#ifndef MS_RTC_RTP_CODECS_VP9_HPP
#define MS_RTC_RTP_CODECS_VP9_HPP

#include "common.hpp"
#include "RTC/RTP/Codecs/PayloadDescriptorHandler.hpp"
#include "RTC/RTP/Packet.hpp"
#include "RTC/SeqManager.hpp"

/* https://tools.ietf.org/html/draft-ietf-payload-vp9-06
 * VP9 Payload Descriptor

   Flexible mode (with the F bit below set to 1)
   =============================================

      0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+
     |I|P|L|F|B|E|V|-| (REQUIRED)
     +-+-+-+-+-+-+-+-+
I:   |M| PICTURE ID  | (REQUIRED)
     +-+-+-+-+-+-+-+-+
M:   | EXTENDED PID  | (RECOMMENDED)
     +-+-+-+-+-+-+-+-+
L:   | TID |U| SID |D| (CONDITIONALLY RECOMMENDED)
     +-+-+-+-+-+-+-+-+                             -\
P,F: | P_DIFF      |N| (CONDITIONALLY REQUIRED)    - up to 3 times
     +-+-+-+-+-+-+-+-+                             -/
V:   | SS            |
     | ..            |
     +-+-+-+-+-+-+-+-+

   Non-flexible mode (with the F bit below set to 0)
   =================================================

      0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+
     |I|P|L|F|B|E|V|-| (REQUIRED)
     +-+-+-+-+-+-+-+-+
I:   |M| PICTURE ID  | (RECOMMENDED)
     +-+-+-+-+-+-+-+-+
M:   | EXTENDED PID  | (RECOMMENDED)
     +-+-+-+-+-+-+-+-+
L:   | TID |U| SID |D| (CONDITIONALLY RECOMMENDED)
     +-+-+-+-+-+-+-+-+
     |   TL0PICIDX   | (CONDITIONALLY REQUIRED)
     +-+-+-+-+-+-+-+-+
V:   | SS            |
     | ..            |
     +-+-+-+-+-+-+-+-+
 */

namespace RTC
{
	namespace RTP
	{
		namespace Codecs
		{
			class VP9
			{
			public:
				struct PayloadDescriptor : public Codecs::PayloadDescriptor
				{
					/* Pure virtual methods inherited from Codecs::PayloadDescriptor. */
					~PayloadDescriptor() override = default;

					void Dump(int indentation = 0) const override;

					// Header.
					uint8_t i : 1; // I: Picture ID (PID) present.
					uint8_t p : 1; // P: Inter-picture predicted layer frame.
					uint8_t l : 1; // L: Layer indices present.
					uint8_t f : 1; // F: Flexible mode.
					uint8_t b : 1; // B: Start of a layer frame.
					uint8_t e : 1; // E: End of a layer frame.
					uint8_t v : 1; // V: Scalability structure (SS) data present.
					// Extension fields.
					uint16_t pictureId{ 0 };
					uint8_t slIndex{ 0 };
					uint8_t tlIndex{ 0 };
					uint8_t tl0PictureIndex;
					uint8_t switchingUpPoint : 1;
					uint8_t interLayerDependency : 1;
					// Parsed values.
					bool isKeyFrame{ false };
					bool hasPictureId{ false };
					bool hasOneBytePictureId{ false };
					bool hasTwoBytesPictureId{ false };
					bool hasSlIndex{ false };
					bool hasTl0PictureIndex{ false };
					bool hasTlIndex{ false };
				};

			public:
				static VP9::PayloadDescriptor* Parse(const uint8_t* data, size_t len);
				static void ProcessRtpPacket(RTP::Packet* packet);

			public:
				class EncodingContext : public Codecs::EncodingContext
				{
				public:
					explicit EncodingContext(Codecs::EncodingContext::Params& params)
					  : Codecs::EncodingContext(params)
					{
					}
					~EncodingContext() override = default;

					/* Pure virtual methods inherited from Codecs::EncodingContext. */
				public:
					void SyncRequired() override
					{
						this->syncRequired = true;
					}

				public:
					RTC::SeqManager<uint16_t, 15> pictureIdManager;
					bool syncRequired{ false };
				};

				class PayloadDescriptorHandler : public Codecs::PayloadDescriptorHandler
				{
				public:
					explicit PayloadDescriptorHandler(PayloadDescriptor* payloadDescriptor);
					~PayloadDescriptorHandler() override = default;

				public:
					void Dump(int indentation = 0) const override
					{
						this->payloadDescriptor->Dump(indentation);
					}
					bool Process(
					  Codecs::EncodingContext* encodingContext, RTP::Packet* packet, bool& marker) override;
					void RtpPacketChanged(RTP::Packet* packet) override {};
					std::unique_ptr<Codecs::PayloadDescriptor::Encoder> GetEncoder() const override
					{
						return nullptr;
					}
					void Encode(RTP::Packet* packet, Codecs::PayloadDescriptor::Encoder* encoder) override
					{
					}
					void Restore(RTP::Packet* packet) override
					{
					}
					uint8_t GetSpatialLayer() const override
					{
						return this->payloadDescriptor->hasSlIndex ? this->payloadDescriptor->slIndex : 0u;
					}
					uint8_t GetTemporalLayer() const override
					{
						return this->payloadDescriptor->hasTlIndex ? this->payloadDescriptor->tlIndex : 0u;
					}
					bool IsKeyFrame() const override
					{
						return this->payloadDescriptor->isKeyFrame;
					}

				private:
					std::unique_ptr<PayloadDescriptor> payloadDescriptor;
				};
			};
		} // namespace Codecs
	} // namespace RTP
} // namespace RTC

#endif