{ pkgs, lib, config, inputs, ... }:
let
  cfg = config.services.minecraft-servers;

  # See https://docs.papermc.io/paper/aikars-flags
  jvmOpts = lib.concatStringsSep " " [
    "-Xms5G"
    "-Xmx15G"
    "-XX:+UseG1GC"
    "-XX:+ParallelRefProcEnabled"
    "-XX:MaxGCPauseMillis=200"
    "-XX:+UnlockExperimentalVMOptions"
    "-XX:+DisableExplicitGC"
    "-XX:+AlwaysPreTouch"
    "-XX:G1NewSizePercent=30"
    "-XX:G1MaxNewSizePercent=40"
    "-XX:G1HeapRegionSize=8M"
    "-XX:G1ReservePercent=20"
    "-XX:G1HeapWastePercent=5"
    "-XX:G1MixedGCCountTarget=4"
    "-XX:InitiatingHeapOccupancyPercent=15"
    "-XX:G1MixedGCLiveThresholdPercent=90"
    "-XX:G1RSetUpdatingPauseTimePercent=5"
    "-XX:SurvivorRatio=32"
    "-XX:+PerfDisableSharedMem"
    "-XX:MaxTenuringThreshold=1"
    "-Dusing.aikars.flags=https://mcflags.emc.gs"
    "-Daikars.new.flags=true"
  ];

  # serverPackage = inputs.minecraft.packages.x86_64-linux.paper-server-1_20_2;
  # serverPackage = pkgs.paperServers.paper-1_20_2;

  # lazymc-config = ((pkgs.formats.toml { }).generate "lazymc.toml" {
  #   # public = {
  #   #   version = builtins.head
  #   #     (builtins.match "([[:digit:]].*[[:digit:]]*.[[:digit:]]*)-build.*" serverPackage.version);
  #   #   protocol = 765;
  #   # };
  #   server = {
  #     directory = "${cfg.dataDir}/kakuland";
  #     command = "${serverPackage}/bin/minecraft-server ${jvmOpts}";
  #     freeze_process = false;
  #     probe_on_start = true;
  #   };
  #   rcon = {
  #     enabled = true;
  #     password = "mcrcond";
  #     randomize_password = false;
  #   };
  #   advanced.rewrite_server_properties = false;
  # }).override {
  #   runCommand = pkgs.runCommandLocal;
  # };

  # lazymcServerPackage = pkgs.writeShellScriptBin "minecraft-server" ''
  #   exec ${lib.getExe pkgs.lazymc} -c ${lazymc-config}
  # '';
in
{
  # ugly hack for https://github.com/Infinidoge/nix-minecraft/pull/54
  services.minecraft-server.dataDir = "/srv/minecraft";

  services.minecraft-servers = {
    enable = true;
    eula = true;
    openFirewall = true;
    dataDir = "/var/lib/minecraft";
    servers.kakuland = {
      enable = true;

      # package = lazymcServerPackage;
      package = pkgs.paperServers.paper-1_20_4;

      serverProperties = {
        allow-flight = true;
        allow-nether = true;
        broadcast-console-to-ops = true;
        broadcast-rcon-to-ops = true;
        debug = false;
        difficulty = "easy";
        enable-command-block = false;
        enable-jmx-monitoring = false;
        enable-query = false;
        enable-status = true;
        enforce-secure-profile = false;
        enforce-whitelist = false;
        entity-broadcast-range-percentage = 100;
        force-gamemode = false;
        function-permission-level = 2;
        gamemode = "survival";
        generate-structures = true;
        # generator-settings={}
        hardcore = false;
        hide-online-players = false;
        level-name = "world";
        # level-seed = 
        level-type = "default";
        max-chained-neighbor-updates = 1000000;
        max-players = 2;
        max-tick-time = 60000;
        max-world-size = 29999984;
        motd = "Yaba Saba";
        network-compression-threshold = 256;
        online-mode = true;
        op-permission-level = 4;
        player-idle-timeout = 0;
        prevent-proxy-connections = false;
        previews-chat = false;
        pvp = true;
        # "query.port" = 25565;
        rate-limit = 0;
        enable-rcon = true;
        "rcon.password" = "mcrcond";
        "rcon.port" = 25575;
        require-resource-pack = false;
        # resource-pack=
        # resource-pack-prompt=
        # resource-pack-sha1=
        server-ip = "0.0.0.0";
        server-port = 25565;
        # server-port = 25566;
        simulation-distance = 10;
        spawn-animals = true;
        spawn-monsters = true;
        spawn-npcs = true;
        spawn-protection = 16;
        sync-chunk-writes = true;
        # text-filtering-config=
        use-native-transport = true;
        view-distance = 10;
        white-list = true;
      };

      inherit jvmOpts;

      symlinks = let
        rawFile = file: pkgs.runCommandLocal (builtins.baseNameOf file) {} ''
          ln -s ${file} $out
        '';

        yamlFormat = pkgs.formats.yaml {};
        yamlConfig = name: file: env:
          yamlFormat.generate "minecraft-server-plugin-${name}-configuration.yml" (import file env);
      in {
        "server-icon.png" = rawFile ./extraFiles/server-icon.png;

        # TODO: pull this through a sops template to render the secret before readding it here.
        # "plugins/dynmap/configuration.txt" = 
        #   yamlConfig "dynmap" ./pluginConfigs/dynmap.nix { inherit secrets; };

        "plugins/VeinMiner/config.yml" =
          yamlConfig "VeinMiner" ./pluginConfigs/veinMiner.nix { };

        "plugins/SmoothTimber/config.yml" =
          yamlConfig "SmoothTimber" ./pluginConfigs/smoothTimber.nix { };

        "plugins/SilkSpawners/config.yml" =
          yamlConfig "SilkSpawners" ./pluginConfigs/silkSpawners.nix { };

        "plugins/OnePlayerSleep/config.yml" =
          yamlConfig "OnePlayerSleep" ./pluginConfigs/onePlayerSleep.nix { };

        "plugins/ServerBackup/config.yml" =
          yamlConfig "ServerBackup" ./pluginConfigs/serverBackup.nix { };
      };
    };
  };

  services.postgresql = let
    o = lib.optional;
    db = name: {
      inherit name;
      ensureDBOwnership = true;
    };
  in {
    enable = true;

    ensureDatabases = 
      (o config.services.minecraft-servers.enable "dynmap");
    ensureUsers =
      (o config.services.minecraft-servers.enable (db "dynmap"));
  };

  systemd.services.minecraft-server-kakuland.requires = [ "postgresql.service" ];
  systemd.services.minecraft-server-kakuland.after = [
    "postgresql.service"
    # "data2-momiji.mount"
  ];

  networking.firewall.allowedTCPPorts = [ 25565 ];
  networking.firewall.allowedUDPPorts = [ 25565 ];
}