refactor code

routes.js

@@ -28,6 +28,32 @@ const get_size = (ratio, dpi, txtlen, padding) => {
     }
 }
 
+const createImage = async (width, height, bg = 'white', options = {}) => {
+    return sharp({
+        create: {
+            width: width,
+            height: height,
+            channels: 3,
+            background: bg,
+            ...options
+        }
+    })
+}
+const drawText = (pic, text, dpi, blend, options = {}) => {
+    return pic.composite([{
+        input: {
+            text: {
+                text,
+                font: 'Open Sans',
+                dpi,
+                rgba: true,
+                ...options
+            }
+        },
+        blend
+    }])
+}
+
 /** @param {import('fastify').FastifyInstance} fastify */
 module.exports = (fastify) => {
     fastify.get('/captcha/v1/:text', async (req, res) => {
@@ -40,34 +66,13 @@ module.exports = (fastify) => {
         console.log(size)
         console.log(settings)
 
-        let pic = (await sharp({
-            create: {
-                width: size.width,
-                height: size.height,
-                channels: 4,
-                background: { r: 0, g: 0, b: 0, alpha: 0 }
-            }
-        }));
+        let pic = await createImage(size.width, size.height);
 
-
-        pic.composite([
-            {
-                input: {
-                    text: {
-                        text: text,
-                        font: 'Arial',
-                        dpi: settings.dpi,
-                        rgba: true
-                    }
-                },
-                blend: 'over',
-                gravity: 0
-            }
-        ]);
+        drawText(pic, text, settings.dpi, 'over');
 
         const textpic = await pic
             .ensureAlpha()
-            .toFormat('png', { compressionLevel: 6 })
+            .toFormat('png', { compressionLevel: 0 })
             .toBuffer();
 
         const draw = canvas.createCanvas(size.width, size.height);
@@ -75,16 +80,13 @@ module.exports = (fastify) => {
         ctx.drawImage(await canvas.loadImage(textpic), 0, 0, size.width, size.height);
 
         const strokes = randint(25, 40);
-        for (let i = 0; i != strokes; i++) {
+        for (let i = 0; i < strokes; i++) {
             ctx.strokeStyle = `rgba(0,0,0,${10})`;
             ctx.beginPath();
             ctx.bezierCurveTo(randint(0, size.width), randint(0, size.height), randint(0, size.width), randint(0, size.height), randint(0, size.width), randint(0, size.height));
             ctx.stroke();
         }
 
-        ctx.bezierCurveTo(20, 20, 20, 30, 70, 25);
-        ctx.stroke();
-
         res.header('Content-Type', 'png');
         return draw.toBuffer();
     })