"""
Django settings for the GAP API.

Configuração partilhada entre desenvolvimento e produção.
Valores sensíveis devem ser definidos em ambiente (ver .env.example).
"""

import os
from datetime import timedelta
from pathlib import Path

from dotenv import load_dotenv

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

load_dotenv(BASE_DIR / ".env")


def env_bool(name: str, default: bool = False) -> bool:
    return os.getenv(name, str(default)).lower() in ("1", "true", "yes", "on")


def env_list(name: str, default: str = "") -> list[str]:
    return [item.strip() for item in os.getenv(name, default).split(",") if item.strip()]


SECRET_KEY = os.getenv("DJANGO_SECRET_KEY", "django-insecure-dev-only-change-me")

DEBUG = env_bool("DJANGO_DEBUG", True)

ALLOWED_HOSTS = env_list("DJANGO_ALLOWED_HOSTS", "localhost,127.0.0.1")

# Application definition
INSTALLED_APPS = [
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.staticfiles",
    # Bibliotecas
    "rest_framework",
    "rest_framework_simplejwt",
    "corsheaders",
    # Apps da GAP
    "accounts",
    "operations",
    "learning",
]

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

ROOT_URLCONF = "gap.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 = "gap.wsgi.application"
ASGI_APPLICATION = "gap.asgi.application"

# Database
# PostgreSQL em produção. Para desenvolvimento local, se DATABASE_URL não
# estiver definido, usa SQLite para arrancar sem dependências externas.
# Exemplo PostgreSQL:
#   DATABASE_URL=postgres://gap:gap@localhost:5432/gap
if os.getenv("DATABASE_URL"):
    import dj_database_url

    DATABASES = {"default": dj_database_url.parse(os.getenv("DATABASE_URL"))}
else:
    DATABASES = {
        "default": {
            "ENGINE": "django.db.backends.sqlite3",
            "NAME": BASE_DIR / "db.sqlite3",
        }
    }

# Password validation
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"},
]

# Custom user model (com papéis: admin, formador, estudante)
AUTH_USER_MODEL = "accounts.User"

# Internationalization
LANGUAGE_CODE = "pt-pt"
TIME_ZONE = "Africa/Maputo"
USE_I18N = True
USE_TZ = True

# Static files (CSS, JavaScript, Images)
STATIC_URL = "static/"
STATIC_ROOT = BASE_DIR / "staticfiles"

# Media (materiais, uploads)
MEDIA_URL = "media/"
MEDIA_ROOT = BASE_DIR / "media"

# Default primary key field type
DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"

# Django REST Framework
REST_FRAMEWORK = {
    "DEFAULT_AUTHENTICATION_CLASSES": (
        "rest_framework_simplejwt.authentication.JWTAuthentication",
    ),
    "DEFAULT_PERMISSION_CLASSES": (
        "rest_framework.permissions.IsAuthenticated",
    ),
    "DEFAULT_PAGINATION_CLASS": "rest_framework.pagination.PageNumberPagination",
    "PAGE_SIZE": 20,
    "DEFAULT_FILTER_BACKENDS": (
        "django_filters.rest_framework.DjangoFilterBackend",
        "rest_framework.filters.SearchFilter",
        "rest_framework.filters.OrderingFilter",
    ),
}

# JWT
SIMPLE_JWT = {
    "ACCESS_TOKEN_LIFETIME": timedelta(minutes=int(os.getenv("JWT_ACCESS_MINUTES", "60"))),
    "REFRESH_TOKEN_LIFETIME": timedelta(days=int(os.getenv("JWT_REFRESH_DAYS", "7"))),
    "ROTATE_REFRESH_TOKENS": True,
    "BLACKLIST_AFTER_ROTATION": False,
    "AUTH_HEADER_TYPES": ("Bearer",),
}

# CORS — o frontend Next.js corre em http://localhost:3000
CORS_ALLOWED_ORIGINS = env_list(
    "CORS_ALLOWED_ORIGINS", "http://localhost:3000,http://127.0.0.1:3000"
)
CORS_ALLOW_CREDENTIALS = True

# LLM — integração com a Groq (ver learning/llm.py)
GROQ_API_KEY = os.getenv("GROQ_API_KEY", "")
GROQ_MODEL = os.getenv("GROQ_MODEL", "llama-3.3-70b-versatile")

# CSRF/segurança em produção
CSRF_TRUSTED_ORIGINS = env_list(
    "CSRF_TRUSTED_ORIGINS", "http://localhost:3000,http://127.0.0.1:3000"
)
if not DEBUG:
    SECURE_SSL_REDIRECT = env_bool("SECURE_SSL_REDIRECT", True)
    SECURE_PROXY_SSL_HEADER = ("HTTP_X_FORWARDED_PROTO", "https")
    SESSION_COOKIE_SECURE = True
    CSRF_COOKIE_SECURE = True