# -*- coding: utf-8 -*-
module ActiveRecord::Turntable
  module ActiveRecordExt
    module SchemaDumper
      extend ActiveSupport::Concern

      included do
        alias_method_chain :table, :turntable
      end

      private

      # @note Override to dump database sequencer method
      def table_with_turntable(table, stream)
        columns = @connection.columns(table)
        begin
          tbl = StringIO.new

          # first dump primary key column
          if @connection.respond_to?(:pk_and_sequence_for)
            pk, _ = @connection.pk_and_sequence_for(table)
          elsif @connection.respond_to?(:primary_key)
            pk = @connection.primary_key(table)
          end

          if table =~ /\A(.*)_id_seq\z/
            tbl.print "  create_sequence_for #{remove_prefix_and_suffix($1).inspect}"
          else
            tbl.print "  create_table #{remove_prefix_and_suffix(table).inspect}"
          end
          pkcol = columns.detect { |c| c.name == pk }
          if pkcol
            if pk != 'id'
              tbl.print %Q(, primary_key: "#{pk}")
            elsif pkcol.sql_type == 'uuid'
              tbl.print ", id: :uuid"
              tbl.print %Q(, default: "#{pkcol.default_function}") if pkcol.default_function
            end
          else
            tbl.print ", id: false"
          end
          tbl.print ", force: true"
          tbl.puts " do |t|"

          # then dump all non-primary key columns
          column_specs = columns.map do |column|
            raise StandardError, "Unknown type '#{column.sql_type}' for column '#{column.name}'" unless @connection.valid_type?(column.type)
            next if column.name == pk
            @connection.column_spec(column, @types)
          end.compact

          # find all migration keys used in this table
          keys = @connection.migration_keys

          # figure out the lengths for each column based on above keys
          lengths = keys.map { |key|
            column_specs.map { |spec|
              spec[key] ? spec[key].length + 2 : 0
            }.max
          }

          # the string we're going to sprintf our values against, with standardized column widths
          format_string = lengths.map{ |len| "%-#{len}s" }

          # find the max length for the 'type' column, which is special
          type_length = column_specs.map{ |column| column[:type].length }.max

          # add column type definition to our format string
          format_string.unshift "    t.%-#{type_length}s "

          format_string *= ''

          column_specs.each do |colspec|
            values = keys.zip(lengths).map{ |key, len| colspec.key?(key) ? colspec[key] + ", " : " " * len }
            values.unshift colspec[:type]
            tbl.print((format_string % values).gsub(/,\s*$/, ''))
            tbl.puts
          end

          tbl.puts "  end"
          tbl.puts

          indexes(table, tbl)

          tbl.rewind
          stream.print tbl.read
        rescue => e
          stream.puts "# Could not dump table #{table.inspect} because of following #{e.class}"
          stream.puts "#   #{e.message}"
          stream.puts
        end

        stream
      end

    end
  end
end