remove premailer

Gemfile

@@ -4,6 +4,7 @@ source 'https://rubygems.org'
 
 ruby '4.0.1'
 
+gem 'addressable'
 gem 'arabic-letter-connector', require: false
 gem 'aws-sdk-s3', require: false
 gem 'aws-sdk-secretsmanager', require: false
@@ -28,7 +29,6 @@ gem 'oj'
 gem 'onnxruntime', require: false
 gem 'pagy'
 gem 'pg', require: false
-gem 'premailer-rails'
 gem 'pretender'
 gem 'puma', require: false
 gem 'rack'

Gemfile.lock

@@ -150,8 +150,6 @@ GEM
       bigdecimal
       rexml
     crass (1.0.6)
-    css_parser (1.21.1)
-      addressable
     csv (3.3.5)
     csv-safe (3.3.1)
       csv (~> 3.0)
@@ -264,7 +262,6 @@ GEM
       geom2d (~> 0.4, >= 0.4.1)
       openssl (>= 2.2.1)
       strscan (>= 3.1.2)
-    htmlentities (4.4.2)
     i18n (1.14.8)
       concurrent-ruby (~> 1.0)
     image_processing (1.14.0)
@@ -370,14 +367,6 @@ GEM
     pg (1.6.3-x86_64-linux-musl)
     pp (0.6.3)
       prettyprint
-    premailer (1.27.0)
-      addressable
-      css_parser (>= 1.19.0)
-      htmlentities (>= 4.0.0)
-    premailer-rails (1.12.0)
-      actionmailer (>= 3)
-      net-smtp
-      premailer (~> 1.7, >= 1.7.9)
     pretender (0.6.0)
       actionpack (>= 7.1)
     prettyprint (0.2.0)
@@ -607,6 +596,7 @@ PLATFORMS
   x86_64-linux-musl
 
 DEPENDENCIES
+  addressable
   annotaterb
   arabic-letter-connector
   aws-sdk-s3
@@ -643,7 +633,6 @@ DEPENDENCIES
   onnxruntime
   pagy
   pg
-  premailer-rails
   pretender
   pry-rails
   puma

app/mailers/application_mailer.rb

@@ -5,6 +5,8 @@ class ApplicationMailer < ActionMailer::Base
   layout 'mailer'
 
   register_interceptor ActionMailerConfigsInterceptor
+  register_interceptor HtmlToPlainTextInterceptor
+  register_preview_interceptor HtmlToPlainTextInterceptor
 
   register_observer ActionMailerEventsObserver
 

lib/html_to_plain_text.rb

@@ -0,0 +1,119 @@
+# frozen_string_literal: true
+
+module HtmlToPlainText
+  module_function
+
+  def call(html, line_length = 65)
+    return '' if html.nil? || html.strip.empty?
+
+    cleaned = html.gsub(%r{<!-- start text/html -->.*?<!-- end text/html -->}m, '')
+
+    doc = Nokogiri::HTML.fragment(cleaned)
+
+    doc.css('script').each(&:remove)
+
+    result = process_nodes(doc, line_length)
+
+    result.gsub!(/\r\n?/, "\n")
+    result.gsub!(/[ \t]*\u00A0+[ \t]*/, ' ')
+    result.gsub!(/\n[ \t]+/, "\n")
+    result.gsub!(/[ \t]+\n/, "\n")
+    result.gsub!(/\n{3,}/, "\n\n")
+
+    result = word_wrap(result, line_length)
+
+    result.gsub!(/\(([ \n])(http[^)]+)([\n ])\)/) do
+      "#{"\n" if ::Regexp.last_match(1) == "\n"}( #{::Regexp.last_match(2)} )#{"\n" if ::Regexp.last_match(3) == "\n"}"
+    end
+
+    result.strip
+  end
+
+  def process_nodes(node, line_length)
+    result = +''
+
+    node.children.each do |child|
+      case child
+      when Nokogiri::XML::Text
+        result << child.text
+      when Nokogiri::XML::Comment
+        next
+      when Nokogiri::XML::Element
+        result << process_element(child, line_length)
+      end
+    end
+
+    result
+  end
+
+  def process_element(node, line_length)
+    case node.name
+    when 'br'
+      "\n"
+    when 'p', 'div'
+      inner = process_nodes(node, line_length)
+      inner.strip.empty? ? '' : "#{inner}\n\n"
+    when 'img'
+      node['alt'] || ''
+    when 'a'
+      process_link(node, line_length)
+    when /\Ah([1-6])\z/
+      process_heading(node, ::Regexp.last_match(1).to_i, line_length)
+    when 'li'
+      inner = process_nodes(node, line_length)
+      "* #{inner.strip}\n"
+    else
+      process_nodes(node, line_length)
+    end
+  end
+
+  def process_link(node, line_length)
+    text = process_nodes(node, line_length).strip
+    return '' if text.empty?
+
+    href = node['href']
+    href = href.sub(/\Amailto:/i, '') if href
+
+    if href.nil? || text.casecmp(href.strip) == 0
+      text
+    else
+      "#{text} ( #{href.strip} )"
+    end
+  end
+
+  def process_heading(node, level, line_length)
+    text = +''
+    node.children.each do |child|
+      text << if child.name == 'br'
+                "\n"
+              else
+                child.text
+              end
+    end
+    text.strip!
+
+    hlength = text.each_line.map { |l| l.strip.length }.max || 0
+    hlength = line_length if hlength > line_length
+
+    decorated = case level
+                when 1
+                  "#{'*' * hlength}\n#{text}\n#{'*' * hlength}"
+                when 2
+                  "#{'-' * hlength}\n#{text}\n#{'-' * hlength}"
+                else
+                  "#{text}\n#{'-' * hlength}"
+                end
+
+    "\n\n#{decorated}\n\n"
+  end
+
+  def word_wrap(txt, line_length)
+    txt.split("\n").map do |line|
+      if line.length > line_length
+        line.gsub(/(.{1,#{line_length}})(\s+|$)/, "\\1\n").strip
+      else
+        line
+      end
+    end.join("\n")
+  end
+end

lib/html_to_plain_text_interceptor.rb

@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+module HtmlToPlainTextInterceptor
+  module_function
+
+  def delivering_email(message)
+    process(message)
+  end
+
+  def previewing_email(message)
+    process(message)
+  end
+
+  def process(message)
+    return message unless html_part(message)
+    return message if message.text_part
+
+    add_text_part(message)
+
+    message
+  end
+
+  def add_text_part(message)
+    html = html_part(message).decoded
+    text = HtmlToPlainText.call(html)
+
+    text_part = Mail::Part.new do
+      content_type 'text/plain; charset=UTF-8'
+      body text
+    end
+
+    if pure_html_message?(message)
+      message.body = nil
+      message.content_type = 'multipart/alternative'
+      message.add_part(text_part)
+      message.add_part(Mail::Part.new do
+        content_type 'text/html; charset=UTF-8'
+        body html
+      end)
+    else
+      alternative = Mail::Part.new(content_type: 'multipart/alternative')
+      alternative.add_part(text_part)
+      alternative.add_part(message.html_part)
+      replace_part(message.parts, message.html_part, alternative)
+    end
+  end
+
+  def pure_html_message?(message)
+    message.content_type.to_s.include?('text/html')
+  end
+
+  def html_part(message)
+    pure_html_message?(message) ? message : message.html_part
+  end
+
+  def replace_part(parts, old_part, new_part)
+    if (index = parts.index(old_part))
+      parts[index] = new_part
+    else
+      parts.each do |part|
+        replace_part(part.parts, old_part, new_part) if part.respond_to?(:parts)
+      end
+    end
+  end
+end