feat: better UCI mate display

1 files changed, 45 insertions, 37 deletions

diff --git a/src/grossmeister/search.rs b/src/grossmeister/search.rs
index c899216..1aa73a0 100644
--- a/src/grossmeister/search.rs
+++ b/src/grossmeister/search.rs
@@ -244,33 +244,12 @@ impl Grossmeister {
         let mut gradual_widening_counter = 0;
 
         while depth <= max_depth {
-            println!("info hashfull {}", 1000 * self.transposition_table.iter().filter(|item| item.is_some()).count() / self.transposition_table.len());
-            println!("info depth {}", depth);
             if self.debug {
                 println!("info string window {:?}", (alpha, beta));
             }
 
             let search_result = self.negamax_search(alpha, beta, depth, 0);
 
-            if search_result.0.abs() >= SCORE_MATE - 128f32 { // TODO: VALUE_WIN - MAX_PLY
-                let score = search_result.0;
-                let mate_distance = (SCORE_MATE - score.abs()) * if score > 0.0 {
-                    1.
-                } else {
-                    -1. // -N means we are mated in N plies
-                };
-                println!("info mate {:.0}", (mate_distance / 2.0).ceil());
-
-                result = Some(search_result);
-
-                if score.abs() == SCORE_MATE {
-                    break;
-                } else {
-                    depth += 1;
-                    continue;
-                }
-            }
-
             if self.should_halt.load(std::sync::atomic::Ordering::SeqCst) {
                 println!("info string halting search");
                 break;
@@ -280,35 +259,50 @@ impl Grossmeister {
                 gradual_widening_counter += 1;
                 beta = alpha + window_size * 0.1;
                 alpha = search_result.0 - window_size * 2.0f32.powi(gradual_widening_counter);
-                println!("info score upperbound {:.0}", beta * 100.0);
+                println!("info depth {} score upperbound {:.0}", depth, beta * 100.0);
                 continue;
             }
             if search_result.0 >= beta { // Beta-cutoff
                 gradual_widening_counter += 1;
                 alpha = beta - window_size * 0.1;
                 beta = search_result.0 + window_size * 2.0f32.powi(gradual_widening_counter);
-                println!("info score lowerbound {:.0}", alpha * 100.0);
+                println!("info depth {} score lowerbound {:.0}", depth, alpha * 100.0);
                 continue;
             }
 
-            if !search_result.1.is_empty() {
-                depth += 1;
-                gradual_widening_counter = 0;
-                alpha = search_result.0 - window_size;
-                beta = search_result.0 + window_size;
+            if search_result.1.is_empty() {
+                panic!("Why the fuck no moves?");
+            }
 
-                {
-                    print!("info score cp {:.0} pv ", search_result.0 * 100.0);
-                    for mov in &search_result.1 {
-                        print!("{} ", mov);
-                    }
-                    println!();
-                }
+            // Print UCI info
+            print!("info depth {} score ", depth);
+            if search_result.0.abs() >= SCORE_MATE - 128f32 { // TODO: VALUE_WIN - MAX_PLY
+                let mate_distance = (SCORE_MATE - search_result.0.abs()) * if search_result.0 > 0.0 {
+                    1.
+                } else {
+                    -1. // -N means we are mated in N plies
+                };
+                print!("mate {:.0} ", (mate_distance / 2.0).ceil());
+            } else {
+                print!("cp {:.0} ", search_result.0 * 100.0)
+            }
+            print!("pv ");
+            for mov in &search_result.1 {
+                print!("{} ", mov);
+            }
+            println!();
 
+            // If our is mate in N, we break at depth N
+            if SCORE_MATE - search_result.0.abs() == depth as f32 {
                 result = Some(search_result);
-            } else {
-                panic!("Why the fuck no moves?");
+                break;
             }
+
+            depth += 1;
+            gradual_widening_counter = 0;
+            alpha = search_result.0 - window_size;
+            beta = search_result.0 + window_size;
+            result = Some(search_result);
         }
 
         if result.is_none() {
@@ -316,6 +310,8 @@ impl Grossmeister {
             result = Some(self.negamax_search(-INFINITY, INFINITY, 1, 0))
         }
 
+        println!("info hashfull {}", 1000 * self.transposition_table.iter().filter(|item| item.is_some()).count() / self.transposition_table.len());
+
         match result {
             Some(r) => {
                 print!("bestmove {}", r.1[0]);
@@ -503,4 +499,16 @@ mod tests {
         dbg!(score, pv);
         assert_eq!(score + SCORE_MATE, 4.0); // Mate in 4 plies
     }
+
+    #[test]
+    fn another_mate_in_2() {
+        let fen = String::from("7r/2pr1pR1/2p2p2/1p2pN2/p3Pk1P/P2P2b1/1PP1K3/R7 w - - 0 33");
+        let board = Board::from_FEN(fen);
+
+        let mut gm = Grossmeister::new(board);
+        gm.debug = true;
+        let (score, pv) = gm.iterative_deepening(5);
+        dbg!(score, pv);
+        assert_eq!(SCORE_MATE - score, 3.0); // Mate in 3 plies
+    }
 }