const Square = @import("Board.zig").Square;
// WARNING: this must be in sync with Chess.PE!
pub const MATERIAL_SCORE: [12]i16 = .{
    100,
    300,
    350,
    500,
    1000,
    10_000,
    -100,
    -300,
    -350,
    -500,
    -1000,
    -10_000,
};
pub const PAWN_SCORE: [64]i8 = .{
    // zig fmt: off
    90,  90,  90,  90,  90,  90,  90,  90,
    30,  30,  30,  40,  40,  30,  30,  30,
    20,  20,  20,  30,  30,  30,  20,  20,
    10,  10,  10,  20,  20,  10,  10,  10,
     5,   5,  10,  20,  20,   5,   5,   5,
     0,   0,   0,   5,   5,   0,   0,   0,
     0,   0,   0, -10, -10,   0,   0,   0,
     0,   0,   0,   0,   0,   0,   0,   0
    // zig fmt: on
};
pub const KNIGHT_SCORE:[64]i8 = .{
    // zig fmt: off
    -5,   0,   0,   0,   0,   0,   0,  -5,
    -5,   0,   0,  10,  10,   0,   0,  -5,
    -5,   5,  20,  20,  20,  20,   5,  -5,
    -5,  10,  20,  30,  30,  20,  10,  -5,
    -5,  10,  20,  30,  30,  20,  10,  -5,
    -5,   5,  20,  10,  10,  20,   5,  -5,
    -5,   0,   0,   0,   0,   0,   0,  -5,
    -5, -10,   0,   0,   0,   0, -10,  -5
    // zig fmt: on
};
pub const BISHOP_SCORE: [64]i8 = .{
    // zig fmt: off
    0,   0,   0,   0,   0,   0,   0,   0,
    0,   0,   0,   0,   0,   0,   0,   0,
    0,   0,   0,  10,  10,   0,   0,   0,
    0,   0,  10,  20,  20,  10,   0,   0,
    0,   0,  10,  20,  20,  10,   0,   0,
    0,  10,   0,   0,   0,   0,  10,   0,
    0,  30,   0,   0,   0,   0,  30,   0,
    0,   0, -10,   0,   0, -10,   0,   0
    // zig fmt: on
};
pub const ROOK_SCORE: [64]i8 = .{
    // zig fmt: off
    50,  50,  50,  50,  50,  50,  50,  50,
    50,  50,  50,  50,  50,  50,  50,  50,
     0,   0,  10,  20,  20,  10,   0,   0,
     0,   0,  10,  20,  20,  10,   0,   0,
     0,   0,  10,  20,  20,  10,   0,   0,
     0,   0,  10,  20,  20,  10,   0,   0,
     0,   0,  10,  20,  20,  10,   0,   0,
     0,   0,   0,  20,  20,   0,   0,   0
    // zig fmt: on
};
pub const KING_SCORE: [64]i8 = .{
    // zig fmt: off
    0,   0,   0,   0,   0,   0,   0,   0,
    0,   0,   5,   5,   5,   5,   0,   0,
    0,   5,   5,  10,  10,   5,   5,   0,
    0,   5,  10,  20,  20,  10,   5,   0,
    0,   5,  10,  20,  20,  10,   5,   0,
    0,   0,   5,  10,  10,   5,   0,   0,
    0,   5,   5,  -5,  -5,   0,   5,   0,
    0,   0,   5,   0, -15,   0,  10,   0
    // zig fmt: on
};
// mirror positional score tables for opposite side
pub const MIRROR_SCORE: [64]Square = .{
    // zig fmt: off
    .a1, .b1, .c1, .d1, .e1, .f1, .g1, .h1,
    .a2, .b2, .c2, .d2, .e2, .f2, .g2, .h2,
    .a3, .b3, .c3, .d3, .e3, .f3, .g3, .h3,
    .a4, .b4, .c4, .d4, .e4, .f4, .g4, .h4,
    .a5, .b5, .c5, .d5, .e5, .f5, .g5, .h5,
    .a6, .b6, .c6, .d6, .e6, .f6, .g6, .h6,
    .a7, .b7, .c7, .d7, .e7, .f7, .g7, .h7,
    .a8, .b8, .c8, .d8, .e8, .f8, .g8, .h8
    // zig fmt: on
};

const eval = @import("eval.zig");

    fn evaluate(self: @This()) isize {
        var score: isize = 0;
        for (self.bitboards) |bb, idx| {
            var board = @bitCast(BoardType, bb);
            const bits = @popCount(board);
            score += eval.MATERIAL_SCORE[idx] * bits;
            while (board != 0) {
                const bit = @ctz(board);
                score += switch (@intToEnum(Chess.PE, idx)) {
                    .P => eval.PAWN_SCORE[bit],
                    .N => eval.KNIGHT_SCORE[bit],
                    .B => eval.BISHOP_SCORE[bit],
                    .R => eval.ROOK_SCORE[bit],
                    .K => eval.KING_SCORE[bit],
                    .Q => break,
                    .p => -eval.PAWN_SCORE[@enumToInt(eval.MIRROR_SCORE[bit])],
                    .n => -eval.KNIGHT_SCORE[@enumToInt(eval.MIRROR_SCORE[bit])],
                    .b => -eval.BISHOP_SCORE[@enumToInt(eval.MIRROR_SCORE[bit])],
                    .r => -eval.ROOK_SCORE[@enumToInt(eval.MIRROR_SCORE[bit])],
                    .k => -eval.KING_SCORE[@enumToInt(eval.MIRROR_SCORE[bit])],
                    .q => break,
                    else => 0,
                };
                board ^= @as(BoardType, 1) << @intCast(u6, bit);
            }
        }
        switch (self.side) {
            .white => return score,
            .black => return -score,
        }
    }

        // gs.show();
    }
}
test "evaluate" {
    {
        // remove white queen
        var gs = try GameState.init("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNB1KBNR w KQkq - 0 1");
        try std.testing.expectEqual(@as(isize, -1000), gs.evaluate());
    }
    {
        // remove white queen, but black comes
        var gs = try GameState.init("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNB1KBNR b KQkq - 0 1");
        try std.testing.expectEqual(@as(isize, 1000), gs.evaluate());
    }
    {
        // Pe2e4
        var gs = try GameState.init("rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR w KQkq - 0 1");
        try std.testing.expectEqual(@as(isize, 30), gs.evaluate());
    }
    {
        // Pe2e4 pe7e5 Ng1f3
        var gs = try GameState.init("rnbqkbnr/pppp1ppp/8/4p3/4P3/5N2/PPPP1PPP/RNBQKB1R w KQkq - 0 1");

        try std.testing.expectEqual(@as(isize, 30), gs.evaluate());