feat: Add new cookie format (#61)

* feat: Add new cookie format

* Fix new format test

Author: zhukaihan

Diff for: src/amplitude_experiment/cookie.py

@@ -1,3 +1,7 @@
+import json
+import logging
+import urllib.parse
+
 from .user import User
 import base64
 
@@ -6,29 +10,52 @@ class AmplitudeCookie:
     """This class provides utility functions for parsing and handling identity from Amplitude cookies."""
 
     @staticmethod
-    def cookie_name(api_key: str) -> str:
+    def cookie_name(api_key: str, new_format: bool = False) -> str:
         """
         Get the cookie name that Amplitude sets for the provided
             Parameters:
                 api_key (str): The Amplitude API Key
+                new_format (bool): True if cookie is in Browser SDK 2.0 format
 
             Returns:
                 The cookie name that Amplitude sets for the provided Amplitude API Key
        """
         if not api_key:
             raise ValueError("Invalid Amplitude API Key")
+
+        if new_format:
+            if len(api_key) < 10:
+                raise ValueError("Invalid Amplitude API Key")
+            return f"AMP_{api_key[0:10]}"
+
+        if len(api_key) < 6:
+            raise ValueError("Invalid Amplitude API Key")
         return f"amp_{api_key[0:6]}"
 
     @staticmethod
-    def parse(amplitude_cookie: str) -> User:
+    def parse(amplitude_cookie: str, new_format: bool = False) -> User:
         """
         Parse a cookie string and returns user
             Parameters:
                 amplitude_cookie (str):  A string from the amplitude cookie
+                new_format: True if cookie is in Browser SDK 2.0 format
 
             Returns:
                 Experiment User context containing a device_id and user_id (if available)
         """
+
+        if new_format:
+            decoding = base64.b64decode(amplitude_cookie).decode("utf-8")
+            try:
+                user_session = json.loads(urllib.parse.unquote_plus(decoding))
+                if "userId" not in user_session:
+                    return User(user_id=None, device_id=user_session["deviceId"])
+                return User(user_id=user_session["userId"], device_id=user_session["deviceId"])
+            except Exception as e:
+                logger = logging.getLogger("Amplitude")
+                logger.error("Error parsing the Amplitude cookie: " + str(e))
+                return User()
+
         values = amplitude_cookie.split('.')
         user_id = None
         if values[1]:
@@ -39,13 +66,24 @@ def parse(amplitude_cookie: str) -> User:
         return User(user_id=user_id, device_id=values[0])
 
     @staticmethod
-    def generate(device_id: str) -> str:
+    def generate(device_id: str, new_format: bool = False) -> str:
         """
         Generates a cookie string to set for the Amplitude Javascript SDK
             Parameters:
                 device_id (str):  A device id to set
+                new_format: True if cookie is in Browser SDK 2.0 format
 
             Returns:
                 A cookie string to set for the Amplitude Javascript SDK to read
         """
-        return f"{device_id}.........."
+        if not new_format:
+            return f"{device_id}.........."
+
+        user_session_hash = {
+            "deviceId": device_id
+        }
+        json_data = json.dumps(user_session_hash)
+        encoded_json = urllib.parse.quote(json_data)
+        base64_encoded = base64.b64encode(bytearray(encoded_json, "utf-8")).decode("utf-8")
+
+        return base64_encoded

Diff for: tests/cookie_test.py

@@ -30,6 +30,33 @@ def test_parse_cookie_with_device_id_and_utf_user_id(self):
     def test_generate(self):
         self.assertEqual(AmplitudeCookie.generate('deviceId'), 'deviceId..........')
 
+    def test_new_format_valid_api_key_return_cookie_name(self):
+        self.assertEqual(AmplitudeCookie.cookie_name('12345678901', new_format=True), 'AMP_1234567890')
+
+    def test_new_format_invalid_api_key_raise_error(self):
+        self.assertRaises(ValueError, AmplitudeCookie.cookie_name, '12345678', new_format=True)
+
+    def test_new_format_parse_cookie_with_device_id_only(self):
+        user = AmplitudeCookie.parse('JTdCJTIyZGV2aWNlSWQlMjIlM0ElMjJzb21lRGV2aWNlSWQlMjIlN0Q=', new_format=True)
+        self.assertIsNotNone(user)
+        self.assertEqual(user.device_id, 'someDeviceId')
+        self.assertIsNone(user.user_id)
+
+    def test_new_format_parse_cookie_with_device_id_and_user_id(self):
+        user = AmplitudeCookie.parse('JTdCJTIyZGV2aWNlSWQlMjIlM0ElMjJzb21lRGV2aWNlSWQlMjIlMkMlMjJ1c2VySWQlMjIlM0ElMjJleGFtcGxlJTQwYW1wbGl0dWRlLmNvbSUyMiU3RA==', new_format=True)
+        self.assertIsNotNone(user)
+        self.assertEqual(user.device_id, 'someDeviceId')
+        self.assertEqual(user.user_id, '[email protected]')
+
+    def test_new_format_parse_cookie_with_device_id_and_utf_user_id(self):
+        user = AmplitudeCookie.parse('JTdCJTIyZGV2aWNlSWQlMjIlM0ElMjJzb21lRGV2aWNlSWQlMjIlMkMlMjJ1c2VySWQlMjIlM0ElMjJjJUMzJUI3JTNFJTIyJTdE', new_format=True)
+        self.assertIsNotNone(user)
+        self.assertEqual(user.device_id, 'someDeviceId')
+        self.assertEqual(user.user_id, 'c÷>')
+
+    def test_new_format_generate(self):
+        self.assertEqual(AmplitudeCookie.generate('someDeviceId', new_format=True), 'JTdCJTIyZGV2aWNlSWQlMjIlM0ElMjAlMjJzb21lRGV2aWNlSWQlMjIlN0Q=')
+
 
 if __name__ == '__main__':
     unittest.main()