Add ruby-vips for processing opengraph image

Gemfile

@@ -40,3 +40,5 @@ group :development do
 end
 
 gem "bridgetown-lit-renderer", "= 2.1.0.beta2"
+
+gem "ruby-vips", "~> 2.2"

Gemfile.lock

@@ -81,7 +81,7 @@ GEM
     i18n (1.14.1)
       concurrent-ruby (~> 1.0)
     jaro_winkler (1.5.6)
-    json (2.6.3)
+    json (2.7.1)
     kramdown (2.4.0)
       rexml
     kramdown-parser-gfm (1.1.0)
@@ -95,13 +95,14 @@ GEM
     minitest (5.20.0)
     mutex_m (0.1.2)
     nio4r (2.5.8)
-    nokogiri (1.15.4)
+    nokogiri (1.16.0)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
-    parallel (1.23.0)
-    parser (3.2.2.4)
+    parallel (1.24.0)
+    parser (3.3.0.3)
       ast (~> 2.4.1)
       racc
+    prism (0.24.0)
     public_suffix (5.0.3)
     puma (5.6.2)
       nio4r (~> 2.0)
@@ -115,22 +116,22 @@ GEM
       ffi (~> 1.0)
     rbs (2.8.4)
     redcarpet (3.6.0)
-    regexp_parser (2.8.2)
+    regexp_parser (2.9.0)
     reverse_markdown (2.1.1)
       nokogiri
     rexml (3.2.6)
     roda (3.73.0)
       rack
     rouge (3.30.0)
-    rubocop (1.57.2)
+    rubocop (1.59.0)
       json (~> 2.3)
       language_server-protocol (>= 3.17.0)
       parallel (~> 1.10)
       parser (>= 3.2.2.4)
       rainbow (>= 2.2.2, < 4.0)
       regexp_parser (>= 1.8, < 3.0)
       rexml (>= 3.2.5, < 4.0)
-      rubocop-ast (>= 1.28.1, < 2.0)
+      rubocop-ast (>= 1.30.0, < 2.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 2.4.0, < 3.0)
     rubocop-ast (1.30.0)
@@ -140,12 +141,14 @@ GEM
       prism (>= 0.22.0, < 0.25)
       sorbet-runtime (>= 0.5.10782)
     ruby-progressbar (1.13.0)
+    ruby-vips (2.2.1)
+      ffi (~> 1.12)
     ruby2_keywords (0.0.5)
     serbea (1.0.1)
       activesupport (>= 6.0)
       erubi (>= 1.10)
       tilt (~> 2.0)
-    solargraph (0.49.0)
+    solargraph (0.50.0)
       backport (~> 1.2)
       benchmark
       bundler (~> 2.0)
@@ -161,8 +164,8 @@ GEM
       thor (~> 1.0)
       tilt (~> 2.0)
       yard (~> 0.9, >= 0.9.24)
-    thor (1.2.2)
     sorbet-runtime (0.5.11351)
+    thor (1.3.0)
     tilt (2.3.0)
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
@@ -182,6 +185,7 @@ DEPENDENCIES
   puma (~> 5.6)
   redcarpet (~> 3.5)
   ruby-lsp (~> 0.14.6)
+  ruby-vips (~> 2.2)
   solargraph
 
 BUNDLED WITH

plugins/utils/opengraph/image.rb

@@ -0,0 +1,73 @@
+require 'vips'
+
+module Utils
+  module Opengraph
+    class Image
+      attr_reader :elements, :canvas, :borders, :canvas_color
+
+      def initialize(width, height, color: '#ffffff')
+        @elements = []
+        @canvas_color = color
+        @canvas = Vips::Image.black(width, height).ifthenelse([0, 0, 0], hex_to_rgb(color))
+        @borders = {}
+      end
+
+      def image(source, resize_with_ratio:)
+        im = source ? Vips::Image.new_from_buffer(source, '') : Vips::Image.black(1, 1).ifthenelse([0, 0, 0], hex_to_rgb(canvas_color))
+        if resize_with_ratio && source
+          width, height = resize_with_ratio
+          ratio = get_ratio(im, width, height, :min)
+          im = im.resize(ratio)
+        end
+        @elements << im
+        self
+      end
+
+      def text(message, width:, height:, dpi: 300, color: '#2f363d', font: 'Open Sans Bold')
+        im = Vips::Image.text(message, width: width, height: height, dpi: dpi, font: font)
+        im = im.new_from_image(hex_to_rgb(color)).copy(interpretation: :srgb).bandjoin(im)
+        @elements << im
+
+        self
+      end
+
+      def border_bottom(height, color: '#000000')
+        im = Vips::Image.black(canvas.width, height).ifthenelse([0, 0, 0], hex_to_rgb(color))
+        borders[:bottom] = im
+
+        self
+      end
+
+      def compose(filename)
+        result = yield(canvas, *elements)
+        @canvas = @canvas.composite(
+          elements + [borders[:bottom]], :over,
+          x: result[:x] + (borders[:bottom] ? [0] : []),
+          y: result[:y] + (borders[:bottom] ? [canvas.height - borders[:bottom].height] : [])
+        )
+
+        @canvas.write_to_file(filename)
+      end
+
+      private
+
+      def hex_to_rgb(input)
+        case input
+        when String
+          input.match(/#(..)(..)(..)/)[1..3].map(&:hex)
+        when Array
+          input
+        else
+          raise ArgumentError, "Unknown input #{input.inspect}"
+        end
+      end
+
+      # https://github.com/dariocravero/vips-process/blob/master/lib/vips-process/resize.rb#L109
+      def get_ratio(image, width, height, min_or_max = :min)
+        width_ratio = width.to_f / image.width
+        height_ratio = height.to_f / image.height
+        [width_ratio, height_ratio].send min_or_max
+      end
+    end
+  end
+end