// Copyright 2012 Google Inc. All Rights Reserved.

//

// Use of this source code is governed by a BSD-style license

// that can be found in the COPYING file in the root of the source

// tree. An additional intellectual property rights grant can be found

// in the file PATENTS. All contributing project authors may

// be found in the AUTHORS file in the root of the source tree.

// -----------------------------------------------------------------------------

//

// TIFF decode.

#include "./tiffdec.h"

#ifdef HAVE_CONFIG_H

#include "webp/config.h"

#endif

#include <limits.h>

#include <stdio.h>

#include <string.h>

#ifdef WEBP_HAVE_TIFF

#include <tiffio.h>

#include "webp/encode.h"

#include "./imageio_util.h"

#include "./metadata.h"

static const struct {

  ttag_t tag;

  size_t storage_offset;

} kTIFFMetadataMap[] = {

  { TIFFTAG_ICCPROFILE, METADATA_OFFSET(iccp) },

  { TIFFTAG_XMLPACKET,  METADATA_OFFSET(xmp) },

  { 0, 0 },

};

// Returns true on success. The caller must use MetadataFree() on 'metadata' in

// all cases.

static int ExtractMetadataFromTIFF(TIFF* const tif, Metadata* const metadata) {

  int i;

  toff_t exif_ifd_offset;

  for (i = 0; kTIFFMetadataMap[i].tag != 0; ++i) {

    MetadataPayload* const payload =

        (MetadataPayload*)((uint8_t*)metadata +

                           kTIFFMetadataMap[i].storage_offset);

    void* tag_data;

    uint32 tag_data_len;

    if (TIFFGetField(tif, kTIFFMetadataMap[i].tag, &tag_data_len, &tag_data) &&

        !MetadataCopy((const char*)tag_data, tag_data_len, payload)) {

      return 0;

    }

  }

  // TODO(jzern): To extract the raw EXIF directory some parsing of it would be

  // necessary to determine the overall size. In addition, value offsets in

  // individual directory entries may need to be updated as, depending on the

  // type, they are file based.

  // Exif 2.2 Section 4.6.2 Tag Structure

  // TIFF Revision 6.0 Part 1 Section 2 TIFF Structure #Image File Directory

  if (TIFFGetField(tif, TIFFTAG_EXIFIFD, &exif_ifd_offset)) {

    fprintf(stderr, "Warning: EXIF extraction from TIFF is unsupported.\n");

  }

  return 1;

}

// Ad-hoc structure to supply read-from-memory functionalities.

typedef struct {

  const uint8_t* data;

  toff_t size;

  toff_t pos;

} MyData;

static int MyClose(thandle_t opaque) {

  (void)opaque;

  return 0;

}

static toff_t MySize(thandle_t opaque) {

  const MyData* const my_data = (MyData*)opaque;

  return my_data->size;

}

static toff_t MySeek(thandle_t opaque, toff_t offset, int whence) {

  MyData* const my_data = (MyData*)opaque;

  offset += (whence == SEEK_CUR) ? my_data->pos

          : (whence == SEEK_SET) ? 0

          : my_data->size;

  if (offset > my_data->size) return (toff_t)-1;

  my_data->pos = offset;

  return offset;

}

static int MyMapFile(thandle_t opaque, void** base, toff_t* size) {

  (void)opaque;

  (void)base;

  (void)size;

  return 0;

}

static void MyUnmapFile(thandle_t opaque, void* base, toff_t size) {

  (void)opaque;

  (void)base;

  (void)size;

}

static tsize_t MyRead(thandle_t opaque, void* dst, tsize_t size) {

  MyData* const my_data = (MyData*)opaque;

  if (my_data->pos + size > my_data->size) {

    size = (tsize_t)(my_data->size - my_data->pos);

  }

  if (size > 0) {

    memcpy(dst, my_data->data + my_data->pos, size);

    my_data->pos += size;

  }

  return size;

}

// Unmultiply Argb data. Taken from dsp/alpha_processing

// (we don't want to force a dependency to a libdspdec library).

#define MFIX 24    // 24bit fixed-point arithmetic

#define HALF ((1u << MFIX) >> 1)

#define KINV_255 ((1u << MFIX) / 255u)

static uint32_t Unmult(uint8_t x, uint32_t mult) {

  const uint32_t v = (x * mult + HALF) >> MFIX;

  return (v > 255u) ? 255u : v;

}

static WEBP_INLINE uint32_t GetScale(uint32_t a) {

  return (255u << MFIX) / a;

}

static void MultARGBRow(uint8_t* ptr, int width) {

  int x;

  for (x = 0; x < width; ++x, ptr += 4) {

    const uint32_t alpha = ptr[3];

    if (alpha < 255) {

      if (alpha == 0) {   // alpha == 0

        ptr[0] = ptr[1] = ptr[2] = 0;

      } else {

        const uint32_t scale = GetScale(alpha);

        ptr[0] = Unmult(ptr[0], scale);

        ptr[1] = Unmult(ptr[1], scale);

        ptr[2] = Unmult(ptr[2], scale);

      }

    }

  }

}

int ReadTIFF(const uint8_t* const data, size_t data_size,

             WebPPicture* const pic, int keep_alpha,

             Metadata* const metadata) {

  MyData my_data = { data, (toff_t)data_size, 0 };

  TIFF* tif;

  uint32_t width, height;

  uint16_t samples_per_px = 0;

  uint16_t extra_samples = 0;

  uint16_t* extra_samples_ptr = NULL;

  uint32_t* raster;

  int64_t alloc_size;

  int ok = 0;

  tdir_t dircount;

  if (data == NULL || data_size == 0 || data_size > INT_MAX || pic == NULL) {

    return 0;

  }

  tif = TIFFClientOpen("Memory", "r", &my_data,

                       MyRead, MyRead, MySeek, MyClose,

                       MySize, MyMapFile, MyUnmapFile);

  if (tif == NULL) {

    fprintf(stderr, "Error! Cannot parse TIFF file\n");

    return 0;

  }

  dircount = TIFFNumberOfDirectories(tif);

  if (dircount > 1) {

    fprintf(stderr, "Warning: multi-directory TIFF files are not supported.\n"

                    "Only the first will be used, %d will be ignored.\n",

                    dircount - 1);

  }

  if (!TIFFGetFieldDefaulted(tif, TIFFTAG_SAMPLESPERPIXEL, &samples_per_px)) {

    fprintf(stderr, "Error! Cannot retrieve TIFF samples-per-pixel info.\n");

    goto End;

  }

  if (samples_per_px < 3 || samples_per_px > 4) goto End;  // not supported

  if (!(TIFFGetField(tif, TIFFTAG_IMAGEWIDTH, &width) &&

        TIFFGetField(tif, TIFFTAG_IMAGELENGTH, &height))) {

    fprintf(stderr, "Error! Cannot retrieve TIFF image dimensions.\n");

    goto End;

  }

  if (!ImgIoUtilCheckSizeArgumentsOverflow((uint64_t)width * height,

                                           sizeof(*raster))) {

    goto End;

  }

  if (samples_per_px > 3 && !TIFFGetField(tif, TIFFTAG_EXTRASAMPLES,

                                          &extra_samples, &extra_samples_ptr)) {

    fprintf(stderr, "Error! Cannot retrieve TIFF ExtraSamples info.\n");

    goto End;

  }

  // _Tiffmalloc uses a signed type for size.

  alloc_size = (int64_t)((uint64_t)width * height * sizeof(*raster));

  if (alloc_size < 0 || alloc_size != (tsize_t)alloc_size) goto End;

  raster = (uint32*)_TIFFmalloc((tsize_t)alloc_size);

  if (raster != NULL) {

    if (TIFFReadRGBAImageOriented(tif, width, height, raster,

                                  ORIENTATION_TOPLEFT, 1)) {

      const int stride = width * sizeof(*raster);

      pic->width = width;

      pic->height = height;

      // TIFF data is ABGR

#ifdef WORDS_BIGENDIAN

      TIFFSwabArrayOfLong(raster, width * height);

#endif

      // if we have an alpha channel, we must un-multiply from rgbA to RGBA

      if (extra_samples == 1 && extra_samples_ptr != NULL &&

          extra_samples_ptr[0] == EXTRASAMPLE_ASSOCALPHA) {

        uint32_t y;

        uint8_t* tmp = (uint8_t*)raster;

        for (y = 0; y < height; ++y) {

          MultARGBRow(tmp, width);

          tmp += stride;

        }

      }

      ok = keep_alpha

         ? WebPPictureImportRGBA(pic, (const uint8_t*)raster, stride)

         : WebPPictureImportRGBX(pic, (const uint8_t*)raster, stride);

    }

    _TIFFfree(raster);

  } else {

    fprintf(stderr, "Error allocating TIFF RGBA memory!\n");

  }

  if (ok) {

    if (metadata != NULL) {

      ok = ExtractMetadataFromTIFF(tif, metadata);

      if (!ok) {

        fprintf(stderr, "Error extracting TIFF metadata!\n");

        MetadataFree(metadata);

        WebPPictureFree(pic);

      }

    }

  }

 End:

  TIFFClose(tif);

  return ok;

}

#else  // !WEBP_HAVE_TIFF

int ReadTIFF(const uint8_t* const data, size_t data_size,

             struct WebPPicture* const pic, int keep_alpha,

             struct Metadata* const metadata) {

  (void)data;

  (void)data_size;

  (void)pic;

  (void)keep_alpha;

  (void)metadata;

  fprintf(stderr, "TIFF support not compiled. Please install the libtiff "

          "development package before building.\n");

  return 0;

}

#endif  // WEBP_HAVE_TIFF

// -----------------------------------------------------------------------------