# core/context_processors.py
from pathlib import Path
import os

from django.contrib.staticfiles import finders
from django.contrib.staticfiles.storage import staticfiles_storage

from .models_ann import Announcement, AnnouncementDismissal


def app_version(request):
    version_file = Path(__file__).resolve().parent.parent / "version.txt"
    try:
        with open(version_file, "r") as f:
            version = f.read().strip()
    except FileNotFoundError:
        version = "v0.0.0"
    return {"APP_VERSION": version}


def available_themes(request):
    """
    Return a list of theme names by scanning /static/themes/*.css.
    Works in development (finders) and production (staticfiles_storage).
    Never returns an empty list.
    """
    names = set()

    # A) Dev/app static: scan all registered static finders
    try:
        for finder in finders.get_finders():
            for path, storage in finder.list(['themes']):
                # e.g. "themes/midnight.css"
                if path.startswith('themes/') and path.endswith('.css'):
                    names.add(os.path.basename(path)[:-4])  # strip ".css"
    except Exception:
        pass

    # B) Prod/collected: scan STATIC_ROOT via staticfiles_storage
    try:
        dirs, files = staticfiles_storage.listdir('themes')
        for f in files:
            if f.endswith('.css'):
                names.add(f[:-4])
    except Exception:
        pass

    # C) Safety net: default themes so the selector is never empty
    if not names:
        names.update({'midnight', 'dawn', 'forest', 'sandstone'})

    return {'available_themes': sorted(names)}


def pending_announcement(request):
    """
    Expose the latest active, current announcement the user has not dismissed.
    We'll only use it on the Search page via include.
    """
    user = getattr(request, "user", None)
    if not (user and user.is_authenticated):
        return {"pending_announcement": None}

    current = [a for a in Announcement.objects.all() if a.is_current()]
    for a in current:
        if not AnnouncementDismissal.objects.filter(user=user, announcement=a).exists():
            return {"pending_announcement": a}
    return {"pending_announcement": None}