refactor(key-wallet): drop FeeLevel

[ZocoLini]

This PR drops FeeLEvel, the struct was just a wrapper around FeeRate that, at the same time, is a wrapper around u64 to represent duffs per kb, unnecessary layer imo

Summary by CodeRabbit

Refactor

• Replaced the predefined fee level system with direct fee rate configuration for transaction building, providing more granular control over transaction fees.
• Updated transaction builder APIs and method signatures across wallet operations to use the new fee rate model for consistency and simplification.

[coderabbitai]

Warning

Rate limit exceeded

@ZocoLini has exceeded the limit for the number of commits that can be reviewed per hour. Please wait 21 minutes and 39 seconds before requesting another review.

⌛ How to resolve this issue?

After the wait time has elapsed, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

We recommend that you space out your commits to avoid hitting the rate limit.

🚦 How do rate limits work?

CodeRabbit enforces hourly rate limits for each developer per organization.

Our paid plans have higher rate limits than the trial, open-source and free plans. In all cases, we re-allow further reviews after a brief timeout.

Please see our FAQ for further information.

📥 Commits

Reviewing files that changed from the base of the PR and between 7f6c198 and d560585.

📒 Files selected for processing (6)

• key-wallet-ffi/src/transaction.rs
• key-wallet-manager/src/wallet_manager/transaction_building.rs
• key-wallet/src/wallet/managed_wallet_info/fee.rs
• key-wallet/src/wallet/managed_wallet_info/transaction_builder.rs
• key-wallet/src/wallet/managed_wallet_info/transaction_building.rs
• key-wallet/src/wallet/managed_wallet_info/wallet_info_interface.rs

📝 Walkthrough

Walkthrough

This pull request removes the FeeLevel enum abstraction and replaces it with direct FeeRate usage throughout the transaction building and wallet management layers. The change simplifies fee configuration by eliminating the intermediate mapping level and directly using FeeRate values across the FFI, manager, and transaction building components.

Changes

Cohort / File(s)	Summary
Fee Model Refactoring key-wallet/src/wallet/managed_wallet_info/fee.rs	Removed FeeLevel enum and its impl block that provided fee_rate mapping, including associated tests.
Transaction Builder Updates key-wallet/src/wallet/managed_wallet_info/transaction_builder.rs	Replaced fee_level field (FeeLevel) with fee_rate (FeeRate); renamed set_fee_level() to set_fee_rate(); updated all internal logic to use FeeRate directly instead of deriving from FeeLevel.
Transaction Building Interface key-wallet/src/wallet/managed_wallet_info/transaction_building.rs, key-wallet/src/wallet/managed_wallet_info/wallet_info_interface.rs	Updated create_unsigned_payment_transaction signatures to use fee_rate: FeeRate parameter instead of fee_level: FeeLevel across trait and implementations.
Wallet Manager & FFI Integration key-wallet-manager/src/wallet_manager/transaction_building.rs, key-wallet-ffi/src/transaction.rs	Updated public API signatures in WalletManager and FFI layer to pass FeeRate directly to transaction building calls.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~15 minutes

Poem

🐰 A hopping refactor, so clean and so neat,
FeeLevel begone, FeeRate's the beat!
From abstract to direct, the fees now flow straight,
No mapping detours—we simplify fate! ✨

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title directly and concisely describes the main change: removing the FeeLevel type from the key-wallet crate.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch refactor/drop-fee-level

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

🧹 Nitpick comments (1)

key-wallet/src/wallet/managed_wallet_info/transaction_builder.rs (1)

48-63: LGTM!

Struct field correctly renamed from fee_level: FeeLevel to fee_rate: FeeRate. The doc comment "Fee rate or level" could be simplified to just "Fee rate" since FeeLevel is being removed.

📝 Optional: Update doc comment

     /// Change address
     change_address: Option<Address>,
-    /// Fee rate or level
+    /// Fee rate (satoshis per kilobyte)
     fee_rate: FeeRate,

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@key-wallet/src/wallet/managed_wallet_info/transaction_builder.rs` around
lines 48 - 63, Update the doc comment for the TransactionBuilder field fee_rate
to remove the obsolete "or level" phrasing—replace "Fee rate or level" with
simply "Fee rate" in the TransactionBuilder struct definition to reflect that
FeeLevel was removed; ensure you edit the doc comment above the fee_rate:
FeeRate field.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@key-wallet/src/wallet/managed_wallet_info/transaction_builder.rs`:
- Around line 48-63: Update the doc comment for the TransactionBuilder field
fee_rate to remove the obsolete "or level" phrasing—replace "Fee rate or level"
with simply "Fee rate" in the TransactionBuilder struct definition to reflect
that FeeLevel was removed; ensure you edit the doc comment above the fee_rate:
FeeRate field.

---

ℹ️ Review info

Configuration used: defaults

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 2fa3224 and 7f6c198.

📒 Files selected for processing (6)

• key-wallet-ffi/src/transaction.rs
• key-wallet-manager/src/wallet_manager/transaction_building.rs
• key-wallet/src/wallet/managed_wallet_info/fee.rs
• key-wallet/src/wallet/managed_wallet_info/transaction_builder.rs
• key-wallet/src/wallet/managed_wallet_info/transaction_building.rs
• key-wallet/src/wallet/managed_wallet_info/wallet_info_interface.rs

💤 Files with no reviewable changes (1)

• key-wallet/src/wallet/managed_wallet_info/fee.rs

[xdustinface]

Suggested change

	/// Fee rate (satoshis per kilobyte)
	/// Fee rate (duffs per kilobyte)

In Dash its duffs. We are anyway not consistent with this yet but generally i think better if we don't introduce more of them.

[ZocoLini]

I could have fixed that :( I did copy paste a coderabbit suggestion and I didn't notice it used satoshis instead of duffs