{
  config,
  lib,
  pkgs,
  ...
}:

{
  imports = [ ];

  options.me = {
    shadps4.enable = lib.mkOption {
      type = lib.types.bool;
      default = false;
      example = true;
      description = "Whether we want to install shadps4.";
    };
  };

  config = lib.mkIf config.me.shadps4.enable (
    lib.mkMerge [
      (lib.mkIf config.me.graphical {
        environment.systemPackages = with pkgs; [
          shadps4
        ];

        me.install.user.talexander.file = {
          ".local/share/shadPS4/config.toml" = {
            source = ./files/config.toml;
          };
        };

        environment.persistence."/persist" = lib.mkIf (!config.me.buildingIso) {
          hideMounts = true;
          users.talexander = {
            directories = [
              {
                # Location of ROMs.
                directory = ".local/share/shadPS4/games";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
              {
                # Firmware.
                directory = ".local/share/shadPS4/sys_modules";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
              {
                # Game saves.
                directory = ".local/share/shadPS4/savedata";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
              {
                # DLC.
                directory = ".local/share/shadPS4/addcont";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
            ];
            files = [
              {
                # play times and recently played
                file = ".local/share/shadPS4/play_time.txt";
                parentDirectory = {
                  mode = "0755";
                };
              }
            ];
          };
        };

        environment.persistence."/state" = lib.mkIf (!config.me.buildingIso) {
          hideMounts = true;
          users.talexander = {
            directories = [
              {
                # Cache.
                directory = ".local/share/shadPS4/data";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
            ];
          };
        };

        nixpkgs.overlays = [
          (final: prev: {
            shadps4 = prev.shadps4.overrideAttrs (old: {
              version = "0.9.0";
              src = final.fetchFromGitHub {
                owner = "AzaharPlus";
                repo = "shadPS4Plus";
                tag = "SHADPS4PLUS_0_9_0_A";
                hash = "sha256-ZwP+bOE4roWt51Ii53blDZzdq/SxK4Q69I4rLCNARLA=";
                fetchSubmodules = true;
              };
            });
          })
        ];
      })
    ]
  );
}