refactor(euclid): refactor logs for evaluation of equality for dynamic routing evaluate response

[prajjwalkumar17]

Type of Change

• Bugfix
• New feature
• Enhancement
• Refactoring
• Dependency updates
• Documentation
• CI/CD

Description

This PR refactors the routing logic to improve how logs are emitted and connector evaluation is handled when dynamic routing is performed using the Decision Engine (Euclid). Key updates include:

• Replaces raw response propagation from perform_decision_euclid_routing with a wrapped RoutingEvaluateResponse containing both output and evaluated_output.
• Introduces a new function extract_de_output_connectors() to deserialize and normalize output from Euclid into a list of ConnectorInfo.
• Adds transform_de_output_for_router() to combine output and evaluated_output, ensuring deduplication and priority order.
• Enhances logging in compare_and_log_result to include diff details between de_result and router_result more clearly.
• Adds TryFrom<ConnectorInfo> for DeRoutableConnectorChoice to safely convert API inputs to internal representations.

Diff Hunk Explanation

crates/router/src/core/payments/routing.rs

• Renamed de_euclid_connectors → de_evaluated_connector to reflect the structured response.
• Wrapped perform_decision_euclid_routing call with success match block to:
  • Extract connectors from output using extract_de_output_connectors.
  • Merge output and evaluated_output using transform_de_output_for_router.
• Updated logs to emit clearer error/debug statements during extraction, transformation, and comparison.

crates/router/src/core/payments/routing/utils.rs

• Refactored perform_decision_euclid_routing to return RoutingEvaluateResponse instead of just connector list.
• Added extract_de_output_connectors: deserializes various output types (single, priority, volume_split, etc.).
• Added transform_de_output_for_router: deduplicates connectors and maintains priority between evaluated_output and fallback output.
• Improved compare_and_log_result to log equality and diff details between Decision Engine result and final connector result.
• Introduced TryFrom<ConnectorInfo> for DeRoutableConnectorChoice.

This refactor sets the stage for cleaner observability and deterministic routing behavior between evaluated and fallback paths.

How did you test it?

The testing guidelines are present in this doc.

Checklist

• I formatted the code cargo +nightly fmt --all
• I addressed lints thrown by cargo clippy
• I reviewed the submitted code
• I added unit tests for my changes where possible

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Changed Files

File	Status
crates/router/src/core/payments/routing.rs	18% smaller
crates/router/src/core/payments/routing/utils.rs	6% smaller