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

{
  options = {
    services.smart-ipv6-rotator = {
      enable = lib.mkOption {
        type = lib.types.bool;
        default = false;
        description = "Enable smart-ipv6-rotator service";
      };

      ipv6range = lib.mkOption {
        type = lib.types.str;
        default = "";
        description = "IPv6 range to rotate (e.g. 2407:7000:9827:4100::/64)";
      };

      rev = lib.mkOption {
        type = lib.types.str;
        default = "master";
        description = "git rev (branch/commit/tag) for the upstream repo";
      };

      sha256 = lib.mkOption {
        type = lib.types.str;
        default = "0000000000000000000000000000000000000000000000000000";
        description = "sha256 for fetchFromGitHub (replace after first build)";
      };
    };
  };

  config = lib.mkIf config.services.smart-ipv6-rotator.enable (let
    rev    = config.services.smart-ipv6-rotator.rev;
    sha256 = config.services.smart-ipv6-rotator.sha256;

    src = pkgs.fetchFromGitHub {
      owner = "iv-org";
      repo  = "smart-ipv6-rotator";
      inherit rev sha256;
    };

    pythonEnv = pkgs.python3.withPackages (ps: with ps; [ requests pyroute2 ]);

    rotatorPkg = pkgs.runCommand "smart-ipv6-rotator" { inherit src; } ''
  mkdir -p $out/bin
  cat > $out/bin/smart-ipv6-rotator <<'EOF'
#!${pkgs.stdenv.shell}
exec ${pythonEnv}/bin/python3 ${src}/smart-ipv6-rotator.py "$@"
EOF
  chmod +x $out/bin/smart-ipv6-rotator
'';

  in {
    environment.systemPackages = [ rotatorPkg ];

    systemd.services.smart-ipv6-rotator = {
      description = "Smart IPv6 Rotator (oneshot)";
      wantedBy = [ "multi-user.target" ];
      serviceConfig = {
        Type = "oneshot";
        ExecStart = "${rotatorPkg}/bin/smart-ipv6-rotator run --cron --ipv6range=${config.services.smart-ipv6-rotator.ipv6range} --services google";
      };
    };

    systemd.timers.smart-ipv6-rotator = {
      description = "Run smart-ipv6-rotator twice a day";
      wantedBy = [ "timers.target" ];
      timerConfig = {
        OnBootSec = "30s";
        OnUnitActiveSec = "12h";
      };
      unitConfig = { Unit = "smart-ipv6-rotator.service"; };
    };
  });
}