module PermissionsBuilder
  class Standard < Base
    attr_reader :permissions

    def initialize(*args)
      super
      @permissions        = {}
      @permissions['RW+'] = {}
      @permissions['RW']  = {}
      @permissions['R']   = {}
    end

    def build
      # Build permissions
      build_permissions

      # Return them
      [merge_permissions(permissions, old_permissions)]
    end

    private

    def build_permissions
      @permissions['RW+'][''] = gitolite_users[:rewind_users] unless no_users?(:rewind_users)
      @permissions['RW']['']  = gitolite_users[:write_users]  unless no_users?(:write_users)
      @permissions['R']['']   = gitolite_users[:read_users]   unless no_users?(:read_users)
    end

    def merge_permissions(current_permissions, old_permissions)
      merge_permissions = {}
      merge_permissions['RW+'] = {}
      merge_permissions['RW'] = {}
      merge_permissions['R'] = {}

      current_permissions.each do |perm, branch_settings|
        branch_settings.each do |branch, user_list|
          next unless user_list.any?

          merge_permissions[perm][branch] = [] unless merge_permissions[perm].key?(branch)
          merge_permissions[perm][branch] += user_list
        end
      end

      old_permissions.each do |perm, branch_settings|
        branch_settings.each do |branch, user_list|
          next unless user_list.any?

          merge_permissions[perm][branch] = [] unless merge_permissions[perm].key?(branch)
          merge_permissions[perm][branch] += user_list
        end
      end

      merge_permissions.each do |perm, _branch_settings|
        merge_permissions.delete(perm) if merge_permissions[perm].empty?
      end

      merge_permissions
    end
  end
end