.files/nix/configurations/vanadium/nixos/display.nix

{
  pkgs,
  lib,
  ...
}:
{
  imports = [
    #
    # builtin screen
    #
    {
      me.extraGroups = [ "video" ];
      programs.light.enable = true;
    }

    #
    # external screen
    #
    {
      me.extraGroups = [ "i2c" ];
      hardware.i2c.enable = true;
      environment.systemPackages = [ pkgs.ddcutil ];
      boot.kernelModules = [ "i2c-dev" ];
    }
  ];

  #
  # Auto setup external screen
  #
  services.autorandr = {
    enable = true;
    hooks.postswitch = {
      "10_xmobar" = "${lib.getExe' pkgs.toybox "pkill"} xmobar"; # make sure there are no duplicated xmobar
      "20_xmonad" = "${lib.getExe pkgs.haskellPackages.xmonad} --restart"; # make sure feh keeps up
    };

    profiles =
      let
        singleton = k: v: { ${k} = v; };

        fingerprints = {
          built-in = singleton "eDP-1" "00ffffffffffff0009e5ca0b000000002f200104a51c137803de50a3544c99260f505400000001010101010101010101010101010101115cd01881e02d50302036001dbe1000001aa749d01881e02d50302036001dbe1000001a000000fe00424f452043510a202020202020000000fe004e4531333546424d2d4e34310a0073";
          amethyst =
            device:
            singleton device "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";
          orchid =
            device:
            singleton device "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";
        };

        devices = rec {
          built-in = "eDP-1";
          # Run `xrandr` to see the max number
          extern = map (portNumber: "DP-${toString portNumber}") (lib.range 1 8);
          all = [ built-in ] ++ extern;
        };

        switches = {
          setDPI =
            { dpi }:
            singleton "10_xrdb-dpi" "${lib.getExe pkgs.xorg.xrdb} -merge ${pkgs.writeText "xrdb-dpi-config" ''
              Xcursor.size: 64
              Xft.dpi:   ${toString dpi}
            ''}";

          # Is scoped to an output device, no need to be called on built-in display
          setSoftwareBrightness =
            {
              device, # obtain with `xrandr`
              brightness, # [0..1]
            }:
            singleton "10_xrandr_brightness" ''
              ${lib.getExe pkgs.xorg.xrandr} --output ${device} --brightness ${toString brightness}
            '';

          # Is scoped to an output device, no need to be called on built-in display
          setDDCBrightness =
            {
              modelName, # obtain with `ddcutil detect`
              brightness, # [0..1]
            }:
            singleton "10_ddc_brightness" ''
              ${lib.getExe pkgs.ddcutil} --model ${modelName} setvcp 10 ${
                toString (builtins.floor (brightness * 100))
              }
            '';

          setDDCContrast =
            {
              modelName, # obtain with `ddcutil detect`
              contrast, # [0..1]
            }:
            singleton "10_ddc_contrast" ''
              ${lib.getExe pkgs.ddcutil} --model ${modelName} setvcp 12 ${
                toString (builtins.floor (contrast * 100))
              }
            '';
        };

        # Note: the "position" field corresponds to the "pos" field outputted by autorandr
        # To get the current config, run `xrandr --auto` and then `autorandr --config`
        configs = {
          allOff = lib.genAttrs devices.all (_: {
            enable = lib.mkDefault false;
          });
          enableBuiltin = {
            eDP-1 = {
              enable = true;
              crtc = 0;
              mode = "2256x1504";
              rate = "60.00";
              primary = true;
            };
          };
          enableAmethyst = name: {
            ${name} = {
              enable = true;
              primary = true;
              crtc = 1;
              mode = "2560x1440";
              rate = "59.95";
            };
          };
          enableOrchid = name: {
            ${name} = {
              enable = true;
              primary = true;
              crtc = 1;
              mode = "1920x1080";
              rate = "60.00";
            };
          };
        };

        frameworkBuiltin = {
          fingerprint = fingerprints.built-in;
          config = lib.mkMerge [
            configs.allOff
            configs.enableBuiltin
          ];
          hooks.postswitch = switches.setDPI { dpi = 150; };
        };

        mkAmethyst = name: {
          fingerprint = lib.mkMerge [
            fingerprints.built-in
            (fingerprints.amethyst name)
          ];
          config = lib.mkMerge [
            configs.allOff
            (configs.enableAmethyst name)
          ];
          hooks.postswitch = lib.mkMerge [
            (switches.setDPI { dpi = 110; })
            (switches.setSoftwareBrightness {
              device = name;
              brightness = 1;
            })
            (switches.setDDCBrightness {
              modelName = "VG27AQL3A";
              brightness = 0;
            })
            (switches.setDDCContrast {
              modelName = "VG27AQL3A";
              contrast = 0.5;
            })
          ];
        };

        mkOrchid = name: {
          fingerprint = lib.mkMerge [
            fingerprints.built-in
            (fingerprints.orchid name)
          ];
          config = lib.mkMerge [
            configs.allOff
            (configs.enableOrchid name)
          ];
          # seems like this display doesn't support DDC
          hooks.postswitch = lib.mkMerge [
            (switches.setDPI { dpi = 100; })
            (switches.setSoftwareBrightness {
              device = name;
              brightness = 0.5;
            })
          ];
        };
      in
      lib.mkMerge [
        { default = frameworkBuiltin; }
        (lib.genAttrs' devices.extern (name: lib.nameValuePair "amethyst-${name}" (mkAmethyst name)))
        (lib.genAttrs' devices.extern (name: lib.nameValuePair "orchid-${name}" (mkOrchid name)))
      ];
  };
}