From 4b75f89c0ab72dbf4e1c4895b6a5b173cab77ff9 Mon Sep 17 00:00:00 2001
From: adithyagenie <adithyagenie@gmail.com>
Date: Fri, 18 Aug 2023 21:04:25 +0530
Subject: [PATCH] Userscript

---
 README.md     |  4 ++-
 userscript.js | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 userscript.js

diff --git a/README.md b/README.md
index 484d4dd..763b722 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,4 @@
 # skillrack-captcha-solver
-Captcha solver for skillrack
+Captcha solver for skillrack.
+
+Use GreaseMonkey/TamperMonkey to run the script.
\ No newline at end of file
diff --git a/userscript.js b/userscript.js
new file mode 100644
index 0000000..8e2190d
--- /dev/null
+++ b/userscript.js
@@ -0,0 +1,85 @@
+// ==UserScript==
+// @name         Math Problem Solver
+// @namespace    https://github.com/adithyagenie/skillrack-captcha-solver
+// @version      0.1
+// @description  Solves math captcha in SkillRack using Tesseract.js
+// @author       adithyagenie
+// @include      https://*.skillrack.com/*
+// @require https://cdn.jsdelivr.net/npm/tesseract.js@4.1.1/dist/tesseract.min.js
+// ==/UserScript==
+
+(function () {
+	// Wait for window to load
+	window.addEventListener("load", function () {
+		console.log("Checking for captchas");
+		// Step 1: Get the Image
+		const image = document.getElementById("j_id_6s");
+		const textbox = document.getElementById("capval");
+		const button = document.getElementById("proceedbtn");
+		if (image == null) {
+			console.log("Captcha not found!");
+			return;
+		}
+
+		// Invert colours for better ocr
+		function invertImageColors(image) {
+			const canvas = document.createElement("canvas");
+			canvas.width = image.width;
+			canvas.height = image.height;
+			const ctx = canvas.getContext("2d");
+			ctx.drawImage(image, 0, 0, image.width, image.height);
+
+			const imageData = ctx.getImageData(0, 0, image.width, image.height);
+			const data = imageData.data;
+
+			for (let i = 0; i < data.length; i += 4) {
+				data[i] = 255 - data[i]; // Red
+				data[i + 1] = 255 - data[i + 1]; // Green
+				data[i + 2] = 255 - data[i + 2]; // Blue
+			}
+
+			ctx.putImageData(imageData, 0, 0);
+			image.src = canvas.toDataURL();
+		}
+
+		function getNums(text) {
+			const a = text
+				.trim()
+				.split(" ")
+				.join("")
+				.replace("=", "")
+				.split("+");
+			return [a[0], a[1]];
+		}
+
+		invertImageColors(image);
+
+		// Step 2: Image Processing with Tesseract.js
+		Tesseract.recognize(image.src, "eng", { whitelist: "1234567890+=" })
+			.then(({ data: { text } }) => {
+				// Step 3: Extract the Math Problem
+				const mathProblem = getNums(text);
+
+				// Step 4: Solve the Math
+				if (mathProblem) {
+					const result =
+						parseInt(mathProblem[0]) + parseInt(mathProblem[1]);
+					console.log(
+						"Found math captcha:",
+						mathProblem,
+						"=",
+						result,
+						"Auto-filling answer"
+					);
+					textbox.value = result;
+					button.click();
+				} else {
+					console.log("No math problem found in the image text.");
+				}
+				return;
+			})
+			.catch((error) => {
+				console.error("Error processing captcha:", error);
+			});
+	});
+})();