const CONSERVATIVE_BLOCK_GAS_LIMIT = 10_000_000; // conservative, hard-coded estimate of the current block gas limit
export const DEFAULT_GAS_REQUIRED = 200_000; // the default value for calls that don't specify gasRequired

// chunks array into chunks
// evenly distributes items among the chunks
export default function chunkArray<T>(
  items: T[],
  gasLimit = CONSERVATIVE_BLOCK_GAS_LIMIT * 10
): T[][] {
  const chunks: T[][] = [];
  let currentChunk: T[] = [];
  let currentChunkCumulativeGas = 0;

  for (let i = 0; i < items.length; i++) {
    const item = items[i];

    // calculate the gas required by the current item
    const gasRequired =
      (item as { gasRequired?: number })?.gasRequired ?? DEFAULT_GAS_REQUIRED;

    // if the current chunk is empty, or the current item wouldn't push it over the gas limit,
    // append the current item and increment the cumulative gas
    if (
      currentChunk.length === 0 ||
      currentChunkCumulativeGas + gasRequired < gasLimit
    ) {
      currentChunk.push(item);
      currentChunkCumulativeGas += gasRequired;
    } else {
      // otherwise, push the current chunk and create a new chunk
      chunks.push(currentChunk);
      currentChunk = [item];
      currentChunkCumulativeGas = gasRequired;
    }
  }
  if (currentChunk.length > 0) chunks.push(currentChunk);

  return chunks;
}