Hardfork.hasEIP4844

import { Hardfork } from 'tevm'

function selectL2DataMethod(fork: BrandedHardfork): string {
  if (fork.hasEIP4844()) {
    return "blobs"  // ~$0.01-0.10 per blob
  }

  return "calldata"  // ~$1-10 per equivalent data
}

// L2 rollups save 10-100x on data costs with blobs

import { Hardfork } from 'tevm'

function buildL2BatchSubmission(
  fork: BrandedHardfork,
  data: Uint8Array
) {
  if (fork.hasEIP4844() && data.length > 50_000) {
    return {
      type: 3,  // Blob transaction
      blobs: chunkIntoBlobs(data),
      maxFeePerBlobGas: estimateBlobFee()
    }
  }

  return {
    type: 2,  // EIP-1559
    data: data  // Expensive calldata
  }
}

import { Hardfork } from 'tevm'

function estimateL2PostingCost(
  fork: BrandedHardfork,
  dataSize: number,
  blobBaseFee: bigint,
  gasPrice: bigint
): bigint {
  if (fork.hasEIP4844()) {
    // Blob cost
    const blobsNeeded = Math.ceil(dataSize / 131_072)
    const blobGas = BigInt(blobsNeeded) * 131_072n
    return blobGas * blobBaseFee
  }

  // Calldata cost (16 gas per non-zero byte)
  const calldataGas = BigInt(dataSize) * 16n
  return calldataGas * gasPrice
}

import { Hardfork } from 'tevm'

function getBlobOpcodes(fork: BrandedHardfork) {
  if (fork.hasEIP4844()) {
    return {
      BLOBHASH: 0x49,
      BLOBBASEFEE: 0x4A
    }
  }

  return null  // Not available
}

import { Hardfork } from 'tevm'

function generateBlobHashLoader(fork: BrandedHardfork): Uint8Array {
  if (!fork.hasEIP4844()) {
    throw new Error("Blob transactions require Cancun or later")
  }

  // Generate bytecode: PUSH1 0, BLOBHASH
  return new Uint8Array([0x60, 0x00, 0x49])
}

import { Hardfork, CANCUN } from 'tevm'

function validateBlobSupport(config: NetworkConfig) {
  const fork = Hardfork(config.hardfork)

  if (!fork.hasEIP4844()) {
    throw new Error(
      `Network ${config.name} does not support blob transactions. ` +
      `Requires Cancun or later, got ${Hardfork.toString(fork)}`
    )
  }
}