# app/config.py
import json
import os
from functools import lru_cache
from urllib.parse import quote

# Make sure ZeroGPU sees it
if "HF_TOKEN" in os.environ:
    os.environ["HUGGINGFACE_HUB_TOKEN"] = os.environ["HF_TOKEN"]


APPSETTINGS_PATH = os.environ.get("APPSETTINGS_JSON", "appsettings.json")


class Settings:
    """Settings object with attribute access."""
    def __init__(self, data: dict):
        for k, v in data.items():
            setattr(self, k, v)


def _load_json(path):
    if not os.path.exists(path):
        return {}
    with open(path, "r", encoding="utf-8") as f:
        return json.load(f)


def _replace_env_vars(d, parent_key=None):
    """
    Replace ".env" values with env var lookups using the same key name
    as in appsettings.json (case-sensitive).
    """
    if isinstance(d, dict):
        return {k: _replace_env_vars(v, k) for k, v in d.items()}
    elif isinstance(d, str) and d.strip() == ".env":
        env_key = parent_key or ""
        return os.environ.get(env_key)
    else:
        return d



def _build_amqp_url(local: dict):
    if not local:
        return None
    scheme = "amqps" if local.get("UseTls", True) else "amqp"
    host = local.get("RabbitHostName")
    port = local.get("RabbitPort") or (5671 if scheme == "amqps" else 5672)
    user = local.get("RabbitUserName")
    pwd = local.get("RabbitPassword") or os.environ.get("RABBIT_PASSWORD")
    vhost = local.get("RabbitVHost") or "/"
    vhost_enc = quote(vhost, safe="")
    if not (host and user and pwd):
        return None
    return f"{scheme}://{user}:{pwd}@{host}:{port}/{vhost_enc}?heartbeat=30"


@lru_cache
def get_settings() -> Settings:
    cfg = _load_json(APPSETTINGS_PATH)
    cfg = _replace_env_vars(cfg)  # <- replaces .env everywhere first

    # Flatten relevant LocalSystemUrl fields
    local = cfg.get("LocalSystemUrl", {})
    if local:
        cfg["RABBIT_INSTANCE_NAME"] = local.get("RabbitInstanceName")
        cfg["RABBIT_HOST_NAME"] = local.get("RabbitHostName")
        cfg["RABBIT_PORT"] = local.get("RabbitPort")
        cfg["RABBIT_USER_NAME"] = local.get("RabbitUserName")
        cfg["RABBIT_PASSWORD"] = local.get("RabbitPassword")  # already resolved
        cfg["RABBIT_VHOST"] = local.get("RabbitVHost")
        cfg["RABBIT_USE_TLS"] = local.get("UseTls")

    # Map JSON keys to Python attributes
    cfg["SERVICE_ID"] = cfg.get("ServiceID")
    cfg["RABBIT_ROUTING_KEY"] = cfg.get("RabbitRoutingKey")
    cfg["RABBIT_EXCHANGE_TYPE"] = cfg.get("RabbitExhangeType") or "topic"
    cfg["REDIS_URL"] = cfg.get("RedisUrl")
    cfg["REDIS_SECRET"] = cfg.get("RedisSecret")
    cfg["EXCHANGE_TYPES"] = cfg.get("RabbitMQ", {}).get("ExchangeTypes", cfg.get("EXCHANGE_TYPES", {}))
    cfg["RABBIT_PREFETCH"] = cfg.get("RABBIT_PREFETCH", 1)
    

    # Build AMQP_URL if not already provided
    if not cfg.get("AMQP_URL"):
        amqp_url = _build_amqp_url(local)
        if amqp_url:
            cfg["AMQP_URL"] = amqp_url

    return Settings(cfg)


settings = get_settings()