node/.gitignore

@@ -2,3 +2,4 @@ node_modules/
 .DS_Store
 hits.db
 hits.db-*
+example_counter_bg.png

node/src/hit-counter.ts

@@ -1,10 +1,10 @@
-import e, { Request, Response, NextFunction } from 'express';
 import { type Database as DB } from 'better-sqlite3';
 import { type Statement } from 'better-sqlite3';
 import Database from 'better-sqlite3';
 // import sharp for images
-import sharp, { FormatEnum, AvailableFormatInfo, Sharp } from 'sharp';
+import sharp, { FormatEnum, AvailableFormatInfo, Sharp, Metadata } from 'sharp';
 import * as fs from 'fs';
+import * as https from 'https';
 
 // Map file extensions to sharp formats
 const imageFormatMap: { [key: string]: keyof FormatEnum | AvailableFormatInfo } = {
@@ -16,6 +16,16 @@ const imageFormatMap: { [key: string]: keyof FormatEnum | AvailableFormatInfo }
     gif: 'gif'
 };
 
+// no need for third party library
+const mimeTypeMap: { [key: string]: string } = {
+    jpg: 'image/jpeg',
+    jpeg: 'image/jpeg',
+    png: 'image/png',
+    webp: 'image/webp',
+    tiff: 'image/tiff',
+    gif: 'image/gif'
+};
+
 interface HitResult {
     hits: number;
 }
@@ -33,6 +43,50 @@ interface HitCounterRenderer {
     render(): Promise<any>;
 }
 
+function fileExt(file: string): string {    
+    const fileExt = file.split('.').pop();
+    if (!fileExt) {
+        throw new Error('Invalid file extension');
+    }
+    return fileExt.toLowerCase();
+}
+
+
+function extToFormat(ext: string): keyof FormatEnum | AvailableFormatInfo {
+    const format = imageFormatMap[ext];
+    if (!format) {
+        throw new Error('Unsupported file extension');
+    }
+    return format;
+}
+
+/**
+ * Determine whether the given `path` is a http(s) URL. This method
+ * accepts a string value and a URL instance.
+ * 
+ * inspiration:
+ * Marcus Pöhls
+ * https://futurestud.io/tutorials/node-js-check-if-a-path-is-a-file-url
+ *
+ * @param {String|URL} path
+ *
+ * @returns {Boolean}
+ */
+function isWebURI(path) {  
+    // `path` is neither a string nor a URL -> early return
+    if (typeof path !== 'string' && !(path instanceof URL)) {
+        return false
+    }
+  
+    try {
+        const url = new URL(path)
+  
+        return url.protocol === 'http:' || url.protocol === 'https:'
+    } catch (error) {
+        return false
+    }
+}
+
 class BaseHitCounterRenderer implements HitCounterRenderer {
     protected counter: HitCounter;
     protected config: HitCounterConfig;
@@ -53,17 +107,31 @@ class BaseHitCounterRenderer implements HitCounterRenderer {
 class ImageHitCounterRenderer extends BaseHitCounterRenderer {
     private imageType: string;
     private imageFormat: keyof FormatEnum | AvailableFormatInfo;
+    private baseImage: Buffer;
+    private baseImageMetadata: Metadata;
     constructor(counter: HitCounter, config: HitCounterConfig) {
         super(counter, config);
-        const fileExt = this.config.imageFile.split('.').pop();
-        if (!fileExt) {
-            throw new Error('Invalid file extension');
-        }
-        this.imageType = fileExt;
-        this.imageFormat = imageFormatMap[fileExt.toLowerCase()];
-        if (!this.imageFormat) {
-            throw new Error('Unsupported file extension');
+        this.imageType = fileExt(this.config.imageFile);
+        this.imageFormat = extToFormat(this.imageType);
     }
+
+    private async downloadImage(): Promise<Buffer> {
+        return new Promise((resolve, reject) => {
+            let buf = Buffer.alloc(0);
+            const request = https.get(this.config.backgroundImageUrl, (response) => {
+                response.on('data', (chunk) => {
+                    buf = Buffer.concat([buf, chunk]);
+                });
+                response.on('end', () => {
+                    resolve(buf);
+                });
+            });
+            request.on('error', (err) => {
+                fs.unlink(this.config.backgroundCacheFile, () => {
+                    reject(err);
+                });
+            });
+        });
     }
 
     private async cachedBackgroundImage(overWrite: boolean = false): Promise<Sharp> {
@@ -78,71 +146,91 @@ class ImageHitCounterRenderer extends BaseHitCounterRenderer {
         }
         
         // store the image in the cache
-        const fileExt = dest.split('.').pop();
-        if (!fileExt) {
-            throw new Error('Invalid file extension');
-        }
-        
-        const format = imageFormatMap[fileExt.toLowerCase()];
-        if (!format) {
-            throw new Error('Unsupported file extension');
-        }
+        const ext = fileExt(this.config.backgroundImageUrl);
         
+        const format = extToFormat(ext);
+        if (isWebURI(this.config.backgroundImageUrl)) {
+            const buf = await this.downloadImage();
+            const image = sharp(buf).toFormat(format);
+            await image.toFile(dest);
+            return image;
+        } else {
+            if (fs.existsSync(this.config.backgroundImageUrl)) {
                 const image = sharp(this.config.backgroundImageUrl).toFormat(format);
                 await image.toFile(dest);
                 return image;
+            } else {
+                throw new Error('Background image does not exist');
+            }
+        }
     }
 
-
-
-    async render(): Promise<Sharp> {
-        const hits = await this.counter.getHits();
+    async prepareBaseImage(): Promise<void> {
+        if (typeof this.baseImage !== 'undefined') {
+            return;
+        }
         const bgImage = await this.cachedBackgroundImage();
         const bgInfo = await bgImage.metadata();
-
-        const text = this.config.customText;
-        const secondaryText = this.config.secondaryText;
-        const textColor = this.config.textColorRGB;
-        const secondaryTextColor = this.config.secondaryTextColorRGB;
-        const numberColor = this.config.numberColorRGB;
-        const frameColor = this.config.frameColorRGB;
-        const drawFrame = this.config.drawFrame;
-        const textX = this.config.textPositionX;
-        const textY = this.config.textPositionY;
-        const numberX = this.config.numberPositionX;
-        const numberY = this.config.numberPositionY;
+        const imgWidth = bgInfo.width;
+        const imgHeight = bgInfo.height;
+        if (typeof imgWidth === 'undefined' || typeof imgHeight === 'undefined') {
+            throw new Error('Invalid image dimensions');
+        }
 
         const svgFrame = `
             <svg width="${bgInfo.width}" height="${bgInfo.height}" xmlns="http://www.w3.org/2000/svg">
-                <rect x="0" y="0" width="${bgInfo.width}" height="${bgInfo.height}" stroke="rgb(${frameColor.r},${frameColor.g},${frameColor.b})" stroke-width="2" fill="none"/>
+                <rect x="${this.config.borderWidth}" y="${this.config.borderWidth}" width="${imgWidth - 2 * this.config.borderWidth}" height="${imgHeight - 2 * this.config.borderWidth}" fill="none" stroke-alignment="inner" stroke="rgb(${this.config.frameColorRGB.r},${this.config.frameColorRGB.g},${this.config.frameColorRGB.b})" stroke-width="${this.config.borderWidth}"/>
             </svg>
         `;
         
         const svgOverlay = `
             <svg width="${bgInfo.width}" height="${bgInfo.height}" xmlns="http://www.w3.org/2000/svg">
-                <text x="${textX}" y="${textY}" fill="rgb(${textColor.r},${textColor.g},${textColor.b})" font-size="12">${text}</text>
-                <text x="${textX}" y="${textY + 15}" fill="rgb(${secondaryTextColor.r},${secondaryTextColor.g},${secondaryTextColor.b})" font-size="12">${secondaryText}</text>
-                <text x="${numberX}" y="${numberY}" fill="rgb(${numberColor.r},${numberColor.g},${numberColor.b})" font-size="12">${hits}</text>
+                <text x="${this.config.textPositionX}" y="${this.config.textPositionY}" fill="rgb(${this.config.textColorRGB.r},${this.config.textColorRGB.g},${this.config.textColorRGB.b})" font-size="${this.config.fontSize}" font-family="${this.config.fontFace}">${this.config.customText}</text>
+                <text x="${this.config.textPositionX}" y="${this.config.textPositionY + 15}" fill="rgb(${this.config.textColorRGB.r},${this.config.textColorRGB.g},${this.config.textColorRGB.b})" font-size="${this.config.fontSize}" font-family="${this.config.fontFace}">${this.config.secondaryText}</text>
             </svg>
         `;
 
-
-
         const overlay = sharp(Buffer.from(svgOverlay));
-        if (drawFrame) {
+
+        if (this.config.drawFrame) {
             const frame = sharp(Buffer.from(svgFrame));
             const composite = bgImage.composite([
                 { input: await overlay.toBuffer(), gravity: 'northwest' },
                 { input: await frame.toBuffer(), gravity: 'northwest' }
             ]);
-            return composite;
+            const preparedImg = composite.toFormat(this.imageFormat);
+            this.baseImageMetadata = await preparedImg.metadata();
+            this.baseImage = await preparedImg.toBuffer();;
         }
 
         const composite = bgImage.composite([
             { input: await overlay.toBuffer(), gravity: 'northwest' }
         ]);
 
-        return composite;
+        const preparedImg = composite.toFormat(this.imageFormat);
+        this.baseImageMetadata = await preparedImg.metadata();
+        this.baseImage = await preparedImg.toBuffer();
+
+    }
+
+    async render(): Promise<Buffer> {
+        const hits = await this.counter.getHits();
+        
+        const numberColor = this.config.numberColorRGB;
+        const numberX = this.config.numberPositionX;
+        const numberY = this.config.numberPositionY;
+
+        await this.prepareBaseImage();
+        const overlay = `
+            <svg width="${this.baseImageMetadata.width}" height="${this.baseImageMetadata.height}" xmlns="http://www.w3.org/2000/svg">
+                <text x="${numberX}" y="${numberY}" fill="rgb(${numberColor.r},${numberColor.g},${numberColor.b})" font-size="12">${hits}</text>
+            </svg>
+        `;
+        const composite = sharp(this.baseImage).composite([
+            { input: Buffer.from(overlay), gravity: 'northwest' }
+        ]);
+        return composite.toBuffer();
+        
     }
 }
 
@@ -163,6 +251,9 @@ interface HitCounterConfig {
     textPositionY: number; // Y position of the text
     numberPositionX: number; // X position of the number
     numberPositionY: number; // Y position of the number
+    fontSize: number; // Font size
+    fontFace: string; // Font face
+    borderWidth: number; // Border width
     textColorRGB: RGBColor; // Text color
     secondaryTextColorRGB: RGBColor; // Secondary text color
     numberColorRGB: RGBColor; // Number color
@@ -184,12 +275,15 @@ const defaultHitCounterConfig: HitCounterConfig = {
     secondaryText: 'Super cyber, super cool!',
     textPositionX: 5,
     textPositionY: 5,
-    numberPositionX: 5,
+    numberPositionX: 160,
     numberPositionY: 15,
+    fontSize: 12,
+    fontFace: 'Arial',
+    borderWidth: 3,
     textColorRGB: { r: 253, g: 252, b: 1 },
     secondaryTextColorRGB: { r: 0, g: 255, b: 0 },
     numberColorRGB: { r: 255, g: 255, b: 255 },
-    frameColorRGB: { r: 255, g: 238, b: 0 },
+    frameColorRGB: { r: 255, g: 0, b: 0 },
     drawFrame: true,
     renderer: ImageHitCounterRenderer
 };
@@ -201,6 +295,7 @@ class HitCounter {
     private preparedGet: Statement;
     private preparedIncrement: Statement;
     private preparedReset: Statement;
+    private mimeType: string;
 
     constructor(renderer: Type<BaseHitCounterRenderer>, config?: HitCounterConfig) {
         this.config = { ...defaultHitCounterConfig, ...config };
@@ -208,6 +303,7 @@ class HitCounter {
         this.openDB();
         this.setupDB();
         this.setupStatements();
+        this.mimeType = mimeTypeMap[fileExt(this.config.imageFile)];
     }
 
     private openDB(): void {
@@ -266,6 +362,14 @@ class HitCounter {
         this.preparedReset.run(this.config.siteId);
     }
 
+    async render(): Promise<any> {
+        return this.renderer.render();
+    }
+
+    getMimeType(): string {
+        return this.mimeType;
+    }
+
     // destructor
     destroy(): void {
         this.closeDB();

node/src/index.ts

@@ -4,10 +4,12 @@ import { HitCounter, ImageHitCounterRenderer } from "./hit-counter";
 const app: Express = express();
 const PORT: number = 8000;
 const hitCounter = new HitCounter(ImageHitCounterRenderer);
+const imageMimeType = hitCounter.getMimeType();
 
 app.get("/", (req: Request, res: Response) => {
-  res.send("Hello World!");
     hitCounter.increment();
+    res.send("Hello dear interlocutor! Your visit has been noted.");
+  
 });
 
 app.get("/hits", async (req: Request, res: Response) => {
@@ -15,7 +17,16 @@ app.get("/hits", async (req: Request, res: Response) => {
     res.send(`This site has ${hits} hits!`);
 });
 
+app.get("/reset", async (req: Request, res: Response) => {
+    await hitCounter.reset();
+    res.send("Hit counter has been reset!");
+});
 
+app.get("/image", async (req: Request, res: Response) => {
+    const image = await hitCounter.render();
+    res.setHeader("Content-Type", imageMimeType);
+    res.send(image);
+});
 
 app.listen(PORT, () => {
     console.log(`[server]: Express server started on port ${PORT}`);