/*

 * Copyright © 2018  Google, Inc.

 *

 *  This is part of HarfBuzz, a text shaping library.

 *

 * Permission is hereby granted, without written agreement and without

 * license or royalty fees, to use, copy, modify, and distribute this

 * software and its documentation for any purpose, provided that the

 * above copyright notice and the following two paragraphs appear in

 * all copies of this software.

 *

 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 *

 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 *

 * Google Author(s): Garret Rieger

 */

#ifndef HB_OT_HDMX_TABLE_HH

#define HB_OT_HDMX_TABLE_HH

#include "hb-open-type.hh"

/*

 * hdmx -- Horizontal Device Metrics

 * https://docs.microsoft.com/en-us/typography/opentype/spec/hdmx

 */

#define HB_OT_TAG_hdmx HB_TAG('h','d','m','x')

namespace OT {

struct DeviceRecord

{

  struct SubsetView

  {

    const DeviceRecord *source_device_record;

    unsigned int sizeDeviceRecord;

    hb_subset_plan_t *subset_plan;

    void init (const DeviceRecord *source_device_record,

               unsigned int sizeDeviceRecord,

               hb_subset_plan_t   *subset_plan)

    {

      this->source_device_record = source_device_record;

      this->sizeDeviceRecord = sizeDeviceRecord;

      this->subset_plan = subset_plan;

    }

    unsigned int len () const

    { return this->subset_plan->glyphs.length; }

    const HBUINT8* operator [] (unsigned int i) const

    {

      if (unlikely (i >= len ())) return nullptr;

      hb_codepoint_t gid = this->subset_plan->glyphs [i];

      if (gid >= sizeDeviceRecord - DeviceRecord::min_size)

        return nullptr;

      return &(this->source_device_record->widthsZ[gid]);

    }

  };

  static unsigned int get_size (unsigned int count)

  { return hb_ceil_to_4 (min_size + count * HBUINT8::static_size); }

  bool serialize (hb_serialize_context_t *c, const SubsetView &subset_view)

  {

    TRACE_SERIALIZE (this);

    unsigned int size = get_size (subset_view.len ());

    if (unlikely (!c->allocate_size<DeviceRecord> (size)))

    {

      DEBUG_MSG(SUBSET, nullptr, "Couldn't allocate enough space for DeviceRecord: %d.",

                 size);

      return_trace (false);

    }

    this->pixelSize.set (subset_view.source_device_record->pixelSize);

    this->maxWidth.set (subset_view.source_device_record->maxWidth);

    for (unsigned int i = 0; i < subset_view.len (); i++)

    {

      const HBUINT8 *width = subset_view[i];

      if (!width)

      {

        DEBUG_MSG(SUBSET, nullptr, "HDMX width for new gid %d is missing.", i);

        return_trace (false);

      }

      widthsZ[i].set (*width);

    }

    return_trace (true);

  }

  bool sanitize (hb_sanitize_context_t *c, unsigned int sizeDeviceRecord) const

  {

    TRACE_SANITIZE (this);

    return_trace (likely (c->check_struct (this) &&

                          c->check_range (this, sizeDeviceRecord)));

  }

  HBUINT8                       pixelSize;      /* Pixel size for following widths (as ppem). */

  HBUINT8                       maxWidth;       /* Maximum width. */

  UnsizedArrayOf<HBUINT8>       widthsZ;        /* Array of widths (numGlyphs is from the 'maxp' table). */

  public:

  DEFINE_SIZE_ARRAY (2, widthsZ);

};

struct hdmx

{

  static constexpr hb_tag_t tableTag = HB_OT_TAG_hdmx;

  unsigned int get_size () const

  { return min_size + numRecords * sizeDeviceRecord; }

  const DeviceRecord& operator [] (unsigned int i) const

  {

    /* XXX Null(DeviceRecord) is NOT safe as it's num-glyphs lengthed.

     * https://github.com/harfbuzz/harfbuzz/issues/1300 */

    if (unlikely (i >= numRecords)) return Null (DeviceRecord);

    return StructAtOffset<DeviceRecord> (&this->firstDeviceRecord, i * sizeDeviceRecord);

  }

  bool serialize (hb_serialize_context_t *c, const hdmx *source_hdmx, hb_subset_plan_t *plan)

  {

    TRACE_SERIALIZE (this);

    if (unlikely (!c->extend_min ((*this))))  return_trace (false);

    this->version.set (source_hdmx->version);

    this->numRecords.set (source_hdmx->numRecords);

    this->sizeDeviceRecord.set (DeviceRecord::get_size (plan->glyphs.length));

    for (unsigned int i = 0; i < source_hdmx->numRecords; i++)

    {

      DeviceRecord::SubsetView subset_view;

      subset_view.init (&(*source_hdmx)[i], source_hdmx->sizeDeviceRecord, plan);

      if (!c->start_embed<DeviceRecord> ()->serialize (c, subset_view))

        return_trace (false);

    }

    return_trace (true);

  }

  static size_t get_subsetted_size (const hdmx *source_hdmx, hb_subset_plan_t *plan)

  {

    return min_size + source_hdmx->numRecords * DeviceRecord::get_size (plan->glyphs.length);

  }

  bool subset (hb_subset_plan_t *plan) const

  {

    size_t dest_size = get_subsetted_size (this, plan);

    hdmx *dest = (hdmx *) malloc (dest_size);

    if (unlikely (!dest))

    {

      DEBUG_MSG(SUBSET, nullptr, "Unable to alloc %lu for hdmx subset output.", (unsigned long) dest_size);

      return false;

    }

    hb_serialize_context_t c (dest, dest_size);

    hdmx *hdmx_prime = c.start_serialize<hdmx> ();

    if (!hdmx_prime || !hdmx_prime->serialize (&c, this, plan))

    {

      free (dest);

      DEBUG_MSG(SUBSET, nullptr, "Failed to serialize write new hdmx.");

      return false;

    }

    c.end_serialize ();

    hb_blob_t *hdmx_prime_blob = hb_blob_create ((const char *) dest,

                                                 dest_size,

                                                 HB_MEMORY_MODE_READONLY,

                                                 dest,

                                                 free);

    bool result = plan->add_table (HB_OT_TAG_hdmx, hdmx_prime_blob);

    hb_blob_destroy (hdmx_prime_blob);

    return result;

  }

  bool sanitize (hb_sanitize_context_t *c) const

  {

    TRACE_SANITIZE (this);

    return_trace (c->check_struct (this) &&

                  !hb_unsigned_mul_overflows (numRecords, sizeDeviceRecord) &&

                  sizeDeviceRecord >= DeviceRecord::min_size &&

                  c->check_range (this, get_size ()));

  }

  protected:

  HBUINT16              version;                /* Table version number (0) */

  HBUINT16              numRecords;             /* Number of device records. */

  HBUINT32              sizeDeviceRecord;       /* Size of a device record, 32-bit aligned. */

  DeviceRecord          firstDeviceRecord;      /* Array of device records. */

  public:

  DEFINE_SIZE_MIN (8);

};

} /* namespace OT */

#endif /* HB_OT_HDMX_TABLE_HH */