require "pact_broker/repositories/page"

Sequel.extension :escaped_like

module PactBroker
  module Repositories
    module Helpers

      extend self

      def all_with_pagination_options(pagination_options)
        if pagination_options&.any?
          query = paginate(pagination_options[:page_number], pagination_options[:page_size])
          Page.new(query.all, query)
        else
          all
        end
      end

      def all_forbidding_lazy_load
        all.each{ | row | row.forbid_lazy_load if row.respond_to?(:forbid_lazy_load) }
      end

      def all_allowing_lazy_load
        all.each{ | row | row.allow_lazy_load if row.respond_to?(:allow_lazy_load) }
      end

      def name_like column_name, value
        if PactBroker.configuration.use_case_sensitive_resource_names
          if mysql?
            # sigh, mysql, this is the only way to perform a case sensitive search
            Sequel.like(column_name, value.gsub("_", "\\_"), { case_insensitive: false })
          else
            { column_name => value }
          end
        else
          Sequel.like(column_name, value.gsub("_", "\\_"), { case_insensitive: true })
        end
      end

      def pacticipant_id_for_name pacticipant_name
        Sequel::Model.db[:pacticipants].select(:id).where(name_like(:name, pacticipant_name)).limit(1)
      end

      def order_ignore_case column_name = :name
        order(Sequel.function(:lower, column_name))
      end

      def order_append_ignore_case column_name = :name
        order_append(Sequel.function(:lower, column_name))
      end

      def mysql?
        Sequel::Model.db.adapter_scheme.to_s =~ /mysql/
      end

      def postgres?
        Sequel::Model.db.adapter_scheme.to_s =~ /postgres/
      end

      def select_all_qualified
        select(Sequel[model.table_name].*)
      end

      def select_append_all_qualified
        select_append(Sequel[model.table_name].*)
      end

      # @param [Symbol] max_column the name of the column of which to calculate the maxiumum
      # @param [Array<Symbol>] group_by_columns the names of the columns by which to group
      def max_group_by(max_column, group_by_columns, &extra_criteria_block)
        maximums_base_query = extra_criteria_block ? extra_criteria_block.call(self) : self
        maximums = maximums_base_query.select_group(*group_by_columns).select_append(Sequel.function(:max, max_column).as(:max_value))

        max_join = group_by_columns.each_with_object({ Sequel[:maximums][:max_value] => max_column }) do | column_name, joins |
          joins[Sequel[:maximums][column_name]] = column_name
        end

        join(maximums, max_join, table_alias: :maximums)
      end

      def select_for_subquery column
        if mysql? #stoopid mysql doesn't allow you to modify datasets with subqueries
          column_name = column.respond_to?(:alias) ? column.alias : column
          select(column).collect{ | it | it[column_name] }
        else
          select(column)
        end
      end

      def no_columns_selected?
        opts[:select].nil?
      end
    end
  end
end