require 'active_support/core_ext/string/inflections'
require 'rails_admin/config/hideable'

module RailsAdmin
  module Config
    module Fields
      # A container for groups of fields in edit views
      class Group < RailsAdmin::Config::Base
        include RailsAdmin::Config::Hideable

        attr_reader :name

        def initialize(parent, name)
          super(parent)
          @name = name.to_s.tr(' ', '_').downcase.to_sym
        end

        # Defines a configuration for a field by proxying parent's field method
        # and setting the field's group as self
        #
        # @see RailsAdmin::Config::Fields.field
        def field(name, type = nil, &block)
          field = parent.field(name, type, &block)
          # Directly manipulate the variable instead of using the accessor
          # as group probably is not yet registered to the parent object.
          field.instance_variable_set("@group", self)
          field
        end

        # Reader for fields attached to this group
        def fields
          parent.fields.select {|f| self == f.group }
        end

        # Defines configuration for fields by their type
        #
        # @see RailsAdmin::Config::Fields.fields_of_type
        def fields_of_type(type, &block)
          selected = fields.select {|f| type == f.type }
          if block
            selected.each {|f| f.instance_eval &block }
          end
          selected
        end

        # Reader for fields that are marked as visible
        def visible_fields
          fields.select {|f| f.with(bindings).visible? }.map{|f| f.with(bindings)}
        end

        # Configurable group label which by default is group's name humanized.
        register_instance_option :label do
          name.to_s.humanize
        end

        # Configurable help text
        register_instance_option :help do
          nil
        end
      end
    end
  end
end