Merge pull request #6 from arpitchakladar/adding-documentation-comments

Adding documentation comments

22 files changed, 502 insertions, 369 deletions

diff --git a/src/scripts/captcha/application-receipt.ts b/src/scripts/captcha/application-receipt.ts
deleted file mode 100644
index 595195e..0000000
--- a/src/scripts/captcha/application-receipt.ts
+++ /dev/null
@@ -1,4 +0,0 @@
-document.addEventListener("DOMContentLoaded", () => {
-	$("#werter > div > form > div:nth-child(4)").hide();
-	(window as any).validateForm = () => true;
-});
diff --git a/src/scripts/captcha/know-your-property.ts b/src/scripts/captcha/know-your-property.ts
deleted file mode 100644
index 6e11a3f..0000000
--- a/src/scripts/captcha/know-your-property.ts
+++ /dev/null
@@ -1,4 +0,0 @@
-document.addEventListener("DOMContentLoaded", () => {
-	$("#khatianPlotDiv > div:nth-child(6) > div").hide();
-	(window as any).validateCaptcha = () => true;
-});
diff --git a/src/scripts/common/login/captcha.ts b/src/scripts/common/login/captcha.ts
new file mode 100644
index 0000000..a63aa24
--- /dev/null
+++ b/src/scripts/common/login/captcha.ts
@@ -0,0 +1,128 @@
+import { observeDOM } from "@/shared/observe-dom";
+import { OCRRequest, OCRResponse } from "@/shared/ocr-request";
+
+/**
+ * Pre-processes a CAPTCHA image on a canvas by removing grayish
+ * background noise while preserving dark pixels, producing a clean
+ * binary image suitable for OCR.
+ *
+ * @param ctx    - The 2D rendering context of the canvas.
+ * @param width  - Canvas width in pixels.
+ * @param height - Canvas height in pixels.
+ */
+export function prepareCaptcha(ctx: CanvasRenderingContext2D, width: number, height: number): void {
+	const imgData = ctx.getImageData(0, 0, width, height);
+	const data = imgData.data;
+	const radius = 1;
+
+	/** Returns true when all three channels are below 50 (very dark). */
+	function isBlack(r: number, g: number, b: number): boolean {
+		return r < 50 && g < 50 && b < 50;
+	}
+
+	/** Returns true when the colour is a mid-range grey (no strong hue). */
+	function isGrayish(r: number, g: number, b: number): boolean {
+		return Math.abs(r - g) < 15 && Math.abs(g - b) < 15 && r > 100 && r < 200;
+	}
+
+	/**
+	 * Checks whether a black pixel exists within `radius` pixels of (x, y).
+	 * Used to preserve dark structures when removing grey noise.
+	 */
+	function hasNearbyBlack(x: number, y: number): boolean {
+		for (let dx = -radius; dx <= radius; dx++) {
+			for (let dy = -radius; dy <= radius; dy++) {
+				const nx = x + dx;
+				const ny = y + dy;
+				if (nx >= 0 && nx < width && ny >= 0 && ny < height) {
+					const i = (ny * width + nx) * 4;
+					if (isBlack(data[i], data[i + 1], data[i + 2])) return true;
+				}
+			}
+		}
+		return false;
+	}
+
+	for (let y = 0; y < height; y++) {
+		for (let x = 0; x < width; x++) {
+			const i = (y * width + x) * 4;
+			const [r, g, b] = [data[i], data[i + 1], data[i + 2]];
+			if (isGrayish(r, g, b) && !hasNearbyBlack(x, y)) {
+				data[i] = data[i + 1] = data[i + 2] = 255;
+			}
+		}
+	}
+	for (let y = 0; y < height; y++) {
+		for (let x = 0; x < width; x++) {
+			const i = (y * width + x) * 4;
+			const [r, g, b] = [data[i], data[i + 1], data[i + 2]];
+
+			if (isGrayish(r, g, b)) {
+				data[i] = data[i + 1] = data[i + 2] = 0; // make black
+			}
+		}
+	}
+	ctx.putImageData(imgData, 0, 0);
+}
+
+observeDOM(() => {
+	const loginFormElement = document.querySelector<HTMLFormElement>("#loginform");
+
+	if (loginFormElement) {
+		const captchaImg = loginFormElement.querySelector<HTMLImageElement>("#captchaImg");
+		const captchaInput = loginFormElement.querySelector<HTMLInputElement>("#txtInput");
+
+		if (!captchaImg || !captchaInput)
+			return false;
+
+		// Wait for image to load to get correct dimensions
+		captchaImg.addEventListener("load", function(): void {
+			const { width, height } = captchaImg;
+
+			// 1. Create canvas
+			const canvas = document.createElement("canvas");
+			canvas.width = width;
+			canvas.height = height;
+			canvas.style.display = "block";
+
+			// 2. Copy styles (optional)
+			canvas.style.cssText = getComputedStyle(captchaImg).cssText;
+			canvas.style.display = "none";
+
+			// 3. Insert canvas before image
+			captchaImg.parentNode?.querySelectorAll("canvas")
+				.forEach((c) => { c.remove(); });
+			captchaImg.parentNode?.insertBefore(canvas, captchaImg);
+
+			// 4. Hide image
+			captchaImg.style.display = "none";
+
+			// 5. Draw the image onto the canvas
+			const ctx = canvas.getContext("2d");
+			if (!ctx)
+				return;
+			ctx.drawImage(captchaImg, 0, 0);
+			prepareCaptcha(ctx, canvas.width, canvas.height);
+			canvas.style.display = "";
+			const dataURL = canvas.toDataURL("image/png");
+
+			// Perform OCR
+			chrome.runtime.sendMessage<OCRRequest, OCRResponse>(
+				{ type: "OCR", dataURL },
+				function(ocrResponse): void {
+					if (ocrResponse.success) {
+						const textResult = ocrResponse.text.trim();
+						if (ocrResponse.confidence < 80 || textResult.length !== 6)
+							// Reset the captcha if confidence is low
+							captchaImg.src = `generateCaptcha?${new Date().getTime().toString()}`;
+						else
+							captchaInput.value = textResult;
+					}
+				}
+			);
+		});
+	}
+
+	// This runs forever
+	return false;
+});
diff --git a/src/scripts/common/login/index.ts b/src/scripts/common/login/index.ts
new file mode 100644
index 0000000..95b9c5b
--- /dev/null
+++ b/src/scripts/common/login/index.ts
@@ -0,0 +1 @@
+import "@/scripts/common/login/captcha";
diff --git a/src/scripts/common/stop-blocking.ts b/src/scripts/common/stop-blocking.ts
new file mode 100644
index 0000000..8588834
--- /dev/null
+++ b/src/scripts/common/stop-blocking.ts
@@ -0,0 +1,52 @@
+/**
+ * Proxies jQuery's `.bind()` (for the `"cut copy paste"` event) and
+ * `.keydown()` so that the website's copy/paste/right-click blocking
+ * is disabled.  Reverts the prototypes after patching to avoid
+ * interfering with other code.
+ */
+
+type JQueryBindFn = (
+	eventName: string,
+	handler: (event: JQuery.Event) => unknown
+) => JQuery;
+
+type JQueryKeydownFn = (
+	handler: (event: JQuery.Event) => unknown
+) => JQuery;
+
+type JQueryPrototypeShape = {
+	bind: JQueryBindFn;
+	keydown: JQueryKeydownFn
+};
+
+const jQueryPrototype = $.prototype as unknown as JQueryPrototypeShape;
+
+document.addEventListener("DOMContentLoaded", () => {
+	const proxiedBind = jQueryPrototype.bind;
+	/** Proxies jQuery `.bind()` to no-op the `"cut copy paste"` event. */
+	jQueryPrototype.bind = function(
+		this: JQuery,
+		...args: Parameters<JQueryBindFn>
+	): JQuery {
+		const [eventName, handler] = args;
+		const noop = (): undefined => undefined;
+		return proxiedBind.call(
+			this,
+			eventName,
+			eventName.trim() === "cut copy paste" ? noop : handler
+		);
+	};
+
+	const proxiedKeydown = jQueryPrototype.keydown;
+	/** Proxies jQuery `.keydown()` so all key presses are allowed. */
+	jQueryPrototype.keydown = function(
+		this: JQuery,
+		..._args: Parameters<JQueryKeydownFn>
+	): JQuery {
+		return proxiedKeydown.call(this, () => true);
+	};
+
+	jQueryPrototype.bind = proxiedBind;
+	jQueryPrototype.keydown = proxiedKeydown;
+	document.oncontextmenu = (): boolean => true;
+});
diff --git a/src/scripts/functionality/mutation-application.ts b/src/scripts/functionality/mutation-application.ts
deleted file mode 100644
index 96aec8a..0000000
--- a/src/scripts/functionality/mutation-application.ts
+++ /dev/null
@@ -1,56 +0,0 @@
-import { PDFDocument, StandardFonts } from "pdf-lib";
-import { observeDOM } from "@/shared/observe-dom";
-
-const sanghaFacilitationCentreBannerUrl = "$l{ /assets/sangha-facilitation-centre-banner.jpg }l$";
-
-document.addEventListener("DOMContentLoaded", () => {
-	observeDOM(() => {
-		const formElement = $("#form_MutationApplication > div > div:nth-child(14) > div.col-sm-2.btreset > form");
-		const submitButtonElement = $("#btnDeclareForm");
-		if (formElement.length > 0 && submitButtonElement.length > 0) {
-			formElement.removeAttr("action");
-			submitButtonElement.click(e => {
-				e.preventDefault();
-
-				(async () => {
-					const pdfDoc = await PDFDocument.load(await fetch("/BanglarBhumi/MutationDeclarationForm.action", {
-						method: "post",
-						credentials: "same-origin",
-						headers: {
-							"Content-Type": "application/x-www-form-urlencoded"
-						},
-						body: "hdnAppNo="
-					}).then(res => res.arrayBuffer()));
-					const pages = pdfDoc.getPages();
-					const lastPage = pages[pages.length - 1];
-					const { width, height } = lastPage.getSize();
-					const bannerImage = await pdfDoc.embedJpg(await fetch(sanghaFacilitationCentreBannerUrl).then(res => res.arrayBuffer()));
-					const bannerImageHeight = width * (bannerImage.height / bannerImage.width);
-
-					lastPage.drawImage(bannerImage, {
-						x: 0,
-						y: 0,
-						width: width,
-						height: bannerImageHeight
-					});
-
-					lastPage.drawText(pdfDoc.getCreationDate()!.toLocaleString(), {
-						x: 10,
-						y: bannerImageHeight,
-						size: 12,
-						font: await pdfDoc.embedFont(StandardFonts.TimesRoman)
-					});
-
-					const link = document.createElement("a");
-					link.href = window.URL.createObjectURL(new Blob([new Uint8Array(await pdfDoc.save())], {type: "application/pdf"}));
-					link.download = "Declaration.pdf";
-					link.click();
-				})();
-			});
-
-			return true;
-		} else {
-			return false;
-		}
-	});
-});
diff --git a/src/scripts/functionality/sheet-map/index.ts b/src/scripts/functionality/sheet-map/index.ts
deleted file mode 100644
index 71228fe..0000000
--- a/src/scripts/functionality/sheet-map/index.ts
+++ /dev/null
@@ -1,160 +0,0 @@
-import { generateWebPage } from "@/shared/generate-web-page";
-import getDownloadMapPDFPageContent from "@/scripts/functionality/sheet-map/download-map-pdf-page-content.html";
-import getMapPlotPolygonPathElement from "@/scripts/functionality/sheet-map/map-plot-polygon-path-element.html";
-import getMapPlotNumberLabelTextElement from "@/scripts/functionality/sheet-map/map-plot-number-label-text-element.html";
-import getPlotInformationElement from "@/scripts/functionality/sheet-map/plot-information-element.html";
-
-interface PlotPolygon {
-	plotArea: number;
-	plotno: string;
-	polygon: string;
-};
-
-interface PlotNumberLabel {
-	plotno: string;
-	point: string;
-}
-
-const headerElement = document.querySelector("#headerTable > tbody > tr")!;
-const plotNumberInput = document.querySelector<HTMLInputElement>("#txtPlotNo")!;
-const plotInformation = document.createElement("div") as HTMLDivElement;
-let plotPolygonPathElements = "";
-let plotNumberLabelTextElements = "";
-
-document.body.appendChild(plotInformation);
-
-const createHeaderButton = (text: string) => {
-	const buttonContainer = document.createElement("td");
-	const button = document.createElement("button");
-	button.innerHTML = text;
-	button.style.display = "none";
-	buttonContainer.appendChild(button);
-	headerElement.appendChild(buttonContainer);
-	return button;
-};
-
-const setPlotInformation = (plotPolygon: PlotPolygon | null | undefined = null) => {
-	plotInformation.innerHTML = plotPolygon ? getPlotInformationElement({
-		area: (plotPolygon.plotArea/1000).toFixed(3),
-		plotNumber: plotPolygon.plotno
-	}) : getPlotInformationElement({
-		area: "0.000",
-		plotNumber: ""
-	});
-};
-
-const downloadPDF = (labelPoints: boolean = true) => {
-	const _getMapDetail = (i: number) => {
-		const detail = document.querySelector(`#headerTable > tbody > tr > td:nth-child(${i})`)!
-			.innerHTML
-			.split("[")[1]
-			.trim();
-		return detail.substr(0, detail.length - 1);
-	};
-	generateWebPage(
-		getDownloadMapPDFPageContent({
-			district: _getMapDetail(1),
-			block: _getMapDetail(2),
-			mouza: _getMapDetail(3),
-			mapContent: plotPolygonPathElements + (labelPoints ? plotNumberLabelTextElements : "")
-		}),
-		"map"
-	);
-};
-
-const downloadPDFButton = createHeaderButton("SAVE PDF");
-const downloadPDFNoLabelButton = createHeaderButton("SAVE PDF (NO LABEL)");
-
-downloadPDFButton.addEventListener("click", e => {
-	e.preventDefault();
-	downloadPDF();
-});
-
-downloadPDFNoLabelButton.addEventListener("click", e => {
-	e.preventDefault();
-	downloadPDF(false);
-});
-
-setPlotInformation();
-
-(async () => {
-	const searchParams = new URLSearchParams(window.location.search);
-	const response1 = await fetch(
-		"/BanglarBhumi/sheetMap_populateLayerData?lstSheetNo=" + searchParams.get("lstSheetNo"),
-		{
-			method: "POST"
-		});
-	const plotPolygonList: PlotPolygon[] = (await response1.json()).features;
-	const response2 = await fetch(
-		"/BanglarBhumi/sheetMap_populateCentroidData?lstSheetNo=" + searchParams.get("lstSheetNo"),
-		{
-			method: "POST"
-		});
-	const plotNumberLabelList: PlotNumberLabel[] = (await response2.json()).features;
-	let plotPolygons: { [key: string]: PlotPolygon } = {};
-
-	for (const plotPolygon of plotPolygonList) {
-		const plotPolygonPoints = plotPolygon.polygon.split("(((")[1].split(")))")[0];
-		plotPolygonPathElements += getMapPlotPolygonPathElement({
-			polygonVertices: plotPolygonPoints
-		});
-	}
-
-	for (const plotNumberLabel of plotNumberLabelList) {
-		const plotNumberLabelPoint = plotNumberLabel.point.split("(")[1].split(")")[0].split(" ");
-		plotNumberLabelTextElements += getMapPlotNumberLabelTextElement({
-			x: plotNumberLabelPoint[0],
-			y: plotNumberLabelPoint[1],
-			plotNumber: plotNumberLabel.plotno
-		});
-	}
-
-	downloadPDFButton.style.display = "inherit";
-	downloadPDFNoLabelButton.style.display = "inherit";
-
-	document.querySelector("#btnSearch")!.addEventListener("click", () => {
-		let plotPolygon;
-		for (const p of plotPolygonList) {
-			if (p.plotno === plotNumberInput.value) {
-				plotPolygon = p;
-				break;
-			}
-		}
-		setPlotInformation(plotPolygon);
-	});
-
-	await new Promise<void>((resolve, reject) => {
-		const plotElementIdsControl = setInterval(() => {
-			let i = 0;
-			let plotElements = document.querySelector("#OpenLayers_Layer_Vector_25_vroot")?.children || [];
-			if (plotElements.length) {
-				clearInterval(plotElementIdsControl);
-				for (let i = 0; i < plotElements.length; i++) {
-					plotPolygons[plotElements[i].id] = plotPolygonList[i];
-				}
-				resolve();
-			}
-		}, 50);
-	});
-
-	setInterval(() => {
-		for (const plotElementId in plotPolygons) {
-			const e = document.getElementById(plotElementId);
-			if (e) {
-				e.removeEventListener("click", handlePlotClick);
-				e.addEventListener("click", handlePlotClick);
-			}
-		}
-	}, 300);
-
-	const handlePlotClick = (e: MouseEvent) => {
-		document.querySelectorAll("path").forEach(e => {
-			e.setAttribute("fill", "#ffcc66");
-		});
-
-		const target = e.target as SVGPathElement;
-
-		target.setAttribute("fill", "#8aeeef");
-		setPlotInformation(plotPolygons[target.id]);
-	};
-})();
diff --git a/src/scripts/login/index.ts b/src/scripts/login/index.ts
deleted file mode 100644
index bed05f9..0000000
--- a/src/scripts/login/index.ts
+++ /dev/null
@@ -1,109 +0,0 @@
-import { interceptPost, interceptGet } from "@/shared/intercept-jquery-ajax";
-
-function prepareCaptcha(ctx: CanvasRenderingContext2D, width: number, height: number) {
-	const imgData = ctx.getImageData(0, 0, width, height);
-	const data = imgData.data;
-	const radius = 1;
-
-	function isBlack(r: number, g: number, b: number) {
-		return r < 50 && g < 50 && b < 50;
-	}
-
-	function isGrayish(r: number, g: number, b: number) {
-		return Math.abs(r - g) < 15 && Math.abs(g - b) < 15 && r > 100 && r < 200;
-	}
-
-	function hasNearbyBlack(x: number, y: number) {
-		for (let dx = -radius; dx <= radius; dx++) {
-			for (let dy = -radius; dy <= radius; dy++) {
-				const nx = x + dx;
-				const ny = y + dy;
-				if (nx >= 0 && nx < width && ny >= 0 && ny < height) {
-					const i = (ny * width + nx) * 4;
-					if (isBlack(data[i], data[i + 1], data[i + 2])) return true;
-				}
-			}
-		}
-		return false;
-	}
-
-	for (let y = 0; y < height; y++) {
-		for (let x = 0; x < width; x++) {
-			const i = (y * width + x) * 4;
-			const [r, g, b] = [data[i], data[i + 1], data[i + 2]];
-			if (isGrayish(r, g, b) && !hasNearbyBlack(x, y)) {
-				data[i] = data[i + 1] = data[i + 2] = 255;
-			}
-		}
-	}
-	for (let y = 0; y < height; y++) {
-		for (let x = 0; x < width; x++) {
-			const i = (y * width + x) * 4;
-			const [r, g, b] = [data[i], data[i + 1], data[i + 2]];
-
-			if (isGrayish(r, g, b)) {
-				data[i] = data[i + 1] = data[i + 2] = 0; // make black
-			}
-		}
-	}
-	ctx.putImageData(imgData, 0, 0);
-}
-
-const observer = new MutationObserver((mutationsList, obs) => {
-	for (const mutation of mutationsList) {
-		for (const node of mutation.addedNodes) {
-			if ((node as any).nodeType === 1 && (node as any).id === "loginform") {
-				const img = (node as HTMLFormElement).querySelector("#captchaImg") as HTMLImageElement;
-				const captchaInput = (node as HTMLFormElement).querySelector("#txtInput") as HTMLInputElement;
-
-				// Wait for image to load to get correct dimensions
-				img.addEventListener("load", async () => {
-					const { width, height } = img;
-
-					// 1. Create canvas
-					const canvas = document.createElement("canvas");
-					canvas.width = width;
-					canvas.height = height;
-					canvas.style.display = "block";
-
-					// 2. Copy styles (optional)
-					canvas.style.cssText = getComputedStyle(img).cssText;
-					canvas.style.display = "none";
-
-					// 3. Insert canvas before image
-					img.parentNode!.querySelectorAll("canvas").forEach(c => c.remove());
-					img.parentNode!.insertBefore(canvas, img);
-
-					// 4. Hide image
-					img.style.display = "none";
-
-					// 5. Draw the image onto the canvas
-					const ctx = canvas.getContext("2d")!;
-					ctx.drawImage(img, 0, 0);
-					prepareCaptcha(ctx, canvas.width, canvas.height);
-					canvas.style.display = "";
-					const dataURL = canvas.toDataURL("image/png");
-
-					// Perform OCR
-					chrome.runtime.sendMessage(
-						{ type: "OCR", dataURL },
-						({ success, text, confidence }) => {
-							if (success) {
-								const textResult = text.trim();
-								if (confidence < 80 || textResult.length !== 6) {
-									// Reset the captcha if confidence is low
-									img.src = "generateCaptcha?" + new Date().getTime();
-								} else {
-									captchaInput.value = textResult;
-								}
-							}
-						},
-					);
-				});
-			}
-		}
-	}
-});
-
-// Start observing the body
-observer.observe(document.body, { childList: true, subtree: true });
diff --git a/src/scripts/pages/application-receipt/captcha.ts b/src/scripts/pages/application-receipt/captcha.ts
new file mode 100644
index 0000000..94e6b0e
--- /dev/null
+++ b/src/scripts/pages/application-receipt/captcha.ts
@@ -0,0 +1,13 @@
+/**
+ * Hides the CAPTCHA section on the application-receipt page and
+ * stubs the form validation so the user can proceed without
+ * solving a CAPTCHA.
+ */
+type WindowApplicationReceipt = {
+	validateForm?: () => boolean
+} & Window;
+
+document.addEventListener("DOMContentLoaded", () => {
+	$("#werter > div > form > div:nth-child(4)").hide();
+	(window as WindowApplicationReceipt).validateForm = () => true;
+});
diff --git a/src/scripts/pages/application-receipt/index.ts b/src/scripts/pages/application-receipt/index.ts
new file mode 100644
index 0000000..5a8d0a6
--- /dev/null
+++ b/src/scripts/pages/application-receipt/index.ts
@@ -0,0 +1 @@
+import "@/scripts/pages/application-receipt/captcha";
diff --git a/src/scripts/pages/know-your-property/captcha.ts b/src/scripts/pages/know-your-property/captcha.ts
new file mode 100644
index 0000000..e304342
--- /dev/null
+++ b/src/scripts/pages/know-your-property/captcha.ts
@@ -0,0 +1,13 @@
+/**
+ * Hides the CAPTCHA section on the Know-Your-Property page and
+ * stubs the captcha validation so the user can proceed without
+ * solving a CAPTCHA.
+ */
+type WindowKnowYourProperty = {
+	validateCaptcha?: () => boolean
+} & Window;
+
+document.addEventListener("DOMContentLoaded", () => {
+	$("#khatianPlotDiv > div:nth-child(6) > div").hide();
+	(window as WindowKnowYourProperty).validateCaptcha = () => true;
+});
diff --git a/src/scripts/pages/know-your-property/index.ts b/src/scripts/pages/know-your-property/index.ts
new file mode 100644
index 0000000..d4d7f63
--- /dev/null
+++ b/src/scripts/pages/know-your-property/index.ts
@@ -0,0 +1 @@
+import "@/scripts/pages/know-your-property/captcha";
diff --git a/src/scripts/pages/mutation-application/download-button.ts b/src/scripts/pages/mutation-application/download-button.ts
new file mode 100644
index 0000000..6463079
--- /dev/null
+++ b/src/scripts/pages/mutation-application/download-button.ts
@@ -0,0 +1,63 @@
+import { PDFDocument, StandardFonts } from "pdf-lib";
+
+import { observeDOM } from "@/shared/observe-dom";
+
+const sanghaFacilitationCentreBannerUrl = "$l{ /assets/sangha-facilitation-centre-banner.jpg }l$";
+
+/**
+ * On the Mutation Application form, removes the form action (to prevent
+ * the default server-side submit) and attaches a custom click handler
+ * that fetches the declaration PDF, overlays a banner image and date
+ * stamp on the last page, then triggers a download.
+ */
+observeDOM(() => {
+	const formElement = $("#form_MutationApplication > div > div:nth-child(14) > div.col-sm-2.btreset > form");
+	const submitButtonElement = $("#btnDeclareForm");
+	if (formElement.length > 0 && submitButtonElement.length > 0) {
+		formElement.removeAttr("action");
+		submitButtonElement.on("click", (submitButtonClickEvent) => {
+			submitButtonClickEvent.preventDefault();
+
+			void (async function(): Promise<void> {
+				const pdfDoc = await PDFDocument.load(await fetch("/BanglarBhumi/MutationDeclarationForm.action", {
+					method: "post",
+					credentials: "same-origin",
+					headers: {
+						"Content-Type": "application/x-www-form-urlencoded"
+					},
+					body: "hdnAppNo="
+				}).then((res) => res.arrayBuffer()));
+				const pages = pdfDoc.getPages();
+				const lastPage = pages[pages.length - 1];
+				const { width } = lastPage.getSize();
+				const bannerImage
+					= await pdfDoc.embedJpg(await fetch(sanghaFacilitationCentreBannerUrl)
+						.then((res) => res.arrayBuffer()));
+				const bannerImageHeight = width * (bannerImage.height / bannerImage.width);
+
+				lastPage.drawImage(bannerImage, {
+					x: 0,
+					y: 0,
+					width: width,
+					height: bannerImageHeight
+				});
+
+				lastPage.drawText(pdfDoc.getCreationDate()?.toLocaleString() ?? "", {
+					x: 10,
+					y: bannerImageHeight,
+					size: 12,
+					font: await pdfDoc.embedFont(StandardFonts.TimesRoman)
+				});
+
+				const link = document.createElement("a");
+				link.href = window.URL.createObjectURL(new Blob([new Uint8Array(await pdfDoc.save())], { type: "application/pdf" }));
+				link.download = "Declaration.pdf";
+				link.click();
+			})();
+		});
+
+		return true;
+	} else {
+		return false;
+	}
+});
diff --git a/src/scripts/pages/mutation-application/index.ts b/src/scripts/pages/mutation-application/index.ts
new file mode 100644
index 0000000..93e07ad
--- /dev/null
+++ b/src/scripts/pages/mutation-application/index.ts
@@ -0,0 +1 @@
+import "@/scripts/pages/mutation-application/download-button";
diff --git a/src/scripts/functionality/sheet-map/download-map-pdf-page-content.html b/src/scripts/pages/sheet-map/download-map-pdf-page-content.html
index da765ec..da765ec 100644
--- a/src/scripts/functionality/sheet-map/download-map-pdf-page-content.html
+++ b/src/scripts/pages/sheet-map/download-map-pdf-page-content.html
diff --git a/src/scripts/pages/sheet-map/index.ts b/src/scripts/pages/sheet-map/index.ts
new file mode 100644
index 0000000..c16a2ae
--- /dev/null
+++ b/src/scripts/pages/sheet-map/index.ts
@@ -0,0 +1,197 @@
+import getDownloadMapPDFPageContent from "@/scripts/pages/sheet-map/download-map-pdf-page-content.html";
+import getMapPlotNumberLabelTextElement from "@/scripts/pages/sheet-map/map-plot-number-label-text-element.html";
+import getMapPlotPolygonPathElement from "@/scripts/pages/sheet-map/map-plot-polygon-path-element.html";
+import getPlotInformationElement from "@/scripts/pages/sheet-map/plot-information-element.html";
+import { generateWebPage } from "@/shared/generate-web-page";
+
+type PlotPolygon = {
+	plotArea: number;
+	plotno: string;
+	polygon: string
+};
+
+type PlotNumberLabel = {
+	plotno: string;
+	point: string
+};
+
+const headerElement = document.querySelector<HTMLTableRowElement>("#headerTable > tbody > tr");
+const plotNumberInput = document.querySelector<HTMLInputElement>("#txtPlotNo");
+const plotInformation = document.createElement("div");
+let plotPolygonPathElements = "";
+let plotNumberLabelTextElements = "";
+
+document.body.appendChild(plotInformation);
+
+/**
+ * Creates a header toolbar button and appends it to the page header.
+ * The button starts hidden and is shown when data is ready.
+ *
+ * @param text - The button label text.
+ * @returns The created button element.
+ */
+function createHeaderButton(text: string): HTMLButtonElement {
+	const buttonContainer = document.createElement("td");
+	const button = document.createElement("button");
+	button.innerHTML = text;
+	button.style.display = "none";
+	buttonContainer.appendChild(button);
+	if (headerElement)
+		headerElement.appendChild(buttonContainer);
+	return button;
+};
+
+/**
+ * Displays the area and plot number for the given polygon in a floating
+ * info panel, or shows "0.000" / empty if no polygon is selected.
+ *
+ * @param plotPolygon - The selected plot's data, or `null`/`undefined` to clear.
+ */
+function setPlotInformation(plotPolygon: PlotPolygon | null | undefined = null): void {
+	plotInformation.innerHTML = plotPolygon
+		? getPlotInformationElement({
+			area: (plotPolygon.plotArea / 1000).toFixed(3),
+			plotNumber: plotPolygon.plotno
+		})
+		: getPlotInformationElement({
+			area: "0.000",
+			plotNumber: ""
+		});
+};
+
+/**
+ * Opens a new window with a printable PDF view of the map, optionally
+ * including plot-number labels.
+ *
+ * @param labelPoints - Whether to include plot number text labels.
+ */
+function downloadPDF(labelPoints = true): void {
+	/** Extracts a detail value (district/block/mouza) from the header table by column index. */
+	function _getMapDetail(i: number): string {
+		const detail = (document.querySelector<HTMLTableCellElement>(`#headerTable > tbody > tr > td:nth-child(${i.toString()})`)?.innerHTML ?? "")
+			.split("[")[1]
+			.trim();
+		return detail.substring(0, detail.length - 1);
+	};
+	generateWebPage(
+		getDownloadMapPDFPageContent({
+			district: _getMapDetail(1),
+			block: _getMapDetail(2),
+			mouza: _getMapDetail(3),
+			mapContent: plotPolygonPathElements + (labelPoints ? plotNumberLabelTextElements : "")
+		}),
+		"map"
+	);
+};
+
+const downloadPDFButton = createHeaderButton("SAVE PDF");
+const downloadPDFNoLabelButton = createHeaderButton("SAVE PDF (NO LABEL)");
+
+downloadPDFButton.addEventListener("click", (e) => {
+	e.preventDefault();
+	downloadPDF();
+});
+
+downloadPDFNoLabelButton.addEventListener("click", (e) => {
+	e.preventDefault();
+	downloadPDF(false);
+});
+
+setPlotInformation();
+
+void (async function(): Promise<void> {
+	const searchParams = new URLSearchParams(window.location.search);
+	const sheetMapLayerDataResponse = await fetch(
+		`/BanglarBhumi/sheetMap_populateLayerData?lstSheetNo=${searchParams.get("lstSheetNo")?.toString() ?? ""}`,
+		{
+			method: "POST"
+		});
+	type SheetMapLayerDataResponseType = {
+		features: PlotPolygon[]
+	};
+	const sheetMapLayerDataResponseJson
+		=	await sheetMapLayerDataResponse.json() as SheetMapLayerDataResponseType;
+	const plotPolygonList: PlotPolygon[] = sheetMapLayerDataResponseJson.features;
+	const sheetMapCentroidDataResponse = await fetch(
+		`/BanglarBhumi/sheetMap_populateCentroidData?lstSheetNo=${searchParams.get("lstSheetNo")?.toString() ?? ""}`,
+		{
+			method: "POST"
+		});
+	type SheetMapCentroidDataResponseType = {
+		features: PlotNumberLabel[]
+	};
+	const sheetMapCentroidDataResponseJson
+		= await sheetMapCentroidDataResponse.json() as SheetMapCentroidDataResponseType;
+	const plotNumberLabelList: PlotNumberLabel[] = sheetMapCentroidDataResponseJson.features;
+	const plotPolygons: Record<string, PlotPolygon> = {};
+
+	for (const plotPolygon of plotPolygonList) {
+		const plotPolygonPoints = plotPolygon.polygon.split("(((")[1].split(")))")[0];
+		plotPolygonPathElements += getMapPlotPolygonPathElement({
+			polygonVertices: plotPolygonPoints
+		});
+	}
+
+	for (const plotNumberLabel of plotNumberLabelList) {
+		const plotNumberLabelPoint = plotNumberLabel.point.split("(")[1].split(")")[0].split(" ");
+		plotNumberLabelTextElements += getMapPlotNumberLabelTextElement({
+			x: plotNumberLabelPoint[0],
+			y: plotNumberLabelPoint[1],
+			plotNumber: plotNumberLabel.plotno
+		});
+	}
+
+	downloadPDFButton.style.display = "inherit";
+	downloadPDFNoLabelButton.style.display = "inherit";
+
+	document.querySelector<HTMLButtonElement>("#btnSearch")?.addEventListener("click", () => {
+		let plotPolygon;
+		for (const p of plotPolygonList) {
+			if (p.plotno === plotNumberInput?.value) {
+				plotPolygon = p;
+				break;
+			}
+		}
+		setPlotInformation(plotPolygon);
+	});
+
+	await new Promise<void>((resolve, _reject) => {
+		const plotElementIdsControl = setInterval(() => {
+			const plotElements = document.querySelector("#OpenLayers_Layer_Vector_25_vroot")?.children ?? [];
+			if (plotElements.length) {
+				clearInterval(plotElementIdsControl);
+				for (let i = 0; i < plotElements.length; i++) {
+					plotPolygons[plotElements[i].id] = plotPolygonList[i];
+				}
+				resolve();
+			}
+		}, 50);
+	});
+
+	setInterval(() => {
+		for (const plotElementId in plotPolygons) {
+			const e = document.getElementById(plotElementId);
+			if (e) {
+				e.removeEventListener("click", handlePlotClick);
+				e.addEventListener("click", handlePlotClick);
+			}
+		}
+	}, 300);
+
+	/**
+	 * Highlights the clicked plot on the SVG map and shows its
+	 * information in the info panel.
+	 *
+	 * @param e - The mouse click event.
+	 */
+	function handlePlotClick(e: MouseEvent): void {
+		document.querySelectorAll("path").forEach((e) => {
+			e.setAttribute("fill", "#ffcc66");
+		});
+
+		const target = e.target as SVGPathElement;
+
+		target.setAttribute("fill", "#8aeeef");
+		setPlotInformation(plotPolygons[target.id]);
+	};
+})();
diff --git a/src/scripts/functionality/sheet-map/map-plot-number-label-text-element.html b/src/scripts/pages/sheet-map/map-plot-number-label-text-element.html
index d220367..d220367 100644
--- a/src/scripts/functionality/sheet-map/map-plot-number-label-text-element.html
+++ b/src/scripts/pages/sheet-map/map-plot-number-label-text-element.html
diff --git a/src/scripts/functionality/sheet-map/map-plot-polygon-path-element.html b/src/scripts/pages/sheet-map/map-plot-polygon-path-element.html
index d4d38a6..d4d38a6 100644
--- a/src/scripts/functionality/sheet-map/map-plot-polygon-path-element.html
+++ b/src/scripts/pages/sheet-map/map-plot-polygon-path-element.html
diff --git a/src/scripts/functionality/sheet-map/plot-information-element.html b/src/scripts/pages/sheet-map/plot-information-element.html
index fd740a8..fd740a8 100644
--- a/src/scripts/functionality/sheet-map/plot-information-element.html
+++ b/src/scripts/pages/sheet-map/plot-information-element.html
diff --git a/src/scripts/functionality/view-khatian/download-information-pdf-page-content.html b/src/scripts/pages/view-khatian/download-information-pdf-page-content.html
index 129608e..129608e 100644
--- a/src/scripts/functionality/view-khatian/download-information-pdf-page-content.html
+++ b/src/scripts/pages/view-khatian/download-information-pdf-page-content.html
diff --git a/src/scripts/functionality/view-khatian/index.ts b/src/scripts/pages/view-khatian/index.ts
index 93d03cf..bb44a38 100644
--- a/src/scripts/functionality/view-khatian/index.ts
+++ b/src/scripts/pages/view-khatian/index.ts
@@ -1,6 +1,6 @@
+import getDownloadInformationPDFPageContent from "@/scripts/pages/view-khatian/download-information-pdf-page-content.html";
 import { generateWebPage } from "@/shared/generate-web-page";
-import { interceptPost } from "@/shared/intercept-jquery-ajax";
-import getDownloadInformationPDFPageContent from "@/scripts/functionality/view-khatian/download-information-pdf-page-content.html";
+import { addPostInterceptor, JQueryAjaxArgs } from "@/shared/intercept-jquery-ajax";
 
 const submitButtonElement = $("#khbutton");
 const separatorElement = $("#bodycover > div > form > hr:nth-child(2)");
@@ -14,18 +14,28 @@ const styles = Array.from(submitButtonElementComputedStyles)
 		""
 	);
 
-const getValueOfSelectElement = (selector: string) => {
-	const element = document.querySelector<HTMLSelectElement>(selector)!;
-	return element.options[element.selectedIndex].text;
+/**
+ * Reads the currently selected text from a `<select>` element.
+ *
+ * @param selector - CSS selector for the select element.
+ * @returns The text of the selected option.
+ */
+function getValueOfSelectElement(selector: string): string {
+	const element = document.querySelector<HTMLSelectElement>(selector);
+	return element?.options[element.selectedIndex].text ?? "";
 };
 
 let isPlotInformation: boolean | null = null;
 
-const downloadInformationPDF = () => {
+/**
+ * Opens a new window with a printable PDF view of the current khatian
+ * or plot details, including district/block/mouza info.
+ */
+function downloadInformationPDF(): void {
 	generateWebPage(
 		getDownloadInformationPDFPageContent({
 			isPlotInformation: !!isPlotInformation,
-			details: $(isPlotInformation ? "#plotdetails" : "#khdetails").html(),
+			details: $(isPlotInformation ? "#plotdetails" : "#khdetails").html() || "",
 			district: getValueOfSelectElement("#lstDistrictCode1"),
 			block: getValueOfSelectElement("#lstBlockCode1"),
 			mouza: getValueOfSelectElement("#lstMouzaList")
@@ -36,11 +46,18 @@ const downloadInformationPDF = () => {
 	);
 };
 
-const showDownloadButton = (args: any) => {
+/**
+ * Intercepts the success callback of a jQuery AJAX call.  When a valid
+ * details table is returned, it inserts a "Download PDF" button;
+ * otherwise it removes an existing button.
+ *
+ * @param args - The `arguments` object from the intercepted `$.post` call.
+ */
+function showDownloadButton(args: JQueryAjaxArgs): void {
 	if (isPlotInformation !== null) {
 		const callback = args[2];
-		args[2] = (data: any) => {
-			callback(data);
+		args[2] = (...data) => {
+			callback(...data);
 			const tableElement = $(isPlotInformation
 				? "#plotdetails > div:nth-child(1) > div:nth-child(4) > table > tbody"
 				: "#khdetails > table > tbody > tr > td:nth-child(1) > div:nth-child(5) > table > tbody"
@@ -56,23 +73,23 @@ const showDownloadButton = (args: any) => {
 					downloadPDFButton[0].style.cssText = styles;
 					downloadPDFButton.css("width", "auto");
 					downloadPDFButton.css("margin-bottom", "1rem");
-					downloadPDFButton.click(downloadInformationPDF);
+					downloadPDFButton.on("click", downloadInformationPDF);
 					formElement[0].insertBefore(downloadPDFButton[0], separatorElement[0]);
 				}
 			} else if (downloadPDFButton) {
-				($(downloadPDFButton as any) as any).remove();
+				($(downloadPDFButton)).remove();
 				isPlotInformation = null;
 				downloadPDFButton = null;
 			}
-		}
+		};
 	}
 };
 
-interceptPost("plotDetailsAction_LandInfo.action", args => {
+addPostInterceptor("plotDetailsAction_LandInfo.action", (args: JQueryAjaxArgs) => {
 	isPlotInformation = true;
 	showDownloadButton(args);
 });
-interceptPost("khDetailsAction_LandInfo.action", args => {
+addPostInterceptor("khDetailsAction_LandInfo.action", (args: JQueryAjaxArgs) => {
 	isPlotInformation = false;
 	showDownloadButton(args);
 });
diff --git a/src/scripts/stop-blocking.ts b/src/scripts/stop-blocking.ts
deleted file mode 100644
index b8f4783..0000000
--- a/src/scripts/stop-blocking.ts
+++ /dev/null
@@ -1,21 +0,0 @@
-document.addEventListener("DOMContentLoaded", () => {
-	const proxiedBind = $.prototype.bind;
-	$.prototype.bind = function() {
-		if (arguments[0].trim() === "cut copy paste") {
-			arguments[1] = (_: any) => {};
-		}
-
-		return proxiedBind.apply(this, Array.from(arguments) as any);
-	}
-
-	const proxiedKeydown = $.prototype.keydown;
-	$.prototype.keydown = function() {
-		arguments[0] = (_: any) => true;
-
-		return proxiedKeydown.apply(this, Array.from(arguments) as any);
-	}
-
-	$.prototype.bind = proxiedBind;
-	$.prototype.keydown = proxiedKeydown;
-	document.oncontextmenu = () => true;
-});