ai-code-battle/PROGRESS.md

AI Code Battle - Implementation Progress

Current Phase: Phase 1 - Core Engine

Status: ✅ COMPLETE

Completed

• Go module initialization (github.com/aicodebattle/acb)
• Project structure (engine/, cmd/acb-local/, cmd/acb-mapgen/)
• Core types (engine/types.go)
  • Position, Tile, Direction, Bot, Core, EnergyNode, Player
  • Config with default values
  • MatchResult, VisibleState (fog-filtered state)
• Grid implementation (engine/grid.go)
  • Toroidal wrapping
  • Distance calculations (squared for performance)
  • Visibility computation
  • Wall/obstacle handling
• Game state (engine/game.go)
  • State management for bots, cores, energy, players
  • Bot spawning and killing
  • Fog of war filtering
• Turn execution (engine/turn.go)
  • Movement phase with collision detection
  • Focus-fire combat resolution
  • Core capture mechanics
  • Energy collection (contested resources)
  • Bot spawning at active cores
  • Energy node ticking
  • Win condition checking (elimination, draw, dominance, turns)
• Replay writer (engine/replay.go)
  • Full replay JSON format
  • Turn-by-turn state recording
• Match runner (engine/match.go)
  • Concurrent bot communication
  • Per-turn timeout
  • Symmetric map generation
• Local bot interface (engine/bot_local.go)
  • RandomBot, IdleBot implementations
• CLI runner (cmd/acb-local/main.go)
  • Configurable parameters (seed, size, turns)
  • Replay output
• Map generator (cmd/acb-mapgen/main.go)
  • Rotational symmetry (2/3/4/6 players)
  • Configurable density
• Unit tests for core engine
  • Grid operations, wrapping, distances
  • Combat resolution (1v1, 2v1, formations)
  • Core capture
  • Energy collection
  • Spawning
  • Win conditions
• Map generator connectivity validation (cmd/acb-mapgen/connectivity.go)
  • BFS-based connectivity check
  • Retry mechanism for connected map generation
• Determinism tests (engine/determinism_test.go)
  • Same seed produces identical replays
  • Turn execution is deterministic
  • Grid operations are deterministic
  • Combat resolution is deterministic
  • Replay serialization round-trip
  • Full 500-turn match validation

Exit Criteria Progress

Criterion	Status
Can run a complete 500-turn match locally	✅ Works
Produce a valid replay file	✅ Works
Comprehensive unit tests	✅ 32 tests passing

Next Phase: Phase 2 - HTTP Protocol & Strategy Bots

Status: Ready to start

File Structure

ai-code-battle/
├── go.mod
├── engine/
│   ├── types.go        # Core data types
│   ├── grid.go         # Toroidal grid implementation
│   ├── game.go         # Game state management
│   ├── turn.go         # Turn execution phases
│   ├── replay.go       # Replay recording
│   ├── match.go        # Match runner
│   ├── bot_local.go    # Local bot interface
│   ├── grid_test.go    # Grid tests
│   └── turn_test.go    # Turn execution tests
├── cmd/
│   ├── acb-local/      # CLI match runner
│   │   └── main.go
│   └── acb-mapgen/     # Map generator
│       └── main.go
└── docs/
    └── plan/
        └── plan.md     # Full implementation plan

Key Design Decisions

1. Position-based moves: Bots are identified by their current position in the move protocol (not bot IDs), which works better with fog of war.

2. Squared distances: Using squared distances throughout (Distance2, Radius2) avoids expensive square root operations.

3. Simultaneous resolution: Combat deaths are computed first, then applied, ensuring true simultaneous resolution.

4. Symmetric map generation: Maps are generated by creating one sector and rotating for all players.

Running Tests

go test ./engine/... -v

Building CLI Tools

go build ./cmd/acb-local
go build ./cmd/acb-mapgen

Example Usage

# Run a match
./acb-local -seed 42 -max-turns 100 -output replay.json -verbose

# Generate a map
./acb-mapgen -players 2 -rows 60 -cols 60 -output map.json