Station flow: ID first, EAN optional, re-measure by ID

Every run opens with the freshly allocated L#### and then asks for
the EAN, which Enter skips. Typing an existing ID re-measures that
lamp with all identification and rated values pre-filled, which also
rewrites old bundles in the current metrics format. Unused IDs are
never burned since numbering derives from written bundles.

README.md

@@ -97,9 +97,13 @@ end to end. Every lamp gets an internal ID (L0001, L0002, ...) as primary key;
 the EAN barcode is optional metadata, so one barcode can cover daylight/warm
 white variants (distinct IDs + variant field) and unbranded lamps work too.
 
-Per lamp: scan the box (or 'n' for no barcode), the EAN is checksum-validated
+Every run opens with a freshly allocated ID (the ID only becomes real once a
-and resolved to manufacturer/model (previously measured lamps, local cache,
+bundle is written, so aborting never burns a number). Then: scan the box's EAN
-then upcitemdb.com; GS1-restricted 20-29 barcodes are flagged as
+(optional, Enter skips it), or type an existing ID like L0004 to re-measure
+that lamp with everything pre-filled, which also rewrites its bundle in the
+current metrics format. Scanned EANs are checksum-validated and resolved to
+manufacturer/model (previously measured lamps, local cache, then
+upcitemdb.com; GS1-restricted 20-29 barcodes are flagged as
 retailer-internal), lamps already measured under the same EAN are offered for
 re-measurement, you confirm the identification and type the ADVERTISED values
 from the packaging (flux, CCT, power, CRI, lifetime, equivalent W -> stored

lamp_station.py

@@ -7,11 +7,15 @@ EAN barcode is optional metadata. This keeps lamps distinct when one barcode
 covers several versions (daylight / warm white in the same box art) and
 supports unbranded lamps without any barcode.
 
-    1. Scan the box with a keyboard-wedge barcode scanner (types EAN + Enter),
+    1. Every run opens with a freshly allocated ID (L0012, ...). The ID only
-       or type 'n' for a lamp without a barcode.
+       becomes real once the bundle is written, so aborting never burns one.
-    2. The EAN is checksum-validated. Lamps already measured with the same
+    2. Scan the box with a keyboard-wedge barcode scanner (types EAN +
-       EAN are listed: pick one to re-measure, or continue as a new lamp
+       Enter), press Enter for a lamp without a barcode, or type an existing
-       (that is how same-EAN variants get their own IDs). Identification is
+       ID (e.g. L0004) to re-measure that lamp with everything pre-filled,
+       which also rewrites its bundle in the current metrics format. Scanned
+       EANs are checksum-validated; lamps already measured with the same EAN
+       are listed (pick one to re-measure, or continue as the new lamp: that
+       is how same-EAN variants get their own IDs). Identification is
        suggested from previous lamps, a local cache, then upcitemdb.com
        (best effort; GS1-restricted 20-29 barcodes skip the online lookup).
     3. Confirm or edit manufacturer / model / variant / notes, then type the
@@ -203,30 +207,31 @@ def commit_bundle(data_repo, lamp_id, label, existed, push):
         print("Pushed.")
 
 
-def measure_one(ean, args, data_repo):
+def measure_one(new_id, ean, lamps, args, data_repo, existing_id=None):
-    lamps = lamp_index(data_repo)
+    # The run already owns its fresh ID (new_id). Typing an existing ID at
-
+    # the scan prompt re-measures that lamp instead (all its identification
-    # Same-EAN lamps already in the database: re-measure or new variant.
+    # pre-filled, bundle rewritten in the current format); an EAN may also
-    lamp_id, previous = None, {}
+    # redirect to a re-measure when it matches an existing lamp.
-    if ean:
+    lamp_id, previous = new_id, {}
+    if existing_id:
+        lamp_id = existing_id
+        previous = lamps[existing_id]
+        ean = previous.get("ean", "")
+        print(f"  Re-measuring {lamp_id}" + (f"  (EAN {ean})" if ean else ""))
+    elif ean:
         same = {i: m for i, m in lamps.items() if m.get("ean") == ean}
         if same:
             print("  Lamps already measured with this EAN:")
             for i, m in same.items():
                 variant = f", {m['variant']}" if m.get("variant") else ""
                 print(f"    {i}: {m.get('manufacturer', '')} {m.get('model', '')}{variant}")
-            choice = prompt("Re-measure one of these (type its ID) or Enter for a NEW lamp/variant").strip()
+            choice = prompt(f"Re-measure one of these (type its ID) or Enter to continue as {new_id}").strip()
             if choice:
                 if choice.upper() not in same:
-                    print(f"  Unknown ID {choice!r}, aborting this scan.")
+                    print(f"  Unknown ID {choice!r}, aborting this run.")
                     return
                 lamp_id = choice.upper()
                 previous = same[lamp_id]
-
-    if lamp_id is None:
-        lamp_id = next_lamp_id(data_repo)
-        print(f"  New lamp: {lamp_id}" + (f"  (EAN {ean})" if ean else "  (no barcode)"))
-    else:
                 print(f"  Re-measuring {lamp_id}")
 
     if previous:
@@ -323,25 +328,34 @@ def main():
         print(f"ERROR: {data_repo} is not a git checkout of comparison-data.")
         sys.exit(1)
 
-    print("Lamp station ready. Scan a barcode, 'n' for a lamp without one, 'q' to quit.")
+    print("Lamp station ready. Every run starts a new lamp ID; the EAN is optional")
+    print("(scan it, or press Enter to skip). 'q' quits.")
     while True:
+        # A fresh ID opens every run. It only becomes real once a bundle is
+        # written, so quitting or re-measuring never burns a number.
+        lamps = lamp_index(data_repo)
+        new_id = next_lamp_id(data_repo)
+        print(f"\n--- New lamp {new_id} ---")
         try:
-            code = input("\nScan barcode: ").strip()
+            code = input("Scan EAN (Enter to skip, L#### re-measures an existing lamp, q quits): ").strip()
         except (EOFError, KeyboardInterrupt):
             break
-        if code == "":
-            continue
         if code.lower() in ("q", "quit", "exit"):
             break
-        if code.lower() in ("n", "none"):
+        existing_id = None
         ean = ""
-        else:
+        if ID_RE.match(code.upper()):
+            existing_id = code.upper()
+            if existing_id not in lamps:
+                print(f"  No lamp {existing_id} in the database.")
+                continue
+        elif code and code.lower() not in ("n", "none"):
             ean = ean_normalize(code)
             if not ean:
-                print(f"  Not a valid EAN-13/UPC-A: {code!r}")
+                print(f"  Not a valid EAN-13/UPC-A: {code!r} (Enter would skip the EAN)")
                 continue
         try:
-            measure_one(ean, args, data_repo)
+            measure_one(new_id, ean, lamps, args, data_repo, existing_id=existing_id)
         except KeyboardInterrupt:
             print("\n  Aborted; lamp skipped. (PSU is switched off by the driver.)")
         except (subprocess.CalledProcessError, SystemExit) as e: