etherscanapi.js

'use strict';

const fetch = require('node-fetch');
const msautils = require('./utils');

let apikey;


function setApiKey(_apikey) {
    apikey = _apikey;
}



// fetch from etherscan api
function getFromUrl(url) {
    console.log('msa.etherscan.getFromURL', url);

    if (apikey) {
        if (url.includes('apikey')) {
            url = url.replace('YourApiKeyToken', apikey);
        } else {
            url = url + `&apikey=${apikey}`;
        }
    } else {
        console.warn('apikey is not set');
    }

    const r = fetch(url).then(msautils.checkError)
        .then((jsonResponse) => {
            return jsonResponse;
        }).catch((error) => {
            console.error(error);
            throw error;
        });
    return r;
}



async function getContractABI(contractAddress) {
    console.log('msa.etherscan.getContractABI', contractAddress);
    let url = `https://api.etherscan.io/api?module=contract&action=getabi&address=${contractAddress}&apikey=YourApiKeyToken`;
    const r = await getFromUrl(url);
    return r;
}


/**  
 * Get transactions for an address
 * recursively binary divide 'startblock' and 'endblock' to avoid 10K transaction limit
 * MUST PROVIDE endblock
 */
async function getTransactionsForAddressRecursive(address, options = {}, startblock, endblock) {
    console.log('msa.etherscan.getTransactionsForAddressRecursive', address, options, startblock, endblock);
    if (startblock <= endblock) {
        options = {...options, startblock: startblock, endblock: endblock };
        const txlist = await getTransactionsForAddress(address, options);
        if (msautils.isEmpty(txlist)) return [];
        if (txlist.length < 10000) return txlist;
        if (startblock == endblock) return txlist;
        // console.log(txlist.length);

        const midblock = (startblock + endblock) >> 1;
        const arr1 = await getTransactionsForAddressRecursive(address, options, startblock, midblock);
        const arr2 = await getTransactionsForAddressRecursive(address, options, midblock + 1, endblock);
        return [...arr1, ...arr2];
    }
    return [];
}


/**  
 * Get transactions for an address, limited to 10K transactions
 * @param {string} address 
 * @param {Object} options
 * @param {int} options.startblock
 * @param {int} options.endblock
 * @param {string} options.sort
 * @param {int} options.page
 * @param {int} options.offset
 * @return nothing, updates this.db
 */
async function getTransactionsForAddress(address, options = {}) {
    console.log('msa.etherscan.getTransactionsForAddress', address, options);
    let url = `https://api.etherscan.io/api?module=account&action=txlist&address=${address}`;
    if (options.startblock !== undefined) url += `&startblock=${options.startblock}`;
    if (options.endblock !== undefined) url += `&endblock=${options.endblock}`;
    if (options.sort !== undefined) url += `&sort=${options.sort}`;
    if (options.page !== undefined) url += `&page=${options.page}`;
    if (options.offset !== undefined) url += `&offset=${options.offset}`;
    const r = await getFromUrl(url);
    if (r.status == 1) return r.result;
    return [];
}



module.exports = {
    setApiKey,
    getFromUrl,
    getContractABI,
    getTransactionsForAddress,
    getTransactionsForAddressRecursive,
};