"""LSB-first bit reader/writer (Vorbis bit packing order)."""


class BitReader:
    def __init__(self, data: bytes, bitpos: int = 0):
        self.data = data
        self.pos = bitpos

    def get(self, n: int) -> int:
        v = 0
        for i in range(n):
            byte = self.data[(self.pos >> 3)] if (self.pos >> 3) < len(self.data) else 0
            v |= ((byte >> (self.pos & 7)) & 1) << i
            self.pos += 1
        return v

    def bits_left(self) -> int:
        return len(self.data) * 8 - self.pos


class BitWriter:
    def __init__(self):
        self.buf = bytearray()
        self.pos = 0

    def put(self, n: int, v: int):
        for i in range(n):
            if (self.pos >> 3) >= len(self.buf):
                self.buf.append(0)
            if (v >> i) & 1:
                self.buf[self.pos >> 3] |= 1 << (self.pos & 7)
            self.pos += 1

    def put_bits_from(self, r: BitReader, n: int):
        """Copy n bits from a reader (fast path in 32-bit chunks)."""
        while n > 0:
            k = 32 if n >= 32 else n
            self.put(k, r.get(k))
            n -= k

    def bytes(self) -> bytes:
        return bytes(self.buf)


def ilog(v: int) -> int:
    r = 0
    while v:
        r += 1
        v >>= 1
    return r


def book_maptype1_quantvals(entries: int, dims: int) -> int:
    bits = ilog(entries)
    vals = entries >> ((bits - 1) * (dims - 1) // dims)
    while True:
        acc = 1
        acc1 = 1
        for _ in range(dims):
            acc *= vals
            acc1 *= vals + 1
        if acc <= entries < acc1:
            return vals
        if acc > entries:
            vals -= 1
        else:
            vals += 1