Refactor momentum_player() for clarity

[pluta-lesnura] / src / lib.rs

diff --git a/src/lib.rs b/src/lib.rs
index 59a47a9d0eb9056c49bb2ae83a97b282c326f12f..c46aa7dcf18eeca8ec17f76e0732a3dd24db828a 100644 (file)
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -178,10 +178,20 @@ impl Hand {
     fn len(&self) -> usize {
         self.cards.len()
     }
-    #[cfg(test)]
     fn random(&self) -> Option<&Card> {
         self.cards.choose(&mut rand::thread_rng())
     }
+    /// Make a new Hand that contains only cards of the requested suit
+    fn filter_by_suit(&self, suit: Suit) -> Self {
+        Self {
+            cards: self
+                .cards
+                .iter()
+                .filter(|c| c.suit().expect("I shouldn't have jokers in my hand") == suit)
+                .copied()
+                .collect(),
+        }
+    }
 }
 
 #[derive(Copy, Clone)]
@@ -204,6 +214,7 @@ pub enum Phase {
     Momentum,
 }
 
+#[derive(Debug)]
 pub enum GameOutcome {
     Loss,
     Win,
@@ -347,7 +358,7 @@ impl Game {
             .progress
             .iter()
             .zip(self.path_lengths.iter())
-            .any(|(&prog, len)| prog >= len.0 .0.try_into().expect("wat?"))
+            .any(|(&prog, len)| prog >= len.0.value().try_into().expect("wat?"))
         {
             GameOutcome::Win
         } else {
@@ -395,27 +406,53 @@ impl Default for Game {
 }
 
 pub struct Player(Box<dyn FnMut(&Game) -> Play>);
+impl Player {
+    #[must_use]
+    pub fn new<T>(f: T) -> Self
+    where
+        T: FnMut(&Game) -> Play + 'static,
+    {
+        Self(Box::new(f))
+    }
+}
 
-#[cfg(test)]
-fn random_player(game: &Game) -> Play {
-    match game.phase {
-        Phase::Play => Play::Play(
-            *game
-                .current_player_hand()
-                .random()
-                .expect("I always have a card to play because I just drew one"),
-        ),
-        Phase::Momentum => {
-            if rand::thread_rng().gen_bool(0.5) {
-                Play::Draw
-            } else {
-                match game.current_player_hand().random() {
-                    Some(card) => Play::Play(*card),
-                    None => Play::Draw,
+#[must_use]
+pub fn random_player(draw_chance: f64) -> Player {
+    Player(Box::new(move |game: &Game| -> Play {
+        match game.phase {
+            Phase::Play => Play::Play(
+                *game
+                    .current_player_hand()
+                    .random()
+                    .expect("I always have a card to play because I just drew one"),
+            ),
+            Phase::Momentum => {
+                if rand::thread_rng().gen_bool(draw_chance) {
+                    Play::Draw
+                } else {
+                    match game.current_player_hand().random() {
+                        Some(card) => Play::Play(*card),
+                        None => Play::Draw,
+                    }
                 }
             }
         }
-    }
+    }))
+}
+
+/// When available, make plays that grant momentum.
+#[must_use]
+pub fn momentum_player(mut fallback: Player) -> Player {
+    Player(Box::new(move |game: &Game| -> Play {
+        if game.phase == Phase::Play {
+            if let Some(suit) = game.discard.top().and_then(Card::suit) {
+                if let Some(card) = game.current_player_hand().filter_by_suit(suit).random() {
+                    return Play::Play(*card);
+                }
+            }
+        }
+        fallback.0(game)
+    }))
 }
 
 /// # Errors
@@ -491,7 +528,7 @@ mod tests {
     #[test]
     fn test_game() {
         for num_players in 1..10 {
-            let players: Vec<_> = std::iter::from_fn(|| Some(Player(Box::new(random_player))))
+            let players: Vec<_> = std::iter::from_fn(|| Some(momentum_player(random_player(0.5))))
                 .take(num_players)
                 .collect();
             let mut game = Game::default();