feat: implement endpoint for createTopic method

[MonaaEid]

Description:
This pull request introduces a new "create topic" feature, along with improvements and refactoring to the key handling. The most significant changes are the addition of topic creation support with custom fee parameters, enhancements to key generation formatting and error handling.

New Topic Creation Feature:

• Added a new handler tck/handlers/topic.py implementing the createTopic RPC method, supporting topic creation with custom fees, admin/submit keys, auto-renew account handling, and error mapping for various account states.
• Introduced parameter classes in tck/param/topic.py (CreateTopicParams, CreateTopicCustomFeeParams, CreateTopicFixedFeeParams) to parse and validate topic creation parameters, including support for custom fees and key lists.
• Added a response dataclass CreateTopicResponse in tck/response/topic.py for standardized topic creation responses.

Key Handling Improvements:

• Refactored key generation in tck/handlers/key.py to use a helper for canonical public key formatting, improved error messages, and standardized recursive key processing and handler signatures for clarity and maintainability.

Related issue(s):

Fixes #2207

Notes for reviewer:
64 tests passed

Checklist

• Documented (Code comments, README, etc.)
• Tested (unit, integration, etc.)

[codacy-production]

Up to standards ✅

🟢 Issues 0 issues

Results:
0 new issues

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[coderabbitai]

Actionable comments posted: 5

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro

Run ID: 48aea2b7-e248-4042-b628-0f2bae8d7d0f

📥 Commits

Reviewing files that changed from the base of the PR and between bcc8417 and d7211e4.

📒 Files selected for processing (8)

• tck/handlers/__init__.py
• tck/handlers/key.py
• tck/handlers/topic.py
• tck/param/common.py
• tck/param/topic.py
• tck/response/topic.py
• tck/util/param_utils.py
• tests/tck/topic_handlers_test.py

[aceppaluni]

Happy to review when changes are addressed.

[coderabbitai]

Actionable comments posted: 2

♻️ Duplicate comments (3)

tck/param/topic.py (2)

23-28: ⚠️ Potential issue | 🟠 Major | ⚡ Quick win

Reject malformed fixedFee.amount during parsing.

When amount is a non-numeric value (e.g., "bad"), to_int() returns None instead of raising an error. This allows invalid input to pass parameter validation and fail later during transaction construction, producing an internal error instead of a proper invalid params response at the JSON-RPC boundary.

🛡️ Proposed fix

 `@classmethod`
 def parse_json_params(cls, params: dict) -> CreateTopicFixedFeeParams:
+    amount = to_int(params.get("amount"))
+    if amount is None:
+        raise ValueError("fixedFee.amount must be an integer")
     return cls(
-        amount=to_int(params.get("amount")),
+        amount=amount,
         denominatingTokenId=non_empty_string_or_none(params.get("denominatingTokenId")),
     )

---

39-51: ⚠️ Potential issue | 🟠 Major | ⚡ Quick win

Validate fixedFee structure when present.

If the caller provides {"fixedFee": "bad"} (a non-dict value), line 50's isinstance check fails and the method silently assigns None instead of raising a validation error. This masks malformed input that should be rejected at the parameter boundary.

🛡️ Proposed fix

 `@classmethod`
 def parse_json_params(cls, params: dict) -> CreateTopicCustomFeeParams:
     fixed_fee = params.get("fixedFee")
+    if fixed_fee is not None and not isinstance(fixed_fee, dict):
+        raise ValueError("fixedFee must be an object")

     fee_collector_account_id = params.get("feeCollectorAccountId")
     if isinstance(fee_collector_account_id, str):
         fee_collector_account_id = fee_collector_account_id.strip()

     return cls(
         feeCollectorAccountId=fee_collector_account_id,
         feeCollectorsExempt=to_bool(params.get("feeCollectorsExempt")),
         fixedFee=(CreateTopicFixedFeeParams.parse_json_params(fixed_fee) if isinstance(fixed_fee, dict) else None),
     )

tck/handlers/topic.py (1)

70-82: ⚠️ Potential issue | 🟠 Major | ⚡ Quick win

Fail fast when the session does not resolve to a client.

get_client() at line 72 can return None, but lines 80 and 82 use client without validation. An unrecognized sessionId will surface as an internal error (likely AttributeError or SDK exception) instead of a deterministic JSON-RPC error.

🛡️ Proposed fix

 `@rpc_method`("createTopic")
 def create_topic(params: CreateTopicParams) -> CreateTopicResponse:
     client = get_client(params.sessionId)
+    if client is None:
+        raise ValueError("Unknown session ID")

     transaction = _build_create_topic_transaction(params)

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro

Run ID: cbbd17ed-a99b-4cd4-9659-c3e2d13cf95a

📥 Commits

Reviewing files that changed from the base of the PR and between 1e8aa1d and a621641.

📒 Files selected for processing (2)

• tck/handlers/topic.py
• tck/param/topic.py

[AntonioCeppellini]

Hi @MonaaEid great work so far :D
i agree with the 3 coderabbit suggestions.
are there any tests incoming for this PR?

[aceppaluni]

I agree with code rabbit. Please let us know if you have questions on the suggestions

Additionally, did you commit test files?

[MonaaEid]

Nope, there are no test files in unit/integration tests if you mean that @AntonioCeppellini @aceppaluni

[manishdait]

@MonaaEid, Please update the branch

[AntonioCeppellini]

LETSGOOOOO 🚀 🥦

integration tests not relevant in this case

[github-actions]

👋 Hi @MonaaEid! Great work completing a Advanced issue! 🎉

Thanks for your contribution! 🚀

Here are some issues you might want to explore next:

• [Advanced]: Integrate Code Coverage for C++ SDK

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