let async = require('async');
let apiInterfaces = require('./apiInterfaces.js')(config.daemon, config.wallet, config.api);
let lastHash;
let observerConfig = config.chainObserver || config.daemon;

let logSystem = 'chainObserver';
let blockData = JSON.stringify({
	id: "0",
	jsonrpc: "2.0",
	method: 'getlastblockheader',
	params: {}
});

require('./exceptionWriter.js')(logSystem);

function runInterval () {
	async.waterfall([
		function (callback) {
			apiInterfaces.jsonHttpRequest(observerConfig.host, observerConfig.port, blockData, function (err, res) {
				if (err) {
					log('error', logSystem, '%s error from chain observer', [config.coin]);
					setTimeout(runInterval, 3000);
					return;
				}
				if (res && res.result && res.result.status === "OK" && res.result.hasOwnProperty('block_header')) {
					let blockHeader = res.result.block_header;
					let hash = blockHeader.hash.toString('hex');
					if (!lastHash || lastHash !== hash) {
						lastHash = hash;
						log('info', logSystem, '%s observed new chain tip %s at height %d', [config.coin, hash, blockHeader.height]);
						process.send({
							type: 'ChainState',
							block_header: blockHeader
						});
					}
					callback(null);
					return;
				}
				log('error', logSystem, 'bad response from chain observer');
				setTimeout(runInterval, 3000);
			});
		}
	], function () {
		setTimeout(function () {
			runInterval();
		}, observerConfig.refreshInterval || config.poolServer.blockRefreshInterval);
	});
}

runInterval();