# this work derives from noneucat's sxmo service/packages, found via NUR
# - <repo:nix-community/nur-combined:repos/noneucat/modules/pinephone/sxmo.nix>
# other nix works:
# - <https://github.com/wentam/sxmo-nix>
#   - implements sxmo atop tinydm (also packaged by wentam)
#   - wentam cleans up sxmo-utils to be sealed. also patches to use systemd poweroff, etc
#   - packages a handful of anjan and proycon utilities
#   - packages <https://gitlab.com/kop316/mmsd/>
#   - packages <https://gitlab.com/kop316/vvmd/>
# - <https://github.com/chuangzhu/nixpkgs-sxmo>
#   - implements sxmo as a direct systemd service -- apparently no DM
#   - packages sxmo-utils
#     - injects PATH into each script
# - perhaps sxmo-utils is best packaged via the `resholve` shell solver?
#
# sxmo documentation:
# - <repo:anjan/sxmo-docs-next>
#
# sxmo technical overview:
# - inputs
#   - dwm: handles vol/power buttons; hardcoded in config.h
#   - lisgd: handles gestures
# - startup
#   - daemon based (lisgsd, idle_locker, statusbar_periodics)
#   - auto-started at login
#   - managable by `sxmo_daemons.sh`
#     - list available daemons: `sxmo_daemons.sh list`
#     - query if a daemon is active: `sxmo_daemons.sh running <my-daemon>`
#     - start daemon: `sxmo_daemons.sh start <my-daemon>`
#   - managable by `superctl`
#     - `superctl status`
# - user hooks:
#   - live in ~/.config/sxmo/hooks/
# - logs:
#   - live in ~/.local/state/sxmo.log
#   - ~/.local/state/superd.log
#   - ~/.local/state/superd/logs/<daemon>.log
#   - `journalctl --user --boot`  (lightm redirects the sxmo session stdout => systemd)
#
# - default components:
#   - DE:                  sway (if wayland), dwm (if X)
#   - menus:               bemenu (if wayland), dmenu (if X)
#   - gestures:            lisgd
#   - on-screen keyboard:  wvkbd (if wayland), svkbd (if X)
#
{ config, lib, pkgs, sane-lib, ... }:

let
  cfg = config.sane.gui.sxmo;
  knownKeyboards = {
    # map keyboard package name -> name of binary to invoke
    wvkbd = "wvkbd-mobintl";
    svkbd = "svkbd-mobile-intl";
  };
  knownTerminals = {
    vte = "vte-2.91";
  };
in
{
  options = with lib; {
    sane.gui.sxmo.enable = mkOption {
      default = false;
      type = types.bool;
    };
    sane.gui.sxmo.greeter = mkOption {
      type = types.enum [ "lightdm-mobile" "sway" ];
      default = "lightdm-mobile";
      description = ''
        which greeter to use.
        "lightdm-mobile" => keypad style greeter. can only enter digits 0-9 as password.
        "sway" => layered sway greeter. behaves as if you booted to swaylock.
      '';
    };
    sane.gui.sxmo.package = mkOption {
      type = types.package;
      default = pkgs.sxmo-utils;
      description = ''
        sxmo base scripts and hooks collection.
        consider overriding the outputs under /share/sxmo/default_hooks
        to insert your own user scripts.
      '';
    };
    sane.gui.sxmo.terminal = mkOption {
      # type = types.nullOr (types.enum [ "foot" "st" "vte" ]);
      type = types.nullOr types.str;
      default = "foot";
      description = ''
        name of terminal to use for sxmo_terminal.sh.
        foot, st, and vte have special integrations in sxmo, but any will work.
      '';
    };
    sane.gui.sxmo.keyboard = mkOption {
      # type = types.nullOr (types.enum ["wvkbd"])
      type = types.nullOr types.str;
      default = "wvkbd";
      description = ''
        name of on-screen-keyboard to use for sxmo_keyboard.sh.
        this sets the KEYBOARD environment variable.
        see also: KEYBOARD_ARGS.
      '';
    };
    sane.gui.sxmo.settings = mkOption {
      description = ''
        environment variables used to configure sxmo.
        e.g. SXMO_UNLOCK_IDLE_TIME or SXMO_VOLUME_BUTTON.
      '';
      type = types.submodule {
        freeformType = types.attrsOf types.str;
        options =
          let
            mkSettingsOpt = default: description: mkOption {
              inherit default description;
              type = types.nullOr types.str;
            };
          in {
            SXMO_BAR_SHOW_BAT_PER = mkSettingsOpt "1" "show battery percentage in statusbar";
            SXMO_UNLOCK_IDLE_TIME = mkSettingsOpt "300" "how many seconds of inactivity before locking the screen";  # lock -> screenoff happens 8s later, not configurable
          };
      };
      default = {};
    };
    sane.gui.sxmo.noidle = mkOption {
      type = types.bool;
      default = false;
      description = "inhibit lock-on-idle and screenoff-on-idle";
    };
  };

  config = lib.mkMerge [
    {
      sane.programs.sxmoApps = {
        package = null;
        suggestedPrograms = [
          "guiApps"
          "sfeed"  # want this here so that the user's ~/.sfeed/sfeedrc gets created
          "superd"  # make superctl (used by sxmo) be on PATH
        ];

        persist.cryptClearOnBoot = [
          # builds to be 10's of MB per day
          ".local/state/superd/logs"
        ];
      };
    }

    {
      # TODO: lift to option declaration
      sane.gui.sxmo.settings.TERMCMD = lib.mkIf (cfg.terminal != null)
        (lib.mkDefault (knownTerminals."${cfg.terminal}" or cfg.terminal));
      sane.gui.sxmo.settings.KEYBOARD = lib.mkIf (cfg.keyboard != null)
        (lib.mkDefault (knownKeyboards."${cfg.keyboard}" or cfg.keyboard));
    }

    (lib.mkIf cfg.enable (lib.mkMerge [
      {
        sane.programs.sxmoApps.enableFor.user.colin = true;
        sane.gui.gtk.enable = lib.mkDefault true;

        # sxmo internally uses doas instead of sudo
        security.doas.enable = true;
        security.doas.wheelNeedsPassword = false;

        # TODO: move this further to the host-specific config?
        networking.useDHCP = false;
        networking.networkmanager.enable = true;
        networking.wireless.enable = lib.mkForce false;

        hardware.bluetooth.enable = true;
        services.blueman.enable = true;

        # TODO: nerdfonts is 4GB. it accepts an option to ship only some fonts: probably want to use that.
        fonts.fonts = [ pkgs.nerdfonts ];

        # some programs (e.g. fractal/nheko) **require** a "Secret Service Provider"
        services.gnome.gnome-keyring.enable = true;

        # lightdm-mobile-greeter: "The name org.a11y.Bus was not provided by any .service files"
        services.gnome.at-spi2-core.enable = true;

        # sxmo has first-class support only for pulseaudio and alsa -- not pipewire.
        # however, pipewire can emulate pulseaudio support via `services.pipewire.pulse.enable = true`
        #   after which the stock pulseaudio binaries magically work
        # administer with pw-cli, pw-mon, pw-top commands
        services.pipewire = {
          enable = true;
          alsa.enable = true;
          alsa.support32Bit = true;  # ??
          pulse.enable = true;
        };
        systemd.user.services."pipewire".wantedBy = [ "graphical-session.target" ];

        # TODO: could use `displayManager.sessionPackages`?
        environment.systemPackages = [
          cfg.package
        ] ++ lib.optionals (cfg.terminal != null) [ pkgs."${cfg.terminal}" ]
          ++ lib.optionals (cfg.keyboard != null) [ pkgs."${cfg.keyboard}" ];

        environment.sessionVariables = {
          XDG_DATA_DIRS = [
            # TODO: only need the share/sxmo directly linked
            "${cfg.package}/share"
          ];
        };

        systemd.services."sxmo-set-permissions" = {
          description = "configure specific /sys and /dev nodes to be writable by sxmo scripts";
          serviceConfig = {
            Type = "oneshot";
            ExecStart = "${cfg.package}/bin/sxmo_setpermissions.sh";
          };
          wantedBy = [ "display-manager.service" ];
        };

        sane.user.fs.".cache/sxmo/sxmo.noidle" = lib.mkIf cfg.noidle (sane-lib.fs.wantedText "");
        sane.user.fs.".config/sxmo/profile".symlink.text = let
          mkKeyValue = key: value: ''export ${key}="${value}"'';
          userConfig = lib.generators.toKeyValue { inherit mkKeyValue; } cfg.settings;
        in ''
          # configversion: 4284f96d91e9550ff8f3b25823e402ad
          # ^ upstream adds new options every now and then, expects user config file
          # to include the md5sum of the template it's based on.
          # see `setup_config_version.sh`
          ${userConfig}
        '';

        sane.user.fs.".config/sxmo/sway".symlink.target = pkgs.substituteAll {
          src = ./sway-config;
          waybar = "${pkgs.waybar}/bin/waybar";
        };

        sane.user.fs.".config/waybar/config".symlink.target =
          let
            waybar-config = import ./waybar-config.nix { inherit pkgs; };
          in
            (pkgs.formats.json {}).generate "waybar-config.json" waybar-config;

        # sane.user.fs.".config/waybar/style.css".symlink.text =
        #   builtins.readFile ./waybar-style.css;

        sane.user.fs.".config/sxmo/conky.conf".symlink.target = let
          battery_estimate = pkgs.static-nix-shell.mkBash {
            pname = "battery_estimate";
            src = ./.;
          };
        in pkgs.substituteAll {
          src = ./conky-config;
          bat = "${battery_estimate}/bin/battery_estimate";
        };
      }

      (lib.mkIf (cfg.greeter == "lightdm-mobile") {
        sane.persist.sys.plaintext = [
          # this takes up 4-5 MB of fontconfig and mesa shader caches.
          # it could optionally be cleared on boot.
          { path = "/var/lib/lightdm"; user = "lightdm"; group = "lightdm"; mode = "0770"; }
        ];

        services.xserver = {
          enable = true;

          displayManager.lightdm.enable = true;
          displayManager.lightdm.greeters.mobile.enable = true;
          displayManager.lightdm.extraSeatDefaults = ''
            user-session = swmo
          '';

          displayManager.sessionPackages = with pkgs; [
            cfg.package  # this gets share/wayland-sessions/swmo.desktop linked
          ];

          # taken from gui/phosh:
          # NB: setting defaultSession has the critical side-effect that it lets org.freedesktop.AccountsService
          # know that our user exists. this ensures lightdm succeeds when calling /org/freedesktop/AccountsServices ListCachedUsers
          # lightdm greeters get the login users from lightdm which gets it from org.freedesktop.Accounts.ListCachedUsers.
          # this requires the user we want to login as to be cached.
          displayManager.job.preStart = ''
            ${pkgs.systemd}/bin/busctl call org.freedesktop.Accounts /org/freedesktop/Accounts org.freedesktop.Accounts CacheUser s colin
          '';
        };
      })

      (lib.mkIf (cfg.greeter == "sway") {
        services.greetd = {
          enable = true;
          # borrowed from gui/sway
          settings.default_session.command =
          let
            # start sway and have it construct the gtkgreeter
            sway-as-greeter = pkgs.writeShellScriptBin "sway-as-greeter" ''
              ${pkgs.sway}/bin/sway --debug --config ${sway-config-into-gtkgreet} > /var/log/sway/sway-as-greeter.log 2>&1
            '';
            # (config file for the above)
            sway-config-into-gtkgreet = pkgs.writeText "greetd-sway-config" ''
              exec "${gtkgreet-launcher}"
            '';
            # gtkgreet which launches a layered sway instance
            gtkgreet-launcher = pkgs.writeShellScript "gtkgreet-launcher" ''
              # NB: the "command" field here is run in the user's shell.
              # so that command must exist on the specific user's path who is logging in. it doesn't need to exist system-wide.
              ${pkgs.greetd.gtkgreet}/bin/gtkgreet --layer-shell --command sxmo_winit.sh
            '';
          in "${sway-as-greeter}/bin/sway-as-greeter";
        };

        sane.fs."/var/log/sway" = {
          dir.acl.mode = "0777";
          wantedBeforeBy = [ "greetd.service" "display-manager.service" ];
        };
      })

      # old, greeterless options:
      # services.xserver.windowManager.session = [{
      #   name = "sxmo";
      #   desktopNames = [ "sxmo" ];
      #   start = ''
      #     ${cfg.package}/bin/sxmo_xinit.sh &
      #     waitPID=$!
      #   '';
      # }];
      # services.xserver.enable = true;

      # services.greetd = {
      #   enable = true;
      #   settings = {
      #     default_session = {
      #       command = "${cfg.package}/bin/sxmo_winit.sh";
      #       user = "colin";
      #     };
      #   };
      # };
    ]))
  ];
}