lhns--steam-frame-nix/modules/dashboard-windows.nix

# Resize and grab-distance limits of SteamVR dashboard windows. Dashboard patch
# (dashboard-windows/patch.js; "systemui" on 127.0.0.1:8087), registered only
# when an option is set; enables steamvr-debugger.nix (one SteamVR restart the
# first time). Unsetting all options reverts to stock.
{ config, lib, pkgs, ... }:
let
  cfg = config.steamFrame.dashboard;
  inherit (lib) mkOption types;
  inherit (import ./lib { inherit pkgs; }) mkPatch;

  # Stock grab distance ranges (meters), matched by the patch.
  stockDistance = {
    world = { min = 0.25; max = 5; };
    theater = { min = 1; max = 6; };
    dashboard = { min = 0.3; max = 4; };
  };

  rangeOption = kind: what: {
    min = mkOption {
      type = types.nullOr types.number;
      default = null;
      description = ''
        Closest distance (m) ${what} can be pulled in to while grabbed; null =
        stock (${toString stockDistance.${kind}.min} m).
      '';
    };
    max = mkOption {
      type = types.nullOr types.number;
      default = null;
      example = stockDistance.${kind}.max * 2;
      description = ''
        Farthest distance (m) ${what} can be pushed back to while grabbed;
        null = stock (${toString stockDistance.${kind}.max} m).
      '';
    };
  };

  effective = kind: {
    min = if cfg.windowDistance.${kind}.min != null then cfg.windowDistance.${kind}.min else stockDistance.${kind}.min;
    max = if cfg.windowDistance.${kind}.max != null then cfg.windowDistance.${kind}.max else stockDistance.${kind}.max;
  };

  distanceSet = lib.any (r: r.min != null || r.max != null) (lib.attrValues cfg.windowDistance);
  enabled = cfg.windowMaxScale != null || distanceSet;
in {
  imports = [ ./steam-ui-patches.nix ./steamvr-debugger.nix ];

  options.steamFrame.dashboard = {
    windowMaxScale = mkOption {
      type = types.nullOr types.number;
      default = null;
      example = 4.0;
      description = ''
        Largest resize factor of SteamVR dashboard windows, relative to their
        default size; null = stock (2). The theater screen starts 2.8x larger,
        so its limit is 2.8x this. Dashboard patch, applied immediately.
      '';
    };
    windowDistance = {
      world = rangeOption "world" "windows placed in the world (not attached to the dashboard)";
      theater = rangeOption "theater" "the theater-mode screen";
      dashboard = rangeOption "dashboard" "the dashboard itself";
    };
  };

  config = lib.mkIf enabled {
    assertions =
      [ {
        assertion = cfg.windowMaxScale == null || cfg.windowMaxScale > 0;
        message = "steamFrame.dashboard.windowMaxScale must be positive.";
      } ]
      ++ map (kind: let r = effective kind; in {
        assertion = r.min > 0 && r.max >= r.min;
        message = "steamFrame.dashboard.windowDistance.${kind}: need 0 < min <= max (stock values fill in unset ones), got ${toString r.min}-${toString r.max}.";
      }) (lib.attrNames stockDistance);

    steamFrame.uiPatches.patches = [ {
      name = "dashboard-windows";
      endpoint = "http://127.0.0.1:8087";
      target.title = "systemui";
      patch = mkPatch {
        name = "dashboard-windows";
        src = ./dashboard-windows/patch.js;
        opts = {
          maxScale = cfg.windowMaxScale;
          distance = cfg.windowDistance;
        };
      };
      unpatch = ./dashboard-windows/unpatch.js;
    } ];
  };
}