feat: Enhance Fragment API with improved error handling and clean_decode utility; (#1) update version and dependencies

app/utils/decoder.py

@@ -0,0 +1,49 @@
+import base64
+import logging
+import re
+import string
+
+logger = logging.getLogger(__name__)
+
+
+def clean_decode(payload: str) -> str:
+    logger.debug(f"Original payload: {payload}")
+
+    # Decode raw bytes first
+    clean = ''.join(c for c in payload if c.isalnum() or c in '+/=')
+    clean += '=' * (-len(clean) % 4)
+    raw_bytes = base64.b64decode(clean)
+    logger.debug(f"Raw decoded bytes: {raw_bytes}")
+
+    # 1. Clean Base64
+    s = re.sub(r'[^A-Za-z0-9+/=]', '', payload.strip())
+    s += '=' * (-len(s) % 4)
+
+    # 2. Base64 -> bytes
+    b = base64.b64decode(s)
+
+    # 3. Decode UTF-8, ignoring invalid bytes
+    t = b.decode('utf-8', errors='ignore')
+
+    # 4. Remove binary characters, keep only printable + whitespace
+    t = ''.join(c for c in t if c in string.printable or c.isspace())
+
+    # 5. Extract main text with Ref#
+    match = re.search(r'([0-9]*\s*Telegram .*?Ref#[A-Za-z0-9]+)', t, re.S)
+    if match:
+        result = match.group(1).strip()
+    else:
+        result = t.strip()
+
+    logger.debug(f"Cleaned result: {result}")
+
+    return result
+
+# payloads = [
+#     "te6ccgEBAgEALwABTgAAAAAxMDAwMDAwIFRlbGVncmFtIFN0YXJzIAoKUmVmI1RQb01wegEABkM3ZQ",
+#     "te6ccgEBAgEANAABTgAAAABUZWxlZ3JhbSBQcmVtaXVtIGZvciAxIHllYXIgCgpSZWYjcgEAEE9OQnM2cmNt",
+#     "te6ccgEBAgEAMAABTgAAAABUZWxlZ3JhbSBhY2NvdW50IHRvcCB1cCAKClJlZiNrMXpDRQEACFkxd3g"
+# ]
+
+# for p in payloads:
+#     logger.debug("\n" + clean_decode(p) + "\n")