Initial version of the E-Invoice solution of JR IT Services

jr_einvoice/invoice_number.py

@@ -0,0 +1,28 @@
+from __future__ import annotations
+from pathlib import Path
+import re
+from datetime import date
+
+DEFAULT_PATTERN = r"(?P<year>\d{4})-(?P<seq>\d{4})"
+
+def suggest_next_invoice_number(invoices_root: Path, year: int | None = None, pattern: str = DEFAULT_PATTERN) -> str:
+    invoices_root = invoices_root.expanduser().resolve()
+    y = year or date.today().year
+    rx = re.compile(pattern)
+
+    max_seq = 0
+    if invoices_root.exists():
+        for d in invoices_root.iterdir():
+            if not d.is_dir():
+                continue
+            m = rx.search(d.name)
+            if not m:
+                continue
+            try:
+                yr = int(m.group("year"))
+                seq = int(m.group("seq"))
+            except Exception:
+                continue
+            if yr == y and seq > max_seq:
+                max_seq = seq
+    return f"{y}-{max_seq+1:04d}"