#ifndef __TRACYFILEWRITE_HPP__
#define __TRACYFILEWRITE_HPP__

#ifdef _MSC_VER
#  pragma warning( disable: 4267 )  // conversion from don't care to whatever, possible loss of data 
#endif

#include <algorithm>
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <utility>

#include "TracyFileHeader.hpp"
#include "../public/common/tracy_lz4.hpp"
#include "../public/common/tracy_lz4hc.hpp"
#include "../public/common/TracyForceInline.hpp"
#include "../zstd/zstd.h"

namespace tracy
{

constexpr size_t FileBufSize = 64 * 1024;
constexpr size_t FileBoundSize = std::max( LZ4_COMPRESSBOUND( FileBufSize ), ZSTD_COMPRESSBOUND( FileBufSize ) );

enum class FileCompression
{
    Fast,
    Slow,
    Extreme,
    Zstd
};

class WriteStream
{
public:
    WriteStream( FileCompression comp, int level )
        : m_stream( nullptr )
        , m_streamHC( nullptr )
        , m_streamZstd( nullptr )
        , m_buf( m_bufData[0] )
        , m_second( m_bufData[1] )
    {
        switch( comp )
        {
        case FileCompression::Fast:
            m_stream = LZ4_createStream();
            break;
        case FileCompression::Slow:
            m_streamHC = LZ4_createStreamHC();
            break;
        case FileCompression::Extreme:
            m_streamHC = LZ4_createStreamHC();
            LZ4_resetStreamHC( m_streamHC, LZ4HC_CLEVEL_MAX );
            break;
        case FileCompression::Zstd:
            m_streamZstd = ZSTD_createCStream();
            ZSTD_CCtx_setParameter( m_streamZstd, ZSTD_c_compressionLevel, level );
            ZSTD_CCtx_setParameter( m_streamZstd, ZSTD_c_contentSizeFlag, 0 );
            break;
        default:
            assert( false );
            break;
        }
    }

    ~WriteStream()
    {
        if( m_stream ) LZ4_freeStream( m_stream );
        if( m_streamHC ) LZ4_freeStreamHC( m_streamHC );
        if( m_streamZstd ) ZSTD_freeCStream( m_streamZstd );
    }

    char* GetBuffer() { return m_buf; }

    const char* Compress( uint32_t& sz )
    {
        if( m_stream )
        {
            sz = LZ4_compress_fast_continue( m_stream, m_buf, m_compressed, sz, FileBoundSize, 1 );
        }
        else if( m_streamZstd )
        {
            ZSTD_outBuffer out = { m_compressed, FileBoundSize, 0 };
            ZSTD_inBuffer in = { m_buf, sz, 0 };
            const auto ret = ZSTD_compressStream2( m_streamZstd, &out, &in, ZSTD_e_flush );
            assert( ret == 0 );
            sz = out.pos;
        }
        else
        {
            sz = LZ4_compress_HC_continue( m_streamHC, m_buf, m_compressed, sz, FileBoundSize );
        }

        std::swap( m_buf, m_second );
        return m_compressed;
    }

private:
    LZ4_stream_t* m_stream;
    LZ4_streamHC_t* m_streamHC;
    ZSTD_CStream* m_streamZstd;

    char m_bufData[2][FileBufSize];
    char* m_buf;
    char* m_second;

    char m_compressed[FileBoundSize];
};

class FileWrite
{
public:
    static FileWrite* Open( const char* fn, FileCompression comp = FileCompression::Fast, int level = 1 )
    {
        auto f = fopen( fn, "wb" );
        return f ? new FileWrite( f, comp, level ) : nullptr;
    }

    ~FileWrite()
    {
        Finish();
        fclose( m_file );
    }

    void Finish()
    {
        if( m_offset > 0 ) WriteBlock();
    }

    tracy_force_inline void Write( const void* ptr, size_t size )
    {
        if( m_offset + size <= FileBufSize )
        {
            WriteSmall( ptr, size );
        }
        else
        {
            WriteBig( ptr, size );
        }
    }

    std::pair<size_t, size_t> GetCompressionStatistics() const { return std::make_pair( m_srcBytes, m_dstBytes ); }

private:
    FileWrite( FILE* f, FileCompression comp, int level )
        : m_stream( comp, level )
        , m_file( f )
        , m_buf( m_stream.GetBuffer() )
        , m_offset( 0 )
        , m_srcBytes( 0 )
        , m_dstBytes( 0 )
    {
        if( comp == FileCompression::Zstd )
        {
            fwrite( ZstdHeader, 1, sizeof( ZstdHeader ), m_file );
        }
        else
        {
            fwrite( Lz4Header, 1, sizeof( Lz4Header ), m_file );
        }
    }

    tracy_force_inline void WriteSmall( const void* ptr, size_t size )
    {
        memcpy( m_buf + m_offset, ptr, size );
        m_offset += size;
    }

    void WriteBig( const void* ptr, size_t size )
    {
        auto src = (const char*)ptr;
        while( size > 0 )
        {
            const auto sz = std::min( size, FileBufSize - m_offset );
            memcpy( m_buf + m_offset, src, sz );
            m_offset += sz;
            src += sz;
            size -= sz;

            if( m_offset == FileBufSize )
            {
                WriteBlock();
            }
        }
    }

    void WriteBlock()
    {
        uint32_t sz = m_offset;
        m_srcBytes += m_offset;
        auto block = m_stream.Compress( sz );
        m_dstBytes += sz;

        fwrite( &sz, 1, sizeof( sz ), m_file );
        fwrite( block, 1, sz, m_file );

        m_offset = 0;
        m_buf = m_stream.GetBuffer();
    }

    WriteStream m_stream;
    FILE* m_file;
    char* m_buf;
    size_t m_offset;
    size_t m_srcBytes;
    size_t m_dstBytes;
};

}

#endif