"""
Django settings for config project.

Generated by 'django-admin startproject' using Django 5.2.7.

For more information on this file, see
https://docs.djangoproject.com/en/5.2/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/5.2/ref/settings/
"""

from pathlib import Path
import os
from django.core.exceptions import ImproperlyConfigured
from dotenv import load_dotenv

BASE_DIR = Path(__file__).resolve().parent.parent
load_dotenv(BASE_DIR.parent / ".env")

# === DEBUG ===
# DEBUG defaults to FALSE — must be explicitly enabled via env var.
# Previously defaulted to "true" which exposed full tracebacks and
# settings to anyone who hit a 500 error in production.
DEBUG = os.getenv("DJANGO_DEBUG", "false").lower() == "true"

# === DEV MODE DETECTION ===
# Local dev uses SQLite (see run_dev.bat). When USE_SQLITE is set we're
# in dev and can relax a few "must be set in prod" checks.
_IS_DEV = os.getenv("USE_SQLITE", "").lower() == "true"

# === SECRET_KEY ===
# Must be provided via DJANGO_SECRET_KEY env var in any non-dev deploy.
# In dev mode (USE_SQLITE=true) we fall back to a known-insecure key so
# local development works out of the box. In prod the absence of the
# env var raises a startup error rather than silently using a weak key.
SECRET_KEY = os.getenv("DJANGO_SECRET_KEY", "")
if not SECRET_KEY:
    if _IS_DEV or DEBUG:
        # Dev-only key — NEVER set this value in a production env var.
        SECRET_KEY = "dev-only-insecure-key-do-not-use-in-production"
    else:
        raise ImproperlyConfigured(
            "DJANGO_SECRET_KEY environment variable is not set. "
            "Set it in the deploy platform's environment variables. "
            "Use `python -c \"import secrets; print(secrets.token_urlsafe(64))\"` "
            "to generate a new one."
        )

ALLOWED_HOSTS = [
    "127.0.0.1",
    "localhost",
    "foxlog.flatlogic.app",
    os.getenv("HOST_FQDN", ""),
]

# === CSRF TRUSTED ORIGINS ===
# Build the list, then normalise each entry to have an https:// prefix.
# Guard against the double-prefix bug: if the user sets HOST_FQDN to
# "https://example.com" (with a scheme), the raw f-string would produce
# "https://https://example.com" which Django rejects.
CSRF_TRUSTED_ORIGINS = [
    origin for origin in [
        "foxlog.flatlogic.app",
        os.getenv("HOST_FQDN", ""),
        os.getenv("CSRF_TRUSTED_ORIGIN", ""),
    ] if origin
]


def _normalize_origin(host):
    """Ensure `host` has an http:// or https:// scheme; default to https.

    Accepts any of:  'example.com' / 'https://example.com' / 'http://localhost'
    Returns a string with a scheme every time.
    """
    host = host.strip()
    if host.startswith(("http://", "https://")):
        return host
    return f"https://{host}"


CSRF_TRUSTED_ORIGINS = [_normalize_origin(h) for h in CSRF_TRUSTED_ORIGINS]

# Cookies must always be HTTPS-only; SameSite=Lax keeps CSRF working behind the proxy.
SESSION_COOKIE_SECURE = True
CSRF_COOKIE_SECURE = True
SESSION_COOKIE_SAMESITE = "None"
CSRF_COOKIE_SAMESITE = "None"

# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/5.2/howto/deployment/checklist/

# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    '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',
    # Disable X-Frame-Options middleware to allow Flatlogic preview iframes.
    # 'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

X_FRAME_OPTIONS = 'ALLOWALL'

ROOT_URLCONF = 'config.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        # Explicitly load core/templates first so we can override specific
        # Django admin templates (e.g. admin/base_site.html) without having
        # to reorder INSTALLED_APPS. Without this entry, the app-dirs loader
        # finds django.contrib.admin's version before ours.
        'DIRS': [BASE_DIR / 'core' / 'templates'],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
                # IMPORTANT: do not remove – injects PROJECT_DESCRIPTION/PROJECT_IMAGE_URL and cache-busting timestamp
                'core.context_processors.project_context',
            ],
        },
    },
]

WSGI_APPLICATION = 'config.wsgi.application'


# Database
# https://docs.djangoproject.com/en/5.2/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': os.getenv('DB_NAME', ''),
        'USER': os.getenv('DB_USER', ''),
        'PASSWORD': os.getenv('DB_PASS', ''),
        'HOST': os.getenv('DB_HOST', '127.0.0.1'),
        'PORT': os.getenv('DB_PORT', '3306'),
        'OPTIONS': {
            'charset': 'utf8mb4',
        },
    },
}


# Password validation
# https://docs.djangoproject.com/en/5.2/ref/settings/#auth-password-validators

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
# https://docs.djangoproject.com/en/5.2/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'Africa/Johannesburg'

USE_I18N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/5.2/howto/static-files/

STATIC_URL = 'static/'
# Collect static into a separate folder; avoid overlapping with STATICFILES_DIRS.
STATIC_ROOT = BASE_DIR / 'staticfiles'

STATICFILES_DIRS = [
    BASE_DIR / 'static',
    BASE_DIR / 'node_modules',
]

MEDIA_URL = '/media/'
MEDIA_ROOT = BASE_DIR / 'media'

# === EMAIL CONFIGURATION ===
# Uses Gmail SMTP with an App Password to send payslip PDFs and receipts.
# The App Password is a 16-character code from Google Account settings —
# it lets the app send email through Gmail without your actual password.
# === EMAIL CONFIGURATION ===
# NO FALLBACKS for credentials — they MUST come from environment variables.
# Previous versions had the Gmail App Password committed in source as a
# fallback default, which is a critical security leak via git history.
# In local dev (USE_SQLITE=true) empty credentials are fine; email sends
# will just fail with an auth error — which is what you want locally.
EMAIL_BACKEND = os.getenv(
    "EMAIL_BACKEND",
    "django.core.mail.backends.smtp.EmailBackend"
)
EMAIL_HOST = os.getenv("EMAIL_HOST", "smtp.gmail.com")
EMAIL_PORT = int(os.getenv("EMAIL_PORT", "587"))
EMAIL_HOST_USER = os.getenv("EMAIL_HOST_USER", "")      # set on deploy platform
EMAIL_HOST_PASSWORD = os.getenv("EMAIL_HOST_PASSWORD", "")  # set on deploy platform
EMAIL_USE_TLS = os.getenv("EMAIL_USE_TLS", "true").lower() == "true"
EMAIL_USE_SSL = os.getenv("EMAIL_USE_SSL", "false").lower() == "true"
# === FROM-ADDRESS ===
# Where outgoing emails appear to come from. If DEFAULT_FROM_EMAIL isn't
# explicitly set, fall back to the Gmail address we authenticate as —
# that's always a valid sender since it's the same account sending the email.
# Without this fallback, emails fail with "Invalid address ''" if the
# env var is missing, even though auth + SMTP are otherwise fine.
DEFAULT_FROM_EMAIL = os.getenv("DEFAULT_FROM_EMAIL", "") or EMAIL_HOST_USER
CONTACT_EMAIL_TO = [
    item.strip()
    for item in os.getenv("CONTACT_EMAIL_TO", DEFAULT_FROM_EMAIL).split(",")
    if item.strip()
]

# Spark Receipt Email — payslip and receipt PDFs routed here for accounting import.
# This is a routing address, not a secret, so a default is acceptable — but override
# via env var for flexibility. Set to empty string if you want to disable sending.
SPARK_RECEIPT_EMAIL = os.getenv("SPARK_RECEIPT_EMAIL", "foxfitt-ed9wc+expense@to.sparkreceipt.com")

# Fail loudly at startup in production if credentials are missing — catches the
# "I forgot to set env vars on the new deploy platform" mistake before a user
# triggers a payroll payment and the email silently fails.
if not DEBUG and not _IS_DEV:
    _missing_email_vars = [
        name for name, val in [
            ("EMAIL_HOST_USER", EMAIL_HOST_USER),
            ("EMAIL_HOST_PASSWORD", EMAIL_HOST_PASSWORD),
            ("DEFAULT_FROM_EMAIL", DEFAULT_FROM_EMAIL),
        ] if not val
    ]
    if _missing_email_vars:
        # Don't crash — email sending isn't critical for the app to boot —
        # but log a loud warning so it's visible in deploy logs.
        import logging
        logging.getLogger(__name__).warning(
            "Email configuration incomplete in production. Missing env vars: %s. "
            "Payslip and receipt emails will fail to send until these are set.",
            ", ".join(_missing_email_vars),
        )

# When both TLS and SSL flags are enabled, prefer SSL explicitly
if EMAIL_USE_SSL:
    EMAIL_USE_TLS = False
# Default primary key field type
# https://docs.djangoproject.com/en/5.2/ref/settings/#default-auto-field

DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
LOGIN_URL = 'login'
LOGIN_REDIRECT_URL = 'home'
LOGOUT_REDIRECT_URL = 'login'

# === MESSAGE TAGS ===
# Django's messages.error() tags messages as "error", but Bootstrap uses "danger"
# for red alerts. Without this mapping, error messages would render as "alert-error"
# which doesn't exist in Bootstrap — making them invisible to the user!
from django.contrib.messages import constants as message_constants
MESSAGE_TAGS = {
    message_constants.ERROR: 'danger',
}

# === LOCAL DEVELOPMENT: SQLite override ===
# Set USE_SQLITE=true in environment to use SQLite instead of MariaDB.
# This lets you test locally without a MySQL/MariaDB server.
if os.getenv('USE_SQLITE', 'false').lower() == 'true':
    DATABASES = {
        'default': {
            'ENGINE': 'django.db.backends.sqlite3',
            'NAME': BASE_DIR / 'db.sqlite3',
        }
    }
    # Disable secure cookies for local http:// testing
    SESSION_COOKIE_SECURE = False
    CSRF_COOKIE_SECURE = False
    SESSION_COOKIE_SAMESITE = 'Lax'
    CSRF_COOKIE_SAMESITE = 'Lax'