Make mvv_lva to map pieces to their material score instead of abritrary matrix

Add time limits, use anyhow crate to improve error handling, remove depth limit on quiescence search

src/search/iterative_deepening.rs

@@ -7,8 +7,8 @@ use crate::{
 };
 
 use super::{
-    negamax, transposition_table::TranspositionTable, HARD_LIMIT_DIVISION, SOFT_EVAL_THRESHOLD,
-    SOFT_LIMIT_DIVISION,
+    negamax, time::TimeInfo, transposition_table::TranspositionTable, HARD_LIMIT_DIVISION,
+    SOFT_EVAL_THRESHOLD, SOFT_LIMIT_DIVISION,
 };
 
 pub fn iterative_deepening(
@@ -16,30 +16,47 @@ pub fn iterative_deepening(
     max_depth: u8,
     remaining_time: u128,
     tt: &mut TranspositionTable,
-) -> Option<Move> {
-    let (mut best_move, mut best_eval): (Option<Move>, i32) = (None, MIN_SCORE);
-    let time_now = std::time::Instant::now();
+) -> anyhow::Result<Option<Move>> {
+    let (mut best_move, mut best_score) = (None, MIN_SCORE);
+    let time = std::time::Instant::now();
 
     for depth in 1..=max_depth {
-        if time_limit_reached(&time_now, remaining_time, best_eval) {
-            return best_move;
+        if time_limit_reached(&time, remaining_time, best_score) {
+            return Ok(best_move);
         }
 
-        (best_move, best_eval) = negamax::negamax(game, MIN_SCORE, MAX_SCORE, depth, 0, tt);
+        let search_result = negamax::negamax(
+            game,
+            MIN_SCORE,
+            MAX_SCORE,
+            depth,
+            0,
+            &TimeInfo::new(time, remaining_time),
+            tt,
+        );
+
+        if let Ok(search_result) = search_result {
+            if search_result.best_move.is_some() {
+                best_move = search_result.best_move;
+            }
+            best_score = search_result.best_score;
+        } else {
+            return Ok(best_move);
+        }
     }
 
-    best_move
+    Ok(best_move)
 }
 
 fn time_limit_reached(time: &Instant, remaining_time: u128, eval: i32) -> bool {
     hard_limit(time, remaining_time) || soft_limit(time, remaining_time, eval)
 }
 
-fn hard_limit(time_now: &Instant, remaining_time: u128) -> bool {
+pub fn hard_limit(time_now: &Instant, remaining_time: u128) -> bool {
     time_now.elapsed().as_millis() >= remaining_time / HARD_LIMIT_DIVISION
 }
 
-fn soft_limit(time: &Instant, remaining_time: u128, eval: i32) -> bool {
+pub fn soft_limit(time: &Instant, remaining_time: u128, eval: i32) -> bool {
     time.elapsed().as_millis() >= remaining_time / SOFT_LIMIT_DIVISION && eval > SOFT_EVAL_THRESHOLD
 }
 
@@ -57,9 +74,9 @@ mod tests {
     const FEN: &str = "1r2k2r/2P1pq1p/2npb3/1p3ppP/p3P3/P2B1Q2/1P1PNPP1/R3K2R w KQk g6 0 1";
 
     #[test]
-    fn test_iterative_deepening() -> Result<(), String> {
+    fn test_iterative_deepening() -> anyhow::Result<()> {
         init_attacks();
-        let mut game = from_fen(FEN)?;
+        let mut game = from_fen(FEN).unwrap();
         let mut tt = TranspositionTable::new(MAX_TT_SIZE);
         let time_now = std::time::Instant::now();
 
@@ -68,7 +85,7 @@ mod tests {
             MAX_DEPTH,
             REMAINING_TIME_DEFAULT,
             &mut tt,
-        );
+        )?;
 
         dbg!(time_now.elapsed());