"""
config/config.py — config loader: file → AppConfig.
Stored as JSON in the same directory as the app.
"""

import json
import os
from pathlib import Path
from .schema import AppConfig, DatabaseConfig, SecurityConfig, ServerConfig, TenorConfig

CONFIG_FILE = os.environ.get("CHAT_CONFIG", "chat_config.json")

def _config_path() -> str:
    """Return absolute path to config file."""
    p = Path(CONFIG_FILE)
    if p.is_absolute():
        return str(p)
    return str(Path(__file__).resolve().parent.parent / CONFIG_FILE)


def load() -> AppConfig:
    path = _config_path()
    cfg = AppConfig()
    if os.path.exists(path):
        with open(path) as f:
            data = json.load(f)
        if "db" in data:
            cfg.db = DatabaseConfig(**{**cfg.db.__dict__, **data["db"]})
        if "security" in data:
            cfg.security = SecurityConfig(**{**cfg.security.__dict__, **data["security"]})
        if "server" in data:
            cfg.server = ServerConfig(**{**cfg.server.__dict__, **data["server"]})
        if "tenor" in data:
            cfg.tenor = TenorConfig(**{**cfg.tenor.__dict__, **data["tenor"]})
    return cfg


def save(cfg: AppConfig):
    path = _config_path()
    data = {
        "db": cfg.db.__dict__,
        "security": cfg.security.__dict__,
        "server": cfg.server.__dict__,
        "tenor": cfg.tenor.__dict__,
    }
    with open(path, "w") as f:
        json.dump(data, f, indent=2)