"""Resolve stored upload paths (Docker-safe)."""

from __future__ import annotations

import re
from pathlib import Path, PureWindowsPath

from app.services.ingest import ensure_upload_dir


def to_stored_path(path: Path) -> str:
    """Store path relative to upload root (portable)."""
    root = ensure_upload_dir().resolve()
    resolved = path.resolve()
    try:
        return resolved.relative_to(root).as_posix()
    except ValueError:
        return resolved.name


def _after_uploads(parts: tuple[str, ...] | list[str]) -> Path | None:
    """Return path segments after an 'uploads' directory."""
    lowered = [p.lower() for p in parts]
    if "uploads" not in lowered:
        return None
    idx = lowered.index("uploads")
    rest = parts[idx + 1 :]
    if not rest:
        return None
    return Path(*rest)


def resolve_stored_path(stored: str) -> Path:
    """
    Resolve a DB file_path to an on-disk Path.

    Supports relative (preferred) and legacy absolute paths
    from Windows host or Linux container.
    """
    root = ensure_upload_dir().resolve()
    raw = Path(stored)

    # Preferred: relative to upload root
    if not raw.is_absolute() and not re.match(r"^[A-Za-z]:[\\/]", stored):
        candidate = (root / raw).resolve()
        if candidate.is_file():
            return candidate
        raise FileNotFoundError(stored)

    # Legacy absolute that still exists (same machine)
    if raw.is_absolute() and raw.is_file():
        return raw.resolve()

    # Windows absolute path string while running in Linux/Docker
    win = PureWindowsPath(stored)
    rel = _after_uploads(win.parts)
    if rel is not None:
        candidate = (root / rel).resolve()
        if candidate.is_file():
            return candidate

    # POSIX absolute with /.../uploads/...
    rel = _after_uploads(raw.parts)
    if rel is not None:
        candidate = (root / rel).resolve()
        if candidate.is_file():
            return candidate

    by_name = root / Path(stored.replace("\\", "/")).name
    if by_name.is_file():
        return by_name.resolve()

    raise FileNotFoundError(stored)