"""
Django settings for the J621 backend.
"""

import os
import subprocess
from pathlib import Path

from dotenv import load_dotenv

BASE_DIR = Path(__file__).resolve().parent.parent

load_dotenv(BASE_DIR / ".env")

SECRET_KEY = os.getenv("SECRET_KEY", "django-insecure-dev-only-change-me")
DEBUG = os.getenv("DEBUG", "True").lower() == "true"
ALLOWED_HOSTS = [
    host.strip()
    for host in os.getenv("ALLOWED_HOSTS", "localhost,127.0.0.1,0.0.0.0").split(",")
    if host.strip()
]


def _git_commit_hash():
    """Short git hash of the running build, mirroring the original app."""
    try:
        return subprocess.check_output(
            ["git", "rev-parse", "--short", "HEAD"],
            cwd=BASE_DIR,
            text=True,
            stderr=subprocess.DEVNULL,
        ).strip()
    except (subprocess.SubprocessError, OSError):
        return "unknown"


GIT_COMMIT_HASH = _git_commit_hash()
APP_ENV = "dev" if DEBUG else "prod"
APP_VERSION = f"{APP_ENV} @ {GIT_COMMIT_HASH}"

# Application definition

INSTALLED_APPS = [
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.staticfiles",
    "rest_framework",
    "rest_framework.authtoken",
    "django_filters",
    "apps.accounts",
    "apps.library",
    "apps.follows",
    "apps.core",
]

MIDDLEWARE = [
    "django.middleware.security.SecurityMiddleware",
    "django.contrib.sessions.middleware.SessionMiddleware",
    "django.middleware.common.CommonMiddleware",
    "django.middleware.csrf.CsrfViewMiddleware",
    "django.contrib.auth.middleware.AuthenticationMiddleware",
    "django.contrib.messages.middleware.MessageMiddleware",
    "django.middleware.clickjacking.XFrameOptionsMiddleware",
    "apps.core.middleware.TimingMiddleware",
]

ROOT_URLCONF = "config.urls"

TEMPLATES = [
    {
        "BACKEND": "django.template.backends.django.DjangoTemplates",
        "DIRS": [],
        "APP_DIRS": True,
        "OPTIONS": {
            "context_processors": [
                "django.template.context_processors.request",
                "django.contrib.auth.context_processors.auth",
                "django.contrib.messages.context_processors.messages",
            ],
        },
    },
]

WSGI_APPLICATION = "config.wsgi.application"

# Database (MariaDB, run via docker compose at the repo root)

DATABASES = {
    "default": {
        "ENGINE": "django.db.backends.mysql",
        "NAME": os.getenv("DB_NAME", "j621"),
        "USER": os.getenv("DB_USER", "j621"),
        "PASSWORD": os.getenv("DB_PASSWORD", "j621"),
        "HOST": os.getenv("DB_HOST", "127.0.0.1"),
        "PORT": os.getenv("DB_PORT", "3307"),
        "OPTIONS": {"charset": "utf8mb4"},
    }
}

# Authentication

AUTH_USER_MODEL = "accounts.User"

AUTH_PASSWORD_VALIDATORS = [
    {
        "NAME": "django.contrib.auth.password_validation.UserAttributeSimilarityValidator",
    },
    {
        "NAME": "django.contrib.auth.password_validation.MinimumLengthValidator",
    },
    {
        "NAME": "django.contrib.auth.password_validation.CommonPasswordValidator",
    },
    {
        "NAME": "django.contrib.auth.password_validation.NumericPasswordValidator",
    },
]

# Internationalization

LANGUAGE_CODE = "en-us"
TIME_ZONE = os.getenv("TIME_ZONE", "America/Bogota")
USE_I18N = True
USE_TZ = True

# Static and media files

STATIC_URL = "static/"
STATIC_ROOT = BASE_DIR / "staticfiles"

MEDIA_URL = "/media/"
MEDIA_ROOT = BASE_DIR / "media"

# Watched folder that gets indexed into the library.
_watched = os.getenv("WATCHED_FOLDER", "").strip()
WATCHED_FOLDER = Path(_watched) if _watched else MEDIA_ROOT / "library"
if not WATCHED_FOLDER.is_absolute():
    WATCHED_FOLDER = BASE_DIR / WATCHED_FOLDER
WATCHED_FOLDER = str(WATCHED_FOLDER)

# e621 integration

E621_BASE_URL = os.getenv("E621_BASE_URL", "https://e621.net").rstrip("/")
USER_AGENT = os.getenv("USER_AGENT", "J621/0.1 (by J621 on e621)")
# Hosts the client-download proxy is allowed to stream from.
E621_MEDIA_HOSTS = [
    host.strip()
    for host in os.getenv(
        "E621_MEDIA_HOSTS",
        "static1.e621.net,static2.e621.net,static3.e621.net",
    ).split(",")
    if host.strip()
]

# Guest visibility: e621's anonymous default blacklist is mirrored into the
# cache by `manage.py refresh_guest_blacklist`. This fallback is used until
# that command runs or when e621 is unreachable.
GUEST_BLACKLIST_FALLBACK = [
    tag.strip()
    for tag in os.getenv(
        "GUEST_BLACKLIST_FALLBACK", "young,cub,shota,loli,child,underage"
    ).split(",")
    if tag.strip()
]
GUEST_BLACKLIST_TTL = int(os.getenv("GUEST_BLACKLIST_TTL", "3600"))

# Similarity threshold for flagging staged uploads that match library items.
VISUAL_MATCH_THRESHOLD = float(os.getenv("VISUAL_MATCH_THRESHOLD", "0.9"))

# Ephemeral similarity-check uploads are deleted after this many minutes
# (and always on startup).
SIMILARITY_TTL_MINUTES = int(os.getenv("SIMILARITY_TTL_MINUTES", "30"))

# Redis cache (run via docker compose at the repo root), shared by web
# workers and management commands (e.g. the mirrored guest blacklist).
CACHES = {
    "default": {
        "BACKEND": "django.core.cache.backends.redis.RedisCache",
        "LOCATION": os.getenv("REDIS_URL", "redis://127.0.0.1:6380/1"),
    }
}

# Django REST Framework

REST_FRAMEWORK = {
    "DEFAULT_AUTHENTICATION_CLASSES": [
        "rest_framework.authentication.TokenAuthentication",
    ],
    "DEFAULT_PERMISSION_CLASSES": [
        "rest_framework.permissions.IsAuthenticatedOrReadOnly",
    ],
    "DEFAULT_FILTER_BACKENDS": [
        "django_filters.rest_framework.DjangoFilterBackend",
        "rest_framework.filters.SearchFilter",
        "rest_framework.filters.OrderingFilter",
    ],
    "DEFAULT_PAGINATION_CLASS": "config.pagination.StandardPagination",
    "PAGE_SIZE": 48,
}

DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"

LOGGING = {
    "version": 1,
    "disable_existing_loggers": False,
    "formatters": {
        "simple": {
            "format": "{levelname} {asctime} {name} {message}",
            "style": "{",
        },
    },
    "handlers": {
        "console": {
            "class": "logging.StreamHandler",
            "formatter": "simple",
        },
    },
    "root": {
        "handlers": ["console"],
        "level": "INFO",
    },
}