1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140

use super::*;

#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[derive(Clone, Debug)]
pub struct SearchController {
    move_overhead: Duration,
    max_time: Duration,
    max_depth: Depth,
    stop_search_at_every_node: bool,
}

impl SearchController {
    pub fn new() -> Self {
        Self {
            move_overhead: TIMECAT_DEFAULTS.move_overhead,
            max_time: Duration::MAX,
            max_depth: Depth::MAX,
            stop_search_at_every_node: false,
        }
    }

    pub fn reset_start_time(&mut self) {
        self.stop_search_at_every_node = false;
    }

    pub fn set_max_time(&mut self, duration: Duration) {
        self.max_time = duration;
        self.stop_search_at_every_node = false;
    }

    pub fn max_time(&self) -> Duration {
        self.max_time
    }

    pub fn is_time_up(&mut self, time_elapsed: Duration) -> bool {
        if self.max_time == Duration::MAX {
            return false;
        }
        self.stop_search_at_every_node = time_elapsed + self.move_overhead >= self.max_time;
        self.stop_search_at_every_node
    }
}

impl SearchControl for SearchController {
    #[inline]
    fn get_move_overhead(&self) -> Duration {
        self.move_overhead
    }

    #[inline]
    fn set_move_overhead(&mut self, duration: Duration) {
        self.move_overhead = duration;
    }

    fn reset_variables(&mut self) {
        self.max_time = Duration::MAX;
        self.max_depth = Depth::MAX;
        self.stop_search_at_every_node = false;
    }

    fn on_each_search_completion(&mut self, searcher: &Searcher) {
        if self.max_time != Duration::MAX
            && searcher.is_main_threaded()
            && !searcher.is_outside_aspiration_window()
            && searcher.get_depth_completed() >= 10
            && searcher.get_score() >= WINNING_SCORE_THRESHOLD
            && searcher.get_time_elapsed() > Duration::from_secs(10)
        {
            self.stop_search_at_every_node = true;
        }
    }

    fn on_receiving_go_command(&mut self, command: GoCommand, searcher: &Searcher) {
        let board = searcher.get_board();
        match command {
            GoCommand::MoveTime(duration) => self.set_max_time(duration),
            GoCommand::Timed {
                wtime,
                btime,
                winc,
                binc,
                moves_to_go,
            } => {
                let (self_time, self_inc, opponent_time, _) = match board.turn() {
                    White => (wtime, winc, btime, binc),
                    Black => (btime, binc, wtime, winc),
                };
                let divider = moves_to_go.unwrap_or(
                    (20 as NumMoves)
                        .checked_sub(board.get_fullmove_number() / 2)
                        .unwrap_or_default()
                        .max(5),
                );
                let new_inc = self_inc
                    .checked_sub(Duration::from_secs(1))
                    .unwrap_or_default();
                let self_time_advantage_bonus =
                    self_time.checked_sub(opponent_time).unwrap_or_default();
                let opponent_time_advantage =
                    opponent_time.checked_sub(self_time).unwrap_or_default();
                let mut search_time = self_time
                    .checked_sub(opponent_time_advantage)
                    .unwrap_or_default()
                    / divider as u32
                    + new_inc
                    + self_time_advantage_bonus
                        .checked_sub(Duration::from_secs(10))
                        .unwrap_or_default()
                        / 4;
                search_time = search_time
                    .max((self_time / 2).min(Duration::from_secs(3)))
                    .min(Duration::from_secs(board.get_fullmove_number() as u64) / 2)
                    .max(Duration::from_millis(100));
                self.set_max_time(search_time);
            }
            GoCommand::Depth(depth) => self.max_depth = depth,
            GoCommand::Infinite | GoCommand::Ponder => (),
        }
    }

    fn stop_search_at_root_node(&mut self, searcher: &Searcher) -> bool {
        searcher.get_depth_completed() == self.max_depth || self.stop_search_at_every_node(searcher)
    }

    fn stop_search_at_every_node(&mut self, searcher: &Searcher) -> bool {
        if !searcher.is_main_threaded() {
            return false;
        }
        if self.stop_search_at_every_node {
            return true;
        }
        self.is_time_up(searcher.get_time_elapsed())
    }
}

impl Default for SearchController {
    fn default() -> Self {
        Self::new()
    }
}