// ==UserScript==
// @name         Codeforces Problem Submit Helper
// @namespace    http://tampermonkey.net/
// @version      1.0
// @description  Fetches the current Codeforces URL, and parses it for the problem identifier and automatically puts it in the field that asks for it.
// @author       SirRogue
// @match        *://codeforces.com/*
// @match        *://www.codeforces.com/*
// @run-at       document-idle
// ==/UserScript==
(function(){
    'use strict';
    const currenturl=window.location.href;
    function extractproblemidentifier(urlstr){
        if(!urlstr){
            return null;
        }
        const problemset=/problemset\/problem\/(\d+)\/([A-Za-z0-9]+)/i;
        const match=urlstr.match(problemset);
        if(match){
            return match[1]+match[2].toUpperCase();
        }
        return null;
    }
    const problemidentifier=extractproblemidentifier(currenturl);
    if(problemidentifier){
        localStorage.setItem('problemidentifier',problemidentifier);
        return;
    }
    if(/\/problemset\/submit\b/.test(currenturl)){
        const savedproblemidentifier=localStorage.getItem('problemidentifier');
        if(!savedproblemidentifier){
            return;
        }
        const input=
            document.querySelector('input[name="submittedProblemCode"]')||
            document.querySelector('input[name="submittedProblemIndex"]')||
            document.querySelector('input[type="text"]');
        if(input){
            input.value=savedproblemidentifier;
            input.dispatchEvent(new Event('input',{bubbles:true}));
            input.dispatchEvent(new Event('change',{bubbles:true}));
        }
    }
})();