Add new ParseQRCode operation

src/core/config/Categories.json

@@ -352,6 +352,7 @@
             "Generate TOTP",
             "Generate HOTP",
             "Generate QR Code",
+            "Parse QR Code",
             "Haversine distance",
             "Render Image",
             "Remove EXIF",

src/core/operations/ParseQRCode.mjs

@@ -0,0 +1,82 @@
+/**
+ * @author j433866 [j433866@gmail.com]
+ * @copyright Crown Copyright 2018
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import OperationError from "../errors/OperationError";
+import Magic from "../lib/Magic";
+import jsqr from "jsqr";
+import jimp from "jimp";
+
+/**
+ * Parse QR Code operation
+ */
+class ParseQRCode extends Operation {
+
+    /**
+     * ParseQRCode constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Parse QR Code";
+        this.module = "Image";
+        this.description = "Reads an image file and attempts to detect and read a QR code from the image.";
+        this.infoURL = "https://wikipedia.org/wiki/QR_code";
+        this.inputType = "byteArray";
+        this.outputType = "string";
+        this.args = [];
+    }
+
+    /**
+     * @param {byteArray} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    async run(input, args) {
+        const type = Magic.magicFileType(input);
+        // Make sure that the input is an image
+        if (type && type.mime.indexOf("image") === 0){
+
+            return new Promise((resolve, reject) => {
+                // Read the input
+                jimp.read(Buffer.from(input))
+                    .then(image => {
+                        image.rgba(false); // Disable RGBA (uses just RGB)
+
+                        // Get the buffer of the new image and read it in Jimp
+                        // Don't actually need the new image buffer, just need 
+                        // Jimp to refresh the current object
+                        image.getBuffer(image.getMIME(), (err, buffer) => {
+                            jimp.read(buffer)
+                                .then(newImage =>{
+                                    // If the image has been read correctly, try to find a QR code
+                                    if (image.bitmap != null){
+                                        const qrData = jsqr(image.bitmap.data, image.getWidth(), image.getHeight());
+                                        if (qrData != null) {
+                                            resolve(qrData.data);
+                                        } else {
+                                            log.error(image.bitmap);
+                                            reject(new OperationError("Error parsing QR code from image."));
+                                        }
+                                    } else {
+                                        reject(new OperationError("Error reading the image data."));
+                                    }
+                                });
+                        });
+                    })
+                    .catch(err => {
+                        reject(new OperationError("Error opening the image. Are you sure this is an image file?"));
+                    });
+            });
+        }  else {
+            throw new OperationError("Invalid file type.");
+        }
+
+    }
+
+}
+
+export default ParseQRCode;