From 8166f981ae7b6ef6644b8c9fe7ed652d1ea75c59 Mon Sep 17 00:00:00 2001
From: mshwed <m@ttshwed.com>
Date: Tue, 27 Aug 2019 11:41:16 -0400
Subject: [PATCH] in progress

---
 src/core/operations/MIMEDecoding.mjs | 129 +++++++++++++++++++++++++++
 1 file changed, 129 insertions(+)
 create mode 100644 src/core/operations/MIMEDecoding.mjs

diff --git a/src/core/operations/MIMEDecoding.mjs b/src/core/operations/MIMEDecoding.mjs
new file mode 100644
index 00000000..fb36326f
--- /dev/null
+++ b/src/core/operations/MIMEDecoding.mjs
@@ -0,0 +1,129 @@
+/**
+ * @author mshwed [m@ttshwed.com]
+ * @copyright Crown Copyright 2019
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import OperationError from "../errors/OperationError";
+import Utils from "../Utils";
+import { fromBase64 } from "../lib/Base64";
+
+/**
+ * MIME Decoding operation
+ */
+class MIMEDecoding extends Operation {
+
+    /**
+     * MIMEDecoding constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "MIME Decoding";
+        this.module = "Default";
+        this.description = "";
+        this.infoURL = "";
+        this.inputType = "byteArray";
+        this.outputType = "string";
+        this.args = [
+            /* Example arguments. See the project wiki for full details.
+            {
+                name: "First arg",
+                type: "string",
+                value: "Don't Panic"
+            },
+            {
+                name: "Second arg",
+                type: "number",
+                value: 42
+            }
+            */
+        ];
+    }
+
+    /**
+     * @param {byteArray} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+
+        let mimeEncodedText = Utils.byteArrayToUtf8(input)
+
+        // const encodedWordRegex = /(\=\?)(.*?)(\?\=)/g;
+
+        // let encodedWords = mimeEncodedText.match(encodedWordRegex);
+
+        let parsedString = "";
+        let currentPos = 0;
+        let pastPosition = 0;
+        while (currentPos >= 0) {
+            
+            // Find starting text
+            currentPos = mimeEncodedText.indexOf("=?", pastPosition);
+            console.log('CURRENT POSITION', currentPos);
+            if (currentPos < 0) break;
+
+            // Add existing unparsed string
+            let fillerText = mimeEncodedText.substring(pastPosition, currentPos);
+            console.log("PROCESSING RANGE", pastPosition, ' ' ,currentPos)
+            console.log('FILLER TEXT: ', fillerText);
+            if (fillerText.indexOf('\r') > 0) console.log('CR detected', fillerText.indexOf('\r'));
+            if (fillerText.indexOf('\n') > 0) console.log('LF detected', fillerText.indexOf('\n'));
+            if (fillerText.indexOf('\r\n') > 0) console.log('CRLF detected', fillerText.indexOf('\r\n'));
+            if (fillerText.indexOf('\x20') > 0) console.log('SPACE detected', fillerText.indexOf('\x20'));
+            
+            if (fillerText !== '\r\n')
+                parsedString += fillerText
+
+            pastPosition = currentPos;
+
+            // find ending text
+            currentPos = mimeEncodedText.indexOf("?=", pastPosition);
+
+            // Process block
+            let encodedTextBlock = mimeEncodedText.substring(pastPosition + 2, currentPos);
+            pastPosition = currentPos + 2;
+
+            parsedString += this.parseEncodedWord(encodedTextBlock);
+        }
+
+        return parsedString;
+        // let cleansedWord;
+        // for (let word of encodedWords) {
+        //     cleansedWord = word.replace('=?', '').replace('?=', '').split('?');
+        //     let charset = cleansedWord[0];
+        //     let encoding = cleansedWord[1];
+        //     let encodedText = cleansedWord[2];
+
+        //     if (encoding.toLowerCase() === 'b') {
+        //         encodedText = fromBase64(encodedText);
+        //     }
+
+        //     console.log(cleansedWord);
+        // }
+
+
+        throw new OperationError("Test");
+    }
+
+    parseEncodedWord(encodedWord) {
+        let [charset, encoding, encodedBlock] = encodedWord.split('?');
+
+        console.log('CURRENT BLOCK TO PROCESS', encodedBlock);
+        console.log('CURRENT CHARSET', charset);
+
+        let encodedText = '';
+        if (encoding.toLowerCase() === 'b') {
+            encodedText = fromBase64(encodedBlock);
+        } else {
+            encodedText = encodedBlock;
+        }
+
+        return encodedText;
+    }
+
+}
+
+export default MIMEDecoding;