// Copyright 2014 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com

#include "../../../include/fxcodec/fx_codec.h"
#include "codec_int.h"
CCodec_ModuleMgr::CCodec_ModuleMgr()
  : m_pBasicModule(new CCodec_BasicModule),
    m_pFaxModule(new CCodec_FaxModule),
    m_pJpegModule(new CCodec_JpegModule),
    m_pJpxModule(new CCodec_JpxModule),
    m_pJbig2Module(new CCodec_Jbig2Module),
    m_pIccModule(new CCodec_IccModule),
    m_pFlateModule(new CCodec_FlateModule) {
}
CCodec_ScanlineDecoder::CCodec_ScanlineDecoder()
{
    m_NextLine = -1;
    m_pDataCache = NULL;
    m_pLastScanline = NULL;
}
CCodec_ScanlineDecoder::~CCodec_ScanlineDecoder()
{
    if (m_pDataCache) {
        FX_Free(m_pDataCache);
    }
}
uint8_t* CCodec_ScanlineDecoder::GetScanline(int line)
{
    if (m_pDataCache && line < m_pDataCache->m_nCachedLines) {
        return &m_pDataCache->m_Data + line * m_Pitch;
    }
    if (m_NextLine == line + 1) {
        return m_pLastScanline;
    }
    if (m_NextLine < 0 || m_NextLine > line) {
        if (!v_Rewind()) {
            return NULL;
        }
        m_NextLine = 0;
    }
    while (m_NextLine < line) {
        ReadNextLine();
        m_NextLine ++;
    }
    m_pLastScanline = ReadNextLine();
    m_NextLine ++;
    return m_pLastScanline;
}
bool CCodec_ScanlineDecoder::SkipToScanline(int line, IFX_Pause* pPause)
{
    if (m_pDataCache && line < m_pDataCache->m_nCachedLines) {
        return false;
    }
    if (m_NextLine == line || m_NextLine == line + 1) {
        return false;
    }
    if (m_NextLine < 0 || m_NextLine > line) {
        v_Rewind();
        m_NextLine = 0;
    }
    m_pLastScanline = NULL;
    while (m_NextLine < line) {
        m_pLastScanline = ReadNextLine();
        m_NextLine ++;
        if (pPause && pPause->NeedToPauseNow()) {
            return true;
        }
    }
    return false;
}
uint8_t* CCodec_ScanlineDecoder::ReadNextLine()
{
    uint8_t* pLine = v_GetNextLine();
    if (pLine == NULL) {
        return NULL;
    }
    if (m_pDataCache && m_NextLine == m_pDataCache->m_nCachedLines) {
        FXSYS_memcpy(&m_pDataCache->m_Data + m_NextLine * m_Pitch, pLine, m_Pitch);
        m_pDataCache->m_nCachedLines ++;
    }
    return pLine;
}
void CCodec_ScanlineDecoder::DownScale(int dest_width, int dest_height)
{
    if (dest_width < 0) {
        dest_width = -dest_width;
    }
    if (dest_height < 0) {
        dest_height = -dest_height;
    }
    v_DownScale(dest_width, dest_height);
    if (m_pDataCache) {
        if (m_pDataCache->m_Height == m_OutputHeight && m_pDataCache->m_Width == m_OutputWidth) {
            return;
        }
        FX_Free(m_pDataCache);
        m_pDataCache = NULL;
    }
    m_pDataCache = (CCodec_ImageDataCache*)FX_TryAlloc(uint8_t, sizeof(CCodec_ImageDataCache) + m_Pitch * m_OutputHeight);
    if (m_pDataCache == NULL) {
        return;
    }
    m_pDataCache->m_Height = m_OutputHeight;
    m_pDataCache->m_Width = m_OutputWidth;
    m_pDataCache->m_nCachedLines = 0;
}
bool CCodec_BasicModule::RunLengthEncode(const uint8_t* src_buf, FX_DWORD src_size, uint8_t*& dest_buf,
        FX_DWORD& dest_size)
{
    return false;
}
extern "C" double FXstrtod(const char* nptr, char** endptr)
{
    double ret = 0.0;
    const char* ptr = nptr;
    const char* exp_ptr = NULL;
    int	e_number = 0,
        e_signal = 0,
        e_point = 0,
        is_negative = 0;
    int exp_ret = 0, exp_sig = 1,
        fra_ret = 0, fra_count = 0, fra_base = 1;
    if(nptr == NULL) {
        return 0.0;
    }
    for (;; ptr++) {
        if(!e_number && !e_point && (*ptr == '\t' || *ptr == ' ')) {
            continue;
        }
        if(*ptr >= '0' && *ptr <= '9') {
            if(!e_number) {
                e_number = 1;
            }
            if(!e_point) {
                ret *= 10;
                ret += (*ptr - '0');
            } else {
                fra_count++;
                fra_ret *= 10;
                fra_ret += (*ptr - '0');
            }
            continue;
        }
        if(!e_point && *ptr == '.') {
            e_point = 1;
            continue;
        }
        if(!e_number && !e_point && !e_signal) {
            switch(*ptr) {
                case '-':
                    is_negative = 1;
                case '+':
                    e_signal = 1;
                    continue;
            }
        }
        if(e_number && (*ptr == 'e' || *ptr == 'E')) {
#define EXPONENT_DETECT(ptr)	\
    for(;;ptr++){		\
        if(*ptr < '0' || *ptr > '9'){	\
            if(endptr)	*endptr = (char*)ptr;	\
            break;	\
        }else{		\
            exp_ret *= 10;	\
            exp_ret += (*ptr - '0');	\
            continue;		\
        }	\
    }
            exp_ptr = ptr++;
            if(*ptr == '+' || *ptr == '-') {
                exp_sig = (*ptr++ == '+') ? 1 : -1;
                if(*ptr < '0' || *ptr > '9') {
                    if(endptr)	{
                        *endptr = (char*)exp_ptr;
                    }
                    break;
                }
                EXPONENT_DETECT(ptr);
            } else if(*ptr >= '0' && *ptr <= '9') {
                EXPONENT_DETECT(ptr);
            } else {
                if(endptr)	{
                    *endptr = (char*)exp_ptr;
                }
                break;
            }
#undef EXPONENT_DETECT
            break;
        }
        if(ptr != nptr && !e_number) {
            if(endptr)	{
                *endptr = (char*)nptr;
            }
            break;
        }
        if(endptr)	{
            *endptr = (char*)ptr;
        }
        break;
    }
    while(fra_count--) {
        fra_base *= 10;
    }
    ret += (double)fra_ret / (double)fra_base;
    if(exp_sig == 1) {
        while(exp_ret--) {
            ret *= 10.0;
        }
    } else {
        while(exp_ret--) {
            ret /= 10.0;
        }
    }
    return is_negative ? -ret : ret;
}
bool CCodec_BasicModule::A85Encode(const uint8_t* src_buf, FX_DWORD src_size, uint8_t*& dest_buf,
                                      FX_DWORD& dest_size)
{
    return false;
}
class CCodec_RLScanlineDecoder : public CCodec_ScanlineDecoder
{
public:
    CCodec_RLScanlineDecoder();
    virtual ~CCodec_RLScanlineDecoder();
    bool				Create(const uint8_t* src_buf, FX_DWORD src_size, int width, int height, int nComps, int bpc);
    virtual void		v_DownScale(int dest_width, int dest_height) {}
    virtual bool		v_Rewind();
    virtual uint8_t*	v_GetNextLine();
    virtual FX_DWORD	GetSrcOffset()
    {
        return m_SrcOffset;
    }
protected:
    bool				CheckDestSize();
    void				GetNextOperator();
    void				UpdateOperator(uint8_t used_bytes);

    uint8_t*			m_pScanline;
    const uint8_t*			m_pSrcBuf;
    FX_DWORD			m_SrcSize;
    FX_DWORD			m_dwLineBytes;
    FX_DWORD			m_SrcOffset;
    bool				m_bEOD;
    uint8_t				m_Operator;
};
CCodec_RLScanlineDecoder::CCodec_RLScanlineDecoder()
    : m_pScanline(NULL)
    , m_pSrcBuf(NULL)
    , m_SrcSize(0)
    , m_dwLineBytes(0)
    , m_SrcOffset(0)
    , m_bEOD(false)
    , m_Operator(0)
{
}
CCodec_RLScanlineDecoder::~CCodec_RLScanlineDecoder()
{
    if (m_pScanline) {
        FX_Free(m_pScanline);
    }
}
bool CCodec_RLScanlineDecoder::CheckDestSize()
{
    FX_DWORD i = 0;
    FX_DWORD old_size = 0;
    FX_DWORD dest_size = 0;
    while (i < m_SrcSize) {
        if (m_pSrcBuf[i] < 128) {
            old_size = dest_size;
            dest_size += m_pSrcBuf[i] + 1;
            if (dest_size < old_size) {
                return false;
            }
            i += m_pSrcBuf[i] + 2;
        } else if (m_pSrcBuf[i] > 128) {
            old_size = dest_size;
            dest_size += 257 - m_pSrcBuf[i];
            if (dest_size < old_size) {
                return false;
            }
            i += 2;
        } else {
            break;
        }
    }
    if (((FX_DWORD)m_OrigWidth * m_nComps * m_bpc * m_OrigHeight + 7) / 8 > dest_size) {
        return false;
    }
    return true;
}
bool CCodec_RLScanlineDecoder::Create(const uint8_t* src_buf, FX_DWORD src_size, int width, int height, int nComps, int bpc)
{
    m_pSrcBuf = src_buf;
    m_SrcSize = src_size;
    m_OutputWidth = m_OrigWidth = width;
    m_OutputHeight = m_OrigHeight = height;
    m_nComps = nComps;
    m_bpc = bpc;
    m_bColorTransformed = false;
    m_DownScale = 1;
    m_Pitch = (width * nComps * bpc + 31) / 32 * 4;
    m_dwLineBytes = (width * nComps * bpc + 7) / 8;
    m_pScanline = FX_Alloc(uint8_t, m_Pitch);
    return CheckDestSize();
}
bool CCodec_RLScanlineDecoder::v_Rewind()
{
    FXSYS_memset(m_pScanline, 0, m_Pitch);
    m_SrcOffset = 0;
    m_bEOD = false;
    m_Operator = 0;
    return true;
}
uint8_t* CCodec_RLScanlineDecoder::v_GetNextLine()
{
    if (m_SrcOffset == 0) {
        GetNextOperator();
    } else {
        if (m_bEOD) {
            return NULL;
        }
    }
    FXSYS_memset(m_pScanline, 0, m_Pitch);
    FX_DWORD col_pos = 0;
    bool	eol = false;
    while (m_SrcOffset < m_SrcSize && !eol) {
        if (m_Operator < 128) {
            FX_DWORD copy_len = m_Operator + 1;
            if (col_pos + copy_len >= m_dwLineBytes) {
                copy_len = m_dwLineBytes - col_pos;
                eol = true;
            }
            if (copy_len >= m_SrcSize - m_SrcOffset) {
                copy_len = m_SrcSize - m_SrcOffset;
                m_bEOD = true;
            }
            FXSYS_memcpy(m_pScanline + col_pos, m_pSrcBuf + m_SrcOffset, copy_len);
            col_pos += copy_len;
            UpdateOperator((uint8_t)copy_len);
        } else if (m_Operator > 128) {
            int fill = 0;
            if (m_SrcOffset - 1 < m_SrcSize - 1) {
                fill = m_pSrcBuf[m_SrcOffset];
            }
            FX_DWORD duplicate_len = 257 - m_Operator;
            if (col_pos + duplicate_len >= m_dwLineBytes) {
                duplicate_len = m_dwLineBytes - col_pos;
                eol = true;
            }
            FXSYS_memset(m_pScanline + col_pos, fill, duplicate_len);
            col_pos += duplicate_len;
            UpdateOperator((uint8_t)duplicate_len);
        } else {
            m_bEOD = true;
            break;
        }
    }
    return m_pScanline;
}
void CCodec_RLScanlineDecoder::GetNextOperator()
{
    if (m_SrcOffset >= m_SrcSize) {
        m_Operator = 128;
        return;
    }
    m_Operator = m_pSrcBuf[m_SrcOffset];
    m_SrcOffset ++;
}
void CCodec_RLScanlineDecoder::UpdateOperator(uint8_t used_bytes)
{
    if (used_bytes == 0) {
        return;
    }
    if (m_Operator < 128) {
        FXSYS_assert((FX_DWORD)m_Operator + 1 >= used_bytes);
        if (used_bytes == m_Operator + 1) {
            m_SrcOffset += used_bytes;
            GetNextOperator();
            return;
        }
        m_Operator -= used_bytes;
        m_SrcOffset += used_bytes;
        if (m_SrcOffset >= m_SrcSize) {
            m_Operator = 128;
        }
        return;
    }
    uint8_t count = 257 - m_Operator;
    FXSYS_assert((FX_DWORD)count >= used_bytes);
    if (used_bytes == count) {
        m_SrcOffset ++;
        GetNextOperator();
        return;
    }
    count -= used_bytes;
    m_Operator = 257 - count;
}
ICodec_ScanlineDecoder* CCodec_BasicModule::CreateRunLengthDecoder(const uint8_t* src_buf, FX_DWORD src_size, int width, int height,
        int nComps, int bpc)
{
    CCodec_RLScanlineDecoder* pRLScanlineDecoder = new CCodec_RLScanlineDecoder;
    if (!pRLScanlineDecoder->Create(src_buf, src_size, width, height, nComps, bpc)) {
        delete pRLScanlineDecoder;
        return NULL;
    }
    return pRLScanlineDecoder;
}