import os
from pathlib import Path

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


def _load_env_file(env_path: Path) -> None:
    """
    Minimal `.env` loader (KEY=VALUE) for local development.
    This project reads all settings from `os.environ`, so we populate it here
    before the rest of this settings file reads environment variables.
    """
    if not env_path.exists():
        return

    try:
        raw = env_path.read_text(encoding="utf-8")
    except Exception:
        return

    for line in raw.splitlines():
        line = line.strip()
        if not line or line.startswith("#"):
            continue

        # Support optional `export KEY=VALUE`
        if line.lower().startswith("export "):
            line = line[7:].strip()

        if "=" not in line:
            continue

        key, value = line.split("=", 1)
        key = key.strip()
        value = value.strip()

        if not key:
            continue

        # Strip wrapping quotes: KEY="value" or KEY='value'
        if len(value) >= 2 and value[0] == value[-1] and value[0] in ("'", '"'):
            value = value[1:-1]

        # Don't override already-set environment variables.
        os.environ.setdefault(key, value)


_load_env_file(BASE_DIR / ".env")

SECRET_KEY = os.environ.get(
    "DJANGO_SECRET_KEY",
    "django-insecure-%3o%@4414q3k44*k374=m25ea(fyr!7cgs9z-*u)21tw6g^q25",
)

DEBUG = os.environ.get("DJANGO_DEBUG", "True").lower() in ("true", "1", "yes")

ALLOWED_HOSTS = os.environ.get("DJANGO_ALLOWED_HOSTS", "*").split(",")

INSTALLED_APPS = [
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.staticfiles",
    # Third-party
    "rest_framework",
    # Project apps
    "stores.apps.StoresConfig",
    "chat.apps.ChatConfig",
    "ai_engine.apps.AiEngineConfig",
    "gateway.apps.GatewayConfig",
    "vendors.apps.VendorsConfig",
    "cart.apps.CartConfig",
    "escrow.apps.EscrowConfig",
    "whatsapp.apps.WhatsAppConfig",
]

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",
]

ROOT_URLCONF = "config.urls"

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

WSGI_APPLICATION = "config.wsgi.application"

DATABASES = {
    "default": {
        "ENGINE": os.environ.get("DB_ENGINE", "django.db.backends.sqlite3"),
        "NAME": os.environ.get("DB_NAME", str(BASE_DIR / "db.sqlite3")),
        "USER": os.environ.get("DB_USER", ""),
        "PASSWORD": os.environ.get("DB_PASSWORD", ""),
        "HOST": os.environ.get("DB_HOST", ""),
        "PORT": os.environ.get("DB_PORT", ""),
    }
}

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"},
]

LANGUAGE_CODE = "en-us"
TIME_ZONE = "UTC"
USE_I18N = True
USE_TZ = True

STATIC_URL = "static/"
STATICFILES_DIRS = [BASE_DIR / "static"]
STATIC_ROOT = BASE_DIR / "staticfiles"

# ── Media (user-uploaded files) ──────────────────────────────────
MEDIA_URL = "/media/"
MEDIA_ROOT = BASE_DIR / "media"

DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"

# ── REST Framework ──────────────────────────────────────────────────
REST_FRAMEWORK = {
    "DEFAULT_RENDERER_CLASSES": [
        "rest_framework.renderers.JSONRenderer",
        "rest_framework.renderers.BrowsableAPIRenderer",
    ],
}

# ── AI / LLM Providers ─────────────────────────────────────────────
# Anthropic / Claude
ANTHROPIC_API_KEY = os.environ.get("ANTHROPIC_API_KEY", "")
LLM_MODEL = os.environ.get("LLM_MODEL", "claude-haiku-4-5-20251001")
LLM_MAX_TOKENS = int(os.environ.get("LLM_MAX_TOKENS", "300"))

# OpenAI / ChatGPT
OPENAI_API_KEY = os.environ.get("OPENAI_API_KEY", "")
OPENAI_MODEL = os.environ.get("OPENAI_MODEL", "gpt-4o-mini")

# Conversation history sent to Claude (sliding window: most recent messages only).
# Tune down if you hit context limits; WhatsApp defaults are tighter (one thread per phone).
CHAT_HISTORY_MAX_MESSAGES = int(os.environ.get("CHAT_HISTORY_MAX_MESSAGES", "12"))
CHAT_HISTORY_MAX_MSG_CHARS = int(os.environ.get("CHAT_HISTORY_MAX_MSG_CHARS", "1500"))
CHAT_HISTORY_MAX_TOTAL_CHARS = int(os.environ.get("CHAT_HISTORY_MAX_TOTAL_CHARS", "18000"))
WHATSAPP_SESSION_PREFIX = "wa:"
WHATSAPP_CHAT_HISTORY_MAX_MESSAGES = int(os.environ.get("WHATSAPP_CHAT_HISTORY_MAX_MESSAGES", "8"))
WHATSAPP_CHAT_HISTORY_MAX_MSG_CHARS = int(os.environ.get("WHATSAPP_CHAT_HISTORY_MAX_MSG_CHARS", "600"))
WHATSAPP_CHAT_HISTORY_MAX_TOTAL_CHARS = int(os.environ.get("WHATSAPP_CHAT_HISTORY_MAX_TOTAL_CHARS", "8000"))

# ── Cache (Redis when available, fallback to local memory) ─────────
CACHES = {
    "default": {
        "BACKEND": os.environ.get(
            "CACHE_BACKEND", "django.core.cache.backends.filebased.FileBasedCache"
        ),
        "LOCATION": os.environ.get("CACHE_LOCATION", str(BASE_DIR / ".cache" / "django")),
        "TIMEOUT": int(os.environ.get("CACHE_TIMEOUT", "600")),
    }
}

# ── Gateway settings ───────────────────────────────────────────────
LOGIN_URL = "/accounts/login/"
LOGIN_REDIRECT_URL = "/accounts/redirect/"
LOGOUT_REDIRECT_URL = "/"

GATEWAY_REQUEST_TIMEOUT = int(os.environ.get("GATEWAY_REQUEST_TIMEOUT", "10"))
GATEWAY_MAX_CONCURRENT = int(os.environ.get("GATEWAY_MAX_CONCURRENT", "20"))


# ── Paystack ───────────────────────────────────────────────────────────────
PAYSTACK_SECRET_KEY = os.environ.get("PAYSTACK_SECRET_KEY", "")
PAYSTACK_PUBLIC_KEY = os.environ.get("PAYSTACK_PUBLIC_KEY", "")
 
# ── mNotify SMS ────────────────────────────────────────────────────────────
MNOTIFY_API_KEY    = os.environ.get("MNOTIFY_API_KEY", "")
MNOTIFY_SENDER_ID  = os.environ.get("MNOTIFY_SENDER_ID", "Mirjy")
 
# ── Escrow Config ──────────────────────────────────────────────────────────
ESCROW_PLATFORM_FEE_RATE  = 0.02          # 2% platform fee
ESCROW_AUTO_RELEASE_HOURS = 48            # hours before auto-release
ESCROW_ADMIN_PHONE        = os.environ.get("ESCROW_ADMIN_PHONE", "")  # dispute alerts
 
# ── Default currency (all checkout amounts in GHS) ─────────────────────────
DEFAULT_CURRENCY = "GHS"

# ── WhatsApp Config ──────────────────────────────────────────────────────────
WHATSAPP_VERIFY_TOKEN = os.environ.get("WHATSAPP_VERIFY_TOKEN", "")
WHATSAPP_ACCESS_TOKEN = os.environ.get("WHATSAPP_ACCESS_TOKEN", "")
WHATSAPP_PHONE_ID = os.environ.get("WHATSAPP_PHONE_ID", "")
WHATSAPP_CLICK_TO_CHAT_URL = os.environ.get("WHATSAPP_CLICK_TO_CHAT_URL", "")


SITE_URL = os.environ.get("SITE_URL", "https://aca.mirjy.com")