'use strict'

/** Suppress duplicate discovery.list span emissions in the same view-build frame (P409-10). */
const DEFAULT_WINDOW_MS = Math.max(
  8,
  Number(process.env.PEARCORD_DISCOVERY_LIST_DEDUPE_MS) || 16
)

function createDiscoveryListFrameDedupe (windowMs = DEFAULT_WINDOW_MS) {
  let lastEmitAt = 0
  let suppressed = 0
  return {
    shouldEmitSpan () {
      const now = Date.now()
      if (now - lastEmitAt < windowMs) {
        suppressed += 1
        return false
      }
      lastEmitAt = now
      return true
    },
    stats () {
      return { suppressed, windowMs, lastEmitAt }
    },
    reset () {
      lastEmitAt = 0
      suppressed = 0
    }
  }
}

module.exports = { createDiscoveryListFrameDedupe, DEFAULT_WINDOW_MS }