add favicon and site icon generation from uploaded images

Upload a source image (PNG, JPEG, or SVG) and get a complete favicon
setup: PNG variants at 32, 180, 192, 512px served from DB via
FaviconController with ETag caching, SVG favicon for vector sources,
dynamic site.webmanifest, and theme-color meta tag. Theme editor gains
a site icon section with "use logo as icon" toggle, dedicated icon
upload, short name, and background colour picker.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/berrypod/media.ex

@@ -6,6 +6,7 @@ defmodule Berrypod.Media do
   import Ecto.Query, warn: false
   alias Berrypod.Repo
   alias Berrypod.Media.Image, as: ImageSchema
+  alias Berrypod.Media.FaviconVariant
   alias Berrypod.Images.Optimizer
   alias Berrypod.Images.OptimizeWorker
 
@@ -170,4 +171,40 @@ defmodule Berrypod.Media do
   def list_images_by_type(type) do
     Repo.all(from i in ImageSchema, where: i.image_type == ^type, order_by: [desc: i.inserted_at])
   end
+
+  @doc """
+  Gets the current icon image (used as favicon source when not using the logo).
+  """
+  def get_icon do
+    Repo.one(
+      from i in ImageSchema,
+        where: i.image_type == "icon",
+        order_by: [desc: i.inserted_at],
+        limit: 1
+    )
+  end
+
+  @doc """
+  Gets the current favicon variants (single row).
+  """
+  def get_favicon_variants do
+    Repo.one(
+      from fv in FaviconVariant,
+        order_by: [desc: fv.generated_at],
+        limit: 1
+    )
+  end
+
+  @doc """
+  Stores favicon variants, replacing any existing set.
+  """
+  def store_favicon_variants(attrs) do
+    Repo.delete_all(FaviconVariant)
+
+    %FaviconVariant{}
+    |> FaviconVariant.changeset(
+      Map.put(attrs, :generated_at, DateTime.utc_now() |> DateTime.truncate(:second))
+    )
+    |> Repo.insert()
+  end
 end

lib/berrypod/media/favicon_variant.ex

@@ -0,0 +1,26 @@
+defmodule Berrypod.Media.FaviconVariant do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  @primary_key {:id, :binary_id, autogenerate: true}
+  @foreign_key_type :binary_id
+
+  schema "favicon_variants" do
+    field :source_image_id, :binary_id
+    field :png_32, :binary
+    field :png_180, :binary
+    field :png_192, :binary
+    field :png_512, :binary
+    field :svg, :string
+    field :generated_at, :utc_datetime
+
+    timestamps(type: :utc_datetime)
+  end
+
+  @doc false
+  def changeset(variant, attrs) do
+    variant
+    |> cast(attrs, [:source_image_id, :png_32, :png_180, :png_192, :png_512, :svg, :generated_at])
+    |> validate_required([:source_image_id, :generated_at])
+  end
+end

lib/berrypod/media/image.ex

@@ -38,7 +38,7 @@ defmodule Berrypod.Media.Image do
       :variants_status
     ])
     |> validate_required([:image_type, :filename, :content_type, :file_size, :data])
-    |> validate_inclusion(:image_type, ~w(logo header product))
+    |> validate_inclusion(:image_type, ~w(logo header product icon))
     |> validate_number(:file_size, less_than: @max_file_size)
     |> detect_svg()
   end

lib/berrypod/settings/theme_settings.ex

@@ -41,6 +41,12 @@ defmodule Berrypod.Settings.ThemeSettings do
     field :product_text_align, :string, default: "left"
     field :image_aspect_ratio, :string, default: "square"
 
+    # Favicon / site icon
+    field :use_logo_as_icon, :boolean, default: true
+    field :icon_image_id, :binary_id
+    field :favicon_short_name, :string, default: ""
+    field :icon_background_color, :string, default: "#ffffff"
+
     # Feature toggles
     field :announcement_bar, :boolean, default: true
     field :sticky_header, :boolean, default: false
@@ -83,6 +89,10 @@ defmodule Berrypod.Settings.ThemeSettings do
       :card_shadow,
       :product_text_align,
       :image_aspect_ratio,
+      :use_logo_as_icon,
+      :icon_image_id,
+      :favicon_short_name,
+      :icon_background_color,
       :announcement_bar,
       :sticky_header,
       :hover_image,

lib/berrypod/workers/favicon_generator_worker.ex

@@ -0,0 +1,95 @@
+defmodule Berrypod.Workers.FaviconGeneratorWorker do
+  @moduledoc """
+  Generates favicon variants from a source image.
+
+  For raster sources: generates PNG variants at 32, 180, 192, and 512px.
+  For SVG sources: stores the SVG as-is and attempts PNG generation
+  (gracefully skipped if libvips lacks SVG support).
+  """
+  use Oban.Worker, queue: :images, max_attempts: 3
+
+  require Logger
+
+  alias Berrypod.Media
+
+  @sizes [512, 192, 180, 32]
+
+  @impl Oban.Worker
+  def perform(%Oban.Job{args: %{"source_image_id" => id}}) do
+    case Media.get_image(id) do
+      nil -> {:cancel, :image_not_found}
+      image -> generate(image)
+    end
+  end
+
+  defp generate(%{is_svg: true} = image) do
+    # Try to rasterize the SVG for PNG variants (may fail if libvips lacks SVG support)
+    png_variants =
+      case load_svg(image) do
+        {:ok, vips_image} -> generate_png_variants(vips_image)
+        {:error, _reason} -> %{}
+      end
+
+    attrs = Map.merge(png_variants, %{source_image_id: image.id, svg: image.svg_content})
+    Media.store_favicon_variants(attrs)
+    :ok
+  end
+
+  defp generate(image) do
+    case Image.from_binary(image.data) do
+      {:ok, vips_image} ->
+        png_variants = generate_png_variants(vips_image)
+        attrs = Map.put(png_variants, :source_image_id, image.id)
+        Media.store_favicon_variants(attrs)
+        :ok
+
+      {:error, reason} ->
+        Logger.error("Favicon generation failed: #{inspect(reason)}")
+        {:error, reason}
+    end
+  end
+
+  defp load_svg(image) do
+    Image.from_svg(image.svg_content)
+  rescue
+    e ->
+      Logger.warning("SVG rasterization unavailable: #{Exception.message(e)}")
+      {:error, :svg_unsupported}
+  end
+
+  defp generate_png_variants(vips_image) do
+    # Crop to square first if needed
+    {w, h, _} = Image.shape(vips_image)
+    side = min(w, h)
+
+    vips_image =
+      if w == h do
+        vips_image
+      else
+        case Image.center_crop(vips_image, side, side) do
+          {:ok, cropped} -> cropped
+          {:error, _} -> vips_image
+        end
+      end
+
+    @sizes
+    |> Enum.reduce(%{}, fn size, acc ->
+      case resize_to_png(vips_image, size) do
+        {:ok, png_data} ->
+          key = :"png_#{size}"
+          Map.put(acc, key, png_data)
+
+        {:error, reason} ->
+          Logger.warning("Favicon #{size}px generation failed: #{inspect(reason)}")
+          acc
+      end
+    end)
+  end
+
+  defp resize_to_png(vips_image, size) do
+    with {:ok, resized} <- Image.thumbnail(vips_image, size),
+         {:ok, png_data} <- Image.write(resized, :memory, suffix: ".png") do
+      {:ok, png_data}
+    end
+  end
+end