = error
      const status = error instanceof HTTPError ? error.response.status : null
      const isRateLimited = status === 429
      if (!isRateLimited || attempt >= maxAttempts - 1) throw error
      const jitter = Math.random() * 500
      const delay = Math.min(baseDelayMs * Math.pow(2, attempt) + jitter, maxDelayMs)
      console.warn(
        `[Jupiter] Rate limited (HTTP 429), retrying in ${Math.round(delay)}ms (attempt ${attempt + 1}/${maxAttempts})`,
      )
      await new Promise((resolve) => setTimeout(resolve, delay))
    }
  }
  throw lastError
}