Refactor ejabberd API integration

app/services/ejabberd_manager/set_avatar.rb

@@ -0,0 +1,80 @@
+require 'digest'
+require "image_processing/vips"
+
+module EjabberdManager
+  class SetAvatar < EjabberdManagerService
+    def initialize(user:, overwrite: false)
+      @user = user
+      @overwrite = overwrite
+    end
+
+    def call
+      unless @overwrite
+        current_avatar = EjabberdManager::GetAvatar.call(user: @user)
+        Rails.logger.info { "User #{user.cn} already has an avatar set" }
+        return if current_avatar.present?
+      end
+
+      Rails.logger.debug { "Setting XMPP avatar for user #{@user.cn}" }
+
+      stanzas = build_xep0084_stanzas
+
+      stanzas.each do |stanza|
+        payload = { from: @user.address, to: @user.address, stanza: stanza }
+        res = send_stanza payload
+        raise res.inspect if res.status != 200
+      end
+    end
+  end
+
+  private
+
+    def process_avatar
+      @user.avatar.blob.open do |file|
+        processed = ImageProcessing::Vips
+          .source(file)
+          .resize_to_fill(256, 256)
+          .convert("png")
+          .call
+        processed.read
+      end
+    end
+
+    # See https://xmpp.org/extensions/xep-0084.html
+    def build_xep0084_stanzas
+      img_data    = process_avatar
+      sha1_hash   = Digest::SHA1.hexdigest(img_data)
+      base64_data = Base64.strict_encode64(img_data)
+
+      [
+        """
+<iq type='set' from='#{@user.address}' id='avatar-data-#{rand(101)}'>
+  <pubsub xmlns='http://jabber.org/protocol/pubsub'>
+    <publish node='urn:xmpp:avatar:data'>
+      <item id='#{sha1_hash}'>
+        <data xmlns='urn:xmpp:avatar:data'>#{base64_data}</data>
+      </item>
+    </publish>
+  </pubsub>
+</iq>
+        """.strip,
+        """
+<iq type='set' from='#{@user.address}' id='avatar-metadata-#{rand(101)}'>
+  <pubsub xmlns='http://jabber.org/protocol/pubsub'>
+    <publish node='urn:xmpp:avatar:metadata'>
+      <item id='#{sha1_hash}'>
+        <metadata xmlns='urn:xmpp:avatar:metadata'>
+          <info bytes='#{img_data.size}'
+                id='#{sha1_hash}'
+                height='256'
+                type='image/png'
+                width='256'/>
+        </metadata>
+      </item>
+    </publish>
+  </pubsub>
+</iq>
+        """.strip,
+      ]
+    end
+end