dawarich/app/services/families/leave.rb

# frozen_string_literal: true

module Families
  class Leave
    attr_reader :user, :error_message

    def initialize(user:)
      @user = user
      @error_message = nil
    end

    def call
      return false unless validate_can_leave

      # Store family info before removing membership
      @family_name = user.family.name
      @family_owner = user.family.owner

      ActiveRecord::Base.transaction do
        handle_ownership_transfer if user.family_owner?
        remove_membership
        send_notifications
      end

      true
    rescue ActiveRecord::RecordInvalid => e
      handle_record_invalid_error(e)
      false
    rescue StandardError => e
      handle_generic_error(e)
      false
    end

    private

    def validate_can_leave
      return false unless validate_in_family
      return false unless validate_owner_can_leave

      true
    end

    def validate_in_family
      return true if user.in_family?

      @error_message = 'You are not currently in a family.'
      false
    end

    def validate_owner_can_leave
      return true unless user.family_owner? && family_has_other_members?

      @error_message = 'You cannot leave the family while you are the owner and there are ' \
                       'other members. Remove all members first or transfer ownership.'
      false
    end

    def family_has_other_members?
      user.family.members.count > 1
    end

    def handle_ownership_transfer
      # If this is the last member (owner), delete the family
      return unless user.family.members.count == 1

      user.family.destroy!

      # If owner tries to leave with other members, it should be prevented in validation
    end

    def remove_membership
      user.family_membership.destroy!
    end

    def send_notifications
      return unless defined?(Notification)

      # Notify the user who left
      Notification.create!(
        user: user,
        kind: :info,
        title: 'Left Family',
        content: "You've left the family \"#{@family_name}\""
      )

      # Notify the family owner
      return unless @family_owner&.persisted?

      Notification.create!(
        user: @family_owner,
        kind: :info,
        title: 'Family Member Left',
        content: "#{user.email} has left the family \"#{@family_name}\""
      )
    end

    def handle_record_invalid_error(error)
      @error_message = if error.record&.errors&.any?
                         error.record.errors.full_messages.first
                       else
                         "Failed to leave family: #{error.message}"
                       end
    end

    def handle_generic_error(error)
      Rails.logger.error "Unexpected error in Families::Leave: #{error.message}"
      Rails.logger.error error.backtrace.join("\n")
      @error_message = 'An unexpected error occurred while leaving the family. Please try again'
    end
  end
end