#ifndef __PDU_H
#define __PDU_H


#include <stdint.h>

namespace Tins {
    
    class PDU {
    public:
        PDU(uint32_t flag, PDU *next_pdu = 0);
        virtual ~PDU();
        
        /* This PDU's header size only. */
        virtual uint32_t header_size() const = 0;
        /* This PDU's trailer size only. Defaults to 0. */
        virtual uint32_t trailer_size() const { return 0; }
        /* The size of the whole chain of PDUs, including this one. */
        inline uint32_t size() const;
        inline uint32_t flag() const { return _flag; }
        inline const PDU *inner_pdu() const { return _inner_pdu; }
        
        void flag(uint32_t new_flag);
        /* When setting a new inner_pdu, the instance takes
         * ownership of the object, therefore deleting it when
         * it's no longer required. */
        void inner_pdu(PDU *next_pdu);
        
        /* Serializes the whole chain of PDU's, including this one. */
        uint8_t *serialize();
        
        /* Serialize this PDU storing the result in buffer. */
        void serialize(uint8_t *buffer, uint32_t total_sz);
    protected:
        /* Each PDU's own implementation of serialization. */
        virtual void write_serialization(uint8_t *buffer, uint32_t total_sz) = 0;
    private:
        uint32_t _flag;
        PDU *_inner_pdu;
    };
};

#endif