/*  GRAPHITE2 LICENSING

    Copyright 2010, SIL International

    All rights reserved.

    This library is free software; you can redistribute it and/or modify

    it under the terms of the GNU Lesser General Public License as published

    by the Free Software Foundation; either version 2.1 of License, or

    (at your option) any later version.

    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Lesser General Public License for more details.

    You should also have received a copy of the GNU Lesser General Public

    License along with this library in the file named "LICENSE".

    If not, write to the Free Software Foundation, 51 Franklin Street,

    Suite 500, Boston, MA 02110-1335, USA or visit their web page on the

    internet at http://www.fsf.org/licenses/lgpl.html.

Alternatively, the contents of this file may be used under the terms of the

Mozilla Public License (http://mozilla.org/MPL) or the GNU General Public

License, as published by the Free Software Foundation, either version 2

of the License or (at your option) any later version.

*/

#include <cstdlib>

#include "graphite2/Segment.h"

#include "inc/debug.h"

#include "inc/Endian.h"

#include "inc/Silf.h"

#include "inc/Segment.h"

#include "inc/Rule.h"

#include "inc/Error.h"

using namespace graphite2;

namespace { static const uint32 ERROROFFSET = 0xFFFFFFFF; }

Silf::Silf() throw()

: m_passes(0),

  m_pseudos(0),

  m_classOffsets(0),

  m_classData(0),

  m_justs(0),

  m_numPasses(0),

  m_numJusts(0),

  m_sPass(0),

  m_pPass(0),

  m_jPass(0),

  m_bPass(0),

  m_flags(0),

  m_dir(0),

  m_aPseudo(0),

  m_aBreak(0),

  m_aUser(0),

  m_aBidi(0),

  m_aMirror(0),

  m_aPassBits(0),

  m_iMaxComp(0),

  m_aCollision(0),

  m_aLig(0),

  m_numPseudo(0),

  m_nClass(0),

  m_nLinear(0),

  m_gEndLine(0)

{

    memset(&m_silfinfo, 0, sizeof m_silfinfo);

}

Silf::~Silf() throw()

{

    releaseBuffers();

}

void Silf::releaseBuffers() throw()

{

    delete [] m_passes;

    delete [] m_pseudos;

    free(m_classOffsets);

    free(m_classData);

    free(m_justs);

    m_passes= 0;

    m_pseudos = 0;

    m_classOffsets = 0;

    m_classData = 0;

    m_justs = 0;

}

bool Silf::readGraphite(const byte * const silf_start, size_t lSilf, Face& face, uint32 version)

{

    const byte * p = silf_start,

               * const silf_end = p + lSilf;

    Error e;

    if (e.test(version >= 0x00060000, E_BADSILFVERSION))

    {

        releaseBuffers(); return face.error(e);

    }

    if (version >= 0x00030000)

    {

        if (e.test(lSilf < 28, E_BADSIZE)) { releaseBuffers(); return face.error(e); }

        be::skip<int32>(p);    // ruleVersion

        be::skip<uint16>(p,2); // passOffset & pseudosOffset

    }

    else if (e.test(lSilf < 20, E_BADSIZE)) { releaseBuffers(); return face.error(e); }

    const uint16 maxGlyph = be::read<uint16>(p);

    m_silfinfo.extra_ascent = be::read<uint16>(p);

    m_silfinfo.extra_descent = be::read<uint16>(p);

    m_numPasses = be::read<uint8>(p);

    m_sPass     = be::read<uint8>(p);

    m_pPass     = be::read<uint8>(p);

    m_jPass     = be::read<uint8>(p);

    m_bPass     = be::read<uint8>(p);

    m_flags     = be::read<uint8>(p);

    be::skip<uint8>(p,2); //  max{Pre,Post}Context.

    m_aPseudo   = be::read<uint8>(p);

    m_aBreak    = be::read<uint8>(p);

    m_aBidi     = be::read<uint8>(p);

    m_aMirror   = be::read<uint8>(p);

    m_aPassBits = be::read<uint8>(p);

    // Read Justification levels.

    m_numJusts  = be::read<uint8>(p);

    if (e.test(maxGlyph >= face.glyphs().numGlyphs(), E_BADMAXGLYPH)

        || e.test(p + m_numJusts * 8 >= silf_end, E_BADNUMJUSTS))

    {

        releaseBuffers(); return face.error(e);

    }

    if (m_numJusts)

    {

        m_justs = gralloc<Justinfo>(m_numJusts);

        if (e.test(!m_justs, E_OUTOFMEM)) return face.error(e);

        for (uint8 i = 0; i < m_numJusts; i++)

        {

            ::new(m_justs + i) Justinfo(p[0], p[1], p[2], p[3]);

            be::skip<byte>(p,8);

        }

    }

    if (e.test(p + sizeof(uint16) + sizeof(uint8)*8 >= silf_end, E_BADENDJUSTS)) { releaseBuffers(); return face.error(e); }

    m_aLig       = be::read<uint16>(p);

    m_aUser      = be::read<uint8>(p);

    m_iMaxComp   = be::read<uint8>(p);

    m_dir        = be::read<uint8>(p) - 1;

    m_aCollision = be::read<uint8>(p);

    be::skip<byte>(p,3);

    be::skip<uint16>(p, be::read<uint8>(p));    // don't need critical features yet

    be::skip<byte>(p);                          // reserved

    if (e.test(p >= silf_end, E_BADCRITFEATURES))   { releaseBuffers(); return face.error(e); }

    be::skip<uint32>(p, be::read<uint8>(p));    // don't use scriptTag array.

    if (e.test(p + sizeof(uint16) + sizeof(uint32) >= silf_end, E_BADSCRIPTTAGS)) { releaseBuffers(); return face.error(e); }

    m_gEndLine  = be::read<uint16>(p);          // lbGID

    const byte * o_passes = p;

    uint32 passes_start = be::read<uint32>(p);

    const size_t num_attrs = face.glyphs().numAttrs();

    if (e.test(m_aPseudo   >= num_attrs, E_BADAPSEUDO)

        || e.test(m_aBreak >= num_attrs, E_BADABREAK)

        || e.test(m_aBidi  >= num_attrs, E_BADABIDI)

        || e.test(m_aMirror>= num_attrs, E_BADAMIRROR)

        || e.test(m_aCollision && m_aCollision >= num_attrs - 5, E_BADACOLLISION)

        || e.test(m_numPasses > 128, E_BADNUMPASSES) || e.test(passes_start >= lSilf, E_BADPASSESSTART)

        || e.test(m_pPass < m_sPass, E_BADPASSBOUND) || e.test(m_pPass > m_numPasses, E_BADPPASS) || e.test(m_sPass > m_numPasses, E_BADSPASS)

        || e.test(m_jPass < m_pPass, E_BADJPASSBOUND) || e.test(m_jPass > m_numPasses, E_BADJPASS)

        || e.test((m_bPass != 0xFF && (m_bPass < m_jPass || m_bPass > m_numPasses)), E_BADBPASS)

        || e.test(m_aLig > 127, E_BADALIG))

    {

        releaseBuffers();

        return face.error(e);

    }

    be::skip<uint32>(p, m_numPasses);

    if (e.test(unsigned(p - silf_start) + sizeof(uint16) >= passes_start, E_BADPASSESSTART)) { releaseBuffers(); return face.error(e); }

    m_numPseudo = be::read<uint16>(p);

    be::skip<uint16>(p, 3); // searchPseudo, pseudoSelector, pseudoShift

    m_pseudos = new Pseudo[m_numPseudo];

    if (e.test(unsigned(p - silf_start) + m_numPseudo*(sizeof(uint32) + sizeof(uint16)) >= passes_start, E_BADNUMPSEUDO)

        || e.test(!m_pseudos, E_OUTOFMEM))

    {

        releaseBuffers(); return face.error(e);

    }

    for (int i = 0; i < m_numPseudo; i++)

    {

        m_pseudos[i].uid = be::read<uint32>(p);

        m_pseudos[i].gid = be::read<uint16>(p);

    }

    const size_t clen = readClassMap(p, passes_start + silf_start - p, version, e);

    m_passes = new Pass[m_numPasses];

    if (e || e.test(clen > unsigned(passes_start + silf_start - p), E_BADPASSESSTART)

          || e.test(!m_passes, E_OUTOFMEM))

    { releaseBuffers(); return face.error(e); }

    for (size_t i = 0; i < m_numPasses; ++i)

    {

        uint32 pass_start = be::read<uint32>(o_passes);

        uint32 pass_end = be::peek<uint32>(o_passes);

        face.error_context((face.error_context() & 0xFF00) + EC_ASILF + unsigned(i << 16));

        if (e.test(pass_start > pass_end, E_BADPASSSTART)

                || e.test(pass_start < passes_start, E_BADPASSSTART)

                || e.test(pass_end > lSilf, E_BADPASSEND)) {

            releaseBuffers(); return face.error(e);

        }

        enum passtype pt = PASS_TYPE_UNKNOWN;

        if (i >= m_jPass) pt = PASS_TYPE_JUSTIFICATION;

        else if (i >= m_pPass) pt = PASS_TYPE_POSITIONING;

        else if (i >= m_sPass) pt = PASS_TYPE_SUBSTITUTE;

        else pt = PASS_TYPE_LINEBREAK;

        m_passes[i].init(this);

        if (!m_passes[i].readPass(silf_start + pass_start, pass_end - pass_start, pass_start, face, pt,

            version, e))

        {

            releaseBuffers();

            return false;

        }

    }

    // fill in gr_faceinfo

    m_silfinfo.upem = face.glyphs().unitsPerEm();

    m_silfinfo.has_bidi_pass = (m_bPass != 0xFF);

    m_silfinfo.justifies = (m_numJusts != 0) || (m_jPass < m_pPass);

    m_silfinfo.line_ends = (m_flags & 1);

    m_silfinfo.space_contextuals = gr_faceinfo::gr_space_contextuals((m_flags >> 2) & 0x7);

    return true;

}

template<typename T> inline uint32 Silf::readClassOffsets(const byte *&p, size_t data_len, Error &e)

{

    const T cls_off = 2*sizeof(uint16) + sizeof(T)*(m_nClass+1);

    const uint32 max_off = (be::peek<T>(p + sizeof(T)*m_nClass) - cls_off)/sizeof(uint16);

    // Check that the last+1 offset is less than or equal to the class map length.

    if (e.test(be::peek<T>(p) != cls_off, E_MISALIGNEDCLASSES)

            || e.test(max_off > (data_len - cls_off)/sizeof(uint16), E_HIGHCLASSOFFSET))

        return ERROROFFSET;

    // Read in all the offsets.

    m_classOffsets = gralloc<uint32>(m_nClass+1);

    if (e.test(!m_classOffsets, E_OUTOFMEM)) return ERROROFFSET;

    for (uint32 * o = m_classOffsets, * const o_end = o + m_nClass + 1; o != o_end; ++o)

    {

        *o = (be::read<T>(p) - cls_off)/sizeof(uint16);

        if (e.test(*o > max_off, E_HIGHCLASSOFFSET))

            return ERROROFFSET;

    }

    return max_off;

}

Unexecuted instantiation: unsigned int graphite2::Silf::readClassOffsets<unsigned int>(unsigned char const*&, unsigned long, graphite2::Error&)

Unexecuted instantiation: unsigned int graphite2::Silf::readClassOffsets<unsigned short>(unsigned char const*&, unsigned long, graphite2::Error&)

size_t Silf::readClassMap(const byte *p, size_t data_len, uint32 version, Error &e)

{

    if (e.test(data_len < sizeof(uint16)*2, E_BADCLASSSIZE)) return ERROROFFSET;

    m_nClass  = be::read<uint16>(p);

    m_nLinear = be::read<uint16>(p);

    // Check that numLinear < numClass,

    // that there is at least enough data for numClasses offsets.

    if (e.test(m_nLinear > m_nClass, E_TOOMANYLINEAR)

     || e.test((m_nClass + 1) * (version >= 0x00040000 ? sizeof(uint32) : sizeof(uint16)) > (data_len - 4), E_CLASSESTOOBIG))

        return ERROROFFSET;

    uint32 max_off;

    if (version >= 0x00040000)

        max_off = readClassOffsets<uint32>(p, data_len, e);

    else

        max_off = readClassOffsets<uint16>(p, data_len, e);

    if (max_off == ERROROFFSET) return ERROROFFSET;

    if (e.test((int)max_off < m_nLinear + (m_nClass - m_nLinear) * 6, E_CLASSESTOOBIG))

        return ERROROFFSET;

    // Check the linear offsets are sane, these must be monotonically increasing.

    assert(m_nClass >= m_nLinear);

    for (const uint32 *o = m_classOffsets, * const o_end = o + m_nLinear; o != o_end; ++o)

        if (e.test(o[0] > o[1], E_BADCLASSOFFSET))

            return ERROROFFSET;

    // Fortunately the class data is all uint16s so we can decode these now

    m_classData = gralloc<uint16>(max_off);

    if (e.test(!m_classData, E_OUTOFMEM)) return ERROROFFSET;

    for (uint16 *d = m_classData, * const d_end = d + max_off; d != d_end; ++d)

        *d = be::read<uint16>(p);

    // Check the lookup class invariants for each non-linear class

    for (const uint32 *o = m_classOffsets + m_nLinear, * const o_end = m_classOffsets + m_nClass; o != o_end; ++o)

    {

        const uint16 * lookup = m_classData + *o;

        if (e.test(*o + 4 > max_off, E_HIGHCLASSOFFSET)                        // LookupClass doesn't stretch over max_off

         || e.test(lookup[0] == 0                                                   // A LookupClass with no looks is a suspicious thing ...

                    || lookup[0] * 2 + *o + 4 > max_off                             // numIDs lookup pairs fits within (start of LookupClass' lookups array, max_off]

                    || lookup[3] + lookup[1] != lookup[0], E_BADCLASSLOOKUPINFO)    // rangeShift:   numIDs  - searchRange

         || e.test(((o[1] - *o) & 1) != 0, ERROROFFSET))                         // glyphs are in pairs so difference must be even.

            return ERROROFFSET;

    }

    return max_off;

}

uint16 Silf::findPseudo(uint32 uid) const

{

    for (int i = 0; i < m_numPseudo; i++)

        if (m_pseudos[i].uid == uid) return m_pseudos[i].gid;

    return 0;

}

uint16 Silf::findClassIndex(uint16 cid, uint16 gid) const

{

    if (cid > m_nClass) return -1;

    const uint16 * cls = m_classData + m_classOffsets[cid];

    if (cid < m_nLinear)        // output class being used for input, shouldn't happen

    {

        for (unsigned int i = 0, n = m_classOffsets[cid + 1] - m_classOffsets[cid]; i < n; ++i, ++cls)

            if (*cls == gid) return i;

        return -1;

    }

    else

    {

        const uint16 *  min = cls + 4,      // lookups array

                     *  max = min + cls[0]*2; // lookups aray is numIDs (cls[0]) uint16 pairs long

        do

        {

            const uint16 * p = min + (-2 & ((max-min)/2));

            if  (p[0] > gid)    max = p;

            else                min = p;

        }

        while (max - min > 2);

        return min[0] == gid ? min[1] : -1;

    }

}

uint16 Silf::getClassGlyph(uint16 cid, unsigned int index) const

{

    if (cid > m_nClass) return 0;

    uint32 loc = m_classOffsets[cid];

    if (cid < m_nLinear)

    {

        if (index < m_classOffsets[cid + 1] - loc)

            return m_classData[index + loc];

    }

    else        // input class being used for output. Shouldn't happen

    {

        for (unsigned int i = loc + 4; i < m_classOffsets[cid + 1]; i += 2)

            if (m_classData[i + 1] == index) return m_classData[i];

    }

    return 0;

}

bool Silf::runGraphite(Segment *seg, uint8 firstPass, uint8 lastPass, int dobidi) const

{

    assert(seg != 0);

    size_t             maxSize = seg->slotCount() * MAX_SEG_GROWTH_FACTOR;

    SlotMap            map(*seg, m_dir, maxSize);

    FiniteStateMachine fsm(map, seg->getFace()->logger());

    vm::Machine        m(map);

    uint8              lbidi = m_bPass;

#if !defined GRAPHITE2_NTRACING

    json * const dbgout = seg->getFace()->logger();

#endif

    if (lastPass == 0)

    {

        if (firstPass == lastPass && lbidi == 0xFF)

            return true;

        lastPass = m_numPasses;

    }

    if ((firstPass < lbidi || (dobidi && firstPass == lbidi)) && (lastPass >= lbidi || (dobidi && lastPass + 1 == lbidi)))

        lastPass++;

    else

        lbidi = 0xFF;

    for (size_t i = firstPass; i < lastPass; ++i)

    {

        // bidi and mirroring

        if (i == lbidi)

        {

#if !defined GRAPHITE2_NTRACING

            if (dbgout)

            {

                *dbgout << json::item << json::object

//              << "pindex" << i   // for debugging

                            << "id"     << -1

                            << "slotsdir" << (seg->currdir() ? "rtl" : "ltr")

                            << "passdir" << (m_dir & 1 ? "rtl" : "ltr")

                            << "slots"  << json::array;

                seg->positionSlots(0, 0, 0, seg->currdir());

                for(Slot * s = seg->first(); s; s = s->next())

                    *dbgout     << dslot(seg, s);

                *dbgout         << json::close

                            << "rules"  << json::array << json::close

                            << json::close;

            }

#endif

            if (seg->currdir() != (m_dir & 1))

                seg->reverseSlots();

            if (m_aMirror && (seg->dir() & 3) == 3)

                seg->doMirror(m_aMirror);

        --i;

        lbidi = lastPass;

        --lastPass;

        continue;

        }

#if !defined GRAPHITE2_NTRACING

        if (dbgout)

        {

            *dbgout << json::item << json::object

//            << "pindex" << i   // for debugging

                        << "id"     << i+1

                        << "slotsdir" << (seg->currdir() ? "rtl" : "ltr")

                        << "passdir" << ((m_dir & 1) ^ m_passes[i].reverseDir() ? "rtl" : "ltr")

                        << "slots"  << json::array;

            seg->positionSlots(0, 0, 0, seg->currdir());

            for(Slot * s = seg->first(); s; s = s->next())

                *dbgout     << dslot(seg, s);

            *dbgout         << json::close;

        }

#endif

        // test whether to reorder, prepare for positioning

        bool reverse = (lbidi == 0xFF) && (seg->currdir() != ((m_dir & 1) ^ m_passes[i].reverseDir()));

        if ((i >= 32 || (seg->passBits() & (1 << i)) == 0 || m_passes[i].collisionLoops())

                && !m_passes[i].runGraphite(m, fsm, reverse))

            return false;

        // only subsitution passes can change segment length, cached subsegments are short for their text

        if (m.status() != vm::Machine::finished

            || (seg->slotCount() && seg->slotCount() > maxSize))

            return false;

    }

    return true;

}