strat-gameplay-webapp/.claude/implementation/NEXT_SESSION.md

Next Session Plan - Week 8: Substitutions & Advanced Gameplay

Current Status: Phase 3 - Week 7 Complete (100%) ✅ → Starting Week 8 Last Commit: 4cf349a - "CLAUDE: Update NEXT_SESSION.md - Week 7 complete at 100%" Date: 2025-10-31 Next Priority: Week 8 - Player substitutions, pitching changes, and game management features

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🎉 Week 7 Summary - COMPLETE!

All 8 tasks completed successfully:

Task 1: Strategic Decision Integration ✅

• Async decision workflow with asyncio.Future
• Defensive decision queue: alignment, infield/outfield depth, hold runners
• Offensive decision queue: approach, steal attempts, bunting
• Full integration with GameEngine

Task 2: Decision Validators ✅ (54 tests)

• DefensiveDecision validation: positioning rules, depth requirements
• OffensiveDecision validation: steal/bunt prerequisites
• Lineup validation: complete defensive positioning
• Game flow validation: inning/out state checks

Task 3: Result Charts + PD Auto Mode ✅ (21 tests)

• ResultChart abstract base class
• PdAutoResultChart for auto-generated outcomes
• ManualResultChart for player submissions
• calculate_hit_location() helper (pull rates, handedness)
• ManualOutcomeSubmission validation model

Task 4: Runner Advancement Logic ✅ (30 tests)

• RunnerAdvancement class with 13 result types
• Infield Back chart (default positioning)
• Infield In chart (runner on 3rd)
• Corners In positioning (hybrid approach)
• Full groundball outcome resolution

Task 5: Double Play Mechanics ✅

• Integrated into Task 4 RunnerAdvancement
• Base probability: 45% with modifiers
• Positioning: Infield In (-15%), Normal (0%)
• Hit location: Middle infield (+10%), Corners (-10%)
• Probabilistic execution (not deterministic)

Task 6: PlayResolver Integration ✅ (9 tests)

• Outcome-first architecture - Manual mode is primary
• resolve_outcome() core method - all game logic
• resolve_manual_play() wrapper for player submissions
• resolve_auto_play() wrapper for PD auto mode
• RunnerAdvancement integrated for all groundballs
• hit_location tracked in PlayResult
• Removed obsolete SimplifiedResultChart and singleton

Task 7: WebSocket Manual Outcome Handlers ✅ (12 tests)

• roll_dice event: Server rolls, broadcasts to players
• submit_manual_outcome event: Players submit after reading cards
• GameEngine.resolve_manual_play() orchestration
• Terminal client commands: roll_dice, manual_outcome

Task 8: Terminal Client Enhancement ✅

• Manual outcome submission commands
• Full REPL integration
• Testing without frontend

Testing Summary

• 180/181 core tests passing (1 pre-existing failure in dice history)
• 126 new tests for Week 7 - all passing
• Manual testing: 8/8 scenarios verified ✅

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🚀 Week 8: Substitutions & Advanced Gameplay

Focus: Player substitutions, pitching management, and advanced game features

Planned Tasks

Task 1: Substitution System

• Pinch hitters - Replace batter mid-at-bat or in lineup
• Pinch runners - Replace runner on base
• Defensive replacements - Swap fielders
• Database tracking: replacing_id, after_play, entered_inning
• Validation: DH rules, position eligibility, one-way substitutions

Task 2: Pitching Changes

• Relief pitcher - Bring in from bullpen
• Pitching fatigue - Track pitch count and is_fatigued flag
• Bullpen management - Available relievers, warmup status
• Closer/setup roles - Strategic substitution timing

Task 3: Advanced Game Rules

• Steal attempts - Use OffensiveDecision.steal_attempts
• Caught stealing resolution - JumpRoll mechanics
• Pick-off attempts - Pitcher vs runner
• Balk detection - Using chaos_d20 rolls

Task 4: Game State Persistence

• Save/load functionality - Store/restore game mid-play
• Replay system - Rebuild state from play history
• Recovery on crash - Automatic state reconstruction

Task 5: Enhanced Terminal Client

• Substitution commands - pinch_hit, pinch_run, defensive_sub
• Pitching commands - change_pitcher, bullpen_status
• Better status display - Show fatigue, available subs

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Quick Start for Next AI Agent

🎯 Where to Begin (Week 8)

1. Read Week 8 plan (to be created): @.claude/implementation/WEEK_8_PLAN.md
2. Review database models: @app/models/db_models.py
   • Check Lineup model: replacing_id, after_play, is_fatigued fields
   • These are already in place from Phase 1!
3. Start with Task 1: Substitution system
   • Create SubstitutionManager class
   • Implement pinch hitter logic first (simplest case)
   • Add validation rules

📍 Current Architecture (Week 7 Complete)

Game Engine Flow:

# Manual mode (SBA + PD manual)
GameEngine.resolve_manual_play(
    game_id, ab_roll, outcome, hit_location
) → PlayResult

# Auto mode (PD only)
GameEngine.resolve_play(game_id) → PlayResult

Play Resolution:

PlayResolver(league_id, auto_mode)
  ├── resolve_manual_play(submission, state, ...) → PlayResult
  ├── resolve_auto_play(state, batter, pitcher, ...) → PlayResult
  └── resolve_outcome(outcome, hit_location, state, ...) → PlayResult (core)

Runner Advancement:

RunnerAdvancement.advance_runners(
    outcome, hit_location, state, defensive_decision
) → AdvancementResult

🔑 Key Files for Week 8

Substitution System:

• app/models/db_models.py - Lineup model (already has substitution fields!)
• app/core/substitution_manager.py (NEW) - Handle substitution logic
• app/core/validators.py - Add substitution validation
• tests/unit/core/test_substitution_manager.py (NEW)

Pitching Changes:

• app/core/game_engine.py - Add change_pitcher() method
• app/models/game_models.py - Add pitching state tracking
• app/core/validators.py - Validate pitcher eligibility

Terminal Client:

• terminal_client/commands.py - Add sub commands
• terminal_client/repl.py - Add REPL integration

🧪 Testing Strategy

# Run substitution tests
export PYTHONPATH=. && pytest tests/unit/core/test_substitution_manager.py -v

# Run all core tests (should still pass)
export PYTHONPATH=. && pytest tests/unit/core/ -v

# Manual testing in terminal client
python -m terminal_client
> new_game
> start_game
> pinch_hit 5 101  # Pinch hit for batting order 5 with lineup_id 101
> status

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Week 7 Architectural Decisions (Reference)

1. Outcome-First PlayResolver Architecture

• Manual mode is primary - Most games use this (all SBA + half of PD)
• Core resolve_outcome() method - All game logic in one place
• Thin wrappers - resolve_manual_play() and resolve_auto_play()
• No hard-coded exceptions - Multi-step plays handled generically by GameEngine

2. Auto Mode Configuration

• Stored per-game - GameState.auto_mode field
• League validation - supports_auto_mode() in config
  • SBA: False (raises error if attempted)
  • PD: True (has digitized ratings)

3. Hit Location Tracking

• Critical for advancement - Determines chart row and conditionals
• Groundballs - Must specify location (1B, 2B, 3B, SS, P, C)
• Flyouts - Track for future tag-up logic (LF, CF, RF)
• Other outcomes - None (walks, strikeouts, etc.)

4. Manual vs Auto Mode

Manual Mode (primary):

1. Server rolls dice → AbRoll
2. Broadcasts dice to players via WebSocket
3. Players read physical cards
4. Players submit outcome + location
5. Server validates ManualOutcomeSubmission
6. Server resolves with RunnerAdvancement
7. Broadcasts result

Auto Mode (PD only, rare):

1. Server rolls dice → AbRoll
2. PdAutoResultChart.get_outcome(roll, batter, pitcher) → outcome + location
3. Server resolves with RunnerAdvancement
4. Broadcasts result

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Important Patterns & Conventions

Testing

• Always use venv: source venv/bin/activate
• Set PYTHONPATH: export PYTHONPATH=.
• Run tests after each change: pytest tests/unit/core/ -v

Git Commits

• Prefix with "CLAUDE: ": All commits must start with this
• Descriptive messages: Include what changed and why
• Reference tasks: "Implement Week 8 Task 1 - Substitution System"

Code Style

• Pydantic dataclasses - For models and validation
• Async/await - All database operations
• Frozen configs - Immutable league configurations
• "Raise or Return" - No Optional unless required
• Pendulum for dates - Never use Python's datetime

Documentation

• Update NEXT_SESSION.md - After completing tasks
• Add TODO comments - For future work
• Docstrings - Google style for classes and public methods

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Current Test Status

Total Tests: ~519 tests

• Config: 79/79 ✅ (58 base + 21 result charts)
• Validators: 54/54 ✅
• Runner Advancement: 30/30 ✅
• PlayResolver: 9/9 ✅ (rewritten for new architecture)
• WebSocket Handlers: 12/12 ✅
• Dice: 34/35 (1 pre-existing failure in get_rolls_since)
• Roll Types: 27/27 ✅
• Player Models: 32/32 ✅
• Game Models: ~150+ ✅
• State Manager: ~80+ ✅

Week 8 Target: Add ~50 new tests for substitutions and pitching

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Database & Environment

Database: PostgreSQL @ 10.10.0.42:5432 (paperdynasty_dev) Python: 3.13.3 Virtual Env: backend/venv/ Branch: implement-phase-2

Key Commands:

# Activate venv
cd backend && source venv/bin/activate

# Run tests
export PYTHONPATH=. && pytest tests/unit/core/ -v

# Terminal client
python -m terminal_client

# Check git status
git status

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What NOT to Do

• ❌ Don't modify database schema without migrations
• ❌ Don't use Python's datetime (use Pendulum)
• ❌ Don't return Optional unless required
• ❌ Don't disable type checking globally
• ❌ Don't skip validation
• ❌ Don't commit without "CLAUDE: " prefix
• ❌ Don't forget export PYTHONPATH=. when running tests
• ❌ Don't hard-code multi-step play logic (keep it generic)

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References

• Implementation Guide: @.claude/implementation/01-infrastructure.md
• Backend Architecture: @.claude/implementation/backend-architecture.md
• Week 7 Plan: @.claude/implementation/WEEK_7_PLAN.md
• Database Design: @.claude/implementation/database-design.md
• Full PRD: @prd-web-scorecard-1.1.md

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Status: ✅ Week 7 Complete - Ready for Week 8! Priority: High - Substitutions are core gameplay feature Estimated Time: Week 8 should take 3-5 sessions Next Milestone: Complete substitution system and pitching management