(function () {
 var //finds import statements
 importre = new RegExp("\\s*import"),
 //finds defining statements
 defre = new RegExp("def.*|class.*"),
 //test for empty line.
 comment = new RegExp("^#.*"),
 //a regex to check if a line is an assignment
 //this regex checks whether or not a line starts with
 //an identifier followed with some whitspace and then an = and then some more white space.
 //it also checks if the identifier is a tuple.
 assignment = /^((\s*\(\s*(\s*((\s*((\s*[_a-zA-Z]\w*\s*)|(\s*\(\s*(\s*[_a-zA-Z]\w*\s*,)*\s*[_a-zA-Z]\w*\s*\)\s*))\s*)|(\s*\(\s*(\s*((\s*[_a-zA-Z]\w*\s*)|(\s*\(\s*(\s*[_a-zA-Z]\w*\s*,)*\s*[_a-zA-Z]\w*\s*\)\s*))\s*,)*\s*((\s*[_a-zA-Z]\w*\s*)|(\s*\(\s*(\s*[_a-zA-Z]\w*\s*,)*\s*[_a-zA-Z]\w*\s*\)\s*))\s*\)\s*))\s*,)*\s*((\s*((\s*[_a-zA-Z]\w*\s*)|(\s*\(\s*(\s*[_a-zA-Z]\w*\s*,)*\s*[_a-zA-Z]\w*\s*\)\s*))\s*)|(\s*\(\s*(\s*((\s*[_a-zA-Z]\w*\s*)|(\s*\(\s*(\s*[_a-zA-Z]\w*\s*,)*\s*[_a-zA-Z]\w*\s*\)\s*))\s*,)*\s*((\s*[_a-zA-Z]\w*\s*)|(\s*\(\s*(\s*[_a-zA-Z]\w*\s*,)*\s*[_a-zA-Z]\w*\s*\)\s*))\s*\)\s*))\s*\)\s*)|(\s*\s*(\s*((\s*((\s*[_a-zA-Z]\w*\s*)|(\s*\(\s*(\s*[_a-zA-Z]\w*\s*,)*\s*[_a-zA-Z]\w*\s*\)\s*))\s*)|(\s*\(\s*(\s*((\s*[_a-zA-Z]\w*\s*)|(\s*\(\s*(\s*[_a-zA-Z]\w*\s*,)*\s*[_a-zA-Z]\w*\s*\)\s*))\s*,)*\s*((\s*[_a-zA-Z]\w*\s*)|(\s*\(\s*(\s*[_a-zA-Z]\w*\s*,)*\s*[_a-zA-Z]\w*\s*\)\s*))\s*\)\s*))\s*,)*\s*((\s*((\s*[_a-zA-Z]\w*\s*)|(\s*\(\s*(\s*[_a-zA-Z]\w*\s*,)*\s*[_a-zA-Z]\w*\s*\)\s*))\s*)|(\s*\(\s*(\s*((\s*[_a-zA-Z]\w*\s*)|(\s*\(\s*(\s*[_a-zA-Z]\w*\s*,)*\s*[_a-zA-Z]\w*\s*\)\s*))\s*,)*\s*((\s*[_a-zA-Z]\w*\s*)|(\s*\(\s*(\s*[_a-zA-Z]\w*\s*,)*\s*[_a-zA-Z]\w*\s*\)\s*))\s*\)\s*))\s*\s*))([+-/*%&\^\|]?|[/<>*]{2})=/;

 Sk.globals = {
 _ih: new Sk.builtin.list(),
 _oh: new Sk.builtin.dict(),
 _: Sk.builtin.str.$empty,
 __: Sk.builtin.str.$empty,
 ___: Sk.builtin.str.$empty,
 _i: Sk.builtin.str.$empty,
 _ii: Sk.builtin.str.$empty,
 _iii: Sk.builtin.str.$empty,
 __name__: new Sk.builtin.str("__main__"),
 };
 Sk.globals.In = Sk.globals._ih;
 Sk.globals.Out = Sk.globals._oh;

 var stopExecution = false;

 const info = "# Python 3.7(ish) (Skulpt ipython, " + new Date() + ") \n" + "# [" + navigator.userAgent + "] on " + navigator.platform;

 ipythonExample = function (dom) {
 if (ace === undefined) {
 throw Error("No ace");
 }
 this.editor = dom;

 // focus the current inCell on clickGuard click event
 this.clickGuard = document.getElementById("clickGuard");
 this.clickGuard.addEventListener("click", () => {
 this.inCell.focus();
 });

 // add a keyboard interrupt feature
 const keyboardInterrupt = (e) => {
 if (e.ctrlKey && e.key === "c") {
 // faile safe for keyboard interrupt
 stopExecution = true;
 }
 };
 this.editor.addEventListener("keydown", keyboardInterrupt);
 this.clickGuard.addEventListener("keydown", keyboardInterrupt);

 // prepend browser info
 const infoElement = document.createElement("DIV");
 infoElement.innerText = info;
 infoElement.style.margin = "5px";
 this.editor.appendChild(infoElement);

 // setup some basics
 this.inputs = [];
 this.idx = 0;
 this.newCells();
 this.outf = this.outf.bind(this);
 this.lineHeight = this.inCell.renderer.lineHeight || 16;
 this.pad = 15;

 // configure the skulpt environment
 Sk.configure({
 output: this.outf,
 __future__: Sk.python3,
 yieldLimit: 1000,
 execLimit: 30000,
 retainGlobals: true,
 inputfunTakesPrompt: true,
 inputfun: (args) => {
 let res;
 this.outf(args + "");
 this.outf((res = prompt(args)));
 return res;
 },
 });
 };

 ipythonExample.prototype.newCells = function () {
 this.idx = this.inputs.length;
 this.inCell = this.newIn();
 this.printCell = this.newPrint();
 this.outCell = this.newOut();
 this.inCell.focus();
 this.inCell.container.scrollIntoView();
 };

 ipythonExample.prototype.execute = function () {
 stopExecution = false;
 const code = this.inCell.getValue();
 const codeAsPyStr = Sk.ffi.remapToPy(code);
 Sk.globals["_i" + this.inputs.length] = codeAsPyStr; // add the input to globals as per ipython
 Sk.globals.In.v.push(codeAsPyStr);
 this.inputs[this.inputs.length - 1] = code;

 let compile_code = code.trimEnd() || "None"; // always have a last line

 const lines = compile_code.split("\n");
 let last_line = lines[lines.length - 1];
 if (
 !assignment.test(last_line) &&
 !defre.test(last_line) &&
 !importre.test(last_line) &&
 !comment.test(last_line) &&
 last_line.length > 0 &&
 last_line[0] !== ""
 ) {
 lines[lines.length - 1] = "_" + this.inputs.length + " = " + last_line;
 }
 compile_code = lines.join("\n");
 // ace editor stuff
 this.inCell.setReadOnly(true);
 this.inCell.renderer.$cursorLayer.element.style.opacity = 0;

 // allow suspension and check the stopExecution flag in case of keyboard interrupt
 const executionPromise = Sk.misceval.asyncToPromise(() => Sk.importMainWithBody("ipython", false, compile_code, true), {
 "*": () => {
 if (stopExecution) {
 throw "\nKeyboard interrupt";
 }
 },
 });
 executionPromise
 .then((res) => {
 const printContent = this.printCell.getValue();
 if (printContent.substring(printContent.length - 1) === "\n") {
 this.printCell.setValue(printContent.substring(0, printContent.length - 1), -1);
 }
 this.printCell.container.style.height = this.printCell.session.getLength() * this.lineHeight + this.pad;
 this.printCell.resize();

 const last_input = Sk.globals["_" + this.inputs.length];
 if (Sk.builtin.checkNone(last_input) || last_input === undefined) {
 delete Sk.globals["_" + this.inputs.length]; // if the last input evaluated to None remove it from globals
 } else {
 this.outCell.setValue(Sk.ffi.remapToJs(Sk.misceval.objectRepr(last_input)), -1);
 if (last_input !== Sk.globals.Out) {
 Sk.abstr.objectSetItem(Sk.globals._oh, Sk.ffi.remapToPy(this.inputs.length), last_input);
 Sk.globals["___"] = Sk.globals["__"];
 Sk.globals["__"] = Sk.globals["_"];
 Sk.globals["_"] = last_input;
 }
 }
 })
 .catch((e) => {
 this.outf(e.toString());
 })
 .finally(() => {
 Sk.globals["_iii"] = Sk.globals["_ii"];
 Sk.globals["_ii"] = Sk.globals["_i"];
 Sk.globals["_i"] = Sk.globals["_i" + this.inputs.length];
 if (this.printCell.isVisible || this.outCell.isVisible) {
 this.inCell.container.style.height = this.inCell.session.getLength() * 16;
 this.inCell.resize();
 }
 this.newCells();
 });
 };

 ipythonExample.prototype.outf = function (text) {
 const curr_val = this.printCell.getValue();
 this.printCell.setValue(curr_val + text, 1);
 };

 ipythonExample.prototype.newIn = function () {
 let cell = document.createElement("DIV");
 this.editor.appendChild(cell);
 cell = ace.edit(cell);
 this.inputs.push("");
 cell.setOptions({
 showLineNumbers: true,
 firstLineNumber: this.inputs.length,
 printMargin: false,
 highlightGutterLine: false,
 highlightActiveLine: false,
 showFoldWidgets: false,
 theme: "ace/theme/gruvbox",
 mode: "ace/mode/python",
 });
 cell.session.addGutterDecoration(0, "in-gutter");
 cell.container.style.height = 30;
 cell.resize();
 cell.on("blur", () => {
 cell.selection.setSelectionRange(new ace.Range(0, 0, 0, 0), false);
 });
 cell.on("change", () => {
 cell.container.style.height = cell.session.getLength() * this.lineHeight + this.pad;
 cell.resize();
 cell.container.scrollIntoView();
 });
 cell.renderer.onResize(() => {});

 cell.commands.addCommands([
 {
 name: "upHistory",
 bindKey: {
 mac: "Up",
 win: "Up",
 },
 exec: (e, t) => {
 if (cell.getCursorPosition().row === 0) {
 if (this.idx > 0) {
 cell.setValue(this.inputs[--this.idx], 1);
 cell.container.scrollIntoView();
 }
 } else {
 cell.commands.commands.golineup.exec(e, t);
 }
 },
 },
 {
 name: "downHistory",
 bindKey: {
 mac: "Down",
 win: "Down",
 },
 exec: (e, t) => {
 if (cell.getCursorPosition().row === cell.session.getLength() - 1) {
 if (this.idx < this.inputs.length - 1) {
 cell.setValue(this.inputs[++this.idx], -1);
 cell.container.scrollIntoView();
 }
 } else {
 cell.commands.commands.golinedown.exec(e, t);
 }
 },
 },
 {
 name: "execute",
 bindKey: {
 win: "ctrl-enter",
 mac: "command-enter",
 },
 exec: (e, t) => {
 this.execute();
 },
 },
 {
 name: "keyboardInterrupt",
 bindKey: {
 mac: "ctrl-C",
 win: "ctrl-C",
 },
 exec: (e, t) => {
 stopExecution = true;
 },
 readOnly: true,
 },
 ]);
 return cell;
 };

 ipythonExample.prototype.newPrint = function () {
 let cell = document.createElement("DIV");
 this.editor.appendChild(cell);
 cell = ace.edit(cell);
 cell.setOptions({
 readOnly: true,
 printMargin: false,
 showGutter: false,
 showLineNumbers: false,
 highlightActiveLine: false,
 highlightGutterLine: false,
 highlightSelectedWord: false,
 theme: "ace/theme/gruvbox",
 });
 cell.renderer.$cursorLayer.element.style.opacity = 0;
 cell.on("blur", () => {
 cell.selection.setSelectionRange(new ace.Range(0, 0, 0, 0), false);
 cell.renderer.$cursorLayer.element.style.opacity = 0;
 });
 cell.on("change", () => {
 if (!cell.isVisible) {
 cell.container.style.display = "block";
 cell.isVisible = true;
 }
 cell.container.style.height = cell.session.getLength() * this.lineHeight + this.pad;
 cell.resize();
 cell.focus();
 cell.renderer.$cursorLayer.element.style.opacity = "";
 cell.container.scrollIntoView();
 });
 cell.container.style.display = "none";
 cell.isVisible = false;
 cell.commands.addCommand({
 name: "keyboardInterrupt",
 bindKey: {
 mac: "ctrl-C",
 win: "ctrl-C",
 },
 exec: (e, t) => {
 stopExecution = true;
 },
 readOnly: true,
 });
 return cell;
 };

 ipythonExample.prototype.newOut = function () {
 let cell = document.createElement("DIV");
 this.editor.appendChild(cell);
 cell = ace.edit(cell);
 cell.setOptions({
 showLineNumbers: true,
 firstLineNumber: this.inputs.length,
 highlightActiveLine: false,
 highlightGutterLine: false,
 highlightSelectedWord: false,
 readOnly: true,
 printMargin: false,
 theme: "ace/theme/gruvbox",
 });
 cell.session.addGutterDecoration(0, "out-gutter");
 cell.renderer.$cursorLayer.element.style.opacity = 0;
 cell.on("blur", () => {
 cell.selection.setSelectionRange(new ace.Range(0, 0, 0, 0), false);
 });
 cell.on("change", () => {
 if (!cell.isVisible) {
 cell.container.style.display = "block";
 this.printCell.container.style.height = this.printCell.session.getLength() * this.lineHeight;
 this.printCell.resize();
 cell.isVisible = true;
 }
 cell.container.style.height = cell.session.getLength() * this.lineHeight + this.pad;
 cell.resize();
 cell.container.scrollIntoView();
 });
 cell.container.style.display = "none";
 cell.isVisible = false;
 return cell;
 };

})();