{ pkgs, lib, config, ... }:
with import <stockholm/lib>;
let
  # see https://github.com/zeropingheroes/lancache for full docs
  cachedir = "/var/lancache/cache";
  logdir = "/var/lancache/log";

  lancache= pkgs.stdenv.mkDerivation rec {
    name = "lancache-2017-06-26";
    src = pkgs.fetchFromGitHub {
      # origin: https://github.com/multiplay/lancache
      # forked: https://github.com/zeropingheroes/lancache
      repo = "lancache";
      owner = "zeropingheroes";
      rev = "143f7bb";
      sha256 = "1ra4l7qz3k231j5wabr89s5hh80n1kk8vgd3dsh0xx5mdpjhvdl6";
    };
    phases = [ "unpackPhase" "installPhase" ];
    # here we can chance to edit `includes/proxy-cache-paths.conf`
    installPhase = ''
      mkdir -p $out
      cp -r * $out/
      sed -i -e 's/^\(user\).*/\1 ${cfg.user} ${cfg.group};/' \
             -e 's/^\(error_log\).*/\1 stderr;\ndaemon off;/' $out/nginx.conf
    '';
  };
  cfg = {
    group = "nginx-lancache";
    user = "nginx-lancache";
    stateDir = "/var/lancache";
    package = pkgs.stdenv.lib.overrideDerivation pkgs.nginx (old:{
      configureFlags = old.configureFlags ++ [
        "--with-http_slice_module"
        "--with-stream"
        "--with-pcre"
        ];
    });
  };
in {
  systemd.services.nginx-lancache = {
      description = "Nginx lancache Server";
      after = [ "network.target" ];
      wantedBy = [ "multi-user.target" ];
      restartIfChanged = true;

      preStart = ''
				PATH_CACHE="/var/lancache/cache"
				PATH_LOGS="/var/lancache/logs"
				WWW_USER="${cfg.user}"
				WWW_GROUP="${cfg.group}"

				mkdir -p $PATH_CACHE
				cd $PATH_CACHE
				mkdir -p installers tmp
				mkdir -p $PATH_LOGS

				chown -R $WWW_USER:$WWW_USER $PATH_CACHE
				chown -R $WWW_USER:$WWW_USER $PATH_LOGS
        '';
      serviceConfig = {
        ExecStart = "${cfg.package}/bin/nginx -c ${lancache}/nginx.conf -p ${lancache}";
        ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
        Restart = "always";
        RestartSec = "10s";
        StartLimitInterval = "1min";
      };
    };
      users.extraUsers = (singleton
    { name = cfg.user;
      group = cfg.group;
      uid = genid cfg.group;
    });

    users.extraGroups = (singleton
      { name = "${cfg.group}";
        gid = genid cfg.group;
    });

}