//----------------------------------------------------------------------------
//
// TSDuck - The MPEG Transport Stream Toolkit
// Copyright (c) 2005-2025, Thierry Lelegard
// BSD-2-Clause license, see LICENSE.txt file or https://tsduck.io/license
//
//----------------------------------------------------------------------------
//!
//!  @file
//!  This class analyzes MPE from TS packets
//!
//----------------------------------------------------------------------------

#pragma once
#include "tsAbstractDemux.h"
#include "tsSectionDemux.h"
#include "tsPMT.h"
#include "tsINT.h"
#include "tsMPEHandlerInterface.h"

namespace ts {
    //!
    //! This class extracts MPE (Multi-Protocol Encapsulation) datagrams from TS packets.
    //! @ingroup libtsduck mpeg
    //!
    //! The signalization is analyzed. MPE components in services are signaled to a handler.
    //! The application decides which MPE PID's should be demuxed. These PID's can
    //! be selected from the beginning or in response to the discovery of MPE PID's.
    //!
    class TSDUCKDLL MPEDemux:
        public AbstractDemux,
        private TableHandlerInterface,
        private SectionHandlerInterface
    {
        TS_NOBUILD_NOCOPY(MPEDemux);
    public:
        //!
        //! Explicit reference to superclass.
        //!
        using SuperClass = AbstractDemux;

        //!
        //! Constructor.
        //! @param [in,out] duck TSDuck execution context. The reference is kept inside the demux.
        //! @param [in] mpe_handler The object to invoke when MPE information is found.
        //! @param [in] pid_filter The set of MPE PID's to demux.
        //!
        explicit MPEDemux(DuckContext& duck, MPEHandlerInterface* mpe_handler = nullptr, const PIDSet& pid_filter = NoPID());

        //!
        //! Destructor.
        //!
        virtual ~MPEDemux() override;

        // Inherited methods from AbstractDemux.
        virtual void feedPacket(const TSPacket& pkt) override;
        virtual void addPID(PID pid) override;
        virtual void addPIDs(const PIDSet& pids) override;
        virtual void removePID(PID pid) override;

        //!
        //! Replace the MPE handler.
        //! @param [in] h The new handler.
        //!
        void setHandler(MPEHandlerInterface* h)
        {
            _handler = h;
        }

    protected:
        // Inherited methods from AbstractDemux.
        virtual void immediateReset() override;

    private:
        // Inherited methods from interfaces.
        virtual void handleTable(SectionDemux&, const BinaryTable&) override;
        virtual void handleSection(SectionDemux& demux, const Section& section) override;

        // Keep a map of all PMT's per service id.
        using PMTPtr = std::shared_ptr<PMT>;
        using PMTMap = std::map<uint16_t, PMTPtr>;

        // We record here all MPE PID's from the IP/MAC Notification Table (INT).
        // In the INT, an MPE PID is defined by a 16-bit service id and an 8-bit component tag.
        // We pack the two values in 32-bit.
        static uint32_t ServiceTagToInt(uint16_t service_id, uint8_t component_tag)
        {
            return (uint32_t(service_id) << 16) | component_tag;
        }

        // Process a PMT.
        void processPMT(const PMT& pmt);

        // Process an INT (IP/MAC Notification Table).
        void processINT(const INT& imnt);

        // Process a descriptor list in the INT.
        void processINTDescriptors(const DescriptorList& descs);

        // Process the discovery of a new MPE PID.
        void processMPEDiscovery(const PMT& pmt, PID pid);

        // Private members:
        MPEHandlerInterface* _handler = nullptr; // Application-defined handler
        SectionDemux         _psi_demux;         // Demux for PSI parsing.
        uint16_t             _ts_id = 0;         // Current transport stream id.
        PMTMap               _pmts {};           // Map of all PMT's in the TS.
        PIDSet               _new_pids {};       // New MPE PID's which where signalled to the application.
        std::set<uint32_t>   _int_tags {};       // Set of service_id / component_tag from the INT.
    };
}
