Add SMTP authentication failure blocking system with admin dashboard

app/controllers/admin_blocked_ips_controller.rb

@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+class AdminBlockedIpsController < ApplicationController
+
+  before_action :admin_required
+
+  def index
+    # Get search query
+    @query = params[:query]
+
+    # Cleanup expired entries periodically
+    SMTPServer::AuthFailureTracker.cleanup_blocked_index if should_cleanup?
+
+    # Get blocked IPs (with search if query present)
+    if @query.present?
+      @blocked_ips = SMTPServer::AuthFailureTracker.search_blocked(@query)
+    else
+      @blocked_ips = SMTPServer::AuthFailureTracker.all_blocked
+    end
+
+    # Pagination
+    @page = (params[:page] || 1).to_i
+    @per_page = 50
+    @total_blocked = @blocked_ips.size
+    @blocked_ips = @blocked_ips.drop((@page - 1) * @per_page).take(@per_page)
+    @total_pages = (@total_blocked.to_f / @per_page).ceil
+  end
+
+  def unblock
+    ip_address = params[:ip]
+
+    if ip_address.blank?
+      flash[:error] = "IP address is required"
+      redirect_to admin_blocked_ips_path
+      return
+    end
+
+    if SMTPServer::AuthFailureTracker.unblock(ip_address)
+      flash[:notice] = "IP address #{ip_address} has been unblocked successfully"
+    else
+      flash[:error] = "Failed to unblock IP address #{ip_address}"
+    end
+
+    redirect_to admin_blocked_ips_path
+  end
+
+  def unblock_all
+    blocked_ips = SMTPServer::AuthFailureTracker.all_blocked
+    count = 0
+
+    blocked_ips.each do |ip_info|
+      if SMTPServer::AuthFailureTracker.unblock(ip_info[:ip_address])
+        count += 1
+      end
+    end
+
+    flash[:notice] = "Successfully unblocked #{count} IP address#{count == 1 ? '' : 'es'}"
+    redirect_to admin_blocked_ips_path
+  end
+
+  def cleanup
+    cleaned = SMTPServer::AuthFailureTracker.cleanup_blocked_index
+    flash[:notice] = "Cleaned up #{cleaned} expired entr#{cleaned == 1 ? 'y' : 'ies'}"
+    redirect_to admin_blocked_ips_path
+  end
+
+  private
+
+  # Cleanup expired entries every 10th request to avoid overhead
+  def should_cleanup?
+    rand(10).zero?
+  end
+
+end