add app call note parser

tests/test.py

@@ -0,0 +1,40 @@
+from base64 import b64encode
+from unittest import TestCase
+
+from tinyman.utils import generate_app_call_note, parse_app_call_note
+
+
+class BaseTestCase(TestCase):
+    maxDiff = None
+
+    def test_app_call_note(self):
+        note = generate_app_call_note(
+            version="v2", client_name="unit-test", extra_data={"extra": "some text"}
+        )
+        expected_result = {
+            "version": "v2",
+            "data": {"extra": "some text", "origin": "unit-test"},
+        }
+
+        # test possible versions
+        string_note = note
+        bytes_note = string_note.encode()
+        base64_note = b64encode(bytes_note).decode()
+
+        result = parse_app_call_note(string_note)
+        self.assertDictEqual(
+            result,
+            expected_result,
+        )
+
+        result = parse_app_call_note(base64_note)
+        self.assertDictEqual(
+            result,
+            expected_result,
+        )
+
+        result = parse_app_call_note(base64_note)
+        self.assertDictEqual(
+            result,
+            expected_result,
+        )

tinyman/utils.py

@@ -1,7 +1,9 @@
 import json
+import re
 import warnings
 from base64 import b64decode, b64encode
 from datetime import datetime
+from json import JSONDecodeError
 from typing import Optional
 
 from algosdk.error import AlgodHTTPError
@@ -129,7 +131,7 @@ def get_version(tinyman_app_id: int) -> str:
 
 def generate_app_call_note(
     version: str, client_name: Optional[str] = None, extra_data: Optional[dict] = None
-):
+) -> str:
     # https://github.com/algorandfoundation/ARCs/blob/main/ARCs/arc-0002.md
     # <dapp-name>:<data-format><data>
     note_template = "{dapp_name}/{dapp_version}:{data_format}{data}"
@@ -145,14 +147,45 @@ def generate_app_call_note(
     )
 
     # spaces are removed from separators, default is (', ', ': ')
-    serialized_data = json.dumps(data, separators=(",", ":"))
+    serialized_data = json.dumps(data, separators=(",", ":"), sort_keys=True)
 
     note = note_template.format(
         dapp_name="tinyman", dapp_version=version, data_format="j", data=serialized_data
     )
     return note
 
 
+def parse_app_call_note(
+    note: [str, bytes], raise_exception: bool = False
+) -> Optional[dict]:
+    if isinstance(note, str):
+        try:
+            note = b64decode(note)
+        except Exception:
+            pass
+        else:
+            note = note.decode()
+    elif isinstance(note, bytes):
+        note = note.decode()
+
+    pattern = r"tinyman/(?P<version>v[1-2]):j(?P<raw_data>.*)$"
+    match = re.match(pattern, note)
+
+    if not match:
+        return None
+
+    try:
+        data = json.loads(match.group("raw_data"))
+    except JSONDecodeError as e:
+        if raise_exception:
+            raise e
+        return None
+
+    # Result
+    result = {"version": match.group("version"), "data": data}
+    return result
+
+
 class TransactionGroup:
     def __init__(self, transactions):
         # Clear previously assigned group ids