import {
  type BlockTag,
  type EIP1193RequestFn,
  type EIP1474Methods,
  formatBlock,
  type GetBlockReturnType,
} from "viem";
import { numberToHex } from "../../utils/encoding/hex.js";

type GetBlockParameters<
  TIncludeTransactions extends boolean = false,
  TBlockTag extends BlockTag = "latest",
> = {
  /** Whether or not to include transaction data in the response. */
  includeTransactions?: TIncludeTransactions;
} & (
  | {
      /** The block number. */
      blockNumber?: bigint;
      blockTag?: never;
    }
  | {
      blockNumber?: never;
      /**
       * The block tag.
       * default: 'latest'
       */
      blockTag?: TBlockTag | BlockTag;
    }
);

/**
 * Retrieves a block by its number or tag from the Ethereum blockchain.
 * @param request - The EIP1193 request function.
 * @param params - The parameters for retrieving the block.
 * @returns A promise that resolves to the requested block.
 * @throws An error if the block is not found.
 * @rpc
 * @example
 * ```ts
 * import { getRpcClient, eth_getBlockByNumber } from "thirdweb/rpc";
 * const rpcRequest = getRpcClient({ client, chain });
 * const block = await eth_getBlockByNumber(rpcRequest, {
 *  blockNumber: 123456,
 *  includeTransactions: true,
 * });
 * ```
 */
export async function eth_getBlockByNumber<
  TIncludeTransactions extends boolean = false,
  TBlockTag extends BlockTag = "latest",
>(
  request: EIP1193RequestFn<EIP1474Methods>,
  params: GetBlockParameters<TIncludeTransactions, TBlockTag>,
): Promise<GetBlockReturnType<undefined, TIncludeTransactions, TBlockTag>> {
  const blockTag = params.blockTag ?? "latest";
  const includeTransactions = params.includeTransactions ?? false;
  const blockNumberHex =
    params.blockNumber !== undefined
      ? numberToHex(params.blockNumber)
      : undefined;

  const block = await request({
    method: "eth_getBlockByNumber",
    params: [blockNumberHex || blockTag, includeTransactions],
  });
  if (!block) {
    throw new Error("Block not found");
  }
  return formatBlock(block) as GetBlockReturnType<
    undefined,
    TIncludeTransactions,
    TBlockTag
  >;
}