# Wallpaper-driven Material-You theming (matugen) for the QuickShell shell.
# `qs-theme <wallpaper>` regenerates:
#   - ~/.cache/quickshell/theme.json  → live-repaints the bar (FileView watcher)
#   - ~/.config/kitty/colors.conf     → kitty palette + ANSI 16
# The Nix-declared colors.conf symlink is restored on the next home-manager
# rebuild; until then the generated palette wins (see the rm in qs-theme).
{
  config,
  pkgs,
  ...
}:
{
  home.packages = [ pkgs.matugen ];

  # Default matugen config — renders our two templates on every run.
  xdg.configFile."matugen/config.toml".text = ''
    [config]

    [templates.quick-shell]
    input_path = "${config.home.homeDirectory}/.config/matugen/themes/theme.json.template"
    output_path = "${config.home.homeDirectory}/.cache/quickshell/theme.json"

    [templates.kitty]
    input_path = "${config.home.homeDirectory}/.config/matugen/themes/kitty-colors.conf.template"
    output_path = "${config.home.homeDirectory}/.config/kitty/colors.conf"
  '';

  # Template sources live in the repo so matugen can read them at runtime.
  xdg.configFile."matugen/themes/theme.json.template".text =
    builtins.readFile ./matugen-themes/theme.json.template;
  xdg.configFile."matugen/themes/kitty-colors.conf.template".text =
    builtins.readFile ./matugen-themes/kitty-colors.conf.template;

  # qs-theme — regenerate the wallpaper palette, then repaint the live bar.
  home.file.".local/bin/qs-theme" = {
    executable = true;
    text = ''
      #!/bin/sh
      # Regenerate the Material-You palette (QuickShell bar + kitty) from a
      # wallpaper. The bar picks it up live via its theme.json watcher.
      set -e

      if [ "$#" -lt 1 ]; then
        echo "usage: qs-theme <wallpaper>" >&2
        exit 1
      fi

      # matugen refuses to overwrite the Nix-declared symlink; unlink it first
      # (home-manager restores it on the next rebuild).
      rm -f "$HOME/.config/kitty/colors.conf"

      exec ${pkgs.matugen}/bin/matugen image "$1" -m dark --prefer darkness
    '';
  };
}