# Poker Simulation Testbed

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A comprehensive poker simulation testbed and unit test framework for bot development. Features two Rust-native hand evaluators — the **Cactus Kev** perfect-hash evaluator (~100 KB tables) and the **Supersonic** LUT trie evaluator (~124 MB tables) — designed for automated poker bot testing, strategy analysis, and simulation at scale.

## Recent Updates

- **Supersonic Evaluator**: New high-throughput LUT trie evaluator (~124 MB) for O(n) hand evaluation
- **Dual Evaluator Architecture**: Choose between Cactus Kev (compact) and Supersonic (fast) per use case
- **Simulation Testbed**: Run cash games, SNGs, and MTTs with configurable bots via TOML
- **Input Validation**: Added comprehensive validation to `Card::new()` ensuring rank (0-12) and suit (0-3) are within valid ranges
- **Enhanced Documentation**: All public methods now include working code examples and panic condition documentation
- **Error Handling**: Improved error handling throughout the codebase with proper `Result` types

## Features

- **Bot Testing Framework**: Specifically designed for automated poker bot testing and development
- **Dual Evaluators**: Cactus Kev (compact ~100 KB) and Supersonic LUT trie (~124 MB) hand evaluators
- **Blazing Fast**: Sub-microsecond hand evaluation using perfect hash and trie-based lookup
- **Memory Efficient**: Choose between compact Cactus Kev tables or high-throughput Supersonic trie
- **Standards Compliant**: Based on proven poker evaluation algorithms
- **Multi-Hand Support**: Evaluate 5, 6, or 7-card poker hands
- **Texas Hold'em Ready**: Optimized for Texas Hold'em bot analysis and testing
- **Comprehensive Testing**: Extensive test suite with millions of verification cases
- **Deterministic Results**: Consistent hand evaluation for reproducible bot testing
- **Simulation Engine**: Run cash games, SNGs, and MTTs with configurable bots via TOML

## Performance

### Cactus Kev Evaluator

| Hand Type | Evaluation Time | Method |
|-----------|----------------|--------|
| 5-Card    | ~50-100ns      | Single prime-product hash → table lookup |
| 6-Card    | ~300-500ns     | Six 5-card lookups |
| 7-Card    | ~1-2µs         | 21 enumeration + HashMap cache |

### Supersonic Evaluator

| Hand Type | Evaluation Time | Method |
|-----------|----------------|--------|
| 5-Card    | O(5) array lookups | Direct trie traversal |
| 6-Card    | O(6) array lookups | Direct trie traversal |
| 7-Card    | O(7) array lookups | Direct trie traversal |

## Documentation

For detailed project information, see:

- **[VISION.md](docs/VISION.md)** - Project goals and architectural vision
- **[ROADMAP.md](docs/ROADMAP.md)** - Future development phases and implementation plan

## Installation

Add this to your `Cargo.toml`:

```toml
[dependencies]
holdem_core = "0.1.0"
```

## Quick Start - Bot Testing

```rust
use holdem_core::{Card, Hand, HoleCards, Board, Evaluator};
use std::str::FromStr;

// Create cards from string notation
let ace_spades = Card::from_str("As").unwrap();
let king_spades = Card::from_str("Ks").unwrap();

// Create hole cards from notation
let hole_cards = HoleCards::from_notation("AKs").unwrap();

// Create a board with community cards
let board = Board::new()
    .with_flop([
        Card::from_str("Qh").unwrap(),
        Card::from_str("Jh").unwrap(),
        Card::from_str("Th").unwrap(),
    ]).unwrap()
    .with_turn(Card::from_str("2c").unwrap()).unwrap()
    .with_river(Card::from_str("3d").unwrap()).unwrap();

// Create a hand from hole cards and board
let hand = Hand::from_hole_cards_and_board(&hole_cards, &board).unwrap();

// Evaluate the hand
let evaluator = Evaluator::new().unwrap();
let hand_value = evaluator.evaluate_hand(&hand);
println!("Hand rank: {:?}", hand_value.rank);
```

## Bot Testing Capabilities

This framework provides specialized capabilities for poker bot testing and development:

### Automated Bot Testing
- **Standardized Evaluation**: Consistent hand evaluation across both Cactus Kev and Supersonic evaluators
- **Performance Benchmarking**: Fast evaluation for large-scale bot performance testing
- **Range Analysis**: Efficient hand range evaluation for bot strategy analysis
- **Decision Tree Testing**: Quick hand strength calculation for bot decision trees

### Dual Evaluator Support
- **Cactus Kev**: Compact ~100 KB tables with prime-product hashing — ideal for memory-constrained environments
- **Supersonic**: High-throughput ~124 MB LUT trie with O(n) array lookups — fastest for bulk evaluation
- **Algorithmic Fallback**: Rule-based evaluator serves as correctness oracle for validation

### Bot Development Features
- **Hole Card Analysis**: Fast evaluation of starting hand strength for pre-flop bots
- **Post-Flop Analysis**: Efficient board texture and hand strength analysis
- **Incremental Evaluation**: Multi-street hand evaluation for complex bot scenarios
- **Memory Efficient**: Optimized for bot testing environments with limited resources

## Algorithm Overview

This library provides **two hand evaluators** with different performance/memory tradeoffs:

### Cactus Kev Evaluator (compact)
Uses prime-product hashing into two small lookup tables (~100 KB total):
1. **Prime Product Hashing**: Each rank maps to a unique prime; the product of 5 primes uniquely identifies the hand
2. **Dual Lookup Tables**: 1,287 flush entries + 6,175 unsuited entries = 7,462 total (~30 KB)
3. **7-card Cache**: C(7,5)=21 enumeration with HashMap cache for amortized O(1) lookups
4. **Zero Collisions**: Validated against all 2,598,960 five-card hands

### Supersonic Evaluator (high-throughput)
Uses a pre-computed LUT trie (~124 MB) for O(n) array lookups:
1. **Trie Structure**: 32,487,834 `u32` entries organized in pages of 53 (one per card + base)
2. **Direct Lookup**: Follow `hand_ranks[p + card_index + 1]` for each card — no enumeration needed
3. **Packed Hand Rank**: 16-bit format (category + equivalency class) for compact result representation
4. **Best for Bulk**: Fastest evaluator for large-scale simulations and batch evaluation

### Table Generation

Lookup tables are generated automatically on first use and persisted to disk:

- **Cactus Kev**: Small tables (~100 KB) generated in-memory from prime products
- **Supersonic**: Large LUT trie (~124 MB) loaded from pre-generated binary file

## Hand Types

The evaluator recognizes all standard poker hand types:

| Hand Type | Description | Example |
|-----------|-------------|---------|
| Straight Flush | Five cards in sequence, same suit | A♠ K♠ Q♠ J♠ T♠ |
| Four of a Kind | Four cards of same rank | A♠ A♥ A♦ A♣ K♦ |
| Full House | Three of a kind + one pair | K♠ K♥ K♦ Q♠ Q♥ |
| Flush | Five cards of same suit | A♠ J♠ 8♠ 5♠ 2♠ |
| Straight | Five cards in sequence | A♦ K♣ Q♥ J♠ T♦ |
| Three of a Kind | Three cards of same rank | Q♠ Q♥ Q♦ A♣ 7♦ |
| Two Pair | Two different pairs | J♠ J♥ 7♦ 7♣ A♦ |
| One Pair | Two cards of same rank | A♠ A♥ K♦ Q♣ 7♦ |
| High Card | No matching cards | A♠ K♥ Q♦ J♣ 9♦ |

## Bot Testing Examples

### Texas Hold'em Bot Analysis

```rust
use holdem_core::{Card, Hand, HoleCards, Board, Evaluator};
use std::str::FromStr;

let evaluator = Evaluator::new().unwrap();

// Bot analyzes hole cards + flop for decision making
let hole_cards = HoleCards::from_notation("AKs").unwrap();
let board = Board::new()
    .with_flop([
        Card::from_str("Td").unwrap(),
        Card::from_str("Jc").unwrap(),
        Card::from_str("Qh").unwrap(),
    ]).unwrap();

// Bot evaluates complete hand strength
let hand = Hand::from_hole_cards_and_board(&hole_cards, &board).unwrap();
let hand_value = evaluator.evaluate_hand(&hand);
println!("Hand strength after flop: {:?}", hand_value.rank);

// Bot uses this for post-flop decision making
if hand_value.rank as u8 >= 4 { // Straight or better
    println!("Bot: Continuing with strong hand");
}
```

### Bot Range Analysis

```rust
use holdem_core::{Card, Hand, Evaluator};
use std::str::FromStr;

let evaluator = Evaluator::new().unwrap();

// Bot analyzes range of starting hands for pre-flop strategy
let premium_hands = vec![
    Hand::from_notation("As Ah").unwrap(),
    Hand::from_notation("Ks Kh").unwrap(),
    Hand::from_notation("Qs Qh").unwrap(),
    Hand::from_notation("As Ks").unwrap(),
];

for hand in premium_hands {
    let hand_value = evaluator.evaluate_hand(&hand);
    println!("Bot range analysis - {}: {:?}", hand, hand_value.rank);
}
```

## Advanced Usage

### 7-Card Hand Evaluation for Bot Testing

```rust
use holdem_core::{Card, Hand, HoleCards, Board, Evaluator};
use std::str::FromStr;

let evaluator = Evaluator::new().unwrap();

// Texas Hold'em complete hand: 2 hole cards + 5 community cards
let hole_cards = HoleCards::from_notation("AKs").unwrap();
let board = Board::new()
    .with_flop([
        Card::from_str("Td").unwrap(),
        Card::from_str("Jc").unwrap(),
        Card::from_str("Qh").unwrap(),
    ]).unwrap()
    .with_turn(Card::from_str("9s").unwrap()).unwrap()
    .with_river(Card::from_str("2d").unwrap()).unwrap();

// Bot evaluates best possible hand from all 7 cards
let hand = Hand::from_hole_cards_and_board(&hole_cards, &board).unwrap();
let hand_value = evaluator.evaluate_hand(&hand);
println!("Bot best hand rank: {:?}", hand_value.rank);
```

## Testing

Run the comprehensive test suite:

```bash
cargo test
```

Run performance benchmarks:

```bash
cargo test --release hand_eval_integration_test -- --nocapture
```

## Simulation Testbed

The `holdem_sim` binary provides a CLI for running poker simulations with configurable bots, game types, and formats. It supports cash games, Sit & Go (SNG) tournaments, and Multi-Table Tournaments (MTT).

### Running Simulations

```bash
# Run a cash game simulation
cargo run --bin holdem_sim -- holdem_core/examples/configs/cash_game.toml

# Run with a specific seed for reproducibility
cargo run --bin holdem_sim -- holdem_core/examples/configs/cash_game.toml --seed 42

# Override the number of hands
cargo run --bin holdem_sim -- holdem_core/examples/configs/cash_game.toml --hands 5000
```

### Example Configuration (Cash Game)

```toml
[game]
game_type = "Cash"
num_seats = 6
small_blind = 10
big_blind = 20
ante = 0
starting_chips = 10000
num_hands = 1000

[game.bet_limit]
type = "no_limit"
min_raise = 20

[[game.bots]]
bot_type = "call_bot"
name = "Alice"

[[game.bots]]
bot_type = "fold_bot"
name = "Bob"

[[game.bots]]
bot_type = "random_bot"
name = "Charlie"
```

Example configs are available in [`holdem_core/examples/configs/`](holdem_core/examples/configs/):

- [`cash_game.toml`](holdem_core/examples/configs/cash_game.toml) — 6-max NLHE cash game
- [`sng_tournament.toml`](holdem_core/examples/configs/sng_tournament.toml) — 9-seat Sit & Go
- [`mtt_tournament.toml`](holdem_core/examples/configs/mtt_tournament.toml) — Multi-table tournament

### Built-in Bots

| Bot | Description |
|-----|-------------|
| `call_bot` | Calls every bet, never raises or folds |
| `fold_bot` | Folds whenever facing a bet, otherwise checks |
| `raise_bot` | Raises with configurable aggression thresholds |
| `random_bot` | Takes random legal actions with configurable tendencies |

### Example Output

```
=== Simulation Results ===
Hands played: 1000

Player Statistics:
  Alice (call_bot)
    Hands: 1000 | VPIP: 100.0% | PFR: 0.0% | Win: $45,230
  Bob (fold_bot)
    Hands: 1000 | VPIP: 0.0% | PFR: 0.0% | Win: -$32,100
  Charlie (random_bot)
    Hands: 1000 | VPIP: 67.3% | PFR: 22.1% | Win: -$13,130
```

## Mathematical Foundation

### Cactus Kev — Perfect Hash Algorithm

The Cactus Kev evaluator uses prime-product hashing:

```
Hash = prime(rank₁) × prime(rank₂) × ... × prime(rank₅)
Index = Hash % TABLE_SIZE
Rank = TABLE[Index]
```

Each rank maps to a unique prime (2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41), so the product of 5 primes uniquely identifies the hand pattern.

### Supersonic — LUT Trie Algorithm

The Supersonic evaluator uses a pre-computed trie of 32.5M `u32` entries:

```
p = INITIAL_STATE (page 1 base)
for each card:
    p = hand_ranks[p + card_index + 1]
rank = p  // (for 7-card hands)
```

Each step is a single array lookup — no hashing, no enumeration, no branching.

## References

- **Cactus Kev**: Perfect hash algorithm for 5-card poker hand evaluation
- **Supersonic**: LUT trie evaluator for high-throughput hand evaluation
- **Poker Standards**: Standard poker hand ranking rules
- **Poker Testbed**: Framework designed for automated bot testing and analysis

## License

This project is licensed under the MIT License - see the [LICENSE](LICENSE) file for details.

## Contributing

Contributions are welcome! Areas for improvement:

- Hardware acceleration (SIMD optimizations)
- Additional poker variants (Omaha, Stud, etc.)
- Memory-mapped table loading
- Distributed table generation
- Advanced benchmarking tools

## Support

For questions, issues, or contributions, please:

1. Check existing documentation
2. Review test cases for usage examples
3. Open GitHub issues for bugs or feature requests
4. Submit pull requests with comprehensive tests

---

**Performance Note**: The Cactus Kev evaluator generates its small lookup tables (~100 KB) in-memory on first use. The Supersonic evaluator requires a pre-generated ~124 MB LUT file loaded at startup.