# set.py - base64, golomb and set-string routines. analog set.c used in alt-rpm

import hashlib
from typing import List
from typing import Tuple
from dataclasses import dataclass


@dataclass
class Set:
    """just a bag of strings and their hash values.

    Attributes:
        count (int): The number of elements in the set.
        labels (List[Tuple[str, int]]): A list of tuples, where each tuple contains a string and its corresponding hash value.
    """

    count: int
    labels: List[Tuple[str, int]]  # List of tuples (string, hash value)


def rpmsetcmp():
    pass


def set_new() -> Set:
    """Create a new Set instance with count initialized to 0 and an empty list of labels."""
    return Set(count=0, labels=[])


def set_add(set: Set, label: str) -> None:
    """Add a label to the set."""
    hash_value = hash(label)
    set.labels.append((label, hash_value))
    set.count += 1


def set_free(set: Set) -> None:
    """Free the resources associated with the set."""
    set.labels.clear()
    set.count = 0


def hash(label: str) -> int:
    """Compute a stable 64-bit hash value for an ASCII label."""
    digest = hashlib.blake2b(label.encode("ascii"), digest_size=8).digest()
    return int.from_bytes(digest, byteorder="little", signed=False)


def set_fini(set: Set, bpp: int) -> str | None:
    """Finalize the set and return a set-string representation."""

    if set.count < 1:
        return None

    # bpp < 10 in original code
    if bpp < 2:
        return None

    if bpp > 64:
        return None

    # Placeholder implementation - replace with actual finalization logic
    return f"Set with {set.count} elements"