#!/usr/bin/env python3
from __future__ import annotations

import hashlib
import html
import re
import unicodedata
from datetime import datetime, timezone
from pathlib import Path
from typing import Any

import sys

COMMON_ROOT = Path(__file__).resolve().parents[1]
if str(COMMON_ROOT) not in sys.path:
    sys.path.insert(0, str(COMMON_ROOT))

from project_loader import load_config  # noqa: E402

_, CONFIG = load_config()
ALLOWED_PRIORITIES = set(CONFIG.domain.priorities)
ALLOWED_CATEGORIES = set(CONFIG.domain.categories)
def now_iso() -> str:
    return datetime.now(timezone.utc).astimezone().isoformat(timespec="seconds")

def normalize_doi(value: Any) -> str | None:
    if value is None:
        return None
    doi = str(value).strip().lower()
    if not doi or doi == "unknown":
        return None
    prefixes = (
        "https://doi.org/",
        "http://doi.org/",
        "http://dx.doi.org/",
        "doi:",
    )
    for prefix in prefixes:
        if doi.startswith(prefix):
            doi = doi[len(prefix):]
            break
    doi = doi.strip().rstrip(".,;:)]}")
    return doi or None

def normalize_text(value: str) -> str:
    value = html.unescape(value)
    value = unicodedata.normalize("NFKC", value)
    value = value.lower()
    value = re.sub(r"[\r\n\t]+", " ", value)
    value = re.sub(r"[^\w\s]", " ", value, flags=re.UNICODE)
    value = re.sub(r"\s+", " ", value).strip()
    return value

def sha256_file(path: Path) -> str:
    h = hashlib.sha256()
    with path.open("rb") as f:
        for block in iter(lambda: f.read(1024 * 1024), b""):
            h.update(block)
    return h.hexdigest()

def resolve_pdf_path(pdf_root: Path, stored_path: str) -> Path:
    path = Path(stored_path)
    if path.is_absolute():
        raise ValueError("pdf_path must be relative to PDF_ROOT")
    resolved = (pdf_root / path).resolve()
    root = pdf_root.resolve()
    try:
        resolved.relative_to(root)
    except ValueError as exc:
        raise ValueError("pdf_path escapes PDF_ROOT") from exc
    return resolved