1 files changed, 152 insertions, 0 deletions
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..a38759d
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,152 @@
+use std::{ io, io::Read };
+
+mod minesweeper {
+    use std::convert::TryFrom;
+    use std::fmt::Display;
+    use rand::{ thread_rng, Rng, distributions::Uniform };
+
+    const HIDDEN_BIT: u8 = 1 << 7;
+    const FLAGGED_BIT: u8 = 1 << 6;
+    const CORRECT_BIT: u8 = 1 << 5; // grading for a rightly flagged mine
+    const MINE_VAL: u8 = !(HIDDEN_BIT | FLAGGED_BIT | CORRECT_BIT);
+    const NEIGH_OFFS: &[(i8,i8)] = &[
+            (-1,-1),(0,-1),(1,-1),
+            (-1, 0),       (1, 0),
+            (-1, 1),(0, 1),(1, 1),
+        ];
+    pub struct Board {
+        pub data: Vec<u8>,
+        pub width: usize,
+        pub height: usize,
+    }
+
+    pub struct Move(pub Board, pub bool);
+
+    impl Board {
+        pub fn new(w: usize, h: usize, mine_count: usize) -> Board {
+            let mut b = Board {
+                data: [HIDDEN_BIT].repeat(w*h),
+                width: w,
+                height: h,
+            };
+
+            let mut rng = thread_rng();
+            let mut c = mine_count;
+            while c > 0 {
+                let x: usize = rng.sample(Uniform::new(0,w-1));
+                let y: usize = rng.sample(Uniform::new(0,h-1));
+                let o = b.pos_to_off(x,y);
+                if b.data[o] == MINE_VAL | HIDDEN_BIT { continue }
+                else {
+                    b.data[o] |= MINE_VAL;
+                    c -= 1;
+                    for (ox,oy) in NEIGH_OFFS {
+                        let nxr = usize::try_from(x as i8 + ox);
+                        let nyr = usize::try_from(y as i8 + oy);
+                        let _ = nxr.and_then(|nx: usize| { nyr.and_then(|ny: usize| {
+                                if nx > w - 1 || ny > h - 1 { return usize::try_from(-1) };
+                                let off = b.pos_to_off(nx,ny);
+                                let c = &mut b.data[off];
+                                if *c != HIDDEN_BIT | MINE_VAL {
+                                    *c += 1;
+                                }
+                                Ok(0)
+                            })
+                        });
+                    }
+                }
+            }
+            b
+        }
+
+        pub fn pos_to_off(&self, x: usize, y: usize) -> usize {
+            x + y * self.width
+        }
+        pub fn flood_reveal(&mut self, x: usize, y: usize) {
+            if x > self.width || y > self.height { return; }
+            let off = self.pos_to_off(x,y);
+            let c = &mut self.data[off];
+            if *c & HIDDEN_BIT > 0 {
+                *c &= !HIDDEN_BIT;
+                if *c > 0 { return }
+                drop(c);
+                for (ox,oy) in NEIGH_OFFS {
+                    let nxr = usize::try_from(x as i8 + ox);
+                    let nyr = usize::try_from(y as i8 + oy);
+                    let _ = nxr.and_then(|nx: usize| { nyr.and_then(|ny: usize| {
+                            if nx > self.width - 1 || ny > self.height - 1 { return usize::try_from(-1) };
+                            let off = self.pos_to_off(nx,ny);
+                            let c = &mut self.data[off];
+                            if *c == HIDDEN_BIT {
+                                self.flood_reveal(nx, ny);
+                            }
+                            Ok(0)
+                        })
+                    });
+                }
+            }
+        }
+        pub fn reveal(mut self, x: usize, y: usize) -> Move {
+            if x > self.width - 1 || y > self.height - 1 { panic!("OOB reveal"); }
+            let off = self.pos_to_off(x,y);
+            self.flood_reveal(x,y);
+            let c = self.data[off];
+            Move { 0: self, 1: (c & !(FLAGGED_BIT | CORRECT_BIT)) == MINE_VAL } // Kaboom
+        }
+    }
+
+    impl Display for Board {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            for y in 0..self.height {
+                for x in 0..self.width {
+                    let c = &self.data[self.pos_to_off(x,y)];
+                    match *c {
+                        0 => write!(f, " ")?,
+                        _ if *c <= 8 => write!(f, "{}", c.to_string())?,
+                        _ if (*c & FLAGGED_BIT) > 0 => write!(f, "F")?,
+                        _ if (*c & HIDDEN_BIT) > 0 => write!(f, "-")?,
+                        _ if (*c & CORRECT_BIT) > 0 => write!(f, "C")?,
+                        _ => write!(f, "?")?,
+                    }
+                }
+                writeln!(f, "\r")?;
+            }
+            Ok(())
+        }
+    }
+}
+
+fn main() -> Result<(), io::Error> {
+    let mut board = minesweeper::Board::new(10,10,100/10);
+    let mut cursor: (usize, usize) = (5,5);
+    let mut gstate = 1;
+    while gstate != 0 {
+        println!("{}", board);
+        let done: bool;
+        let m = playerctrl(board, &mut cursor)?;
+        (board, done) = (m.0, m.1);
+        if done { gstate = 0 }
+    }
+    Ok(())
+}
+
+fn playerctrl(mut board: minesweeper::Board, cursor: &mut (usize, usize)) -> io::Result<minesweeper::Move> {
+    let stdin = io::stdin();
+    let lstdin = stdin.lock();
+    let mut input = lstdin.bytes();
+    let mut kaboom = false;
+    match input.next().expect("bad/no input byte")? {
+        b'w' => cursor.1 -= 1,
+        b's' => cursor.1 += 1,
+        b'a' => cursor.0 -= 1,
+        b'd' => cursor.0 += 1,
+        b'r' => {
+            let m = board.reveal(cursor.0, cursor.1);
+            (board, kaboom) = (m.0, m.1);
+        },
+        b'f' => unimplemented!(),
+        b'q' => kaboom = true,
+        v => println!("{:?}", v),
+    };
+    Ok(minesweeper::Move { 0: board, 1: kaboom })
+}