prioritize turns URLs

[sebvanleuven]

aioirtc only uses the first ICE serverin a list. This might be a problem when default TURN over UDP doesn't work. TURN over TLS has the highest likelihood for success.
As the PythonSDK targets backend use cases, the use of TCP transport is not a major concern.

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Summary by cubic

Prioritize TURNS (turns:) URLs per ICE server so aiortc, which uses the first TURN URI, picks the most reliable endpoint. Sorting is stable during session parsing, preserving original order within each group and improving WebRTC success when UDP TURN fails in backend SDK cases.

^{Written for commit a3baa31. Summary will update on new commits.}

[cubic-dev-ai]

2 issues found across 2 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="src/anam/types.py">

<violation number="1" location="src/anam/types.py:238">
P2: The sort key includes the URL as a secondary key, so non-`turns:` entries are reordered alphabetically. This can unintentionally change the original ICE URL order (e.g., moving `stun:` ahead of `turn:`) when there are no `turns:` entries. If the goal is only to prioritize `turns:`, use a stable key that preserves original order for all other URLs.</violation>

<violation number="2" location="src/anam/types.py:278">
P2: `client_config.get("iceServers", [])` returns `None` if the API sends `iceServers: null`, and `_reorder_ice_server_urls` will then raise a `TypeError` when iterating. Coerce null to an empty list to avoid a runtime crash on valid API responses.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[sebvanleuven]

Decided to not automatically reorder ICE servers