thomis/db_meta

module DbMeta
  module Oracle
    class Table < Base
      register_type("TABLE")

      attr_reader :columns, :temporary, :cache, :iot_type, :duration

      def initialize(args = {})
        super

        @comment = nil # table level comment

        @comment = nil
        @columns = []
        @indexes = []
        @constraints = []
        @triggers = []
      end

      def add_object(object)
        @indexes << object if object.type == "INDEX"
        @constraints << object if object.type == "CONSTRAINT"
        @triggers << object if object.type == "TRIGGER"
      end

      def fetch
        @comment = Comment.find(type: "TABLE", name: @name)
        @columns = Column.all(object_name: @name)

        connection = Connection.instance.get
        cursor = connection.exec("select temporary, cache, iot_type, duration from user_tables where table_name = '#{@name}'")
        while (row = cursor.fetch)
          @temporary = (row[0].to_s.strip == "Y") ? "GLOBAL TEMPORARY" : nil
          @cache = (row[1].to_s.strip == "Y") ? "CACHE" : "NOCACHE"
          @iot_type = row[2].to_s
          @duration = row[3].to_s
        end
        cursor.close
      rescue
        connection.logoff
      end

      def extract(args = {})
        buffer = [block(@name)]
        buffer << "CREATE#{" #{@temporary}" if @temporary} TABLE #{@name}"
        buffer << "("

        # add columns
        @columns.each_with_index do |c, index|
          buffer << "  #{c.extract}#{"," if index + 1 < @columns.size}"
        end

        # Primary key definition must be here for IOT tables
        if @iot_type == "IOT"
          constraint = @constraints.find { |c| c.constraint_type == "PRIMARY KEY" }
          buffer[-1] += ","
          buffer << "  CONSTRAINT #{constraint.name}"
          buffer << "  PRIMARY KEY (#{constraint.columns.join(", ")})"
          buffer << "  ENABLE VALIDATE"
        end

        buffer << ")"
        buffer << translate_duration if @duration.size > 0
        buffer << @cache if @temporary
        buffer << "ORGANIZATION INDEX" if @iot_type == "IOT"
        buffer[-1] += ";"
        buffer << nil

        # table comments
        if @comment
          buffer << "COMMENT ON TABLE #{@name} IS '#{@comment.text("'", "''")}';"
        end

        # table column comments
        @columns.each do |column|
          next if column.comment.nil? || column.comment.size == 0
          buffer << "COMMENT ON COLUMN #{@name}.#{column.name} IS '#{column.comment.gsub("'", "''")}';"
        end

        # indexes
        if @indexes.size > 0
          buffer << block("Indexes", 40)
          @indexes.each do |index|
            line = ""
            line << "-- System Index: " if index.system_object? || @iot_type == "IOT"
            line << index.extract(args)
            buffer << line
          end
          buffer << nil
        end

        # constaints
        if @constraints.size > 0
          buffer << block("Constraints", 40)
          @constraints.sort_by { |c| [Constraint.sort_value(c.constraint_type), c.name] }.each do |constraint|
            buffer << constraint.extract(args.merge({comment: (constraint.constraint_type == "FOREIGN KEY")}))
          end
        end

        # triggers
        if @triggers.size > 0
          buffer << block("Triggers", 40)
          buffer << @triggers.map { |o| o.extract(args) }.join("\n")
          buffer << nil
        end

        buffer.join("\n")
      end

      def ddl_drop
        "DROP #{@type} #{@name} CASCADE CONSTRAINTS PURGE;"
      end

      def get_core_data_where_clause(id = 1000000)
        buffer = []
        @constraints.each do |constraint|
          if constraint.constraint_type == "PRIMARY KEY"
            constraint.columns.each do |column|
              buffer << "#{column} < #{id}"
            end
          end
        end

        return "" if buffer.size == 0

        "where " + buffer.join(" and ")
      end

      private

      def translate_duration
        case @duration
        when "SYS$TRANSACTION"
          "ON COMMIT DELETE ROWS"
        when "SYS$SESSION"
          "ON COMMIT PRESERVE ROWS"
        else
          "-- table duration definition [#{@duration}] is unknown and may need code adaptations"
        end
      end
    end
  end
end