miscs

copienator/commands/plotting.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import argparse
 import copy
+import json
 import queue
 import re
 import threading
@@ -16,6 +17,7 @@ from copienator import (
     EvaluationWorkspace,
     ExitCode,
     atomic_write_json,
+    atomic_write_text,
     execute,
     read_json,
     target_parser,
@@ -31,6 +33,31 @@ MISSING_LABEL_COLOR = "orange"
 COMMON_MISSING_LABEL_COLOR = "#403a00"
 COMMON_MISSING_THRESHOLD = 0.66
 
+
+def prepare_label_json_for_edit(path: Path) -> None:
+    """Leave a trailing comma after the last label so another can be pasted."""
+    data = read_json(path, repair_trailing_commas=True)
+    if not isinstance(data, dict) or not isinstance(data.get("list"), list) or not data["list"]:
+        return
+    text = path.read_text(encoding="utf-8")
+    decoder = json.JSONDecoder()
+    whitespace = re.compile(r"\s*")
+    skip_space = lambda position: whitespace.match(text, position).end()
+    cursor = skip_space(text.index("{") + 1)
+    # Decode top-level values to locate this list without matching delimiters
+    # inside strings or nested bounding-box arrays. Keep the existing layout.
+    while text[cursor] != "}":
+        key, end = decoder.raw_decode(text, cursor)
+        start = skip_space(skip_space(end) + 1)  # Skip the key's colon.
+        _value, end = decoder.raw_decode(text, start)
+        if key == "list":
+            insertion = len(text[:end - 1].rstrip())
+            atomic_write_text(path, text[:insertion] + "," + text[insertion:])
+            return
+        cursor = skip_space(end)
+        if text[cursor] == ",":
+            cursor = skip_space(cursor + 1)
+
 try:
     font = ImageFont.truetype("DejaVuSans.ttf", size=30)
 except OSError:
@@ -100,7 +127,7 @@ def frequently_missing_labels(
         if match is None:
             continue
         try:
-            data = read_json(json_path)
+            data = read_json(json_path, repair_trailing_commas=True)
             entries = data["list"]
             if not isinstance(entries, list):
                 continue
@@ -217,11 +244,11 @@ def _worker_items(base_dir, files_to_process, all_labels, output_queue):
         nb_pages = json_schema["columns_per_file"][copie_part-1]
 
         if json_path.exists():
-            # Read strictly for visualization purposes
+            # Repair accidental trailing commas in user-edited label JSON.
             bb_list = []
             json_name = ""
             try:
-                json_result = read_json(json_path)
+                json_result = read_json(json_path, repair_trailing_commas=True)
                 bb_list = json_result.get("list", [])
                 json_name = json_result.get("name", "")
             except Exception as e:  # noqa: BLE001 - malformed user-editable JSON
@@ -439,7 +466,7 @@ class ImageViewer:
             previous_results = copy.deepcopy(self.accumulated_results)
 
             try:
-                current_data = read_json(self.current_json_path)
+                current_data = read_json(self.current_json_path, repair_trailing_commas=True)
                 items = current_data["list"]
 
                 # Perform the conversion now, post-edit
@@ -532,6 +559,11 @@ class ImageViewer:
 
     def on_edit(self, event):
         if self.is_viewing and self.current_json_path:
+            try:
+                prepare_label_json_for_edit(self.current_json_path)
+            except (OSError, ValueError) as error:
+                # Still let the user open and fix other JSON errors manually.
+                print(f"Could not prepare trailing comma: {error}")
             print(f"Opening {self.current_json_path}")
             open_path(self.current_json_path)