module RailsDbAdmin
  module Extjs
    class JsonDataBuilder

      def initialize(database_connection_class)
        @connection = database_connection_class.connection
      end

      def build_json_data(options)
        unless options[:table]
          raise '!Error Must specify table'
        end

        total_count = self.get_total_count(options[:table])
        arel_table = Arel::Table::new(options[:table])

        if options[:query_filter].present?
          table_name = options[:table].classify.constantize
          accepted_columns = table_name.columns.select {|column| column.type == :string or column.type == :text}
          where_clause = ""
          accepted_columns.each_with_index do |column, index|
            if index == 0
              where_clause = table_name.arel_table[column.name.to_sym].matches("%#{options[:query_filter]}%")
            else
              where_clause = where_clause.or(table_name.arel_table[column.name.to_sym].matches("%#{options[:query_filter]}%"))
            end
          end
          rows = table_name.where(where_clause)
        else

          if options[:limit] && options[:offset] && options[:order]
            query = arel_table.project(Arel.sql('*')).order(options[:order]).
              take(@connection.sanitize_limit(options[:limit])).
              skip(options[:offset].to_i)
          elsif options[:limit] && options[:order]
            query = arel_table.project(Arel.sql('*')).order(options[:order]).
              take(@connection.sanitize_limit(options[:limit]))
          elsif options[:limit] && !options[:order]
            query = arel_table.project(Arel.sql('*')).
              take(@connection.sanitize_limit(options[:limit]))
          elsif !options[:limit] && options[:order]
            query = arel_table.project(Arel.sql('*')).order(options[:order])
          else
            query = arel_table.project(Arel.sql('*'))
          end

          # This is a temporary partial fix to handle postgres boolean columns which is use activerecord when possible
          begin
            rows = options[:table].classify.constantize.find_by_sql(query.to_sql)
          rescue
            rows = @connection.select_all(query.to_sql)
          end

        end

        records = RailsDbAdmin::TableSupport.database_rows_to_hash(rows)

        if !records.empty? && !records[0].has_key?("id")
          records = RailsDbAdmin::TableSupport.add_fake_id_col(records)
        end

        {:total => total_count, :data => records}
      end

      def get_row_data(table, id)
        arel_table = Arel::Table::new(table)

        query = arel_table.project(
          Arel.sql('*')).where(arel_table[id[0].to_sym].eq(id[1]))

        rows = @connection.select_all(query.to_sql)
        records = RailsDbAdmin::TableSupport.database_rows_to_hash(rows)
        records[0]
      end

      #This will retrieve data from tables without an
      #'id' field.  Will also add a 'fake_id' so that it can
      #be used by editable ExtJS grids.
      def get_row_data_no_id(table, row_hash)

        arel_table = Arel::Table::new(table)
        query = arel_table.project(Arel.sql('*'))
        row_hash.each do |k, v|
          query = query.where(arel_table[k.to_sym].eq(v))
        end

        rows = @connection.select_all(query.to_sql)
        records = RailsDbAdmin::TableSupport.database_rows_to_hash(rows)
        records = RailsDbAdmin::TableSupport.add_fake_id_col(records)
        records[0]
      end

      def get_total_count(table)
        total_count = 0
        rows = @connection.select_all("SELECT COUNT(*) as count FROM #{table}")
        records = RailsDbAdmin::TableSupport.database_rows_to_hash(rows)
        total_count = records[0][:count]

        total_count
      end
	end
  end
end