/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/

#pragma once

#include <AzNetworking/Serialization/ISerializer.h>
#include <AzNetworking/Serialization/AbstractValue.h>
#include <AzNetworking/Serialization/NetworkInputSerializer.h>
#include <AzNetworking/Serialization/NetworkOutputSerializer.h>
#include <AzNetworking/DataStructures/FixedSizeVectorBitset.h>
#include <AzNetworking/DataStructures/ByteBuffer.h>
#include <AzCore/Utils/TypeHash.h>
#include <AzCore/std/containers/unordered_map.h>

namespace AzNetworking
{
    //! SerializerDelta
    //! Encodes information used by DeltaSerializer to create and apply serialization deltas
    class SerializerDelta
    {
    public:

        SerializerDelta();

        uint32_t GetNumDirtyBits() const;
        bool GetDirtyBit(uint32_t index) const;
        bool InsertDirtyBit(bool dirtyBit);

        uint8_t* GetBufferPtr();
        uint32_t GetBufferSize() const;
        uint32_t GetBufferCapacity() const;

        void SetBufferSize(uint32_t size);

        bool Serialize(ISerializer& serializer);

    private:

        FixedSizeVectorBitset<255> m_dirtyBits;
        ByteBuffer<1024> m_deltaBytes;
    };

    //! A serializer that is used to produce a SerializerDelta between two objects.
    //! This delta can be reapplied to the same base object to reconstruct the second object using 
    //! the DeltaSerializerApply serializer
    //! NOTE: The objects serialized must have a consistent serialization footprint i.e. no changes in branches during serialization
    class DeltaSerializerCreate
        : public ISerializer
    {
    public:

        DeltaSerializerCreate(SerializerDelta& delta);
        ~DeltaSerializerCreate();

        template <typename TYPE>
        bool CreateDelta(TYPE& base, TYPE& current);

        // ISerializer interfaces
        SerializerMode GetSerializerMode() const override;
        bool Serialize(    bool& value, const char* name) override;
        bool Serialize(    char& value, const char* name,     char minValue,     char maxValue) override;
        bool Serialize(  int8_t& value, const char* name,   int8_t minValue,   int8_t maxValue) override;
        bool Serialize( int16_t& value, const char* name,  int16_t minValue,  int16_t maxValue) override;
        bool Serialize( int32_t& value, const char* name,  int32_t minValue,  int32_t maxValue) override;
        bool Serialize( int64_t& value, const char* name,  int64_t minValue,  int64_t maxValue) override;
        bool Serialize( uint8_t& value, const char* name,  uint8_t minValue,  uint8_t maxValue) override;
        bool Serialize(uint16_t& value, const char* name, uint16_t minValue, uint16_t maxValue) override;
        bool Serialize(uint32_t& value, const char* name, uint32_t minValue, uint32_t maxValue) override;
        bool Serialize(uint64_t& value, const char* name, uint64_t minValue, uint64_t maxValue) override;
        bool Serialize(   float& value, const char* name,    float minValue,    float maxValue) override;
        bool Serialize(  double& value, const char* name,   double minValue,   double maxValue) override;
        bool SerializeBytes(uint8_t* buffer, uint32_t bufferCapacity, bool isString, uint32_t& outSize, const char* name) override;
        bool BeginObject(const char *name, const char* typeName) override;
        bool EndObject(const char *name, const char* typeName) override;

        const uint8_t* GetBuffer() const override;
        uint32_t GetCapacity() const override;
        uint32_t GetSize() const override;
        void ClearTrackedChangesFlag() override {}
        bool GetTrackedChangesFlag() const override { return false; }
        // ISerializer interfaces

    private:

        DeltaSerializerCreate(const DeltaSerializerCreate&) = delete;
        DeltaSerializerCreate& operator=(const DeltaSerializerCreate&) = delete;

        AZStd::string GetNextObjectName(const char* name);

        template <typename T>
        bool SerializeHelper(T& value, uint32_t bufferCapacity, bool isString, uint32_t& outSize, const char* name);

        template <typename T>
        bool SerializeHelperImpl(T& value, uint32_t, bool, uint32_t&, const char* name);
        bool SerializeHelperImpl(uint8_t* buffer, uint32_t bufferCapacity, bool isString, uint32_t& outSize, const char* name);

    private:

        SerializerDelta& m_delta;

        bool m_gatheringRecords = false;
        uint32_t m_objectCounter = 0;
        AZStd::string m_namePrefix;
        AZStd::vector<size_t> m_nameLengthStack;
        AZStd::unordered_map<AZ::HashValue32, AbstractValue::BaseValue*> m_records;
        NetworkInputSerializer m_dataSerializer;
    };

    //! A serializer that is used to apply a SerializerDelta to a base object in order to reconstruct the second object.
    //! NOTE: The objects serialized must have a consistent serialization footprint i.e. no changes in branches during serialization
    class DeltaSerializerApply
        : public ISerializer
    {
    public:

        DeltaSerializerApply(SerializerDelta& delta);

        template <typename TYPE>
        bool ApplyDelta(TYPE& output);

        // ISerializer interfaces
        SerializerMode GetSerializerMode() const override;
        bool Serialize(    bool& value, const char* name) override;
        bool Serialize(    char& value, const char* name,     char minValue,     char maxValue) override;
        bool Serialize(  int8_t& value, const char* name,   int8_t minValue,   int8_t maxValue) override;
        bool Serialize( int16_t& value, const char* name,  int16_t minValue,  int16_t maxValue) override;
        bool Serialize( int32_t& value, const char* name,  int32_t minValue,  int32_t maxValue) override;
        bool Serialize( int64_t& value, const char* name,  int64_t minValue,  int64_t maxValue) override;
        bool Serialize( uint8_t& value, const char* name,  uint8_t minValue,  uint8_t maxValue) override;
        bool Serialize(uint16_t& value, const char* name, uint16_t minValue, uint16_t maxValue) override;
        bool Serialize(uint32_t& value, const char* name, uint32_t minValue, uint32_t maxValue) override;
        bool Serialize(uint64_t& value, const char* name, uint64_t minValue, uint64_t maxValue) override;
        bool Serialize(   float& value, const char* name,    float minValue,    float maxValue) override;
        bool Serialize(  double& value, const char* name,   double minValue,   double maxValue) override;
        bool SerializeBytes(uint8_t* buffer, uint32_t bufferCapacity, bool isString, uint32_t& outSize, const char* name) override;
        bool BeginObject(const char *name, const char* typeName) override;
        bool EndObject(const char *name, const char* typeName) override;

        const uint8_t* GetBuffer() const override;
        uint32_t GetCapacity() const override;
        uint32_t GetSize() const override;
        void ClearTrackedChangesFlag() override {}
        bool GetTrackedChangesFlag() const override { return false; }
        // ISerializer interfaces

    private:
 
        DeltaSerializerApply(const DeltaSerializerApply&) = delete;
        DeltaSerializerApply& operator=(const DeltaSerializerApply&) = delete;

        template <typename T>
        bool SerializeHelper(T& value, uint32_t bufferCapacity, bool isString, uint32_t& outSize, const char* name);

        template <typename T>
        bool SerializeHelperImpl(T& value, uint32_t, bool, uint32_t&, const char* name);
        bool SerializeHelperImpl(uint8_t* buffer, uint32_t bufferCapacity, bool isString, uint32_t& outSize, const char* name);

    private:

        SerializerDelta& m_delta;
        uint32_t m_nextDirtyBit = 0;
        NetworkOutputSerializer m_dataSerializer;
    };
}

#include <AzNetworking/Serialization/DeltaSerializer.inl>