week-6-7-database-planning

Week 6-7: Database Migration Planning & Pattern 3 Review

Period: October 21-26, 2025 Agent: Agent 2 (AAM - Architecture, Android, Multi-platform) Status: ✅ COMPLETE

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Overview

Week 6-7 focused on two critical deliverables:

1. Week 6: Create comprehensive entity migration execution plan for Week 9-10
2. Week 7: Review Agent 1’s Pattern 3 implementation (Context Abstraction)

Strategic Goal: Make Week 9-10 entity migration “paint by numbers” through detailed planning and ensure Pattern 3 quality for Week 8 service migrations.

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Week 6: Entity Migration Execution Plan

Objective

Create a comprehensive execution plan for migrating 17 Room entities from app module to shared:database with kotlinx.serialization support.

Deliverable

PR #150: Added Phase 1 section to DATABASE_MIGRATION_PLAN.md (+789 lines)

Key Components:

1. Entity Inventory (22 total)

   • ✅ 5 already migrated to shared:domain
   • 🎯 17 to migrate in Week 9-10

2. Migration Tracker Table (23 rows)

   • Entity name
   • Current location
   • Target location
   • Android dependencies identified
   • Migration complexity
   • Estimated effort

3. Daily Breakdown (Week 9-10)

   • Day 1-3: kotlinx.serialization migration (Agent 2 lead)
   • Day 4-5: Simple entities (7 entities, ~2 hours)
   • Day 6-8: Medium entities (6 entities, ~3 hours)
   • Day 9-10: Complex entities (4 entities, ~1 hour)

4. Migration Patterns (4 documented)

   • Pattern 1: Simple entity (just add @Serializable)
   • Pattern 2: Date→Long conversion
   • Pattern 3: Enum handling
   • Pattern 4: Foreign key relationships

5. Testing Strategy

   • Incremental: Test each entity after migration
   • Daily: End-of-day smoke tests
   • Comprehensive: Final validation suite

Key Findings

Android Dependency Analysis:

• ✅ Only 1 entity needs conversion: ArrowEquipmentSnapshot
  • Uses java.util.Date at line 57
  • Migration: capturedAt: Date → capturedAt: Long
• ✅ 16/17 entities are KMP-ready (just need @Serializable)

Complexity Assessment:

• Simple (7 entities): ~15 min each = 2 hours
• Medium (6 entities): ~30 min each = 3 hours
• Complex (4 entities): ~15 min each = 1 hour
• Total: ~6 hours for 17 entities

Challenges & Solutions

Challenge 1: Merge Conflict

• Issue: DATABASE_MIGRATION_PLAN.md had 6 PRs merged since branch creation
• Conflict: Both my Section 7 (Phase 1 plan) and main’s Section 7 (Risks) at different lines
• Solution: Kept both sections, renumbered main’s Section 7→8, updated all subsequent sections (8→9, 9→10, etc.)
• Outcome: Clean merge with all 14 sections properly numbered

Challenge 2: Git Worktree

• Issue: git checkout main failed (main branch used by another worktree)
• Solution: Used git pull origin main directly (worked despite worktree)
• Learning: Can pull from remote without checking out branch locally

Challenge 3: Uncommitted local.properties

• Issue: Machine-specific SDK path changes in local.properties
• Solution: git restore local.properties to discard
• Prevention: Confirmed local.properties in .gitignore

Files Changed

• docs/kmp-migration/DATABASE_MIGRATION_PLAN.md (+789 lines, now 2,109 total)
  • Section 7: Phase 1 Entity Migration Execution Plan
  • Entity inventory table
  • Week 9-10 daily breakdown
  • Migration patterns with code examples
  • Testing strategy

Impact

• ✅ Week 9-10 is now “paint by numbers” (~6 hours for 17 entities)
• ✅ Migration patterns documented for team reference
• ✅ Android dependencies de-risked (only 1/17 needs conversion)

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Week 7: Pattern 3 PR Review

Objective

Comprehensive review of Agent 1’s Pattern 3 implementation before merge.

Deliverable

PR #152 Review: APPROVED with EXCELLENT rating across all criteria

PR Details:

• 12 new files
• ~1,900 lines of code
• 57 tests (53 production + 4 fake implementations)

Review Methodology

6-Point Comprehensive Review (3 hours):

1. Interface Design Quality (30 min) - ✅ EXCELLENT

   • Read all 3 interfaces: FileSystemProvider, PreferenceStorage, ResourceProvider
   • Verified suspend functions for async operations
   • Confirmed platform-agnostic signatures

2. Android Implementation Quality (45 min) - ✅ EXCELLENT

   • Reviewed AndroidFileSystemProvider, AndroidPreferenceStorage, AndroidResourceProvider
   • Validated Dispatchers.IO usage for I/O operations
   • Checked proper Android context handling

3. Test Fake Quality (30 min) - ✅ EXCELLENT

   • Examined FakeFileSystemProvider, FakePreferenceStorage, FakeResourceProvider
   • Verified in-memory storage for test isolation
   • Confirmed thread-safe implementations

4. Test Coverage Quality (45 min) - ✅ EXCELLENT

   • Counted and categorized all 57 tests
   • Verified edge cases covered (empty strings, null handling, concurrency)
   • Validated error scenarios tested

5. Build & Integration (30 min) - ✅ EXCELLENT

   • Ran builds: All passed
   • Ran tests: 100% pass rate
   • No compilation warnings

6. Documentation Quality (15 min) - ✅ EXCELLENT

   • Reviewed KDoc for all interfaces
   • Verified usage examples
   • Confirmed migration guide clarity

Key Architectural Strengths

Pattern 3: Context Abstraction

• Platform-agnostic interfaces for Android context dependencies
• Proper separation of concerns (Interface Segregation Principle)
• Test-friendly design with comprehensive fakes
• Consistent async patterns (suspend functions)

Code Quality:

• Comprehensive test coverage (57 tests)
• Thread-safe implementations
• Proper error handling
• Clear documentation

Review Outcome

• Rating: EXCELLENT across all 6 criteria
• Recommendation: APPROVE for merge
• Confidence: High - Pattern 3 validated for Week 8 service migrations

Impact

• ✅ Pattern 3 approved for production use
• ✅ Agent 1’s architecture validated
• ✅ Foundation ready for Week 8 service migrations (ArcherService, TournamentService, StatisticsService)

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Week 6-7 Combined Impact

Strategic Achievements

1. Week 9-10 Planning Complete

   • Detailed execution plan created
   • Effort estimated at ~6 hours for 17 entities
   • Migration patterns documented
   • Risk de-escalated (only 1 Android dependency)

2. Pattern 3 Validated

   • Comprehensive review completed
   • Quality confirmed across 6 dimensions
   • Ready for Week 8 service migrations

3. Documentation Enhanced

   • DATABASE_MIGRATION_PLAN.md now 2,109 lines
   • Agent context updated (AGENT_2_AAM.md)
   • Obsidian vault updated

Success Metrics

• ✅ PR #150 merged (Week 6 planning)
• ✅ PR #152 reviewed and approved (Week 7 review)
• ✅ 0 blockers for Week 8-10
• ✅ 100% test pass rate maintained
• ✅ 58% ahead of schedule (cumulative)

Lessons Learned

Git Workflow:

• Merge conflicts manageable with systematic section renumbering
• Worktree conflicts can be bypassed with direct remote pulls
• Always check for uncommitted machine-specific files (local.properties)

Planning Approach:

• Incremental entity analysis (sample first, then comprehensive)
• Daily breakdown creates actionable tasks
• Code examples in documentation reduce implementation time

Review Methodology:

• 6-point checklist ensures thorough evaluation
• Running builds/tests validates integration
• Time-boxed review prevents scope creep (3 hours total)

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Week 8 Preview

Agent 1 Lead: Week 8 service migrations using Pattern 3

• ArcherService
• TournamentService
• StatisticsService

Agent 2 Support: Review and validation as needed

Week 9 Transition: Agent 2 leads kotlinx.serialization migration (Days 1-3)

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Related Documentation

Main Repository:

• docs/kmp-migration/DATABASE_MIGRATION_PLAN.md (Section 7: Phase 1)
• docs/AGENT_CONTEXTS/AGENT_2_AAM.md (Session Resume Point)

PRs:

• PR #150: Week 6 entity migration plan (merged)
• PR #152: Week 7 Pattern 3 review (merged)

Obsidian Vault:

• projects/kmp-migration/Week 6-7 Database Planning.md (this file)
• Architecture/Database-Migration-Status.md (status tracker)

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Last Updated: 2025-10-26 Status: Week 6-7 COMPLETE ✅