{
  config,
  lib,
  ...
}:
# The Hyprland compositor.
{
  options.modules.desktop.session.hyprland.enable = lib.mkEnableOption "the Hyprland compositor";

  config = lib.mkIf config.modules.desktop.session.hyprland.enable {

    # This program integration owns the session, portals, and polkit, launched
    # through the universal Wayland session manager.
    programs.hyprland = {
      enable = true;
      withUWSM = true;
    };

    home-manager.users.${config.user.name}.wayland.windowManager.hyprland = {
      enable = true;

      # One package drives the whole session, so there is never a version split.
      # The program integration above installs it and the portal, leaving home-
      # manager to write only the config.
      package = null;
      portalPackage = null;

      # uwsm owns the systemd graphical-session targets.
      systemd.enable = false;

      # Write the native Lua Hyprland config. Home Manager renders the Nix
      # settings below as hl.* calls.
      configType = "lua";

      settings = {
        config = {
          input = {
            kb_layout = config.services.xserver.xkb.layout;
            repeat_delay = 250;
            repeat_rate = 45;
            accel_profile = "flat";
            touchpad = {
              natural_scroll = true;
              tap_to_click = true;
              disable_while_typing = true;
            };
          };

          general = {
            gaps_in = 4;
            gaps_out = 8;
            border_size = 2;
            layout = "dwindle";
          };

          decoration = {
            rounding = 6;
            blur.enabled = false;
          };

          xwayland.force_zero_scaling = true;

          dwindle.preserve_split = true;
        };

        bind = lib.mapAttrsToList (_name: keybind: {
          _args = [
            keybind.keys
            (lib.generators.mkLuaInline (
              {
                exec = "hl.dsp.exec_cmd(${lib.generators.toLua { } keybind.action.command})";
                focus = "hl.dsp.focus(${
                  lib.generators.toLua { } { inherit (keybind.action) direction workspace; }
                })";
                "move-window" = "hl.dsp.window.move(${
                  lib.generators.toLua { } { inherit (keybind.action) direction workspace; }
                })";
                "resize-window" = "hl.dsp.window.resize(${
                  lib.generators.toLua { } (
                    {
                      down = {
                        x = 0;
                        y = 10;
                        relative = true;
                      };
                      left = {
                        x = -10;
                        y = 0;
                        relative = true;
                      };
                      right = {
                        x = 10;
                        y = 0;
                        relative = true;
                      };
                      up = {
                        x = 0;
                        y = -10;
                        relative = true;
                      };
                    }
                    .${keybind.action.direction}
                  )
                })";
                "toggle-floating" = ''hl.dsp.window.float({ action = "toggle" })'';
                "toggle-fullscreen" = "hl.dsp.window.fullscreen()";
                "close-window" = "hl.dsp.window.close()";
              }
              .${keybind.action.kind}
            ))
          ]
          ++ lib.optional keybind.repeating {
            repeating = true;
          };
        }) (lib.attrByPath [ config.networking.hostName ] { } config.registry.keybind);
      };
    };
    registry.keybind.${config.networking.hostName} = lib.mkMerge [
      # Generate numeric workspace keybinds.
      (lib.listToAttrs (
        lib.concatMap (workspace: [
          {
            name = "hyprland-workspace-${toString workspace}";
            value = {
              keys = "SUPER + ${toString workspace}";
              action = {
                kind = "focus";
                inherit workspace;
              };
            };
          }
          {
            name = "hyprland-move-to-workspace-${toString workspace}";
            value = {
              keys = "SUPER + SHIFT + ${toString workspace}";
              action = {
                kind = "move-window";
                inherit workspace;
              };
            };
          }
        ]) (lib.range 1 9)
      ))

      # Generate directional keybinds.
      (lib.listToAttrs (
        lib.concatMap
          (
            { direction, key }:
            [
              {
                name = "hyprland-focus-${direction}";
                value = {
                  keys = "SUPER + ${key}";
                  action = {
                    kind = "focus";
                    inherit direction;
                  };
                };
              }
              {
                name = "hyprland-move-${direction}";
                value = {
                  keys = "SUPER + SHIFT + ${key}";
                  action = {
                    kind = "move-window";
                    inherit direction;
                  };
                };
              }
              {
                name = "hyprland-resize-${direction}";
                value = {
                  keys = "SUPER + ALT + ${key}";
                  repeating = true;
                  action = {
                    kind = "resize-window";
                    inherit direction;
                  };
                };
              }
            ]
          )
          [
            {
              key = "H";
              direction = "left";
            }
            {
              key = "J";
              direction = "down";
            }
            {
              key = "K";
              direction = "up";
            }
            {
              key = "L";
              direction = "right";
            }
          ]
      ))
      {
        hyprland-toggle-floating = {
          keys = "SUPER + Space";
          action.kind = "toggle-floating";
        };

        hyprland-toggle-fullscreen = {
          keys = "SUPER + F";
          action.kind = "toggle-fullscreen";
        };

        hyprland-close-window = {
          keys = "SUPER + SHIFT + Q";
          action.kind = "close-window";
        };
      }
    ];
  };
}