#ifndef MS_RTC_RTP_CODECS_VP8_HPP
#define MS_RTC_RTP_CODECS_VP8_HPP

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

/* RFC 7741
 * VP8 Payload Descriptor

  Single octet PictureID (M = 0)        Dual octet PictureID (M = 1)
  ==============================        ============================

      0 1 2 3 4 5 6 7                       0 1 2 3 4 5 6 7
     +-+-+-+-+-+-+-+-+                     +-+-+-+-+-+-+-+-+
     |X|R|N|S|R| PID | (REQUIRED)          |X|R|N|S|R| PID | (REQUIRED)
     +-+-+-+-+-+-+-+-+                     +-+-+-+-+-+-+-+-+
X:   |I|L|T|K| RSV   | (OPTIONAL)       X: |I|L|T|K| RSV   | (OPTIONAL)
     +-+-+-+-+-+-+-+-+                     +-+-+-+-+-+-+-+-+
I:   |M| PictureID   | (OPTIONAL)       I: |M| PictureID   | (OPTIONAL)
     +-+-+-+-+-+-+-+-+                     +-+-+-+-+-+-+-+-+
L:   |   TL0PICIDX   | (OPTIONAL)          |   PictureID   |
     +-+-+-+-+-+-+-+-+                     +-+-+-+-+-+-+-+-+
T/K: |TID|Y| KEYIDX  | (OPTIONAL)       L: |   TL0PICIDX   | (OPTIONAL)
     +-+-+-+-+-+-+-+-+                     +-+-+-+-+-+-+-+-+
                                      T/K: |TID|Y| KEYIDX  | (OPTIONAL)
                                           +-+-+-+-+-+-+-+-+
 */

namespace RTC
{
	namespace RTP
	{
		namespace Codecs
		{
			class VP8
			{
			public:
				struct PayloadDescriptor : public Codecs::PayloadDescriptor
				{
					struct EncodingData
					{
						uint16_t pictureId;
						uint8_t tl0PictureIndex;
					};

					struct Encoder : public Codecs::PayloadDescriptor::Encoder
					{
						~Encoder() override = default;
						explicit Encoder(EncodingData encodingData) : encodingData(encodingData)
						{
						}
						void Encode(uint8_t* data, const VP8::PayloadDescriptor* payloadDescriptor) const;

						EncodingData encodingData;
					};

					/* Pure virtual methods inherited from Codecs::PayloadDescriptor. */
					~PayloadDescriptor() override = default;

					void Dump(int indentation = 0) const override;
					// Rewrite the buffer with the given pictureId and tl0PictureIndex values.
					void Encode(uint8_t* data, uint16_t pictureId, uint8_t tl0PictureIndex) const;
					void Encode(uint8_t* data) const;
					void Restore(uint8_t* data) const;
					std::unique_ptr<Codecs::PayloadDescriptor::Encoder> GetEncoder() const
					{
						if (this->encoder.has_value())
						{
							return std::make_unique<Encoder>(this->encoder.value());
						}
						else
						{
							return nullptr;
						}
					}

					void CreateEncoder(EncodingData encodingData)
					{
						this->encoder = Encoder(encodingData);
					}

					// Mandatory fields.
					uint8_t extended : 1;
					uint8_t nonReference : 1;
					uint8_t start : 1;
					uint8_t partitionIndex : 4;
					// Optional field flags.
					uint8_t i : 1; // PictureID present.
					uint8_t l : 1; // TL0PICIDX present.
					uint8_t t : 1; // TID present.
					uint8_t k : 1; // KEYIDX present.
					// Optional fields.
					uint16_t pictureId;
					uint8_t tl0PictureIndex;
					uint8_t tlIndex : 2;
					uint8_t y : 1;
					uint8_t keyIndex : 5;
					// Parsed values.
					bool isKeyFrame{ false };
					bool hasPictureId{ false };
					bool hasOneBytePictureId{ false };
					bool hasTwoBytesPictureId{ false };
					bool hasTl0PictureIndex{ false };
					bool hasTlIndex{ false };

					std::optional<Encoder> encoder{ std::nullopt };
				};

			public:
				static VP8::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;
					RTC::SeqManager<uint8_t> tl0PictureIndexManager;
					bool syncRequired{ false };
				};

			public:
				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 this->payloadDescriptor->GetEncoder();
					}
					void Encode(RTP::Packet* packet, Codecs::PayloadDescriptor::Encoder* encoder) override;
					void Restore(RTP::Packet* packet) override;
					uint8_t GetSpatialLayer() const override
					{
						return 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<VP8::PayloadDescriptor> payloadDescriptor;
				};
			};
		} // namespace Codecs
	} // namespace RTP
} // namespace RTC

#endif