#!/usr/bin/env python3
"""Share-list search/publish helpers for the musician service.

Paths are environment-overridable and the share database / directory are
accessed lazily, so importing this module has no side effects (the previous
version ran ``SHARE_DIR.mkdir()`` and read the JSON DB at import time, which
crashed on any host without the Pi's ``/var/www`` / ``/var/log`` layout — and
made the service untestable).
"""
import json
import os
import uuid
from pathlib import Path

# CONFIGURATION (env-overridable)
JSON_DB = os.getenv("CONJURER_SHARE_DB", "/var/log/share_scan.json")
SHARE_DIR = Path(os.getenv("CONJURER_SHARE_DIR", "/var/www/html/share"))
BASE_URL = os.getenv("CONJURER_SHARE_BASE_URL", "https://czernobog.pl/share")

_entries_cache = None


def _ensure_share_dir():
    SHARE_DIR.mkdir(parents=True, exist_ok=True)


def load_db():
    """Load share entries, returning [] when the DB is missing/corrupt."""
    try:
        with open(JSON_DB) as handle:
            return json.load(handle).get("entries", [])
    except (FileNotFoundError, json.JSONDecodeError):
        return []


def _entries():
    global _entries_cache
    if _entries_cache is None:
        _entries_cache = load_db()
    return _entries_cache


def relevancy(path, keywords):
    score = 0
    low = path.lower()
    for kw in keywords:
        if kw.lower() in low:
            score += low.count(kw.lower())
    return score


def find_matches(count, keywords):
    scored = []
    for entry in _entries():
        score = relevancy(entry["path"], keywords)
        if score > 0:
            scored.append((score, entry["path"]))
    scored.sort(reverse=True, key=lambda x: x[0])
    result = [p for _, p in scored]
    return result[:count]


def publish(paths):
    _ensure_share_dir()
    urls = []
    for path in paths:
        token = uuid.uuid4().hex
        link = SHARE_DIR / token
        try:
            os.symlink(path, link)
        except FileExistsError:
            pass
        urls.append(f"{BASE_URL}/{token}")
    return urls