import unfetch from "isomorphic-unfetch";
/**
 * Makes a post request with the specified JSON data, normally to the a AURORA JSON RPC API endpoint
 */
export function post(url: string, body: Record<string, unknown>) {
  return unfetch(url, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
    },
    body: JSON.stringify(body),
  })
    .then(async (r) => {
      const t = await r.text();
      try {
        return JSON.parse(t);
      } catch {
        throw new Error(`Invalid JSON RPC response: "${t}"`);
      }
    })
    .then((response) => {
      const result = response?.result;
      if (!result) {
        throw new Error(
          `Invalid JSON RPC response: ${JSON.stringify(response)}`
        );
      }
      return response.result;
    });
}

type RPCMethodName =
  | "eth_getBlockByNumber"
  | "eth_getBlockByHash"
  | "eth_call"
  | "eth_chainId"
  | "eth_gasPrice"
  | "eth_getBalance"
  | "eth_getTransactionByHash"
  | "eth_getTransactionReceipt"
  | "eth_getTransactionCount"
  | "eth_getCode"
  | "eth_blockNumber"
  | "eth_estimateGas"
  | "eth_getLogs";

/**
 * Prepares data to be sent using the {@link post} function. Data is prepared per the {@link https://en.wikipedia.org/wiki/JSON-RPC#Examples JSON RPC v2 spec}
 */
export function buildRPCPostBody(method: RPCMethodName, params: unknown[]) {
  return {
    jsonrpc: "2.0",
    // TODO: Increment ID will be needed when websocket support is added
    id: 1,
    method,
    params,
  };
}