Refactor Registry.kt with Polymorphic Behavior Model

[candour]

This refactoring replaces a conditional-heavy architecture with a polymorphic behavior model in Registry.kt. It improves code maintainability and follows clean coding principles by delegating type-specific logic to specialized behavior classes.

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PR created automatically by Jules for task 9736991352443048903 started by @candour

Summary by CodeRabbit

• Bug Fixes

  • Puddle slow now correctly applies when enemies occupy permanently wet tiles, improving slowdown consistency.

• Refactor

  • Stall and enemy behavior logic reorganized into per-type behavior strategies for more consistent and maintainable effects.

• Documentation

  • Added a release note entry documenting the behavior refactor.

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ℹ️ Recent review info

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Configuration used: Organization UI

Review profile: CHILL

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Run ID: d1de2a0e-d955-426c-8009-7f0fc3aff830

📥 Commits

Reviewing files that changed from the base of the PR and between 41cf259 and 0c7a5a6.

📒 Files selected for processing (1)

• app/src/main/java/com/messark/hawker/registry/Registry.kt

🚧 Files skipped from review as they are similar to previous changes (1)

• app/src/main/java/com/messark/hawker/registry/Registry.kt

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📝 Walkthrough

Walkthrough

This PR refactors stall and enemy combat behavior from type-based conditional logic into a polymorphic strategy pattern, introducing StallBehavior and EnemyBehavior interfaces. Concrete behavior implementations replace hardcoded when expressions in definitions, registries wire each stall and enemy type to the appropriate behavior strategy, and MainViewModel's puddle-slow logic is simplified to delegate through the behavior interface.

Changes

Behavior Strategy Pattern and Registry Refactor

Layer / File(s)	Summary
Behavior interfaces and defaults app/src/main/java/com/messark/hawker/registry/Registry.kt	StallBehavior and EnemyBehavior interfaces define method contracts for damage modifiers, freeze modifiers, speed boosts, puddle slow, and special behavior updates. DefaultStallBehavior and DefaultEnemyBehavior provide baseline implementations.
Stall behavior implementations app/src/main/java/com/messark/hawker/registry/Registry.kt	TehTarikStallBehavior creates sticky puddles with DRAIN tile duration halving. SatayStallBehavior applies enemy-type-specific damage and fires arc projectiles. DurianStallBehavior grants speed boost against SALARYMAN. IceKachangStallBehavior applies freeze durations by enemy type and fires freeze projectiles.
Enemy behavior implementations app/src/main/java/com/messark/hawker/registry/Registry.kt	TouristEnemyBehavior implements time-based stop/start logic with configurable stop duration. DeliveryRiderEnemyBehavior and AuntieEnemyBehavior specialize puddle slow multipliers.
Definition delegation and registry wiring app/src/main/java/com/messark/hawker/registry/Registry.kt	StallDefinition and EnemyDefinition add behavior fields and delegate modifier computation, firing, puddle slow, and special behavior updates to configured strategies. StallRegistry entries for TEH_TARIK, SATAY, DURIAN, ICE_KACHANG and EnemyRegistry entries for TOURIST, DELIVERY_RIDER, AUNTIE are updated to instantiate the correct behavior implementations.
MainViewModel enemy movement app/src/main/java/com/messark/hawker/MainViewModel.kt	Enemy puddle slow calculation now delegates to enemyDef.getPuddleSlowMultiplier() and applies slow when the enemy stands on a permanently wet hex, replacing prior proximity-based puddle lookups.
Changelog entry fixes.md	REF-007 documents the behavior refactor, registry polymorphism, and MainViewModel simplification.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~60 minutes

Possibly related PRs

• candour/towerpower#147: Both PRs touch the same puddle-slow mechanic: they modify MainViewModel.updateGame to apply additional enemy speed slowdown when a tile is isPermanentlyWet, relying on the registry’s per-enemy puddle slow multiplier logic.
• candour/towerpower#151: Both PRs modify Registry.kt’s stall-firing logic for TEH_TARIK and SATAY and related registry wiring concerns.
• candour/towerpower#125: Both PRs modify MainViewModel’s enemy movement/puddle slow logic and are related at the code-level for slow computation.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 3.23% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately reflects the main change in the pull request—a refactoring of Registry.kt to implement a polymorphic behavior model that replaces type-based conditional logic with delegated behavior classes.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

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• Create stacked PR
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🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch refactor-registry-polymorphism-9736991352443048903

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[github-actions]

Build Successful! 🚀

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[coderabbitai]

Actionable comments posted: 1

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 50b7d86f-07b1-434d-8cbb-ce3d86fa954f

📥 Commits

Reviewing files that changed from the base of the PR and between 3fd62d6 and 41cf259.

📒 Files selected for processing (3)

• app/src/main/java/com/messark/hawker/MainViewModel.kt
• app/src/main/java/com/messark/hawker/registry/Registry.kt
• fixes.md

[candour]

Initialize Tourist lastStopMs at spawn time to prevent immediate stall.

The Enemy model defaults lastStopMs to 0L, and EnemyRegistry.toEnemy() does not override this. When a Tourist spawns at any time after ~8 seconds, the condition on line 203 (currentTimeMs - lastStopMs > 8000) evaluates true immediately, causing the tourist to stall on its first update tick. Initialize lastStopMs = currentTimeMs when spawning tourists, or set it on first behavior update.

[google-labs-jules]

Initialize Tourist lastStopMs at spawn time to prevent immediate stall.

The Enemy model defaults lastStopMs to 0L, and EnemyRegistry.toEnemy() does not override this. When a Tourist spawns at any time after ~8 seconds, the condition on line 203 (currentTimeMs - lastStopMs > 8000) evaluates true immediately, causing the tourist to stall on its first update tick. Initialize lastStopMs = currentTimeMs when spawning tourists, or set it on first behavior update.

Great catch! I've updated TouristEnemyBehavior.updateSpecialBehavior to initialize lastStopMs to currentTimeMs if it's currently 0L. This ensures Tourists don't stall immediately upon spawning if the game has already been running for a while.

[github-actions]

Build Successful! 🚀

Download APK

Note: This link will be removed when the PR is closed.