/******************************************************************************
 *
 * Project:  VICAR Driver; JPL/MIPL VICAR Format
 * Purpose:  Implementation of VICARKeywordHandler - a class to read
 *           keyword data from VICAR data products.
 * Author:   Sebastian Walter <sebastian dot walter at fu-berlin dot de>
 *
 * NOTE: This driver code is loosely based on the ISIS and PDS drivers.
 * It is not intended to diminish the contribution of the authors.
 ******************************************************************************
 * Copyright (c) 2014, Sebastian Walter <sebastian dot walter at fu-berlin dot
 *de>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "cpl_string.h"
#include "vicarkeywordhandler.h"
#include "vicardataset.h"

#include <algorithm>
#include <limits>

/************************************************************************/
/* ==================================================================== */
/*                          VICARKeywordHandler                         */
/* ==================================================================== */
/************************************************************************/

/************************************************************************/
/*                         VICARKeywordHandler()                        */
/************************************************************************/

VICARKeywordHandler::VICARKeywordHandler()
    : papszKeywordList(nullptr), pszHeaderNext(nullptr)
{
    oJSon.Deinit();
}

/************************************************************************/
/*                        ~VICARKeywordHandler()                        */
/************************************************************************/

VICARKeywordHandler::~VICARKeywordHandler()

{
    CSLDestroy(papszKeywordList);
}

/************************************************************************/
/*                               Ingest()                               */
/************************************************************************/

bool VICARKeywordHandler::Ingest(VSILFILE *fp, const GByte *pabyHeader)

{
    /* -------------------------------------------------------------------- */
    /*      Read in label at beginning of file.                             */
    /* -------------------------------------------------------------------- */
    if (VSIFSeekL(fp, 0, SEEK_SET) != 0)
        return false;

    // Find LBLSIZE Entry
    const char *pszLBLSIZE =
        strstr(reinterpret_cast<const char *>(pabyHeader), "LBLSIZE");
    if (!pszLBLSIZE)
        return false;

    const char *pch1 = strchr(pszLBLSIZE, '=');
    if (pch1 == nullptr)
        return false;
    ++pch1;
    while (isspace(static_cast<unsigned char>(*pch1)))
        ++pch1;
    const char *pch2 = strchr(pch1, ' ');
    if (pch2 == nullptr)
        return false;

    std::string keyval;
    keyval.assign(pch1, static_cast<size_t>(pch2 - pch1));
    int LabelSize = atoi(keyval.c_str());
    if (LabelSize <= 0 || LabelSize > 10 * 1024 * 124)
        return false;

    char *pszChunk = reinterpret_cast<char *>(VSIMalloc(LabelSize + 1));
    if (pszChunk == nullptr)
        return false;
    int nBytesRead = static_cast<int>(VSIFReadL(pszChunk, 1, LabelSize, fp));
    pszChunk[nBytesRead] = '\0';

    osHeaderText += pszChunk;
    VSIFree(pszChunk);
    pszHeaderNext = osHeaderText.c_str();

    /* -------------------------------------------------------------------- */
    /*      Process name/value pairs                                        */
    /* -------------------------------------------------------------------- */
    if (!Parse())
        return false;

    /* -------------------------------------------------------------------- */
    /*      Now check for the Vicar End-of-Dataset Label...                 */
    /* -------------------------------------------------------------------- */
    const char *pszResult = CSLFetchNameValueDef(papszKeywordList, "EOL", "0");
    if (!EQUAL(pszResult, "1"))
        return true;

    /* -------------------------------------------------------------------- */
    /*      There is a EOL!   e.G.  h4231_0000.nd4.06                       */
    /* -------------------------------------------------------------------- */

    GUInt64 nPixelOffset;
    GUInt64 nLineOffset;
    GUInt64 nBandOffset;
    GUInt64 nImageOffsetWithoutNBB;
    GUInt64 nNBB;
    GUInt64 nImageSize;
    if (!VICARDataset::GetSpacings(*this, nPixelOffset, nLineOffset,
                                   nBandOffset, nImageOffsetWithoutNBB, nNBB,
                                   nImageSize))
        return false;

    // Position of EOL in case of compressed data
    const vsi_l_offset nEOCI1 = static_cast<vsi_l_offset>(
        CPLAtoGIntBig(CSLFetchNameValueDef(papszKeywordList, "EOCI1", "0")));
    const vsi_l_offset nEOCI2 = static_cast<vsi_l_offset>(
        CPLAtoGIntBig(CSLFetchNameValueDef(papszKeywordList, "EOCI2", "0")));
    const vsi_l_offset nEOCI = (nEOCI2 << 32) | nEOCI1;

    if (nImageOffsetWithoutNBB >
        std::numeric_limits<GUInt64>::max() - nImageSize)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Invalid label values");
        return false;
    }

    const vsi_l_offset nStartEOL =
        nEOCI ? nEOCI : nImageOffsetWithoutNBB + nImageSize;

    if (VSIFSeekL(fp, nStartEOL, SEEK_SET) != 0)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Error seeking to EOL");
        return false;
    }
    char *pszEOLHeader = static_cast<char *>(VSIMalloc(32));
    if (pszEOLHeader == nullptr)
        return false;
    nBytesRead = static_cast<int>(VSIFReadL(pszEOLHeader, 1, 31, fp));
    pszEOLHeader[nBytesRead] = '\0';
    pszLBLSIZE = strstr(pszEOLHeader, "LBLSIZE");
    if (!pszLBLSIZE)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "END-OF-DATASET LABEL NOT FOUND!");
        VSIFree(pszEOLHeader);
        return false;
    }
    pch1 = strchr(pszLBLSIZE, '=');
    if (pch1 == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "END-OF-DATASET LABEL NOT FOUND!");
        VSIFree(pszEOLHeader);
        return false;
    }
    ++pch1;
    while (isspace(static_cast<unsigned char>(*pch1)))
        ++pch1;
    pch2 = strchr(pch1, ' ');
    if (pch2 == nullptr)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "END-OF-DATASET LABEL NOT FOUND!");
        VSIFree(pszEOLHeader);
        return false;
    }
    keyval.assign(pch1, static_cast<size_t>(pch2 - pch1));
    const auto nSkipEOLLBLSize = static_cast<size_t>(pch2 - pszEOLHeader);
    VSIFree(pszEOLHeader);

    int EOLabelSize = atoi(keyval.c_str());
    if (EOLabelSize <= 0 ||
        static_cast<size_t>(EOLabelSize) <= nSkipEOLLBLSize ||
        EOLabelSize > 100 * 1024 * 1024)
        return false;
    if (VSIFSeekL(fp, nStartEOL, SEEK_SET) != 0)
    {
        CPLError(CE_Failure, CPLE_AppDefined, "Error seeking to EOL");
        return false;
    }
    char *pszChunkEOL = (char *)VSIMalloc(EOLabelSize + 1);
    if (pszChunkEOL == nullptr)
        return false;
    nBytesRead = static_cast<int>(VSIFReadL(pszChunkEOL, 1, EOLabelSize, fp));
    pszChunkEOL[nBytesRead] = '\0';
    osHeaderText += pszChunkEOL + nSkipEOLLBLSize;
    VSIFree(pszChunkEOL);
    CSLDestroy(papszKeywordList);
    papszKeywordList = nullptr;
    pszHeaderNext = osHeaderText.c_str();
    return Parse();
}

/************************************************************************/
/*                               Parse()                                */
/************************************************************************/

#define SYNTHETIC_END_MARKER "__END__"

bool VICARKeywordHandler::Parse()
{
    CPLString osName, osValue, osGroupName;
    CPLJSONObject oProperties;
    CPLJSONObject oTasks;
    CPLJSONObject oCurObj;
    bool bHasProperties = false;
    bool bHasTasks = false;

    oJSon = CPLJSONObject();
    for (; true;)
    {
        if (!ReadPair(osName, osValue, osGroupName.empty() ? oJSon : oCurObj))
            return false;

        if (EQUAL(osName, SYNTHETIC_END_MARKER))
            break;

        if (EQUAL(osName, "PROPERTY"))
        {
            osGroupName = osValue;
            oCurObj = CPLJSONObject();
            bHasProperties = true;
            oProperties.Add(osValue, oCurObj);
        }
        else if (EQUAL(osName, "TASK"))
        {
            osGroupName = osValue;
            oCurObj = CPLJSONObject();
            bHasTasks = true;
            oTasks.Add(osValue, oCurObj);
        }
        else
        {
            if (!osGroupName.empty())
                osName = osGroupName + "." + osName;
            papszKeywordList =
                CSLSetNameValue(papszKeywordList, osName, osValue);
        }
    }
    if (bHasProperties)
        oJSon.Add("PROPERTY", oProperties);
    if (bHasTasks)
        oJSon.Add("TASK", oTasks);
    return true;
}

/************************************************************************/
/*                              ReadPair()                              */
/*                                                                      */
/*      Read a name/value pair from the input stream.  Strip off        */
/*      white space, ignore comments, split on '='.                     */
/*      Returns TRUE on success.                                        */
/************************************************************************/

bool VICARKeywordHandler::ReadPair(CPLString &osName, CPLString &osValue,
                                   CPLJSONObject &oCur)
{
    osName.clear();
    osValue.clear();

    if (!ReadName(osName))
    {
        // VICAR has no NULL string termination
        if (*pszHeaderNext == '\0')
        {
            osName = SYNTHETIC_END_MARKER;
            return true;
        }
        return false;
    }

    bool bIsString = false;
    if (*pszHeaderNext == '(')
    {
        CPLString osWord;
        pszHeaderNext++;
        CPLJSONArray oArray;
        oCur.Add(osName, oArray);
        while (ReadValue(osWord, true, bIsString))
        {
            if (!osValue.empty())
                osValue += ',';
            osValue += osWord;
            if (bIsString)
            {
                oArray.Add(osWord);
            }
            else if (CPLGetValueType(osWord) == CPL_VALUE_INTEGER)
            {
                oArray.Add(atoi(osWord));
            }
            else
            {
                oArray.Add(CPLAtof(osWord));
            }
            if (*pszHeaderNext == ')')
            {
                pszHeaderNext++;
                break;
            }
            pszHeaderNext++;
        }
    }
    else
    {
        if (!ReadValue(osValue, false, bIsString))
            return false;
        if (!EQUAL(osName, "PROPERTY") && !EQUAL(osName, "TASK"))
        {
            if (bIsString)
            {
                oCur.Add(osName, osValue);
            }
            else if (CPLGetValueType(osValue) == CPL_VALUE_INTEGER)
            {
                oCur.Add(osName, atoi(osValue));
            }
            else
            {
                oCur.Add(osName, CPLAtof(osValue));
            }
        }
    }

    return true;
}

/************************************************************************/
/*                              ReadName()                              */
/************************************************************************/

bool VICARKeywordHandler::ReadName(CPLString &osWord)

{
    osWord.clear();

    SkipWhite();

    if (*pszHeaderNext == '\0')
        return false;

    while (*pszHeaderNext != '=' && !isspace((unsigned char)*pszHeaderNext))
    {
        if (*pszHeaderNext == '\0')
            return false;
        osWord += *pszHeaderNext;
        pszHeaderNext++;
    }

    SkipWhite();

    if (*pszHeaderNext != '=')
        return false;
    pszHeaderNext++;

    SkipWhite();

    return true;
}

/************************************************************************/
/*                              ReadWord()                              */
/************************************************************************/

bool VICARKeywordHandler::ReadValue(CPLString &osWord, bool bInList,
                                    bool &bIsString)

{
    osWord.clear();

    SkipWhite();

    if (*pszHeaderNext == '\0')
        return false;

    if (*pszHeaderNext == '\'')
    {
        bIsString = true;
        pszHeaderNext++;
        while (true)
        {
            if (*pszHeaderNext == '\0')
                return false;
            if (*(pszHeaderNext) == '\'')
            {
                if (*(pszHeaderNext + 1) == '\'')
                {
                    // Skip Double Quotes
                    pszHeaderNext++;
                }
                else
                    break;
            }
            osWord += *pszHeaderNext;
            pszHeaderNext++;
        }
        pszHeaderNext++;
    }
    else
    {
        while (!isspace((unsigned char)*pszHeaderNext))
        {
            if (*pszHeaderNext == '\0')
                return !bInList;
            if (bInList && (*pszHeaderNext == ',' || *pszHeaderNext == ')'))
            {
                return true;
            }
            osWord += *pszHeaderNext;
            pszHeaderNext++;
        }
        bIsString = CPLGetValueType(osWord) == CPL_VALUE_STRING;
    }

    SkipWhite();
    if (bInList && *pszHeaderNext != ',' && *pszHeaderNext != ')')
        return false;

    return true;
}

/************************************************************************/
/*                             SkipWhite()                              */
/*  Skip white spaces                                                   */
/************************************************************************/

void VICARKeywordHandler::SkipWhite()

{
    for (; true;)
    {
        if (isspace((unsigned char)*pszHeaderNext))
        {
            pszHeaderNext++;
            continue;
        }

        // not white space, return.
        return;
    }
}

/************************************************************************/
/*                             GetKeyword()                             */
/************************************************************************/

const char *VICARKeywordHandler::GetKeyword(const char *pszPath,
                                            const char *pszDefault) const

{
    const char *pszResult = CSLFetchNameValue(papszKeywordList, pszPath);

    if (pszResult == nullptr)
        return pszDefault;

    return pszResult;
}
