{ lib, config, pkgs, ... }:
let
  ewwBar = "${pkgs.custom.eww-bar}/bin/eww-bar";

  # Every script ships as a bash wrapper that pins PATH to its dependencies
  # and inlines the shared helpers, so the sources under bar/scripts stay
  # plain shell files.
  baseInputs = with pkgs; [ coreutils findutils gawk gnugrep gnused systemd util-linux ];
  mkScript = name: src: inputs: pkgs.writeShellScriptBin name ''
    export PATH="${lib.makeBinPath (baseInputs ++ inputs)}:$PATH"
    ${builtins.readFile ./bar/scripts/_lib.sh}
    ${builtins.readFile src}
  '';

  scripts = with pkgs; {
    # bar
    "scripts/workspaces"       = mkScript "workspaces"       ./bar/scripts/workspaces       [ hyprland jaq socat ripgrep ];
    "scripts/panel-toggle"     = mkScript "panel-toggle"     ./bar/scripts/panel-toggle     [ eww custom.eww-bar ];
    "scripts/powermenu-toggle" = mkScript "powermenu-toggle" ./bar/scripts/powermenu-toggle [ eww custom.eww-bar ];
    "scripts/net/net"          = mkScript "net"              ./bar/scripts/net/net          [ iproute2 wpa_supplicant ];
    "scripts/net/bt"           = mkScript "bt"               ./bar/scripts/net/bt           [ jq glib ];
    "scripts/net/bt-toggle"    = mkScript "bt-toggle"        ./bar/scripts/net/bt-toggle    [ bluez ];
    "scripts/net/wg-toggle"    = mkScript "wg-toggle"        ./bar/scripts/net/wg-toggle    [ ];
    "scripts/sys/gpu"          = mkScript "gpu"              ./bar/scripts/sys/gpu          [ custom.amdgpu_top jq ];
    "scripts/sys/memory"       = mkScript "memory"           ./bar/scripts/sys/memory       [ ];
    "scripts/sys/battery"      = mkScript "battery"          ./bar/scripts/sys/battery      [ ];
    "scripts/sys/cputemp"      = mkScript "cputemp"          ./bar/scripts/sys/cputemp      [ ];
    # popup panels
    "scripts/volume"           = mkScript "volume"           ./bar/scripts/volume           [ wireplumber pulseaudio ];
    "scripts/brightness"       = mkScript "brightness"       ./bar/scripts/brightness       [ brightnessctl ];
    "scripts/weather"          = mkScript "weather"          ./bar/scripts/weather          [ jq curl ];
    "scripts/radio"            = mkScript "radio"            ./bar/scripts/radio            [ eww jq curl mpv playerctl wireplumber ];
    "scripts/media"            = mkScript "media"            ./bar/scripts/media            [ playerctl ];
    # quick actions (long-running ones are detached via systemd-run)
    "scripts/nightlight"       = mkScript "nightlight"       ./bar/scripts/nightlight       [ eww wlsunset procps ];
    "scripts/read-mode"        = mkScript "read-mode"        ./bar/scripts/read-mode        [ eww hyprland ];
    "scripts/airplane-mode"    = mkScript "airplane-mode"    ./bar/scripts/airplane-mode    [ eww ];
    "scripts/do-not-disturb"   = mkScript "do-not-disturb"   ./bar/scripts/do-not-disturb   [ eww dunst ];
    "scripts/power-save"       = mkScript "power-save"       ./bar/scripts/power-save       [ eww power-profiles-daemon ];
    "scripts/lock"             = mkScript "lock"             ./bar/scripts/lock             [ eww hyprlock ];
    "scripts/screenshot"       = mkScript "screenshot"       ./bar/scripts/screenshot       [ eww hyprshot satty wl-clipboard ];
    "scripts/color-pick"       = mkScript "color-pick"       ./bar/scripts/color-pick       [ eww hyprpicker ];
    "scripts/wallpaper"        = mkScript "wallpaper"        ./bar/scripts/wallpaper        [ eww ];
  };
in {

  config = lib.mkIf (config.usercfg.wm == "Wayland") {
    home.packages = [ pkgs.eww pkgs.custom.eww-bar ];

    # The daemon and the bar are one unit: it starts and stops with the
    # graphical session, opens the bar once the daemon answers, and is
    # restarted on crash.  `eww-bar` (packages/eww-bar) does the heavy
    # lifting; kanshi calls `eww-bar place` to move the bar between outputs.
    systemd.user.services.eww = {
      Unit = {
        Description = "eww daemon and bar";
        Documentation = "https://elkowar.github.io/eww/";
        PartOf = [ "graphical-session.target" ];
        After = [ "graphical-session.target" ];
        ConditionEnvironment = "WAYLAND_DISPLAY";
        # Cap crash loops (e.g. a broken config) without giving up for good:
        # the watchdog resets the counter and tries again later.
        StartLimitIntervalSec = 60;
        StartLimitBurst = 5;
      };
      Service = {
        Type = "simple";
        ExecStartPre = "${ewwBar} clean";
        ExecStart = "${lib.getExe pkgs.eww} daemon --no-daemonize";
        ExecStartPost = "${ewwBar} open";
        ExecReload = "${ewwBar} reload";
        Restart = "always";
        RestartSec = 2;
        TimeoutStartSec = 30;
        TimeoutStopSec = 5;
      };
      Install.WantedBy = [ "graphical-session.target" ];
    };

    # Liveness check: `eww ping` only proves the socket is up, so the check
    # also lists the windows through the GTK main loop.  Two consecutive
    # failures (≈40 s) restart the daemon; a missing bar is simply reopened.
    systemd.user.services.eww-watchdog = {
      Unit = {
        Description = "eww health check";
        After = [ "eww.service" ];
      };
      Service = {
        Type = "oneshot";
        ExecStart = "${ewwBar} check";
      };
    };
    systemd.user.timers.eww-watchdog = {
      Unit = {
        Description = "Periodic eww health check";
        PartOf = [ "graphical-session.target" ];
        After = [ "graphical-session.target" ];
      };
      Timer = {
        OnActiveSec = "30s";
        OnUnitActiveSec = "20s";
        AccuracySec = "5s";
      };
      Install.WantedBy = [ "graphical-session.target" ];
    };

    xdg.configFile = lib.mkMerge [
      {
        "eww" = {
          source = lib.cleanSourceWith {
            # scripts/ is shipped through the wrappers below, never verbatim
            filter = name: _type:
              let
                baseName = baseNameOf (toString name);
                relPath = lib.removePrefix (toString ./bar + "/") (toString name);
              in !(lib.hasSuffix ".nix" baseName)
              && (baseName != "_colors.scss")
              && !(lib.hasPrefix "scripts/" relPath);
            src = lib.cleanSource ./bar/.;
          };
          recursive = true;
        };

        "eww/css/_colors.scss".text = ''
          $base00: #${config.colorScheme.palette.base00};
          $base01: #${config.colorScheme.palette.base01};
          $base02: #${config.colorScheme.palette.base02};
          $base03: #${config.colorScheme.palette.base03};
          $base04: #${config.colorScheme.palette.base04};
          $base05: #${config.colorScheme.palette.base05};
          $base06: #${config.colorScheme.palette.base06};
          $base07: #${config.colorScheme.palette.base07};
          $base08: #${config.colorScheme.palette.base08};
          $base09: #${config.colorScheme.palette.base09};
          $base0A: #${config.colorScheme.palette.base0A};
          $base0B: #${config.colorScheme.palette.base0B};
          $base0C: #${config.colorScheme.palette.base0C};
          $base0D: #${config.colorScheme.palette.base0D};
          $base0E: #${config.colorScheme.palette.base0E};
          $base0F: #${config.colorScheme.palette.base0F};


          $fg: $base07;
          $bg0: $base00;
          $bg1: $base01;

          $border-color: $base03;
          $border-color-focus: $base04;
          $border-radius: ${config.colorScheme.palette.border-radius}px;
          $border-width: ${config.colorScheme.palette.border-width}px;

          $gaps-screen: ${config.colorScheme.palette.gaps-screen}px;
          $gaps-window: ${config.colorScheme.palette.gaps-window}px;

          $panel-font-size: 10pt;
          $popup-scale: 1.25;
        '';
      }

      (lib.mapAttrs' (rel: drv: {
        name = "eww/${rel}";
        value.source = "${drv}/bin/${drv.name}";
      }) scripts)
    ];
  };
}