From 58ca94348cda6eceb63d2c637fcf48b0a24c24ed Mon Sep 17 00:00:00 2001
From: ff137 <ff137@proton.me>
Date: Sat, 17 Feb 2024 17:25:29 +0200
Subject: [PATCH] :sparkles: define `coroutine_with_retry_until_value`

Specifically to be used in setting the tails public uri for a revocation registry. We must assert that the URI is updated before proceeding, and this coroutine will check a coroutine call until an expected value is returned
---
 app/util/retry_method.py | 60 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/app/util/retry_method.py b/app/util/retry_method.py
index d462993ceb..6a3abd51b4 100644
--- a/app/util/retry_method.py
+++ b/app/util/retry_method.py
@@ -23,3 +23,63 @@ async def coroutine_with_retry(
             )
             await asyncio.sleep(retry_delay)
     return result
+
+
+async def coroutine_with_retry_until_value(
+    coroutine_func: Callable,
+    args: Tuple,
+    expected_value: Any,
+    logger: Logger,
+    max_attempts: int = 5,
+    retry_delay: int = 2,
+) -> Any:
+    """
+    Executes a coroutine function with retries until it returns an expected value
+    or until a maximum number of attempts is reached.
+
+    Args:
+        coroutine_func (Callable): The coroutine function to be called. It should be awaitable.
+        args (Tuple): The arguments to pass to the coroutine function.
+        expected_value (Any): The value that the coroutine should return for the call to be considered successful.
+        logger (Logger): Logger instance used to log information and warnings about the retry attempts and exceptions.
+        max_attempts (int, optional): The maximum number of attempts to make. Defaults to 5.
+        retry_delay (int, optional): The delay in seconds between attempts. Defaults to 2.
+
+    Returns:
+        Any: The result of the coroutine if it matches the expected value within the allowed number of attempts.
+             Returns `None` if the maximum number of attempts is reached without achieving the expected result.
+
+    Raises:
+        Exception: Re-raises any exception encountered on the final attempt.
+    """
+    for attempt in range(max_attempts):
+        try:
+            result = await coroutine_func(*args)
+            if result == expected_value:
+                return result
+            else:
+                if attempt + 1 < max_attempts:
+                    logger.info(
+                        f"Coroutine returned {result} instead of expected {expected_value} "
+                        f"(attempt {attempt + 1}). Retrying in {retry_delay} seconds..."
+                    )
+                else:
+                    logger.error(
+                        "Maximum number of retries exceeded without returning expected value."
+                    )
+                    return
+
+        except Exception as e:
+            if attempt + 1 == max_attempts:
+                logger.error(
+                    "Maximum number of retries exceeded with exception. Failing."
+                )
+                raise e  # Re-raise the exception if max attempts exceeded
+
+            logger.warning(
+                f"Exception encountered (attempt {attempt + 1}). "
+                f"Reason: \n{e}.\n"
+                f"Retrying in {retry_delay} seconds..."
+            )
+
+        await asyncio.sleep(retry_delay)