var CommandParser = function() {
    var parse = function(str, lookForQuotes) {
        var args = [];
        var readingPart = false;
        var part = "";
        for (var i = 0; i < str.length; i++) {
            if (str.charAt(i) === " " && !readingPart) {
                args.push(part);
                part = "";
            } else {
                if (str.charAt(i) === '"' && lookForQuotes) {
                    readingPart = !readingPart;
                } else {
                    part += str.charAt(i);
                }
            }
        }
        args.push(part);
        return args;
    };
    return {
        parse: parse
    };
}();

(function() {
    var brightness = 0, commandLine, commandInput, scanlines, commandHistory, typing;
    var escapeHTML = function(html) {
        var fn = function(tag) {
            var charsToReplace = {
                "&": "&amp;",
                "<": "&lt;",
                ">": "&gt;",
                '"': "&#34;"
            };
            return charsToReplace[tag] || tag;
        };
        return html.replace(/[&<>"]/g, fn);
    };
    var syncTyping = function() {
        var beforeSelection, selection, afterSelection;
        beforeSelection = this.value.slice(0, this.selectionStart);
        selection = this.value.slice(this.selectionStart, this.selectionEnd);
        afterSelection = this.value.slice(this.selectionEnd);
        typing.innerHTML = beforeSelection + (this.selectionStart === this.selectionEnd ? "<span id='cursor'></span>" : "") + "<span id='selection'>" + selection + "</span>" + afterSelection;
    };
    var alterBrightness = function(delta) {
        brightness = Math.max(0, Math.min(1, brightness + delta));
        this.scanlines.style.backgroundColor = "hsla(120, 100%, 32%, " + brightness * .6 + ")";
    };
    var setInputEnabled = function(enabled) {
        console.log(enabled);
        if (enabled) {
            commandInput.readOnly = false;
            commandLine.style.display = "block";
        } else {
            commandInput.readOnly = true;
            commandInput.value = "";
            typing.innerHTML = "";
            commandLine.style.display = "none";
        }
    };
    var showResponse = function(response) {
        commandHistory.innerHTML += response + "\n";
        setInputEnabled(true);
    };
    var handleForm = function() {
        var val = this.command.value;
        setInputEnabled(false);
        commandHistory.innerHTML += "a&gt;" + escapeHTML(val) + "\n";
        setTimeout(function() {
            showResponse("Command not found.");
        }, 500);
        return false;
    };
    var init = function() {
        console.log("init");
        commandLine = document.getElementById("commandLine");
        commandInput = document.getElementById("command");
        scanlines = document.getElementById("scanlines");
        commandHistory = document.getElementById("history");
        typing = document.getElementById("typing");
        commandInput.value = "";
        commandInput.oninput = syncTyping;
        commandInput.onkeydown = syncTyping;
        commandInput.onkeyup = syncTyping;
        commandInput.onselect = syncTyping;
        commandInput.onfocus = syncTyping;
        commandInput.focus();
        document.body.onmousedown = function() {
            commandInput.focus();
            return false;
        };
        document.getElementById("knobup").onmousedown = function() {
            alterBrightness(1 / 6);
        };
        document.getElementById("knobdown").onmousedown = function() {
            alterBrightness(-1 / 6);
        };
        document.forms[0].onsubmit = handleForm;
        alterBrightness(-1);
    };
    document.addEventListener("DOMContentLoaded", init);
})();