Added SnapshotAutoUpdater to handle snapshot updates

.gitignore

@@ -22,6 +22,7 @@ coverage.xml
 cover
 .pytest_cache
 .env
+tests/snapshots/temp/
 
 # PyBuilder
 target/

switcher_client/client.py

@@ -4,6 +4,7 @@
 from switcher_client.lib.remote_auth import RemoteAuth
 from switcher_client.lib.globals.global_context import Context, ContextOptions
 from switcher_client.lib.globals.global_context import DEFAULT_ENVIRONMENT
+from switcher_client.lib.snapshot_auto_updater import SnapshotAutoUpdater
 from switcher_client.lib.snapshot_loader import load_domain, validate_snapshot
 from switcher_client.lib.utils import get
 from switcher_client.switcher import Switcher
@@ -121,8 +122,18 @@ def schedule_snapshot_auto_update(interval: Optional[int] = None, callback: Opti
         if interval is not None:
             Client.context.options.snapshot_auto_update_interval = interval
 
-        if Client.__is_auto_update_snapshot_available():
-            callback(None, True)
+        if Client.context.options.snapshot_auto_update_interval is not None and \
+            Client.context.options.snapshot_auto_update_interval > 0:
+            SnapshotAutoUpdater.schedule(
+                interval=Client.context.options.snapshot_auto_update_interval,
+                check_snapshot=Client.check_snapshot,
+                callback=callback
+            )
+
+    @staticmethod
+    def terminate_snapshot_auto_update():
+        """ Terminate Snapshot auto update """
+        SnapshotAutoUpdater.terminate()
 
     @staticmethod
     def snapshot_version() -> int:
@@ -136,9 +147,4 @@ def snapshot_version() -> int:
 
     @staticmethod
     def __is_check_snapshot_available(fetch_remote = False) -> bool:
-        return Client.snapshot_version() == 0 and (fetch_remote or not Client.context.options.local)
-
-    @staticmethod
-    def __is_auto_update_snapshot_available() -> bool:
-        return Client.context.options.snapshot_auto_update_interval is not None and \
-               Client.context.options.snapshot_auto_update_interval > 0
+        return Client.snapshot_version() == 0 and (fetch_remote or not Client.context.options.local)

switcher_client/lib/globals/global_auth.py

@@ -5,7 +5,7 @@ class GlobalAuth:
     __exp = None
 
     @staticmethod
-    def init(url: Optional[str]):
+    def init():
         GlobalAuth.__token = None
         GlobalAuth.__exp = None
 

switcher_client/lib/globals/global_context.py

@@ -1,14 +1,22 @@
+from typing import Optional
+
+
 DEFAULT_ENVIRONMENT = 'default'
 DEFAULT_LOCAL = False
 
 class ContextOptions:
-    def __init__(self, local = DEFAULT_LOCAL, snapshot_location = None, snapshot_auto_update_interval = None):
+    def __init__(self, 
+                 local = DEFAULT_LOCAL, 
+                 snapshot_location: Optional[str] = None, 
+                 snapshot_auto_update_interval: Optional[int] = None):
         self.local = local
         self.snapshot_location = snapshot_location
         self.snapshot_auto_update_interval = snapshot_auto_update_interval
 
 class Context:
-    def __init__(self, domain, url, api_key, component, environment, options = ContextOptions()):
+    def __init__(self, 
+                 domain: Optional[str], url: Optional[str], api_key: Optional[str], component: Optional[str], 
+                 environment: Optional[str], options: ContextOptions = ContextOptions()):
         self.domain = domain
         self.url = url
         self.api_key = api_key

switcher_client/lib/remote_auth.py

@@ -10,7 +10,7 @@ class RemoteAuth:
     @staticmethod
     def init(context: Context):
         RemoteAuth.__context = context
-        GlobalAuth.init(context.url)
+        GlobalAuth.init()
 
     @staticmethod
     def auth():

switcher_client/lib/snapshot_auto_updater.py

@@ -0,0 +1,56 @@
+import threading
+import time
+from typing import Callable, Optional
+
+class SnapshotAutoUpdater:
+    _timer_thread: Optional[threading.Thread] = None
+    _stop_event: Optional[threading.Event] = None
+
+    @staticmethod
+    def schedule(interval: int, check_snapshot: Callable[[], bool], callback: Callable[[Optional[Exception], bool], None]) -> None:
+        """
+        Schedule periodic snapshot updates in a background thread.
+
+        :param interval: Update interval in seconds
+        :param check_snapshot: Function that checks and updates snapshot, returns True if updated
+        :param callback: Callback function called with (error, updated) after each check
+        """
+
+        SnapshotAutoUpdater.terminate()
+        SnapshotAutoUpdater._stop_event = threading.Event() 
+
+        SnapshotAutoUpdater._timer_thread = threading.Thread(
+            target=SnapshotAutoUpdater.__update_worker,
+            args=(interval, check_snapshot, callback),
+            daemon=True,
+            name="SnapshotAutoUpdater"
+        )
+        SnapshotAutoUpdater._timer_thread.start()
+
+    @staticmethod
+    def terminate() -> None:
+        """
+        Terminate the scheduled snapshot auto-update thread gracefully.
+        """
+        if SnapshotAutoUpdater._stop_event is not None:
+            SnapshotAutoUpdater._stop_event.set()
+
+        if SnapshotAutoUpdater._timer_thread is not None and SnapshotAutoUpdater._timer_thread.is_alive():
+            SnapshotAutoUpdater._timer_thread.join(timeout=5.0)
+
+        SnapshotAutoUpdater._timer_thread = None
+        SnapshotAutoUpdater._stop_event = None
+
+    @staticmethod
+    def __update_worker(interval: int, check_snapshot: Callable[[], bool], callback: Callable[[Optional[Exception], bool], None]) -> None:
+        stop_event = SnapshotAutoUpdater._stop_event
+
+        time.sleep(interval) # delay start
+        while stop_event is not None and not stop_event.is_set():
+            try:
+                updated = check_snapshot()
+                callback(None, updated)
+            except Exception as error:
+                callback(error, False)
+
+            stop_event.wait(interval)

tests/__init__.py

@@ -0,0 +1,7 @@
+import os
+
+SNAPSHOT_TEMP_DIR = 'tests/snapshots/temp'
+
+if os.path.exists(SNAPSHOT_TEMP_DIR):
+    for f in os.listdir(SNAPSHOT_TEMP_DIR):
+        os.remove(os.path.join(SNAPSHOT_TEMP_DIR, f))

tests/snapshots/default_load_2.json

@@ -0,0 +1,26 @@
+{
+    "data": {
+        "domain": {
+            "name": "Business",
+            "description": "Business description",
+            "version": 1588557288041,
+            "activated": true,
+            "group": [
+                {
+                    "name": "Rollout 2030",
+                    "description": "Changes that will be applied during the rollout",
+                    "activated": true,
+                    "config": [
+                        {
+                            "key": "FF2FOR2030",
+                            "description": "Feature Flag",
+                            "activated": false,
+                            "strategies": [],
+                            "components": []
+                        }
+                    ]
+                }
+            ]
+        }
+    }
+}

tests/test_client_load_snapshot_file.py

@@ -29,7 +29,7 @@ def test_load_from_snapshot_empty():
         environment='generated-clean',
         options=ContextOptions(
             local=True,
-            snapshot_location='./tests/snapshots'
+            snapshot_location='./tests/snapshots/temp'
         )
     )
 

tests/test_client_load_snapshot_remote.py

@@ -1,4 +1,5 @@
 import json
+import os
 import pytest
 import time
 
@@ -76,51 +77,136 @@ def test_resolve_snapshot_error(httpx_mock):
 
     assert '[resolve_snapshot] failed with status: 500' in str(excinfo.value)
 
-def test_auto_update_snapshot():
-    """ WIP: Should auto-update snapshot every second """
+def test_auto_update_snapshot_from_context(httpx_mock):
+    """ Should auto-update snapshot every second from context """
 
-    # given
+    # given - load initial snapshot
+    given_auth(httpx_mock)
+    given_check_snapshot_version(httpx_mock, version=0, status=False)
+    given_resolve_snapshot(httpx_mock, data=load_snapshot_fixture('tests/snapshots/default_load_1.json'))
+
+    # given - snapshot out-of-date, needs update
+    given_check_snapshot_version(httpx_mock, version=1588557288040, status=False) # needs update
+    given_resolve_snapshot(httpx_mock, data=load_snapshot_fixture('tests/snapshots/default_load_2.json'))
+
+    # given - context
     given_context(
-        snapshot_location='tests/snapshots', 
-        environment='default_load_1', 
+        snapshot_location='tests/snapshots/temp', 
+        environment='generated-auto-update',
         snapshot_auto_update_interval=1
     )
+
+    # test
+    Client.load_snapshot(LoadSnapshotOptions(fetch_remote=True))
+    assert Client.snapshot_version() == 1588557288040
 
-    callback_args = []
+    time.sleep(1.5) # wait for auto-update to trigger
+    assert Client.snapshot_version() == 1588557288041
+
+    # tear down
+    Client.terminate_snapshot_auto_update()
+    delete_snapshot_file('./tests/snapshots/temp', 'generated-auto-update')
+
+def test_auto_update_snapshot(httpx_mock):
+    """ Should auto-update snapshot every second """
+
+    # given - load initial snapshot
+    given_auth(httpx_mock)
+    given_check_snapshot_version(httpx_mock, version=0, status=False)
+    given_resolve_snapshot(httpx_mock, data=load_snapshot_fixture('tests/snapshots/default_load_1.json'))
+
+    # given - snapshot out-of-date, needs update
+    given_check_snapshot_version(httpx_mock, version=1588557288040, status=False) # needs update
+    given_resolve_snapshot(httpx_mock, data=load_snapshot_fixture('tests/snapshots/default_load_2.json'))
+
+    # given - context
+    given_context(
+        snapshot_location='tests/snapshots/temp', 
+        environment='generated-auto-update'
+    )
+
+    Client.load_snapshot(LoadSnapshotOptions(fetch_remote=True))
 
     # test
+    callback_args = []
     Client.schedule_snapshot_auto_update(interval=1,
         callback=lambda error, updated: callback_args.append((error, updated))
     )
 
+    time.sleep(1.5) # wait for auto-update to trigger
+
     error, updated = callback_args[0]
     assert error is None
     assert updated
 
+    # tear down
+    Client.terminate_snapshot_auto_update()
+    delete_snapshot_file('./tests/snapshots/temp', 'generated-auto-update')
+
+def test_not_auto_update_snapshot_when_error(httpx_mock):
+    """ Should not auto-update snapshot if there is an error """
+
+    # given - load initial snapshot
+    given_auth(httpx_mock)
+    given_check_snapshot_version(httpx_mock, version=0, status=False)
+    given_resolve_snapshot(httpx_mock, data=load_snapshot_fixture('tests/snapshots/default_load_1.json'))
+
+    # given - snapshot out-of-date, needs update
+    given_check_snapshot_version(httpx_mock, version=1588557288040, status=False) # needs update
+    given_resolve_snapshot(httpx_mock, status_code=500) # will cause error
+
+    # given - context
+    given_context(
+        snapshot_location='tests/snapshots/temp', 
+        environment='generated-auto-update-error'
+    )
+
+    Client.load_snapshot(LoadSnapshotOptions(fetch_remote=True))
+
+    # test
+    callback_args = []
+    Client.schedule_snapshot_auto_update(interval=1,
+        callback=lambda error, updated: callback_args.append((error, updated))
+    )
+
+    time.sleep(1.5) # wait for auto-update to trigger
+
+    error, updated = callback_args[0]
+    assert isinstance(error, RemoteError)
+    assert '[resolve_snapshot] failed with status: 500' in str(error)
+    assert not updated
+
+    # tear down
+    Client.terminate_snapshot_auto_update()
+    delete_snapshot_file('./tests/snapshots/temp', 'generated-auto-update-error')
+
 # Helpers
 
-def given_auth(httpx_mock: HTTPXMock, status=200, token: Optional[str]='[token]', exp=int(round(time.time() * 1000))):
+def given_auth(httpx_mock: HTTPXMock, status=200, token: Optional[str]='[token]', exp=int(round(time.time() * 1000)), is_reusable=False):
     httpx_mock.add_response(
         url='https://api.switcherapi.com/criteria/auth',
         method='POST',
         status_code=status,
-        json={'token': token, 'exp': exp}
+        json={'token': token, 'exp': exp},
+        is_reusable=is_reusable
     )
 
-def given_check_snapshot_version(httpx_mock: HTTPXMock, status_code=200, version=0, status=False):
+def given_check_snapshot_version(httpx_mock: HTTPXMock, status_code=200, version=0, status=False, is_reusable=False):
     httpx_mock.add_response(
         url=f'https://api.switcherapi.com/criteria/snapshot_check/{version}',
         method='GET',
         status_code=status_code,
-        json={'status': status}
+        json={'status': status},
+        is_reusable=is_reusable
     )
 
-def given_resolve_snapshot(httpx_mock: HTTPXMock, status_code=200, data=[]):
+def given_resolve_snapshot(httpx_mock: HTTPXMock, status_code=200, data=[], is_reusable=False):
     httpx_mock.add_response(
         url='https://api.switcherapi.com/graphql',
         method='POST',
         status_code=status_code,
-        json={'data': data}
+        json={'data': data},
+        is_reusable=is_reusable
     )
 
 def given_context(url='https://api.switcherapi.com', 
@@ -143,4 +229,9 @@ def given_context(url='https://api.switcherapi.com',
 
 def load_snapshot_fixture(file_path: str):
     with open(file_path, 'r') as f:
-        return json.loads(f.read()).get('data', {})
+        return json.loads(f.read()).get('data', {})
+
+def delete_snapshot_file(snapshot_location: str, environment: str):
+    snapshot_file = f"{snapshot_location}/{environment}.json"
+    if os.path.exists(snapshot_file):
+        os.remove(snapshot_file)