"""
FiveK dataset path resolution.
Maps image ID (e.g. a2621-_DSC5468) to DNG path using range folders.
"""
from pathlib import Path
from typing import List

# Range folders under raw_photos (inclusive low–high)
_RANGES = [
    (1, 700, "HQa1to700"),
    (701, 1400, "HQa701to1400"),
    (1401, 2100, "HQa1400to2100"),
    (2101, 2800, "HQa2101to2800"),
    (2801, 3500, "HQa2801to3500"),
    (3501, 4200, "HQa3501to4200"),
    (4201, 5000, "HQa4201to5000"),
]


def _id_to_number(image_id: str) -> int:
    """Extract numeric part from id, e.g. a2621-_DSC5468 -> 2621."""
    prefix = image_id.split("-")[0]
    if prefix.startswith("a"):
        try:
            return int(prefix[1:])
        except ValueError:
            pass
    return 0


def image_id_to_dng_path(image_id: str, raw_photos_dir: Path) -> Path:
    """
    Resolve image ID to DNG file path under raw_photos_dir.
    Returns path like raw_photos_dir/HQa2101to2800/photos/a2621-_DSC5468.dng
    """
    num = _id_to_number(image_id)
    for low, high, folder_name in _RANGES:
        if low <= num <= high:
            return raw_photos_dir / folder_name / "photos" / f"{image_id}.dng"
    return raw_photos_dir / "HQa1to700" / "photos" / f"{image_id}.dng"


def list_all_image_ids(file_list_path: Path) -> List[str]:
    """Read ordered list of image IDs from filesAdobe.txt (or similar)."""
    if not file_list_path.exists():
        return []
    ids = []
    with open(file_list_path, "r", encoding="utf-8") as f:
        for line in f:
            line = line.strip()
            if line and not line.startswith("#"):
                ids.append(line)
    return ids