# SPDX-FileCopyrightText: 2026 Dennis Fink <me+coding@dennisfink.me>
#
# SPDX-License-Identifier: BSD-3-Clause

"""Types used throughout the duplicate-file finder."""

from collections import defaultdict
from dataclasses import dataclass
from pathlib import Path

type FileIdentity = tuple[int, int]
type FileSize = int
type FileHash = str
type FileExtension = str


@dataclass(frozen=True, slots=True)
class FileInfo:
    """Store filesystem metadata collected while discovering a file.

    :param path: Path through which the file was discovered.
    :param size: File size in bytes.
    :param identity: Filesystem identity as ``(device, inode)``.
    """

    path: Path
    size: FileSize
    identity: FileIdentity


type FileSet = set[FileInfo]
type FilesByIdentity = defaultdict[FileIdentity, FileSet]

type CandidateGroupKey = FileSize | tuple[FileSize, FileExtension]
type FilesByCandidateGroup = dict[CandidateGroupKey, FilesByIdentity]
type FilesByHash = dict[FileHash, FileSet]