From e213df2255878e8f2d3c42331f8d10dbddff3ab2 Mon Sep 17 00:00:00 2001
From: Andris Reinman <andris@reinman.eu>
Date: Tue, 20 Sep 2022 15:49:14 +0300
Subject: [PATCH] started with import stream parser

---
 lib/api/users.js | 61 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/lib/api/users.js b/lib/api/users.js
index 49ef758..8dfb52c 100644
--- a/lib/api/users.js
+++ b/lib/api/users.js
@@ -104,6 +104,67 @@ class ExportStream extends Transform {
     }
 }
 
+class ImportStream extends Transform {
+    constructor() {
+        super({ readableObjectMode: true, writableObjectMode: false });
+        this.TYPE_HEADER = 0x01;
+        this.TYPE_CONTENT = 0x02;
+
+        this.magickBuffer = [];
+        this.magickFound = false;
+
+        this.entryBuffer = false;
+    }
+
+    readMagick(data) {
+        if (this.magickFound) {
+            return data;
+        }
+
+        let removeSuffix = 0;
+        for (let i = 0; i < data.length; i++) {
+            this.magickBuffer.push(data[i]);
+            removeSuffix++;
+            if (this.magickBuffer.length === 3) {
+                if (Buffer.concat(this.magickBuffer).compare(Buffer.from([0x09, 0x06, 0x82]))) {
+                    this.magickFound = true;
+                    break;
+                } else {
+                    let error = new Error('Invalid content sequence');
+                    error.code = 'INVALID_SEQUENCE';
+                    throw error;
+                }
+            }
+        }
+
+        if (removeSuffix) {
+            return data.slice(removeSuffix);
+        }
+
+        return data;
+    }
+
+    async readRecords(data) {}
+
+    _transform(data, encoding, done) {
+        try {
+            data = this.readMagick(data);
+        } catch (err) {
+            if (err) {
+                return done(err);
+            }
+        }
+
+        this.readRecords(data)
+            .then(() => done())
+            .catch(err => done(err));
+    }
+
+    _flush(done) {
+        done();
+    }
+}
+
 module.exports = (db, server, userHandler, settingsHandler) => {
     const taskHandler = new TaskHandler({ database: db.database });