import ctypes
import platform
import unittest
from pathlib import Path


WHITE, BLACK = 0, 1
FILES = {c:i for i,c in enumerate("abcdefgh")}


def sq(name: str) -> int:
    f = FILES[name[0].lower()]
    r = int(name[1]) - 1
    return f + 8 * r


def bb_from(*algebraic):
    m = 0
    for s in algebraic:
        m |= (1 << sq(s))
    return m


def popcount(x: int) -> int:
    return x.bit_count()


def draw_bb(mask: int, origin: int | None = None) -> str:
    print("\n")
    lines = []
    for r in range(7, -1, -1):
        row = []
        for f in range(8):
            sqi = r * 8 + f
            bit = (mask >> sqi) & 1
            if origin is not None and sqi == origin:
                ch = 'O'
            elif bit:
                ch = 'x'
            else:
                ch = '.'
            row.append(ch)
        lines.append(f"{r+1} " + " ".join(row))
    lines.append("  " + " ".join(FILES))
    lines = "\n".join(lines)
    print(lines, "\n")


class ChessLibTestBase(unittest.TestCase):
    @classmethod
    def setUpClass(cls):
        root = Path(__file__).resolve().parents[1]
        libname = "libchess.so"
        libpath = root / "build" / libname
        cls.lib = ctypes.CDLL(str(libpath))

        attack_cache_functions = [
            "create_knight_attack_cache",
            "create_pawn_attack_cache",
            "create_king_attack_cache",
        ]

        # init functions
        for fn in attack_cache_functions:
            getattr(cls.lib, fn).argtypes = []
            getattr(cls.lib, fn).restype = None
     
        cls.lib.create_knight_attack_cache()
        cls.lib.create_pawn_attack_cache()
        cls.lib.create_king_attack_cache()

        KnightArr = ctypes.c_uint64 * 64
        KingArr   = ctypes.c_uint64 * 64
        PawnRow   = ctypes.c_uint64 * 64
        PawnArr   = PawnRow * 2

        cls.KNIGHT_ATTACKS = KnightArr.in_dll(cls.lib, "KNIGHT_ATTACKS")
        cls.KING_ATTACKS   = KingArr.in_dll(cls.lib, "KING_ATTACKS")
        cls.PAWN_ATTACKS   = PawnArr.in_dll(cls.lib, "PAWN_ATTACKS")