From d7a7502d8948eed9a39cbc64fe447957295dc560 Mon Sep 17 00:00:00 2001
From: Philip Lundrigan <lundrigan@byu.edu>
Date: Wed, 7 Jan 2026 12:04:12 -0700
Subject: [PATCH] Start the implementation of EIC for QR codes

Right now, there is a dummy implementation of EIC
---
 qrcode/main.py | 12 +++++++++++-
 qrcode/util.py | 14 ++++++++++++--
 test.py        | 17 +++++++++++++++++
 3 files changed, 40 insertions(+), 3 deletions(-)
 create mode 100644 test.py

diff --git a/qrcode/main.py b/qrcode/main.py
index be62de81..4146482b 100644
--- a/qrcode/main.py
+++ b/qrcode/main.py
@@ -123,6 +123,7 @@ def clear(self):
         self.modules_count = 0
         self.data_cache = None
         self.data_list = []
+        self.eic_data = b""
 
     def add_data(self, data, optimize=20):
         """
@@ -140,6 +141,15 @@ def add_data(self, data, optimize=20):
             self.data_list.append(util.QRData(data))
         self.data_cache = None
 
+    def add_eic_data(self, data: bytes):
+        """
+        Add Error Insertion Coding data to this QR Code.
+
+        :param data: The EIC data as bytes.
+        """
+        self.eic_data = data
+        self.data_cache = None
+
     def make(self, fit=True):
         """
         Compile the data into a QR Code array.
@@ -178,7 +188,7 @@ def makeImpl(self, test, mask_pattern):
 
         if self.data_cache is None:
             self.data_cache = util.create_data(
-                self.version, self.error_correction, self.data_list
+                self.version, self.error_correction, self.data_list, self.eic_data
             )
         self.map_data(self.data_cache, mask_pattern)
 
diff --git a/qrcode/util.py b/qrcode/util.py
index 4187aa5e..a6a723fd 100644
--- a/qrcode/util.py
+++ b/qrcode/util.py
@@ -552,7 +552,7 @@ def create_bytes(buffer: BitBuffer, rs_blocks: list[RSBlock]):
     return data
 
 
-def create_data(version, error_correction, data_list):
+def create_data(version, error_correction, data_list, eic_data=b""):
     buffer = BitBuffer()
     for data in data_list:
         buffer.put(data.mode, 4)
@@ -585,4 +585,14 @@ def create_data(version, error_correction, data_list):
         else:
             buffer.put(PAD1, 8)
 
-    return create_bytes(buffer, rs_blocks)
+    fec_data = create_bytes(buffer, rs_blocks)
+
+    # Add EIC data if provided
+    if eic_data:
+        # TODO: Brian: put your magical EIC data integration here
+
+        # Naive implementation placeholder
+        for i, byte in enumerate(eic_data):
+            fec_data[i] = byte
+
+    return fec_data
diff --git a/test.py b/test.py
new file mode 100644
index 00000000..07c7c4e7
--- /dev/null
+++ b/test.py
@@ -0,0 +1,17 @@
+import qrcode
+
+qr = qrcode.QRCode(
+    version=1,
+    error_correction=qrcode.constants.ERROR_CORRECT_L,
+    box_size=10,
+    border=4,
+)
+qr.add_data("Some data")
+img = qr.make_image(fill_color="black", back_color="white")
+img.save("before-eic.png")
+
+# Can't add too much EIC data or the QR code will get corrupted (because of my naive approach)
+qr.add_eic_data(b"EIC")
+
+img = qr.make_image(fill_color="black", back_color="white")
+img.save("after-eic.png")