Add generation of customer tokens as PDF

foobarpay.py

-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import logging
 from sys import exit
@@ -11,6 +11,7 @@ from foobarpay.display import Display
 from foobarpay.scanner import EvdevScanner, FifoScanner
 from foobarpay.logic import Logic
 from foobarpay.model.product import Product
+from foobarpay.tokens import TokenGenerator
 
 class FooBarPay:
     DEFAULT_SCANNER  = '/dev/input/by-id/usb-©_Symbol_Technologies__Inc__2000_Symbol_Bar_Code_Scanner_S_N:ac08a7010000_Rev:NBRXUAAQ3-event-kbd'
@@ -48,6 +49,12 @@ if __name__ == "__main__":
     parser.add_argument('--scanner', dest='scanner', default=FooBarPay.DEFAULT_SCANNER, help='specify scanner device')
     parser.add_argument('--scanner-driver', dest='scanner_driver', choices=['evdev', 'fifo'], default='evdev', help='specify scanner driver')
     parser.add_argument('--db', dest='database', default=FooBarPay.DEFAULT_DATABASE, help='specify database file')
+    parser.add_argument('--gen-tokens', dest='gen_tokens', action='store_true', help='generate customer tokens')
     parser.set_defaults(debug=False, debug_sql=False)
 
-    FooBarPay(parser.parse_args()).start()
+    args = parser.parse_args()
+
+    if args.gen_tokens:
+        TokenGenerator(Database(args.database, debug=args.debug_sql)).generate()
+    else:
+        FooBarPay(args).start()

foobarpay/logic.py

@@ -10,7 +10,7 @@ class Logic(object):
         Idle = 0
         Started = 1
 
-    USER_ID_PREFIX = 'U-'
+    USER_ID_PREFIX = '999'
     LOAD_PREFIX = '980'
 
     def __init__(self, display, database):

foobarpay/tokens.py

+import base64
+
+from barcode import EAN13
+from cairosvg import svg2pdf
+from io import BytesIO
+from jinja2 import Template
+from random import randrange
+from time import time
+
+from foobarpay.model.customer import Customer
+from foobarpay.logic import Logic
+
+class TokenGenerator(object):
+
+    def __init__(self, db):
+        self.db = db
+
+    def make_barcode(self):
+        while True:
+            id = randrange(999999999)
+            if not self.db.get(Customer, id=id):
+                self.db.get_or_create(Customer, id=id)
+                self.db.commit()
+                break
+        ean = EAN13(Logic.USER_ID_PREFIX + str(id).zfill(9))
+        f = BytesIO()
+        ean.write(f, {'write_text': False})
+        return base64.encodestring(f.getvalue()).decode('utf-8')
+
+    def generate(self):
+        with open('resources/customer_tokens_template.svg') as f:
+            t = Template(f.read())
+        with open('customer_tokens_%i.pdf' % time(), 'wb') as f:
+            f.write(svg2pdf(t.render(make_barcode=self.make_barcode)))