(function(){
    var lookup_block_height = document.createElement("INPUT");
    lookup_block_height.setAttribute("type", "text"); 
    var input_info = document.createElement("h8");
    input_info.innerHTML = "block number: ";
    document.body.appendChild(document.createElement("br"));
    document.body.appendChild(input_info);
    document.body.appendChild(lookup_block_height);
    
    var lookup_block_button = document.createElement("BUTTON");
    lookup_block_button.id = "lookup block number";
    var lookup_block_button_text = document.createTextNode("lookup block");
    lookup_block_button.appendChild(lookup_block_button_text);
    lookup_block_button.onclick = async function() {
	var num = parseInt(lookup_block_height.value, 10);
	var x = await rpc.apost(["block", num]);
        lookup_block2(x);
    };
    document.body.appendChild(lookup_block_button);
    var current_block = document.createElement("div");
    current_block.id = "block div";
    document.body.appendChild(current_block);

    function to_now(t) {
        var start_time = 15192951759;
        var n = (t + start_time);//10 * seconds since jan 1 1970
        var curdate = new Date(null);
        curdate.setTime(n*100);
        var final_now = curdate.toLocaleString();
        console.log(final_now);
        return final_now;
    }
    function lookup_block2(block) {
        block2 = block[1];
        var current_block = document.getElementById("block div");
        if (block == "empty") {
	    current_block.innerHTML = "this block doesn't exist.";
        } else {
	    var miner = block[10][1][1];
	    var time0 = block[4];
            var prev_hash = toHex(atob(block[2]));
	    var time = to_now(time0);
	    //acc, number, hash, txs, power, nonce, total_coins, db_root
	    current_block.innerHTML = "block: ".concat(block[1]).concat("<br />was mined by: ").concat(miner).concat("<br />has timestamp: ").concat(time).concat("<br />prev hash: ").concat(prev_hash);
        }
    }
}
)();