Hotfix: Add missing import

README.md

@@ -1,18 +1,23 @@
 # Receipt Printer
 
-This software is designed to run on a debian based system and acts as a middle-man between the EZ LAN Manager database and the USB interface of the receipt printer.
+This software is designed to run on a debian based system and acts as a middle-man between the EZGG LAN Manager database and the USB interface of the receipt printer.
 
 # Notes
 
 - Does only work on Linux
-- Needs root privileges or udev config to work
-- Designed to run alone on a Raspberry Pi
 - Not meant to be exposed to the internet, local deployment only
-- For EZ LAN Manager configuration, check README in that repo
+- For EZGG LAN Manager configuration, check README in that repo
 
 # Deploy
 
 1. Configure password and port in `main.py`
 2. Make sure USB printer is connected to device
-3. Install requirements with sudo
+3. Install requirements in venv
-4. Run `main.py` with sudo
+4. Adapt `receipt-printer.service` as needed and move to `~/.config/systemd/user`
+5. Enable unit in systemd:
+```sh
+systemctl --user daemon-reexec
+systemctl --user daemon-reload
+systemctl --user enable receipt-printer
+systemctl --user start receipt-printer
+```

main.py

@@ -1,5 +1,6 @@
 from datetime import datetime
 from typing import List
+import unicodedata
 
 import uvicorn
 from fastapi import FastAPI, HTTPException, Header
@@ -9,8 +10,6 @@ from escpos.printer import Usb
 from escpos.capabilities import get_profile
 from PIL import Image
 
-PRINTER = Usb(0x28e9, 0x0289, profile="simple")
-
 MAX_LINE_LEN = 32
 SECRET_PASSWORD = "Alkohol1"
 
@@ -27,13 +26,11 @@ class Order(BaseModel):
     seat_id: str
     items: List[OrderItem]
 
+def get_printer() -> Usb:
+    return Usb(0x28e9, 0x0289, profile="simple")
 
 def sanitize_text(text: str) -> str:
-    return (text.replace("ä", "ae")
+    return unicodedata.normalize("NFKD", text).encode("ascii", "ignore").decode()
-                .replace("ö", "oe")
-                .replace("ü", "ue")
-                .replace("ß", "ss"))
-
 
 def build_header(order: Order, copy_num: int) -> str:
     return (
@@ -89,7 +86,7 @@ api = FastAPI()
 
 
 @api.post("/print_order")
-async def print_order_api_endpoint(order: Order, x_password: str = Header(None)):
+def print_order_api_endpoint(order: Order, x_password: str = Header(None)):
     if x_password != SECRET_PASSWORD:
         raise HTTPException(status_code=401, detail="Unauthorized")
 
@@ -99,7 +96,9 @@ async def print_order_api_endpoint(order: Order, x_password: str = Header(None))
 
     for copy_num in range(1, 3):
         try:
-            print_order(order, PRINTER, copy_num)
+            printer = get_printer()
+            print_order(order, printer, copy_num)
+            printer.close()
         except Exception as e:
             raise HTTPException(status_code=500, detail=f"Printing failed: {str(e)}")
 

receipt-printer.service

@@ -0,0 +1,14 @@
+[Unit]
+Description=Receipt Printer
+After=network.target
+
+[Service]
+WorkingDirectory=/opt/ReceiptPrinter
+ExecStart=/opt/ReceiptPrinter/printer-venv/bin/python main.py
+Restart=always
+RestartSec=3
+
+Environment=PYTHONUNBUFFERED=1
+
+[Install]
+WantedBy=default.target