Add example script for importing customers

script/import-customers.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+# Read customer entries in CSV format from STDIN and create those records in
+# the database. Example:
+#
+#   rails runner script/import-customers.rb 3359 < FND-customers-Emails.csv
+#
+# This script was written for a once-off import. If we want to perform this
+# task more often, we can make it more flexible and eventually add a
+# feature to the user interface.
+require 'csv'
+
+enterprise_id = ARGV.first
+
+def check_enterprise_exists(id)
+  enterprise = Enterprise.find(id)
+  puts "Importing customers for #{enterprise.name}:"
+end
+
+def import_customer(row, enterprise_id)
+  email = row["Email"].downcase
+  tag = row["Tag"]
+
+  print email
+  customer = find_or_create_customer(email, enterprise_id)
+  add_tag(customer, tag)
+  puts ""
+end
+
+def find_or_create_customer(email, enterprise_id)
+  Customer.find_or_create_by(
+    email: email,
+    enterprise_id: enterprise_id,
+  ) { print " - newly imported" }
+  print " - user exists" if Spree::User.where(email: email).exists?
+end
+
+def add_tag(customer, tag)
+  return if tag.blank?
+
+  customer.tag_list.add(tag)
+  customer.save!
+end
+
+check_enterprise_exists(enterprise_id)
+
+CSV($stdin, headers: true, row_sep: "\r\n") do |csv|
+  csv.each do |row|
+    import_customer(row, enterprise_id)
+  end
+end