{ config, lib, pkgs, ... }:

with lib;
let
  cfg = config.nix-bitcoin.nodeinfo;

  # Services included in the output
  services = {
    bitcoind = mkInfo "";
    clightning = mkInfo ''
      info["nodeid"] = shell("lightning-cli getinfo | jq -r '.id'")
      if 'onion_address' in info:
          info["id"] = f"{info['nodeid']}@{info['onion_address']}"
    '';
    lnd = mkInfo ''
      info["nodeid"] = shell("lightning-cli getinfo | jq -r '.id'")
    '';
    electrs = mkInfo "";
    spark-wallet = mkInfo "";
    btcpayserver = mkInfo "";
    liquidd = mkInfo "";
    joinmarket-ob-watcher = mkInfo "";
    # Only add sshd when it has an onion service
    sshd = name: cfg: mkIfOnionPort "sshd" (onionPort: ''
      add_service("sshd", """set_onion_address(info, "sshd", ${onionPort})""")
    '');
  };

  script = pkgs.writeScriptBin "nodeinfo" ''
    #!${pkgs.python3}/bin/python

    import json
    import subprocess
    from collections import OrderedDict

    def success(*args):
        return subprocess.call(args, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL) == 0

    def is_active(unit):
        return success("systemctl", "is-active", "--quiet", unit)

    def is_enabled(unit):
        return success("systemctl", "is-enabled", "--quiet", unit)

    def cmd(*args):
        return subprocess.run(args, stdout=subprocess.PIPE).stdout.decode('utf-8')

    def shell(*args):
        return cmd("bash", "-c", *args).strip()

    infos = OrderedDict()
    operator = "${config.nix-bitcoin.operator.name}"

    def set_onion_address(info, name, port):
        path = f"/var/lib/onion-addresses/{operator}/{name}"
        try:
            with open(path, "r") as f:
                onion_address = f.read().strip()
        except OSError:
            print(f"error reading file {path}", file=sys.stderr)
            return
        info["onion_address"] = f"{onion_address}:{port}"

    def add_service(service, make_info):
        if not is_active(service):
            infos[service] = "service is not running"
        else:
            info = OrderedDict()
            exec(make_info, globals(), locals())
            infos[service] = info

    if is_enabled("onion-adresses") and not is_active("onion-adresses"):
        print("error: service 'onion-adresses' is not running")
        exit(1)

    ${concatStrings infos}

    print(json.dumps(infos, indent=2))
  '';

  infos = map (service:
    let cfg = config.services.${service};
    in optionalString cfg.enable (services.${service} service cfg)
  ) (builtins.attrNames services);

  mkInfo = extraCode: name: cfg:
    ''
      add_service("${name}", """
      info["local_address"] = "${cfg.address}:${toString cfg.port}"
    '' + mkIfOnionPort name (onionPort: ''
      set_onion_address(info, "${name}", ${onionPort})
    '') + extraCode + ''

      """)
    '';

   mkIfOnionPort = name: fn:
     if hiddenServices ? ${name} then
       fn (toString (builtins.elemAt hiddenServices.${name}.map 0).port)
     else
       "";

  inherit (config.services.tor) hiddenServices;
in {
  options = {
    nix-bitcoin.nodeinfo = {
      enable = mkEnableOption "nodeinfo";
      program = mkOption {
        readOnly = true;
        default = script;
      };
    };
  };

  config = {
    environment.systemPackages = optional cfg.enable script;
  };
}