module Pagy::Backend

def self.included(controller)
  controller.define_method(:params) { {} } unless controller.method_defined?(:params)
end

def pagy(collection, **vars)
  vars[:count] ||= pagy_get_count(collection, vars)
  vars[:limit] ||= pagy_get_limit(vars)
  vars[:page]  ||= pagy_get_page(vars)
  pagy = Pagy.new(**vars)
  [pagy, pagy_get_items(collection, pagy)]
end

def pagy_get_count(collection, vars)
  count_args = vars[:count_args] || DEFAULT[:count_args]
  (count     = collection.count(*count_args)).is_a?(Hash) ? count.size : count
end

def pagy_get_items(collection, pagy)
  collection.offset(pagy.offset).limit(pagy.limit)
end

def pagy_get_limit(_vars)
  DEFAULT[:limit]
end

def pagy_get_page(vars, force_integer: true)
  page = params[vars[:page_param] || DEFAULT[:page_param]]
  force_integer ? (page || 1).to_i : page
end