feat: improve Raffl Protocol to v2

[ubinatus]

Overview

This PR introduces significant improvements to the Raffl Protocol, including a comprehensive VRF recovery system, performance optimizations, security enhancements, and extensive documentation. The changes represent a major version bump to v2.0.0.

📊 Summary Statistics

• Files Changed: 65 files
• Additions: +13,066 lines
• Deletions: -273 lines
• Net Change: +12,793 lines
• New Test Files: 10
• New Documentation Files: 7

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🚀 Major Features

1. VRF Recovery System

Problem Solved: Previously, raffles could get permanently stuck if Chainlink VRF requests failed or timed out, leaving user funds locked in the contract.

Solution: Implemented a comprehensive recovery system with two permissionless mechanisms:

Retry VRF Request (retryVRFRequest)

• Allows anyone to retry a stuck VRF request
• Available immediately when a raffle is in pending state
• Creates a new VRF request with updated tracking
• Emits VRFRequestRetried event for monitoring

Emergency Fail (emergencyFailRaffle)

• Time-locked recovery mechanism (24-hour timeout)
• Marks raffle as failed and enables refunds for all participants
• Permissionless - anyone can trigger after timeout
• Emits RaffleEmergencyFailed event

Key Changes:

• Added VRFRequest struct to track request status and timing
• Added VRFStatus enum (None, Pending, Fulfilled, Failed)
• New mappings: _raffleVRFRequests and _requestIds
• Enhanced fulfillRandomWords to handle retry scenarios
• Comprehensive test coverage (34 new tests)

Documentation Added:

• VRF-RECOVERY-USER-GUIDE.md - User-friendly guide
• VRF-RECOVERY-TECHNICAL.md - Developer documentation
• VRF-RECOVERY-QUICK-REFERENCE.md - Quick reference card
• VRF-RECOVERY-README.md - Overview and index

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2. Performance Optimizations

Storage Layout Optimization

• Raffl.sol: Reduced from ~17 storage slots to ~11 slots

  • Packed factory, settled, prizesRefunded, gameStatus into single slot
  • Reordered state variables for optimal 32-byte alignment

• RafflFactory.sol: Optimized struct packing

  • Packed callbackGasLimit, requestConfirmations, nativePayment into one slot
  • Changed VRFRequest.requestTime from uint256 to uint64 (2 slots → 1 slot)
  • Changed ActiveRaffle.deadline from uint256 to uint64 (2 slots → 1 slot)

O(1) Raffle Removal

• Added _raffleToActiveIndex mapping for O(1) lookup
• Replaced O(n) linear search with O(1) index lookup in _removeRaffleFromActive
• Significant gas savings when removing raffles from active list

Storage Read Caching

• Raffl.sol:

  • Cache entryPrice in buyEntries() to avoid redundant SLOAD
  • Cache entryToken in refundEntries() and _purchaseEntry()
  • Pass cached values to helper functions as parameters

• RafflFactory.sol:

  • Cache _activeRaffles.length in checkUpkeep() loop
  • Pre-calculate loop iterations to avoid repeated subtraction
  • Use unchecked increment in loops where overflow is impossible

Gas Impact: Reduces gas costs for frequently called functions by minimizing storage reads (SLOAD = 2100 gas cold, 100 gas warm).

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3. Security Enhancements

Slither Warning Fixes

• Renamed requestId parameter to vrfRequestId to avoid shadowing state variable
• Added SubscriptionConfigUpdated event to handleSubscription() for better monitoring
• Added indexed parameter to RaffleCreated event for efficient log filtering
• Updated IRaffl interface with improved NatSpec documentation

Enhanced Error Handling

• Improved validation checks for prize and entry conditions
• Better error messages for ETH transfers and token operations in TokenLib
• Refactored contract modifiers for improved readability

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4. Comprehensive Test Suite

Added 10 new test files covering:

• Access Control (RafflFactory.AccessControl.t.sol) - 467 lines
• Edge Cases (RafflFactory.EdgeCases.t.sol) - 579 lines
• VRF Retry (RafflFactory.VRFRetry.t.sol) - 547 lines
• VRF Retry ERC20 (RafflFactory.VRFRetryERC20.t.sol) - 161 lines
• Chainlink Exceptions (Raffl.ChainlinkExceptions.t.sol) - 531 lines
• Disperse Rewards (Raffl.DisperseRewards.t.sol) - 481 lines
• Fuzz Testing (Raffl.Fuzz.t.sol) - 545 lines
• Integration Tests (Raffl.Integration.t.sol) - 550 lines
• Security Tests (Raffl.Security.t.sol) - 622 lines
• VRF Callback Failure (Raffl.VRFCallbackFailure.t.sol) - 325 lines
• VRF Edge Cases (Raffl.VRFEdgeCases.t.sol) - 447 lines
• Entries Edge Cases (Raffl.EntriesEdgeCases.t.sol) - 493 lines
• Extra Recipient Edge Cases (Raffl.ExtraRecipientEdgeCases.t.sol) - 540 lines
• ERC721 Prizes (Raffl.ERC721Prizes.t.sol) - 594 lines
• Token Gating (Raffl.TokenGating.t.sol) - 464 lines

Total New Test Coverage: ~6,500+ lines of comprehensive test cases

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5. Documentation

Added comprehensive documentation suite:

1. PROTOCOL_OVERVIEW.md (1,624 lines)

   • Complete protocol architecture
   • Lifecycle flowcharts
   • Data structures
   • Fee system details
   • Entry system explanation
   • Security features

2. ENTERPRISE-AUDIT-PREPARATION-SUMMARY.md (699 lines)

   • Audit readiness checklist
   • Security considerations
   • Testing methodology

3. AUDIT-READINESS-REPORT.md (577 lines)

   • Detailed audit preparation status
   • Code quality metrics

4. VRF Recovery Documentation (4 files, ~2,100 lines total)

   • User guide
   • Technical documentation
   • Quick reference
   • Overview and index

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6. Code Quality Improvements

Solidity Version Upgrade

• Upgraded from previous version to Solidity 0.8.33 across all contracts
• Improved compiler optimizations and gas efficiency

Code Refactoring

• Enhanced contract modifiers with internal functions for better readability
• Improved loop patterns using length variables
• Better separation of concerns in helper functions
• Updated interfaces with comprehensive NatSpec

Dependency Updates

• Updated bun.lockb with latest dependencies
• Updated package.json dependencies
• Upgraded Solidity linter configuration

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🔧 Technical Details

Contract Changes

RafflFactory.sol

• Added VRF recovery system with retry and emergency fail
• Optimized storage layout (packed structs)
• Added O(1) raffle removal mechanism
• Enhanced event emissions for monitoring
• Improved gas efficiency in checkUpkeep()

Raffl.sol

• Optimized storage layout (reduced slots)
• Added storage read caching
• Enhanced error handling
• Improved modifier patterns

Interface Updates

• IRaffl.sol: Added new functions and improved documentation
• IFactoryFeeManager.sol: Enhanced interface definitions
• IFeeManager.sol: Updated interface

Error Libraries

• RafflErrors.sol: Added new error types
• RafflFactoryErrors.sol: Added VRF-related errors

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📝 Breaking Changes

Version Bump

• Version: Bumped to v2.0.0 across all contracts
• Indicates major feature additions and improvements

Interface Changes

• New functions in RafflFactory:
  • retryVRFRequest(address raffle)
  • emergencyFailRaffle(address raffle)
  • getVRFRequestInfo(address raffle)
  • hasVRFRequestTimedOut(address raffle)

Event Changes

• New events:
  • VRFRequestRetried(address indexed raffle, uint256 indexed requestId)
  • RaffleEmergencyFailed(address indexed raffle)
  • SubscriptionConfigUpdated(...)
• Enhanced RaffleCreated event with indexed parameter

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✅ Testing

Test Coverage

• Total Tests: 127+ (34 new + 93 existing)
• Status: ✅ All Passing
• New Test Categories:
  • VRF recovery scenarios
  • Edge cases and boundary conditions
  • Security vulnerability tests
  • Fuzz testing
  • Integration tests
  • Access control tests

Test Files Modified

• Updated existing tests to reflect new contract interfaces
• Enhanced mock contracts (VRFCoordinatorV2PlusMock.sol)
• Improved test utilities (Common.sol)

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🔒 Security Considerations

1. Time-locked Emergency Fail: 24-hour timeout prevents abuse
2. Permissionless Recovery: No single point of failure
3. Strict Validation: All recovery functions have comprehensive checks
4. Event Monitoring: Full event history for transparency
5. Test Coverage: Comprehensive security test suite

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📦 Dependencies

• Updated bun.lockb (110,477 → 131,008 bytes)
• Updated package.json dependencies
• Solidity version: 0.8.33

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🎯 Migration Notes

For Users

• No action required - all changes are backward compatible for existing raffles
• New recovery features are available for all raffles created after deployment

For Developers

• Review new RafflFactory functions for integration
• Update frontend to handle new events
• Consider implementing monitoring for VRF recovery events

For Auditors

• See ENTERPRISE-AUDIT-PREPARATION-SUMMARY.md for detailed audit information
• All security warnings addressed
• Comprehensive test coverage provided

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📚 Documentation

All documentation is located in the /docs directory:

• Protocol Overview: PROTOCOL_OVERVIEW.md
• VRF Recovery: VRF-RECOVERY-README.md (start here)
• Audit Preparation: ENTERPRISE-AUDIT-PREPARATION-SUMMARY.md
• Quick Reference: VRF-RECOVERY-QUICK-REFERENCE.md

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🚦 Deployment Checklist

• All tests passing
• Security warnings addressed
• Documentation complete
• Version bumped to v2.0.0
• Gas optimizations verified
• Interface changes documented
• Breaking changes identified

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📈 Impact

User Experience

• ✅ Funds can never be permanently locked
• ✅ Clear recovery paths for stuck raffles
• ✅ Better gas efficiency for participants

Developer Experience

• ✅ Comprehensive documentation
• ✅ Well-tested codebase
• ✅ Clear interfaces and events

Protocol Health

• ✅ Improved security posture
• ✅ Better gas efficiency
• ✅ Enhanced monitoring capabilities

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🔗 Related Issues

This PR addresses:

• VRF timeout and failure scenarios
• Gas optimization opportunities
• Security audit preparation
• Documentation gaps
• Test coverage improvements

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📅 Version

v2.0.0 - Major Release

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This PR represents a significant milestone in the Raffl Protocol's development, introducing critical recovery mechanisms, performance improvements, and comprehensive documentation to ensure a robust and user-friendly raffle platform.