andela-akabiru/panda

module Panda
  module Record
    module BaseHelper
      def self.included(base)
        class << base
          attr_reader :properties, :table

          private

          def column_names_with_constraints
            name_with_constraints = []
            properties.each do |column_name, constraints|
              query_string = []
              query_string << column_name.to_s
              parse_constraints(constraints, query_string)
              name_with_constraints << query_string.join(" ")
            end
            name_with_constraints
          end

          def parse_constraints(constraints, query_string)
            constraints.each do |attribute, value|
              query_string << send(attribute.to_s, value)
            end
          end

          def build_column_methods
            properties.keys.each(&method(:attr_accessor))
          end

          def get_model_object(row)
            return nil unless row
            model ||= new
            properties.keys.each_with_index do |key, index|
              model.send("#{key}=", row[index])
            end
            model
          end

          def type(value)
            value.to_s
          end

          def primary_key(is_primary)
            "PRIMARY KEY AUTOINCREMENT" if is_primary
          end

          def nullable(is_null)
            "NOT NULL" unless is_null
          end
        end
      end

      private

      def model_table
        self.class.table
      end

      def current_table_columns
        columns_without_id.map(&:to_s).join(", ")
      end

      def current_table_placeholders
        (["?"] * (self.class.properties.keys.size - 1)).join(", ")
      end

      def record_values
        columns_without_id.map(&method(:send))
      end

      def update_placeholders(columns = self.class.properties.keys)
        columns.delete(:id)
        columns.map { |column| "#{column} = ?" }.join(", ")
      end

      def columns_without_id
        columns ||= self.class.properties.keys
        columns.delete(:id)
        columns
      end
    end
  end
end