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

with lib;
with config.lib.stylix.colors;

let
  theme = pkgs.runCommand "stylix-plymouth" { } ''
    themeDir="$out/share/plymouth/themes/stylix"
    mkdir -p $themeDir

    # Convert in case the input image is not PNG
    # A transparent border of 42% ensures that the image is not clipped when rotated
    ${pkgs.imagemagick}/bin/convert \
      -background transparent \
      -bordercolor transparent \
      -border 42% \
      ${config.stylix.targets.plymouth.logo} \
      $themeDir/logo.png

    cp ${./theme.script} $themeDir/stylix.script
    ${
      if config.stylix.targets.plymouth.blackBackground
      then ''
        substituteInPlace $themeDir/stylix.script \
          --replace "%BASE00%" "0, 0, 0" \
          --replace "%BASE05%" "1, 1, 1"
      ''
      else ''
        substituteInPlace $themeDir/stylix.script \
          --replace "%BASE00%" "${base00-dec-r}, ${base00-dec-g}, ${base00-dec-b}" \
          --replace "%BASE05%" "${base05-dec-r}, ${base05-dec-g}, ${base05-dec-b}"
      ''
    }

    echo "
    [Plymouth Theme]
    Name=Stylix
    ModuleName=script

    [script]
    ImageDir=$themeDir
    ScriptFile=$themeDir/stylix.script
    " > $themeDir/stylix.plymouth
  '';

in {
  options.stylix.targets.plymouth = {
    enable = config.lib.stylix.mkEnableTarget "the Plymouth boot screen" true;

    logo = mkOption {
      description = mdDoc ''
        Logo to be used on the boot screen.

        This defaults to the NixOS logo, but you could set it to your OEM logo
        if it suits the theme.
      '';
      type = with types; either path package;
      defaultText = literalMD "NixOS snowflake";
      default = pkgs.fetchurl {
        url = "https://raw.githubusercontent.com/NixOS/nixos-artwork/master/logo/nix-snowflake.svg";
        # Reduce size
        postFetch = ''
          substituteInPlace $out \
            --replace "141.5919" "70.79595" \
            --replace "122.80626" "61.40313"
        '';
        sha256 = "4+MWdqESKo9omd3q0WfRmnrd3Wpe2feiayMnQlA4izU=";
      };
    };

    blackBackground = mkOption {
      description = mdDoc ''
        Whether to use a black background rather than a theme colour.

        This looks good in combination with systemd-boot, as it means that the
        background colour doesn't change throughout the boot process.
      '';
      type = types.bool;
      defaultText = literalMD "`true` if systemd-boot is enabled";
      default = config.boot.loader.systemd-boot.enable;
    };
  };

  config.boot.plymouth = mkIf config.stylix.targets.plymouth.enable {
    theme = "stylix";
    themePackages = [ theme ];
  };
}