tests.c

#define FEATURE_STOPPABLE_SEARCH
#define FEATURE_USE_PRINTF
#undef NSTATS 

#define _XOPEN_SOURCE 500
#include <unistd.h> /* usleep */
#include <pthread.h>

#include "engine.h"
#include "board_print.h"

#include <stdio.h>
#include <assert.h>
#include <stdlib.h>

/* Tests are mostly generated by ChatGPT */

#define test_expect(expr) if (!(expr)) { fprintf(stderr, "test failed: expected <" #expr ">\n"); exit(EXIT_FAILURE); }

static void print_rook_test(const char *label,
                            Sq8 sq,
                            Bb64 all_occ,
                            Bb64 own_occ)
{
    printf("\n%s\n", label);
    printf("All occ:\n");
    bitboard_print(all_occ, stdout);
    printf("Own occ:\n");
    bitboard_print(own_occ, stdout);

    const Bb64 attacks = rook_attacks_from_index(sq, all_occ) & ~own_occ;
    printf("Rook attacks:\n");
    bitboard_print(attacks, stdout);
}

static void test_rooks()
{
    {
        const Sq8 sq = SQ_A1;
        const Bb64 rook       = SQMASK_A1;
        const Bb64 all_occ    = rook;
        const Bb64 own_occ    = rook;

        /* Expected: full rank 1 and file A, except A1 */
        Bb64 expected = (FILE_MASK_A | RANK_MASK_1) & ~SQMASK_A1;

        print_rook_test("Test 1: Rook at A1, empty board", sq, all_occ, own_occ);

        const Bb64 attacks = rook_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }

    {
        const Sq8 sq = SQ_A1;
        const Bb64 rook        = SQMASK_A1;
        const Bb64 own_block   = SQMASK_A2 | SQMASK_B1;
        const Bb64 all_occ     = rook | own_block;
        const Bb64 own_occ     = all_occ;

        /* Expected: no legal moves (immediately blocked both directions) */
        const Bb64 expected = 0ULL;

        print_rook_test("Test 2: Rook at A1, own blockers A2, B1", sq, all_occ, own_occ);

        const Bb64 attacks = rook_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }

    {
        const Sq8 sq = SQ_A1;
        const Bb64 rook        = SQMASK_A1;
        const Bb64 enemies     = SQMASK_A3 | SQMASK_C1;
        const Bb64 all_occ     = rook | enemies;
        const Bb64 own_occ     = rook;

        /*
         * Expected:
         *  - Along file A: A2, A3 (enemy at A3 is capturable, stop there)
         *  - Along rank 1: B1, C1 (enemy at C1 capturable, stop there)
         */
        Bb64 expected = 0ULL;
        expected |= SQMASK_A2 | SQMASK_A3;
        expected |= SQMASK_B1 | SQMASK_C1;

        print_rook_test("Test 3: Rook at A1, enemy blockers A3, C1", sq, all_occ, own_occ);

        const Bb64 attacks = rook_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }

        /* Rook Test 6: center rook on empty board */
    {
        const Sq8 sq = SQ_E5;
        const Bb64 rook        = SQMASK_E5;
        const Bb64 all_occ     = rook;
        const Bb64 own_occ     = rook;

        /* Full rank 5 and file E, except E5 itself */
        Bb64 expected = (FILE_MASK_E | RANK_MASK_5) & ~SQMASK_E5;

        print_rook_test("Rook Test 6: E5, empty board", sq, all_occ, own_occ);

        Bb64 attacks = rook_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }

    /* Rook Test 7: center rook, mixed blockers on rays */
    {
        const Sq8 sq = SQ_E5;
        const Bb64 rook        = SQMASK_E5;

        /* Friendly: E7 and C5; Enemy: E3 and H5 */
        const Bb64 friends     = rook | SQMASK_E7 | SQMASK_C5;
        const Bb64 enemies     = SQMASK_E3 | SQMASK_H5;
        const Bb64 all_occ     = friends | enemies;
        const Bb64 own_occ     = friends;

        /*
         * From E5:
         *  Up:   E6, then friendly E7 (stop before E7)
         *  Down: E4, E3 (enemy, included, then stop)
         *  Left: D5, then friendly C5 (stop before C5)
         *  Right:F5, G5, H5 (enemy, included, then stop)
         */
        Bb64 expected = 0ULL;
        expected |= SQMASK_E6;
        expected |= SQMASK_E4 | SQMASK_E3;
        expected |= SQMASK_D5;
        expected |= SQMASK_F5 | SQMASK_G5 | SQMASK_H5;

        print_rook_test("Rook Test 7: E5, friends E7/C5, enemies E3/H5", sq, all_occ, own_occ);

        Bb64 attacks = rook_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }

    /* Rook Test 8: edge rook on empty board (top edge, not corner) */
    {
        const Sq8 sq = SQ_C8;
        const Bb64 rook        = SQMASK_C8;
        const Bb64 all_occ     = rook;
        const Bb64 own_occ     = rook;

        /*
         * From C8:
         *  Down file C: C7..C1
         *  Across rank 8: A8,B8,D8,E8,F8,G8,H8
         */
        Bb64 expected = 0ULL;
        expected |= (FILE_MASK_C & ~SQMASK_C8);
        expected |= (RANK_MASK_8 & ~SQMASK_C8);

        print_rook_test("Rook Test 8: C8, empty board", sq, all_occ, own_occ);

        Bb64 attacks = rook_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }

    /* Rook Test 9: rook completely boxed in by friendly orthogonal neighbors */
    {
        const Sq8 sq = SQ_D4;
        const Bb64 rook        = SQMASK_D4;
        const Bb64 friends     = rook |
                                     SQMASK_D5 | SQMASK_D3 |
                                     SQMASK_C4 | SQMASK_E4;
        const Bb64 enemies     = 0ULL;
        const Bb64 all_occ     = friends | enemies;
        const Bb64 own_occ     = friends;

        /* All four rays are immediately blocked by own pieces */
        const Bb64 expected = 0ULL;

        print_rook_test("Rook Test 9: D4, boxed by own pieces at D5/D3/C4/E4",
                        sq, all_occ, own_occ);

        Bb64 attacks = rook_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }

    /* Rook Test 10: rook on file with non-interfering off-ray pieces */
    {
        const Sq8 sq = SQ_A4;
        const Bb64 rook        = SQMASK_A4;

        /* Pieces placed off the rook's rank/file; they should have no effect */
        const Bb64 off_ray     = SQMASK_C1 | SQMASK_F6 | SQMASK_H8;
        (void)off_ray;
        const Bb64 friends     = rook | SQMASK_C1;
        const Bb64 enemies     = SQMASK_F6 | SQMASK_H8;
        const Bb64 all_occ     = friends | enemies;
        const Bb64 own_occ     = friends;

        /*
         * From A4:
         *  File A: A1..A8 except A4
         *  Rank 4: B4..H4
         * Pieces not on file A or rank 4 must not change attacks.
         */
        Bb64 expected = 0ULL;
        expected |= (FILE_MASK_A | RANK_MASK_4) & ~SQMASK_A4;

        print_rook_test("Rook Test 10: A4, random off-ray pieces C1/F6/H8",
                        sq, all_occ, own_occ);

        Bb64 attacks = rook_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }
}

static void print_bishop_test(const char *label,
                              Sq8        sq,
                              Bb64       all_occ,
                              Bb64       own_occ)
{
    fprintf(stderr, "\n%s\n", label);
    fprintf(stderr, "All occ:\n");
    bitboard_print(all_occ, stderr);
    fprintf(stderr, "Own occ:\n");
    bitboard_print(own_occ, stderr);

    const Bb64 attacks = bishop_attacks_from_index(sq, all_occ) & ~own_occ;
    fprintf(stderr, "Bishop attacks:\n");
    bitboard_print(attacks, stderr);
}

static void test_bishops(void)
{
    /* Test 1: Bishop at D4 on empty board (only bishop present) */
    {
        const Sq8 sq = SQ_D4;
        const Bb64 bishop  = SQMASK_D4;
        const Bb64 all_occ = bishop;
        const Bb64 own_occ = bishop;

        /*
         * Expected diagonals from D4:
         *  NE: E5, F6, G7, H8
         *  NW: C5, B6, A7
         *  SE: E3, F2, G1
         *  SW: C3, B2, A1
         */
        Bb64 expected = 0ULL;
        expected |= SQMASK_E5 | SQMASK_F6 | SQMASK_G7 | SQMASK_H8;
        expected |= SQMASK_C5 | SQMASK_B6 | SQMASK_A7;
        expected |= SQMASK_E3 | SQMASK_F2 | SQMASK_G1;
        expected |= SQMASK_C3 | SQMASK_B2 | SQMASK_A1;

        print_bishop_test("Bishop Test 1: D4, empty board", sq, all_occ, own_occ);

        const Bb64 attacks = bishop_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }

    /* Test 2: Bishop at C1 on empty board (only bishop present) */
    {
        const Sq8 sq = SQ_C1;
        const Bb64 bishop      = SQMASK_C1;
        const Bb64 all_occ     = bishop;
        const Bb64 own_occ     = bishop;

        /*
         * From C1, diagonals:
         *  NE: D2, E3, F4, G5, H6
         *  NW: B2, A3
         *  SE / SW: none (edge of board)
         */
        Bb64 expected = 0ULL;
        expected |= SQMASK_D2 | SQMASK_E3 | SQMASK_F4 |
                    SQMASK_G5 | SQMASK_H6;
        expected |= SQMASK_B2 | SQMASK_A3;

        print_bishop_test("Bishop Test 2: C1, empty board", sq, all_occ, own_occ);

        const Bb64 attacks = bishop_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }

    /* Test 3: Bishop at D4, friendly blockers at F6 and B2 (no enemies) */
    {
        const Sq8 sq = SQ_D4;
        const Bb64 bishop      = SQMASK_D4;
        const Bb64 friends     = bishop | SQMASK_F6 | SQMASK_B2;
        const Bb64 enemies     = 0ULL;
        const Bb64 all_occ     = friends | enemies;
        const Bb64 own_occ     = friends;

        /*
         * From D4:
         *  NE: E5, then blocked by friendly F6 (F6 not included)
         *  SW: C3, then blocked by friendly B2 (B2 not included)
         *  NW: C5, B6, A7 (no blockers)
         *  SE: E3, F2, G1 (no blockers)
         */
        Bb64 expected = 0ULL;
        expected |= SQMASK_E5;
        expected |= SQMASK_C3;
        expected |= SQMASK_C5 | SQMASK_B6 | SQMASK_A7;
        expected |= SQMASK_E3 | SQMASK_F2 | SQMASK_G1;

        print_bishop_test("Bishop Test 3: D4, friendly blockers F6, B2", sq, all_occ, own_occ);

        const Bb64 attacks = bishop_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }

    /* Test 4: Bishop at D4, enemy blockers at F6 and B2 (no other friends) */
    {
        const Sq8 sq = SQ_D4;
        const Bb64 bishop      = SQMASK_D4;
        const Bb64 friends     = bishop;
        const Bb64 enemies     = SQMASK_F6 | SQMASK_B2;
        const Bb64 all_occ     = friends | enemies;
        const Bb64 own_occ     = friends;

        /*
         * From D4:
         *  NE: E5, F6 (enemy, included, then stop)
         *  SW: C3, B2 (enemy, included, then stop)
         *  NW: C5, B6, A7
         *  SE: E3, F2, G1
         */
        Bb64 expected = 0ULL;
        expected |= SQMASK_E5 | SQMASK_F6;
        expected |= SQMASK_C3 | SQMASK_B2;
        expected |= SQMASK_C5 | SQMASK_B6 | SQMASK_A7;
        expected |= SQMASK_E3 | SQMASK_F2 | SQMASK_G1;

        print_bishop_test("Bishop Test 4: D4, enemy blockers F6, B2", sq, all_occ, own_occ);

        const Bb64 attacks = bishop_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }

    /* Test 5: Bishop at D4, mixed friend/enemy + another friendly bishop elsewhere */
    {
        const Sq8 sq = SQ_D4;
        const Bb64 bishop1     = SQMASK_D4;  /* tested bishop */
        const Bb64 bishop2     = SQMASK_F4;  /* another friendly bishop */
        const Bb64 friends     = bishop1 | bishop2 | SQMASK_F6;
        const Bb64 enemies     = SQMASK_B2;
        const Bb64 all_occ     = friends | enemies;
        const Bb64 own_occ     = friends;

        /*
         * From D4:
         *  NE: E5, then friendly F6 (stop; F6 not included)
         *  SW: C3, B2 (enemy, included, then stop)
         *  NW: C5, B6, A7
         *  SE: E3, F2, G1
         *  Bishop at F4 is irrelevant; it does not sit on a diagonal from D4.
         */
        Bb64 expected = 0ULL;
        expected |= SQMASK_E5;
        expected |= SQMASK_C3 | SQMASK_B2;
        expected |= SQMASK_C5 | SQMASK_B6 | SQMASK_A7;
        expected |= SQMASK_E3 | SQMASK_F2 | SQMASK_G1;

        print_bishop_test("Bishop Test 5: D4, mixed friend/enemy + extra bishop F4", sq, all_occ, own_occ);

        const Bb64 attacks = bishop_attacks_from_index(sq, all_occ) & ~own_occ;
        test_expect(attacks == expected);
    }

    /* Test 6: Bishop at H8, no occupancy */
    {
        const Sq8 sq = SQ_H8;
        const Bb64 all_occ     = 0ULL;
        const Bb64 own_occ     = MASK_FROM_SQ(sq);

        /*
         * From D4:
         *  NE: E5, then friendly F6 (stop; F6 not included)
         *  SW: C3, B2 (enemy, included, then stop)
         *  NW: C5, B6, A7
         *  SE: E3, F2, G1
         *  Bishop at F4 is irrelevant; it does not sit on a diagonal from D4.
         */
        Bb64 expected = 0ULL;
        expected = SQMASK_G7 | SQMASK_F6 | SQMASK_E5 | SQMASK_D4 |
            SQMASK_C3 | SQMASK_B2 | SQMASK_A1;

        print_bishop_test("Bishop Test 6: H8, no occupancy", sq, all_occ, own_occ);

        const Bb64 attacks = bishop_attacks_from_index(sq, all_occ) & ~own_occ;
        if (attacks != expected) {
            bitboard_print(attacks, stderr);
        }
        test_expect(attacks == expected);
    }

    printf("\nAll bishop_attacks_from_index tests passed.\n");
}

struct timeout_params {
    struct searching_flag* x;
    uint32_t v;
    useconds_t us;
};
void* set_after_timeout(void* x)
{
    struct timeout_params* p = x;
    usleep(p->us);
    searching_stop(p->x);
    return NULL;
}

int main()
{
    bool const print_threats = true;

    printf("sizeof pos:            %zu\n", sizeof (struct pos));
    printf("sizeof tt:             %zu\n", sizeof (struct tt));
    printf("sizeof board:          %zu\n", sizeof (struct board));
    printf("sizeof search_option:  %zu\n", sizeof (struct search_option));
    printf("sizeof all tt entries: %zu\n", (1<<26) * sizeof (struct search_option));

#if 0
    test_rooks();
    test_bishops();
#endif

    for (int i = 40; i < 47; i++) {
        fprintf(stdout, "\033[30;%dm ", i);
    }
    fprintf(stdout, "\033[0m\n"); /* reset background color */

    /* board could be too big for the stack */
    struct board* b = malloc(sizeof *b);
    if (!b) {
        abort();
    }
    *b = BOARD_INIT;
    board_init(b);

    //board_load_fen_unsafe(b, "1n1q1rk1/r1p2P2/1p1pp2p/pB2P3/2P5/PPN5/6b1/3QK1NR b - - 0 1");
    //board_load_fen_unsafe(b, "8/8/2kr4/6R1/4K3/6P1/8/8 b - - 0 1");
    //board_load_fen_unsafe(b, "8/8/5R2/8/2K3PP/1B2k3/8/8 b - - 1 4");
    //board_load_fen_unsafe(b, "4r1k1/b1P1B3/P5pK/1p4P1/7q/8/4p3/1R6 w - - 1 54");
    //board_print_fen(b->pos, stdout);
    board_print(&b->pos, NULL, stdout, print_threats);

    for (int turn = 0; turn < 200; ++turn) {
        /*
        move_count = 0;
        all_pseudolegal_moves(&b->pos, MG_ALL, b->pos.moving_side, &move_count, moves);

        if (move_count == 0) {
            printf("no moves for %s, aborting\n", side_str[b->pos.moving_side]);
            board_print(&b->pos, NULL, stdout, print_threats);
            b->pos.moving_side = other_side(b->pos.moving_side);
            board_print(&b->pos, NULL, stdout, print_threats);
            break;
        }
        */

        pthread_t timer;
        struct searching_flag searching;
        searching_start(&searching);
        //atomic_init(&searching, 1);
#if 1
        struct timeout_params timer_params = {
            .x = &searching,
            .v = false,
            .us = 2*1000*1000,
        };
        pthread_create(&timer, NULL, set_after_timeout, &timer_params);
#endif

        struct search_result sr = search(b, b->pos.moving_side, 25, &searching);

        struct move move = sr.move;
        Score16 const score = sr.score;

        printf("move %d: {\n"
               "    .from = %s, (%s)\n"
               "    .to = %s,\n"
               "    .score = %d,\n"
               "    .mask = "
               "",
               turn,
               sq8_display[move.from],
               piece_str[b->mailbox[move.from]],
               sq8_display[move.to],
               score
               );
        printf("\n}\n");

        enum move_result const r = board_move(b, move);

        /* illegal board state from an engine move (i.e. hanging king) means checkmate */
        if (!board_is_legal(b)) {
            printf("checkmate!\n");
            break;
        }

#if 1
        board_print_fen(&b->pos, stdout);
        tt_print_stats(&b->tt, stdout);
        board_print(&b->pos, &move, stdout, print_threats);
        fprintf(stderr, "board hist len: %zu\n", b->hist.length);
        fprintf(stderr, "\n------------------------\n\n\n");
#endif

        if (r == MR_STALEMATE) {
            printf("stalemate\n");
            break;
        }

        if (b->pos.pieces[SIDE_WHITE][PIECE_KING] == 0ULL) {
            printf("white king gone!!\n");
            exit(EXIT_FAILURE);
        }

        if (b->pos.pieces[SIDE_BLACK][PIECE_KING] == 0ULL) {
            printf("black king gone!!\n");
            exit(EXIT_FAILURE);
        }
    }

    return EXIT_SUCCESS;
}