{ config, lib, pkgs, ... }:
let
  dcrdEnabled = config.services.dcrd.enable or false;
  cfg = config.services.dcrwallet;
in
{
  options.services.dcrwallet = with lib; {
    enable = mkEnableOption "Decred wallet daemon";

    package = mkOption {
      type = types.package;
      default = pkgs.dcrwallet;
      description = "Package providing the dcrwallet binary";
    };

    user = mkOption {
      type = types.str;
      default = "dcrwallet";
      description = "User to run dcrwallet as";
    };

    group = mkOption {
      type = types.str;
      default = cfg.user;
      description = "Group to run dcrwallet as";
    };

    dataDir = mkOption {
      type = types.path;
      default = "/var/lib/dcrwallet";
      description = "State directory for dcrwallet (appdata)";
    };

    configFile = mkOption {
      type = types.path;
      description = "Path to dcrwallet configuration file (runtime path)";
    };

    extraPackages = mkOption {
      type = types.listOf types.package;
      default = [];
      example = [ pkgs.dcrctl ];
      description = "Additional packages to add to the dcrwallet user's environment";
    };

  };

  config = lib.mkIf cfg.enable {
    users.users.${cfg.user} = {
      group = cfg.group;
      home = cfg.dataDir;
      isNormalUser = true;
      packages = [ cfg.package ] ++ cfg.extraPackages;
      # dcrwallet needs read access to the dcrd RPC certificate
      extraGroups = lib.optional (dcrdEnabled && config.services.dcrd.group != cfg.group) config.services.dcrd.group;
    };
    users.groups.${cfg.group} = {};

    systemd.tmpfiles.rules = [
      "d ${cfg.dataDir} 0750 ${cfg.user} ${cfg.group} -"
    ];

    systemd.services.dcrwallet = {
      description = "Decred wallet daemon";
      after = [ "network-online.target" ] ++ lib.optional dcrdEnabled "dcrd.service";
      wants = [ "network-online.target" ] ++ lib.optional dcrdEnabled "dcrd.service";
      wantedBy = [ "multi-user.target" ];
      serviceConfig = {
        User = cfg.user;
        Group = cfg.group;
        RuntimeDirectory = "dcrwallet";
        StateDirectory = "dcrwallet";
        StateDirectoryMode = "0750";
        ExecStart = ''${lib.getExe cfg.package} --appdata=${cfg.dataDir} --configfile=${cfg.configFile}'';
        ExecStartPost = "+${pkgs.coreutils}/bin/chmod 0750 ${cfg.dataDir}";
      };
      restartTriggers = [ cfg.configFile ];
    };
  };
}