1 files changed, 99 insertions, 0 deletions
diff --git a/src/shuffle.rs b/src/shuffle.rs
index e69de29..8d421b6 100644
--- a/src/shuffle.rs
+++ b/src/shuffle.rs
@@ -0,0 +1,99 @@
+use rand::{distributions::{Distribution, Standard}, Rng};
+
+#[derive(PartialEq)]
+enum MoveDirection {
+    Front,
+    Back,
+    Down,
+    Up,
+    Right,
+    Left,
+}
+
+enum MoveModifier {
+    None,
+    Twice,
+    Prime,
+}
+
+pub struct Move {
+    direction: MoveDirection,
+    modifier: MoveModifier,
+}
+
+
+// https://stackoverflow.com/questions/48490049
+impl Distribution<MoveDirection> for Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> MoveDirection {
+        use MoveDirection::*;
+
+        match rng.gen_range(0, 6) {
+            0  => Front,
+            1  => Back,
+            2  => Down,
+            3  => Up,
+            4  => Right,
+            _  => Left,
+        }
+    }
+}
+
+impl Distribution<MoveModifier> for Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> MoveModifier {
+        use MoveModifier::*;
+
+        match rng.gen_range(0, 3) {
+            0  => None,
+            1  => Twice,
+            _  => Prime,
+        }
+    }
+}
+
+impl Move {
+    pub fn sequence(n: usize) -> Vec<Move> {
+        let mut sequence: Vec<Move> = Vec::with_capacity(n);
+
+        while sequence.len() != n {
+            let direction = rand::random::<MoveDirection>();
+            let modifier = rand::random::<MoveModifier>();
+
+            if let Some(l) = sequence.last() {
+                if l.direction == direction {
+                    continue;
+                }
+            }
+            sequence.push(Move { direction, modifier });
+        }
+        sequence
+    }
+
+    pub fn string_sequence(n: usize) -> String {
+        let seq = Move::sequence(n);
+        seq.iter().map(|m| m.to_string() + " ").collect::<Vec<String>>().join(" ")
+    }
+}
+
+use std::fmt;
+
+impl fmt::Display for Move {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        use MoveDirection::*;
+        use MoveModifier::*;
+
+        let letter = match self.direction {
+            Front  => "F",
+            Back   => "B",
+            Down   => "D",
+            Up     => "U",
+            Right  => "R",
+            Left   => "L",
+        };
+        let modifier = match self.modifier {
+            None  => "",
+            Twice => "2",
+            Prime => "'",
+        };
+        write!(f, "{}{}", letter, modifier)
+    }
+}