chore(tds-1): rake task for assignment v2 migration (#13828)

lib/tasks/assignment_v2_migration.rake

@@ -0,0 +1,81 @@
+# Migrate max_assignment_limit to Agent Capacity Policies
+#
+# Converts legacy per-inbox max_assignment_limit settings into
+# AgentCapacityPolicy records used by Assignment V2.
+#
+# Usage Examples:
+#   # Migrate a single account
+#   ACCOUNT_ID=1 bundle exec rake assignment_v2:migrate
+#
+#   # Migrate all accounts in the installation
+#   bundle exec rake assignment_v2:migrate
+#
+# Parameters:
+#   ACCOUNT_ID: (optional) ID of the account to migrate. If omitted, migrates all accounts.
+#
+# rubocop:disable Metrics/BlockLength
+namespace :assignment_v2 do
+  desc 'Migrate max_assignment_limit inbox settings to agent capacity policies'
+  task migrate: :environment do
+    int_max = (2**31) - 1
+    policy_name = 'Auto Assignment Capacity'
+
+    account_id = ENV.fetch('ACCOUNT_ID', nil)
+    accounts = account_id.present? ? Account.where(id: account_id) : Account.all
+
+    if account_id.blank?
+      print 'No ACCOUNT_ID specified. This will migrate ALL accounts. Continue? [y/N] '
+      abort 'Aborted.' unless $stdin.gets.chomp.casecmp('y').zero?
+    end
+
+    if account_id.present? && accounts.empty?
+      puts "Error: Account with ID #{account_id} not found"
+      exit(1)
+    end
+
+    total = accounts.count
+    puts "Migrating assignment policies for #{total} account(s)..."
+    puts "Started at: #{Time.current}"
+
+    migrated = 0
+    skipped = 0
+    errored = 0
+
+    accounts.find_each do |account|
+      inboxes_with_limit = account.inboxes.where("auto_assignment_config->>'max_assignment_limit' ~ '[1-9]'")
+
+      if inboxes_with_limit.empty?
+        skipped += 1
+        puts "  [#{migrated + skipped + errored}/#{total}] Account #{account.id} — skipped (no inboxes with limit)"
+        next
+      end
+
+      ActiveRecord::Base.transaction do
+        policy = AgentCapacityPolicy.find_or_create_by!(account: account, name: policy_name) do |p|
+          p.description = 'Migrated from inbox settings'
+        end
+
+        inboxes_with_limit.each do |inbox|
+          next if InboxCapacityLimit.exists?(agent_capacity_policy_id: policy.id, inbox_id: inbox.id)
+
+          limit = [inbox.auto_assignment_config['max_assignment_limit'].to_i, int_max].min
+          InboxCapacityLimit.create!(agent_capacity_policy: policy, inbox: inbox, conversation_limit: limit)
+        end
+
+        member_user_ids = InboxMember.where(inbox_id: inboxes_with_limit.select(:id)).distinct.pluck(:user_id)
+        account.account_users
+               .where(user_id: member_user_ids, agent_capacity_policy_id: nil)
+               .find_each { |au| au.update!(agent_capacity_policy_id: policy.id) }
+      end
+
+      migrated += 1
+      puts "  [#{migrated + skipped + errored}/#{total}] Account #{account.id} — migrated"
+    rescue StandardError => e
+      errored += 1
+      puts "  [#{migrated + skipped + errored}/#{total}] Account #{account.id} — error: #{e.message}"
+    end
+
+    puts "\nDone! Migrated: #{migrated}, Skipped: #{skipped}, Errored: #{errored}, Total: #{total}"
+  end
+end
+# rubocop:enable Metrics/BlockLength