"""Configuration loader and defaults for hbd."""

import logging
import os

try:
    import yaml
except Exception:
    yaml = None

DEFAULTS = {
    "hb_port": 50003,
    "hbd_port": 50004,
    "hbd_host": "",
    "pickfile": "/tmp/hb.pick",
    "logfile": "/var/log/heartbeat.log",
    "logfmt": "text",
    "pushsrv": "pushover",
    "pushover_token": "",
    "pushover_user": "",
    "interval": 20,
    "grace": 2,
    "dyndomains": ["wrede.org"],
    "watchhosts": [],
    "dyndnshosts": [],
    "drophosts": [],
    "nsupdate_bin": "/usr/bin/nsupdate",
    "foreground": False,
    "verbose": False,
    "debug": 0,
    "smtpserver": "smtp.fastmail.com",
    "smtpuser": "andreas@wrede.ca",
    "smtppassword": "pvtvefyp5gbhnch2",
    "smtpport": 587,
    "toemail": ["aew.hbd.notify@wrede.ca"],
    "fromemail": "aew.hbd@wrede.ca",
    "ws_port": 50005,
    "wss_port": None,
    "cert_path": "/usr/local/etc/ssl/",
    "wss_pem": "fullchain.pem",
    "wss_key": "privkey.pem",
}


def load_config(path=None):
    """Load configuration from a YAML file and merge with defaults.

    If YAML is not available or the file does not exist, defaults are returned.
    """
    cfg = DEFAULTS.copy()
    if not path:
        # default path (~/.hb.yaml)
        path = os.path.join(os.path.expanduser("~"), ".hb.yaml")

    if os.path.exists(path):
        if yaml:
            with open(path) as fh:
                data = yaml.safe_load(fh)
            # only keep known keys
            for k, v in data.items():
                if k in cfg:
                    cfg[k] = v
                else:
                    logging.warning("unknown config key %s in %s", k, path)
        else:
            # yaml not installed: do not attempt to parse; user must ensure defaults
            pass
    return cfg