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

let
  rpcs3_config_yaml = settingsFormat.generate "config.yml" config.me.rpcs3.config;
  settingsFormat = pkgs.formats.yaml { };
in
{
  imports = [ ];

  options.me = {
    rpcs3.enable = lib.mkOption {
      type = lib.types.bool;
      default = false;
      example = true;
      description = "Whether we want to install rpcs3.";
    };

    rpcs3.config = lib.mkOption rec {
      apply = lib.recursiveUpdate default;
      inherit (settingsFormat) type;
      default = {
        Core = {
          "Use LLVM CPU" = lib.mkIf (config.me.optimizations.enable) config.me.optimizations.arch;
        };
        VFS = {
          "Enable /host_root/" = false;
        };
        Video = {
          "Write Color Buffers" = false;
          VSync = true;
          "Performance Overlay" = {
            Enabled = true;
          };
        };
        Miscellaneous = {
          "Pause emulation on RPCS3 focus loss" = true;
          "Start games in fullscreen mode" = true;
          "Pause Emulation During Home Menu" = true;
        };
      };
      example = null;
      description = "RPCS3's config.yml in nix form.";
    };
  };

  config = lib.mkIf config.me.rpcs3.enable (
    lib.mkMerge [
      (lib.mkIf config.me.graphical {
        environment.systemPackages = with pkgs; [
          rpcs3
        ];

        security.pam.loginLimits = [
          {
            domain = "@wheel";
            item = "memlock";
            type = "hard";
            value = "unlimited";
          }
          {
            domain = "@wheel";
            item = "memlock";
            type = "soft";
            value = "unlimited";
          }
        ];

        home-manager.users.talexander =
          { pkgs, ... }:
          {
            home.file.".config/rpcs3/config.yml" = lib.mkIf (config.me.rpcs3.config != null) {
              source = rpcs3_config_yaml;
            };
            home.file.".config/rpcs3/GuiConfigs/CurrentSettings.ini" = {
              source = ./files/CurrentSettings.ini;
            };
          };

        environment.persistence."/persist" = lib.mkIf (!config.me.buildingIso) {
          hideMounts = true;
          users.talexander = {
            directories = [
              {
                # Location of ROMs.
                directory = ".config/rpcs3/games";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
              {
                directory = ".config/rpcs3/dev_hdd0";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
              {
                directory = ".config/rpcs3/dev_hdd1";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
              {
                directory = ".config/rpcs3/savestates";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
              {
                directory = ".config/rpcs3/dev_usb000";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
              {
                # Seems to be where the firmware is installed.
                directory = ".config/rpcs3/dev_flash";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
              {
                # Controller config.
                directory = ".config/rpcs3/input_configs";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
            ];
          };
        };

        environment.persistence."/state" = lib.mkIf (!config.me.buildingIso) {
          hideMounts = true;
          users.talexander = {
            directories = [
              {
                # Game saves
                directory = ".cache/rpcs3";
                user = "talexander";
                group = "talexander";
                mode = "0755";
              }
            ];
          };
        };
      })
    ]
  );
}