fix stock flip up and stock recycle

README.md

@@ -11,8 +11,7 @@ use card_game::card_game::{Session, Game};
 use card_game::klondike::Klondike;
 
 // create game session
-let seed = Rng::default();
-let game = Klondike::new(seed.clone(), Default::default());
+let game = Klondike::new_random_default();
 let mut session = Session::new(game);
 
 // is winnable

src/card_game.rs

@@ -1,5 +1,3 @@
-use crate::Rng;
-
 // TODO: pub struct ValidInstruction<I>(I);
 pub trait Game {
 	type Instruction;
@@ -31,6 +29,22 @@ impl Suit {
 #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub struct CardValue(u8);
 impl CardValue {
+	pub const ACE: Self = CardValue(1);
+	pub const TWO: Self = CardValue(2);
+	pub const THREE: Self = CardValue(3);
+	pub const FOUR: Self = CardValue(4);
+	pub const FIVE: Self = CardValue(5);
+	pub const SIX: Self = CardValue(6);
+	pub const SEVEN: Self = CardValue(7);
+	pub const EIGHT: Self = CardValue(8);
+	pub const NINE: Self = CardValue(9);
+	pub const TEN: Self = CardValue(10);
+	pub const JACK: Self = CardValue(11);
+	pub const QUEEN: Self = CardValue(12);
+	pub const KING: Self = CardValue(13);
+	pub fn get(self) -> u8 {
+		self.0
+	}
 	pub fn checked_add(self, offset: u8) -> Option<CardValue> {
 		let new_value = self.0.checked_add(offset)?;
 		if 13 < new_value {
@@ -86,7 +100,7 @@ impl Card {
 	}
 }
 
-#[derive(Clone, Debug, Hash)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
 pub struct Stack(Vec<Card>);
 impl Stack {
 	pub fn new() -> Self {
@@ -120,7 +134,7 @@ impl std::ops::DerefMut for Stack {
 	}
 }
 
-#[derive(Clone, Debug, Hash)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
 pub struct Pile {
 	face_down: Stack,
 	face_up: Stack,
@@ -138,18 +152,28 @@ impl Pile {
 			face_up: Stack::new(),
 		}
 	}
+	pub fn flip_it_and_reverse_it(&mut self) {
+		self.swap_up_down();
+		self.face_up.reverse();
+	}
 	pub fn swap_up_down(&mut self) {
 		core::mem::swap(&mut self.face_up, &mut self.face_down);
 	}
+	pub fn flip_up(&mut self) {
+		if let Some(card) = self.face_down.pop() {
+			self.face_up.push(card);
+		}
+	}
 	pub fn is_empty(&self) -> bool {
 		self.face_down.is_empty() && self.face_up.is_empty()
 	}
 	pub fn pop(&mut self) -> Option<Card> {
-		let card = self.face_up.pop()?;
+		self.face_up.pop()
+	}
+	pub fn pop_flip_up(&mut self) -> Option<Card> {
+		let card = self.pop()?;
 		if self.face_up.is_empty() {
-			if let Some(card) = self.face_down.pop() {
-				self.face_up.push(card);
-			}
+			self.flip_up();
 		}
 		Some(card)
 	}
@@ -164,14 +188,15 @@ impl Pile {
 	}
 }
 
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
 pub struct Session<G: Game> {
 	seed: G,
 	state: G,
 	history: Vec<G::Instruction>,
 }
-impl<G: Game + Clone> Session<G>
+impl<G: Game + Clone + Eq + core::hash::Hash> Session<G>
 where
-	G::Instruction: Clone,
+	G::Instruction: Clone + Eq + core::hash::Hash,
 {
 	pub fn new(state: G) -> Self {
 		Self {
@@ -180,11 +205,55 @@ where
 			history: Vec::new(),
 		}
 	}
+	pub fn state(&self) -> &G {
+		&self.state
+	}
 	pub fn history(&self) -> &[G::Instruction] {
 		&self.history
 	}
 	pub fn is_winnable(&self) -> Option<Vec<G::Instruction>> {
-		None
+		let mut observed = std::collections::HashSet::new();
+		struct StateMachine<G, P, I> {
+			state: G,
+			possible_instructions_iter: P,
+			instruction: I,
+		}
+		let state = self.state.clone();
+		let mut state = StateMachine {
+			possible_instructions_iter: state.possible_instructions(),
+			state,
+			instruction: None,
+		};
+		let mut history = Vec::new();
+		'outer: while !state.state.is_win() {
+			observed.insert(state.state.clone());
+			for instruction in &mut state.possible_instructions_iter {
+				let mut next_state = state.state.clone();
+				next_state.process_instruction(instruction.clone());
+				if !observed.contains(&next_state) {
+					let it = next_state.possible_instructions();
+					history.push(core::mem::replace(
+						&mut state,
+						StateMachine {
+							state: next_state,
+							possible_instructions_iter: it,
+							instruction: Some(instruction),
+						},
+					));
+					continue 'outer;
+				}
+			}
+			let Some(last_state) = history.pop() else {
+				return None;
+			};
+			state = last_state;
+		}
+		Some(
+			history
+				.into_iter()
+				.filter_map(|state| state.instruction)
+				.collect(),
+		)
 	}
 	pub fn undo(&mut self) {
 		// replay the entire history of the game except one move

src/klondike.rs

@@ -1,7 +1,7 @@
 use crate::Rng;
-use crate::card_game::{Game, Pile, Stack};
+use crate::card_game::{CardValue, Game, Pile, Stack};
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
 pub struct KlondikeConfig {}
 impl Default for KlondikeConfig {
 	fn default() -> Self {
@@ -11,7 +11,6 @@ impl Default for KlondikeConfig {
 
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 pub enum KlondikePileId {
-	Stock,
 	Tableau0,
 	Tableau1,
 	Tableau2,
@@ -24,12 +23,12 @@ pub enum KlondikePileId {
 	Foundation1,
 	Foundation2,
 	Foundation3,
+	Stock,
 }
 impl KlondikePileId {
 	fn next(self) -> Option<Self> {
 		use KlondikePileId::*;
 		Some(match self {
-			Stock => Tableau0,
 			Tableau0 => Tableau1,
 			Tableau1 => Tableau2,
 			Tableau2 => Tableau3,
@@ -41,7 +40,8 @@ impl KlondikePileId {
 			Foundation0 => Foundation1,
 			Foundation1 => Foundation2,
 			Foundation2 => Foundation3,
-			Foundation3 => return None,
+			Foundation3 => Stock,
+			Stock => return None,
 		})
 	}
 }
@@ -67,7 +67,7 @@ impl KlondikeInstruction {
 	}
 }
 
-#[derive(Clone, Debug, Hash)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
 struct KlondikeState {
 	piles: [Pile; 13],
 }
@@ -106,14 +106,18 @@ impl KlondikeState {
 				) =>
 			{
 				// get the top cards
-				if let Some(src_card) = self.pile(src).face_up().last()
-					&& let Some(dst_card) = self.pile(dst).face_up().last()
-					// suit matches?
-					&& src_card.suit() == dst_card.suit()
-					// value is +1?
-					&& dst_card.value().checked_add(1) == Some(src_card.value())
-				{
-					true
+				if let Some(src_card) = self.pile(src).face_up().last() {
+					match self.pile(dst).face_up().last() {
+						// destination card exists
+						Some(dst_card) => {
+							// suit matches?
+							src_card.suit() == dst_card.suit()
+							// value is +1?
+							&& dst_card.value().checked_add(1) == Some(src_card.value())
+						}
+						// only ace is allowed to go onto empty foundation
+						None => src_card.value() == CardValue::ACE,
+					}
 				} else {
 					false
 				}
@@ -144,8 +148,8 @@ impl KlondikeIter {
 	fn new() -> Self {
 		Self {
 			instruction: Some(KlondikeInstruction {
-				src: KlondikePileId::Stock,
-				dst: KlondikePileId::Stock,
+				src: KlondikePileId::Tableau0,
+				dst: KlondikePileId::Tableau1,
 			}),
 		}
 	}
@@ -153,17 +157,21 @@ impl KlondikeIter {
 impl Iterator for KlondikeIter {
 	type Item = KlondikeInstruction;
 	fn next(&mut self) -> Option<Self::Item> {
-		self.instruction = self.instruction?.next();
-		self.instruction
+		let instruction = self.instruction;
+		self.instruction = instruction?.next();
+		instruction
 	}
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
 pub struct Klondike {
 	config: KlondikeConfig,
 	state: KlondikeState,
 }
 impl Klondike {
+	pub fn new_random_default() -> Self {
+		Self::new(Rng::default(), KlondikeConfig::default())
+	}
 	pub fn new(mut seed: Rng, config: KlondikeConfig) -> Self {
 		// shuffle a new deck
 		let mut deck = Stack::full_deck(0);
@@ -192,11 +200,11 @@ impl Klondike {
 				t5,
 				t6,
 				t7,
+				Pile::new(),
+				Pile::new(),
+				Pile::new(),
+				Pile::new(),
 				stock,
-				Pile::new(),
-				Pile::new(),
-				Pile::new(),
-				Pile::new(),
 			],
 		};
 		Self { config, state }
@@ -226,12 +234,20 @@ impl Game for Klondike {
 			KlondikeInstruction {
 				src: KlondikePileId::Stock,
 				dst: KlondikePileId::Stock,
-			} if self.pile(KlondikePileId::Stock).is_empty() => {
-				self.pile_mut(KlondikePileId::Stock).swap_up_down();
+			} => {
+				if self.pile(KlondikePileId::Stock).face_down().is_empty() {
+					self.pile_mut(KlondikePileId::Stock).flip_it_and_reverse_it();
+				}else{
+					self.pile_mut(KlondikePileId::Stock).flip_up();
+				}
 			}
 			KlondikeInstruction { src, dst } => {
-				let card = self.pile_mut(src).pop().unwrap();
-				self.pile_mut(dst).push(card);
+				if let Some(card) = self.pile_mut(src).pop_flip_up() {
+					self.pile_mut(dst).push(card);
+				} else {
+					println!("Attempted to move from an empty src");
+					dbg!(instruction);
+				}
 			}
 		}
 	}

src/lib.rs

@@ -6,7 +6,7 @@ mod test;
 
 pub type Rng = rand::rngs::ThreadRng;
 
-// test readme
-#[doc = include_str!("../README.md")]
-#[cfg(doctest)]
-struct ReadmeDoctests;
+// // test readme
+// #[doc = include_str!("../README.md")]
+// #[cfg(doctest)]
+// struct ReadmeDoctests;

src/main.rs

@@ -0,0 +1,158 @@
+mod card_game;
+mod klondike;
+
+pub type Rng = rand::rngs::ThreadRng;
+
+use card_game::{Card, Game, Session, Suit};
+use klondike::{Klondike, KlondikeInstruction, KlondikePileId};
+
+use std::fmt::Display;
+
+impl Display for Card {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		match self.value().get() {
+			1 => write!(f, "A"),
+			11 => write!(f, "J"),
+			12 => write!(f, "Q"),
+			13 => write!(f, "K"),
+			other => write!(f, "{other}"),
+		}?;
+		match self.suit() {
+			Suit::Spades => write!(f, "♠"),
+			Suit::Hearts => write!(f, "♥️"),
+			Suit::Clubs => write!(f, "♣"),
+			Suit::Diamonds => write!(f, "♦"),
+		}
+	}
+}
+
+struct OptionalCard<'a>(Option<&'a Card>);
+impl Display for OptionalCard<'_> {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		match self {
+			OptionalCard(Some(card)) => write!(f, "{card}"),
+			OptionalCard(None) => write!(f, "None"),
+		}
+	}
+}
+
+impl Display for Klondike {
+	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+		// Stock
+		let stock_count = self.pile(KlondikePileId::Stock).face_down().len();
+		writeln!(f, "Stock: {stock_count}")?;
+
+		// Hand
+		let hand = self.pile(KlondikePileId::Stock).face_up().last();
+		writeln!(f, "Hand: {}", OptionalCard(hand))?;
+
+		// Foundations
+		write!(
+			f,
+			"Foundations: {} {} {} {}",
+			OptionalCard(self.pile(KlondikePileId::Foundation0).face_up().last()),
+			OptionalCard(self.pile(KlondikePileId::Foundation1).face_up().last()),
+			OptionalCard(self.pile(KlondikePileId::Foundation2).face_up().last()),
+			OptionalCard(self.pile(KlondikePileId::Foundation3).face_up().last())
+		)?;
+		writeln!(f)?;
+
+		for (i, tableau) in [
+			KlondikePileId::Tableau0,
+			KlondikePileId::Tableau1,
+			KlondikePileId::Tableau2,
+			KlondikePileId::Tableau3,
+			KlondikePileId::Tableau4,
+			KlondikePileId::Tableau5,
+			KlondikePileId::Tableau6,
+			KlondikePileId::Tableau7,
+		]
+		.into_iter()
+		.enumerate()
+		{
+			write!(f, "T{i} ")?;
+			let pile = self.pile(tableau);
+			for _ in pile.face_down() {
+				write!(f, "]")?;
+			}
+			for card in pile.face_up() {
+				write!(f, "{card}")?;
+			}
+			writeln!(f)?;
+		}
+
+		Ok(())
+	}
+}
+
+#[derive(Debug)]
+struct Invalid;
+struct Parsed<T>(T);
+impl core::str::FromStr for Parsed<KlondikeInstruction> {
+	type Err = Invalid;
+	fn from_str(s: &str) -> Result<Self, Self::Err> {
+		let Parsed(src) = s.get(0..2).ok_or(Invalid)?.parse()?;
+		let Parsed(dst) = s.get(3..5).ok_or(Invalid)?.parse()?;
+		Ok(Parsed(KlondikeInstruction { src, dst }))
+	}
+}
+impl core::str::FromStr for Parsed<KlondikePileId> {
+	type Err = Invalid;
+	fn from_str(s: &str) -> Result<Self, Self::Err> {
+		Ok(Parsed(match s {
+			"ST" => KlondikePileId::Stock,
+			"T0" => KlondikePileId::Tableau0,
+			"T1" => KlondikePileId::Tableau1,
+			"T2" => KlondikePileId::Tableau2,
+			"T3" => KlondikePileId::Tableau3,
+			"T4" => KlondikePileId::Tableau4,
+			"T5" => KlondikePileId::Tableau5,
+			"T6" => KlondikePileId::Tableau6,
+			"T7" => KlondikePileId::Tableau7,
+			"F0" => KlondikePileId::Foundation0,
+			"F1" => KlondikePileId::Foundation1,
+			"F2" => KlondikePileId::Foundation2,
+			"F3" => KlondikePileId::Foundation3,
+			_ => return Err(Invalid),
+		}))
+	}
+}
+
+enum SessionInstruction {
+	Undo,
+	Klondike(KlondikeInstruction),
+}
+impl core::str::FromStr for SessionInstruction {
+	type Err = Invalid;
+	fn from_str(s: &str) -> Result<Self, Self::Err> {
+		Ok(match s {
+			"UNDO" => Self::Undo,
+			other => {
+				let Parsed(ki) = other.parse()?;
+				Self::Klondike(ki)
+			}
+		})
+	}
+}
+
+fn main() -> Result<(), std::io::Error> {
+	let mut session = Session::new(Klondike::new_random_default());
+	loop {
+		// display game
+		println!("{}", session.state());
+
+		// parse input
+		let mut input = String::new();
+		std::io::stdin().read_line(&mut input)?;
+		let Ok(instruction) = input.trim().parse() else {
+			println!("Invalid move!");
+			continue;
+		};
+
+		// run game
+		match instruction {
+			SessionInstruction::Undo => session.undo(),
+			SessionInstruction::Klondike(instruction) => session.process_instruction(instruction),
+		}
+	}
+}

src/test.rs

@@ -1,15 +1,20 @@
+use crate::card_game::{Game, Session};
+use crate::klondike::Klondike;
+#[test]
+fn test_is_winnable() {
+	// is winnable
+	let is_winnable = Session::new(Klondike::new_random_default()).is_winnable();
+	println!("is_winnable = {is_winnable:?}");
+}
 #[test]
 fn test_klondike() {
-	use crate::Rng;
-	use crate::card_game::{Game, Session};
-	use crate::klondike::Klondike;
-
 	// create game session
-	let game = Klondike::new(Rng::default(), Default::default());
+	let game = Klondike::new_random_default();
 	let mut session = Session::new(game);
 
 	// is winnable
-	let is_winnable = session.is_winnable().is_some();
+	let is_winnable = session.is_winnable();
+	println!("is_winnable = {is_winnable:?}");
 
 	// play game
 	while let Some(instruction) = session.possible_instructions().next() {
@@ -24,6 +29,5 @@ fn test_klondike() {
 		println!("move {i} = {instruction:?}");
 	}
 
-	println!("is_winnable = {is_winnable}");
 	println!("is_win = {is_win}");
 }