infrastructure/modules/nixos/steam/account-switch.nix

{
  config,
  lib,
  inputs,
  pkgs,
  ...
}: let
  inherit (inputs.self.lib.lib) mkWinPath userIs;
  inherit (lib.options) mkOption mkEnableOption;
  inherit (lib.modules) mkIf mkMerge mkDefault mkOptionDefault;
  inherit (lib.attrsets) filterAttrs mapAttrsToList listToAttrs nameValuePair;
  inherit (lib.lists) singleton;
  inherit (lib.strings) removePrefix;
  cfg = config.services.steam.accountSwitch;
  machineModule = { config, name, ... }: {
    options = with lib.types; {
      name = mkOption {
        type = str;
        default = name;
      };
      owner = mkOption {
        type = str;
        default = "admin";
      };
    };
  };
in {
  options.services.steam.accountSwitch = with lib.types; {
    enable = mkEnableOption "steam-account-switch";
    setup = mkEnableOption "steam-account-switch data";
    group = mkOption {
      type = str;
      default = "steamaccount";
    };
    sharePath = mkOption {
      type = str;
    };
    rootDir = mkOption {
      type = path;
    };
    binDir = mkOption {
      type = path;
      default = cfg.rootDir + "/bin";
    };
    gamesDir = mkOption {
      type = path;
      default = cfg.rootDir + "/games";
    };
    dataDir = mkOption {
      type = path;
      default = cfg.rootDir + "/data";
    };
    sharedDataDir = mkOption {
      type = path;
      default = cfg.dataDir + "/shared";
    };
    workingDir = mkOption {
      type = path;
      default = cfg.rootDir + "/working";
    };
    sharedWorkingDir = mkOption {
      type = path;
      default = cfg.workingDir + "/shared";
    };
    users = mkOption {
      type = listOf str;
    };
    machines = mkOption {
      type = attrsOf (submodule machineModule);
      default = { };
    };
  };

  config = let
    steamUsers = filterAttrs (_: userIs cfg.group) config.users.users;
  in {
    services.steam.accountSwitch = {
      users = mkOptionDefault (
        mapAttrsToList (_: user: user.name) steamUsers
      );
    };
    services.tmpfiles = let
      toplevel = {
        owner = mkDefault "admin";
        group = mkDefault cfg.group;
        mode = mkDefault "3775";
      };
      shared = {
        inherit (toplevel) owner group;
        mode = "2775";
      };
      personal = owner: {
        inherit owner;
        inherit (shared) group mode;
      };
      setupFiles = singleton {
        ${cfg.rootDir} = toplevel;
        ${cfg.binDir} = toplevel;
        ${cfg.binDir + "/users"} = shared;
        ${cfg.dataDir} = toplevel;
        ${cfg.sharedDataDir} = shared;
        ${cfg.workingDir} = toplevel;
        ${cfg.sharedWorkingDir} = shared;
      } ++ map (owner: {
        ${cfg.dataDir + "/${owner}"} = personal owner;
        ${cfg.workingDir + "/${owner}"} = personal owner;
      }) cfg.users
      ++ mapAttrsToList (_: machine: {
        ${cfg.dataDir + "/${machine.name}"} = personal machine.owner;
        ${cfg.workingDir + "/${machine.name}"} = personal machine.owner;
      }) cfg.machines;
      userBinFiles = listToAttrs (map (user: nameValuePair "${cfg.binDir}/users/${user}.bat" {
        inherit (toplevel) owner group;
        mode = "0755";
        type = "copy";
        src = pkgs.writeTextFile {
          name = "steam-${user}.bat";
          executable = true;
          text = ''
            setx GENSO_STEAM_USER ${user}
          '';
        };
      }) cfg.users);
    in {
      enable = mkIf (cfg.enable || cfg.setup) true;
      files = mkMerge [
        (mkIf cfg.setup (mkMerge setupFiles))
        (mkIf cfg.enable userBinFiles)
      ];
    };
    lib.steam = {
      mkSharePathWith = {
        path,
        winRoot ? "%GENSO_SMB_SHARED_MOUNT%",
      }: mkWinPath (
        winRoot
        + "/${cfg.sharePath}"
        + "/${removePrefix (cfg.rootDir + "/") path}"
      );
      mkSharePath = path: config.lib.steam.mkSharePathWith {
        inherit path;
      };
    };
  };
}