// Copyright 2011 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.

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

//

// Internal objects and utils for mux.

//

// Authors: Urvang (urvang@google.com)

//          Vikas (vikasa@google.com)

#include <assert.h>

#include <stddef.h>

#include <string.h>

#include "src/mux/muxi.h"

#include "src/utils/utils.h"

#include "src/webp/format_constants.h"

#include "src/webp/mux.h"

#include "src/webp/mux_types.h"

#include "src/webp/types.h"

#define UNDEFINED_CHUNK_SIZE ((uint32_t)(-1))

const ChunkInfo kChunks[] = {

    {MKFOURCC('V', 'P', '8', 'X'), WEBP_CHUNK_VP8X, VP8X_CHUNK_SIZE},

    {MKFOURCC('I', 'C', 'C', 'P'), WEBP_CHUNK_ICCP, UNDEFINED_CHUNK_SIZE},

    {MKFOURCC('A', 'N', 'I', 'M'), WEBP_CHUNK_ANIM, ANIM_CHUNK_SIZE},

    {MKFOURCC('A', 'N', 'M', 'F'), WEBP_CHUNK_ANMF, ANMF_CHUNK_SIZE},

    {MKFOURCC('A', 'L', 'P', 'H'), WEBP_CHUNK_ALPHA, UNDEFINED_CHUNK_SIZE},

    {MKFOURCC('V', 'P', '8', ' '), WEBP_CHUNK_IMAGE, UNDEFINED_CHUNK_SIZE},

    {MKFOURCC('V', 'P', '8', 'L'), WEBP_CHUNK_IMAGE, UNDEFINED_CHUNK_SIZE},

    {MKFOURCC('E', 'X', 'I', 'F'), WEBP_CHUNK_EXIF, UNDEFINED_CHUNK_SIZE},

    {MKFOURCC('X', 'M', 'P', ' '), WEBP_CHUNK_XMP, UNDEFINED_CHUNK_SIZE},

    {NIL_TAG, WEBP_CHUNK_UNKNOWN, UNDEFINED_CHUNK_SIZE},

    {NIL_TAG, WEBP_CHUNK_NIL, UNDEFINED_CHUNK_SIZE}};

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

int WebPGetMuxVersion(void) {

  return (MUX_MAJ_VERSION << 16) | (MUX_MIN_VERSION << 8) | MUX_REV_VERSION;

}

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

// Life of a chunk object.

void ChunkInit(WebPChunk* const chunk) {

  assert(chunk);

  memset(chunk, 0, sizeof(*chunk));

  chunk->tag = NIL_TAG;

}

WebPChunk* ChunkRelease(WebPChunk* const chunk) {

  WebPChunk* next;

  if (chunk == NULL) return NULL;

  if (chunk->owner) {

    WebPDataClear(&chunk->data);

  }

  next = chunk->next;

  ChunkInit(chunk);

  return next;

}

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

// Chunk misc methods.

CHUNK_INDEX ChunkGetIndexFromTag(uint32_t tag) {

  int i;

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

    if (tag == kChunks[i].tag) return (CHUNK_INDEX)i;

  }

  return IDX_UNKNOWN;

}

WebPChunkId ChunkGetIdFromTag(uint32_t tag) {

  int i;

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

    if (tag == kChunks[i].tag) return kChunks[i].id;

  }

  return WEBP_CHUNK_UNKNOWN;

}

uint32_t ChunkGetTagFromFourCC(const char fourcc[4]) {

  return MKFOURCC(fourcc[0], fourcc[1], fourcc[2], fourcc[3]);

}

CHUNK_INDEX ChunkGetIndexFromFourCC(const char fourcc[4]) {

  const uint32_t tag = ChunkGetTagFromFourCC(fourcc);

  return ChunkGetIndexFromTag(tag);

}

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

// Chunk search methods.

// Returns next chunk in the chunk list with the given tag.

static WebPChunk* ChunkSearchNextInList(WebPChunk* chunk, uint32_t tag) {

  while (chunk != NULL && chunk->tag != tag) {

    chunk = chunk->next;

  }

  return chunk;

}

WebPChunk* ChunkSearchList(WebPChunk* first, uint32_t nth, uint32_t tag) {

  uint32_t iter = nth;

  first = ChunkSearchNextInList(first, tag);

  if (first == NULL) return NULL;

  while (--iter != 0) {

    WebPChunk* next_chunk = ChunkSearchNextInList(first->next, tag);

    if (next_chunk == NULL) break;

    first = next_chunk;

  }

  return ((nth > 0) && (iter > 0)) ? NULL : first;

}

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

// Chunk writer methods.

WebPMuxError ChunkAssignData(WebPChunk* chunk, const WebPData* const data,

                             int copy_data, uint32_t tag) {

  // For internally allocated chunks, always copy data & make it owner of data.

  if (tag == kChunks[IDX_VP8X].tag || tag == kChunks[IDX_ANIM].tag) {

    copy_data = 1;

  }

  ChunkRelease(chunk);

  if (data != NULL) {

    if (copy_data) {  // Copy data.

      if (!WebPDataCopy(data, &chunk->data)) return WEBP_MUX_MEMORY_ERROR;

      chunk->owner = 1;  // Chunk is owner of data.

    } else {             // Don't copy data.

      chunk->data = *data;

    }

  }

  chunk->tag = tag;

  return WEBP_MUX_OK;

}

WebPMuxError ChunkSetHead(WebPChunk* const chunk,

                          WebPChunk** const chunk_list) {

  WebPChunk* new_chunk;

  assert(chunk_list != NULL);

  if (*chunk_list != NULL) {

    return WEBP_MUX_NOT_FOUND;

  }

  new_chunk = (WebPChunk*)WebPSafeMalloc(1ULL, sizeof(*new_chunk));

  if (new_chunk == NULL) return WEBP_MUX_MEMORY_ERROR;

  *new_chunk = *chunk;

  chunk->owner = 0;

  new_chunk->next = NULL;

  *chunk_list = new_chunk;

  return WEBP_MUX_OK;

}

WebPMuxError ChunkAppend(WebPChunk* const chunk,

                         WebPChunk*** const chunk_list) {

  WebPMuxError err;

  assert(chunk_list != NULL && *chunk_list != NULL);

  if (**chunk_list == NULL) {

    err = ChunkSetHead(chunk, *chunk_list);

  } else {

    WebPChunk* last_chunk = **chunk_list;

    while (last_chunk->next != NULL) last_chunk = last_chunk->next;

    err = ChunkSetHead(chunk, &last_chunk->next);

    if (err == WEBP_MUX_OK) *chunk_list = &last_chunk->next;

  }

  return err;

}

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

// Chunk deletion method(s).

WebPChunk* ChunkDelete(WebPChunk* const chunk) {

  WebPChunk* const next = ChunkRelease(chunk);

  WebPSafeFree(chunk);

  return next;

}

void ChunkListDelete(WebPChunk** const chunk_list) {

  while (*chunk_list != NULL) {

    *chunk_list = ChunkDelete(*chunk_list);

  }

}

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

// Chunk serialization methods.

static uint8_t* ChunkEmit(const WebPChunk* const chunk, uint8_t* dst) {

  const size_t chunk_size = chunk->data.size;

  assert(chunk);

  // Do not check chunk->tag != NIL as NIL_TAG could have been read from a file.

  PutLE32(dst + 0, chunk->tag);

  PutLE32(dst + TAG_SIZE, (uint32_t)chunk_size);

  assert(chunk_size == (uint32_t)chunk_size);

  memcpy(dst + CHUNK_HEADER_SIZE, chunk->data.bytes, chunk_size);

  if (chunk_size & 1) dst[CHUNK_HEADER_SIZE + chunk_size] = 0;  // Add padding.

  return dst + ChunkDiskSize(chunk);

}

uint8_t* ChunkListEmit(const WebPChunk* chunk_list, uint8_t* dst) {

  while (chunk_list != NULL) {

    dst = ChunkEmit(chunk_list, dst);

    chunk_list = chunk_list->next;

  }

  return dst;

}

size_t ChunkListDiskSize(const WebPChunk* chunk_list) {

  size_t size = 0;

  while (chunk_list != NULL) {

    size += ChunkDiskSize(chunk_list);

    chunk_list = chunk_list->next;

  }

  return size;

}

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

// Life of a MuxImage object.

void MuxImageInit(WebPMuxImage* const wpi) {

  assert(wpi);

  memset(wpi, 0, sizeof(*wpi));

}

WebPMuxImage* MuxImageRelease(WebPMuxImage* const wpi) {

  WebPMuxImage* next;

  if (wpi == NULL) return NULL;

  // There should be at most one chunk of 'header', 'alpha', 'img' but we call

  // ChunkListDelete to be safe

  ChunkListDelete(&wpi->header);

  ChunkListDelete(&wpi->alpha);

  ChunkListDelete(&wpi->img);

  ChunkListDelete(&wpi->unknown);

  next = wpi->next;

  MuxImageInit(wpi);

  return next;

}

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

// MuxImage search methods.

// Get a reference to appropriate chunk list within an image given chunk tag.

static WebPChunk** GetChunkListFromId(const WebPMuxImage* const wpi,

                                      WebPChunkId id) {

  assert(wpi != NULL);

  switch (id) {

    case WEBP_CHUNK_ANMF:

      return (WebPChunk**)&wpi->header;

    case WEBP_CHUNK_ALPHA:

      return (WebPChunk**)&wpi->alpha;

    case WEBP_CHUNK_IMAGE:

      return (WebPChunk**)&wpi->img;

    default:

      return NULL;

  }

}

int MuxImageCount(const WebPMuxImage* wpi_list, WebPChunkId id) {

  int count = 0;

  const WebPMuxImage* current;

  for (current = wpi_list; current != NULL; current = current->next) {

    if (id == WEBP_CHUNK_NIL) {

      ++count;  // Special case: count all images.

    } else {

      const WebPChunk* const wpi_chunk = *GetChunkListFromId(current, id);

      if (wpi_chunk != NULL) {

        const WebPChunkId wpi_chunk_id = ChunkGetIdFromTag(wpi_chunk->tag);

        if (wpi_chunk_id == id) ++count;  // Count images with a matching 'id'.

      }

    }

  }

  return count;

}

// Outputs a pointer to 'prev_wpi->next',

//   where 'prev_wpi' is the pointer to the image at position (nth - 1).

// Returns true if nth image was found.

static int SearchImageToGetOrDelete(WebPMuxImage** wpi_list, uint32_t nth,

                                    WebPMuxImage*** const location) {

  uint32_t count = 0;

  assert(wpi_list);

  *location = wpi_list;

  if (nth == 0) {

    nth = MuxImageCount(*wpi_list, WEBP_CHUNK_NIL);

    if (nth == 0) return 0;  // Not found.

  }

  while (*wpi_list != NULL) {

    WebPMuxImage* const cur_wpi = *wpi_list;

    ++count;

    if (count == nth) return 1;  // Found.

    wpi_list = &cur_wpi->next;

    *location = wpi_list;

  }

  return 0;  // Not found.

}

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

// MuxImage writer methods.

WebPMuxError MuxImagePush(const WebPMuxImage* wpi, WebPMuxImage** wpi_list) {

  WebPMuxImage* new_wpi;

  while (*wpi_list != NULL) {

    WebPMuxImage* const cur_wpi = *wpi_list;

    if (cur_wpi->next == NULL) break;

    wpi_list = &cur_wpi->next;

  }

  new_wpi = (WebPMuxImage*)WebPSafeMalloc(1ULL, sizeof(*new_wpi));

  if (new_wpi == NULL) return WEBP_MUX_MEMORY_ERROR;

  *new_wpi = *wpi;

  new_wpi->next = NULL;

  if (*wpi_list != NULL) {

    (*wpi_list)->next = new_wpi;

  } else {

    *wpi_list = new_wpi;

  }

  return WEBP_MUX_OK;

}

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

// MuxImage deletion methods.

WebPMuxImage* MuxImageDelete(WebPMuxImage* const wpi) {

  // Delete the components of wpi. If wpi is NULL this is a noop.

  WebPMuxImage* const next = MuxImageRelease(wpi);

  WebPSafeFree(wpi);

  return next;

}

WebPMuxError MuxImageDeleteNth(WebPMuxImage** wpi_list, uint32_t nth) {

  assert(wpi_list);

  if (!SearchImageToGetOrDelete(wpi_list, nth, &wpi_list)) {

    return WEBP_MUX_NOT_FOUND;

  }

  *wpi_list = MuxImageDelete(*wpi_list);

  return WEBP_MUX_OK;

}

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

// MuxImage reader methods.

WebPMuxError MuxImageGetNth(const WebPMuxImage** wpi_list, uint32_t nth,

                            WebPMuxImage** wpi) {

  assert(wpi_list);

  assert(wpi);

  if (!SearchImageToGetOrDelete((WebPMuxImage**)wpi_list, nth,

                                (WebPMuxImage***)&wpi_list)) {

    return WEBP_MUX_NOT_FOUND;

  }

  *wpi = (WebPMuxImage*)*wpi_list;

  return WEBP_MUX_OK;

}

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

// MuxImage serialization methods.

// Size of an image.

size_t MuxImageDiskSize(const WebPMuxImage* const wpi) {

  size_t size = 0;

  if (wpi->header != NULL) size += ChunkDiskSize(wpi->header);

  if (wpi->alpha != NULL) size += ChunkDiskSize(wpi->alpha);

  if (wpi->img != NULL) size += ChunkDiskSize(wpi->img);

  if (wpi->unknown != NULL) size += ChunkListDiskSize(wpi->unknown);

  return size;

}

// Special case as ANMF chunk encapsulates other image chunks.

static uint8_t* ChunkEmitSpecial(const WebPChunk* const header,

                                 size_t total_size, uint8_t* dst) {

  const size_t header_size = header->data.size;

  const size_t offset_to_next = total_size - CHUNK_HEADER_SIZE;

  assert(header->tag == kChunks[IDX_ANMF].tag);

  PutLE32(dst + 0, header->tag);

  PutLE32(dst + TAG_SIZE, (uint32_t)offset_to_next);

  assert(header_size == (uint32_t)header_size);

  memcpy(dst + CHUNK_HEADER_SIZE, header->data.bytes, header_size);

  if (header_size & 1) {

    dst[CHUNK_HEADER_SIZE + header_size] = 0;  // Add padding.

  }

  return dst + ChunkDiskSize(header);

}

uint8_t* MuxImageEmit(const WebPMuxImage* const wpi, uint8_t* dst) {

  // Ordering of chunks to be emitted is strictly as follows:

  // 1. ANMF chunk (if present).

  // 2. ALPH chunk (if present).

  // 3. VP8/VP8L chunk.

  assert(wpi);

  if (wpi->header != NULL) {

    dst = ChunkEmitSpecial(wpi->header, MuxImageDiskSize(wpi), dst);

  }

  if (wpi->alpha != NULL) dst = ChunkEmit(wpi->alpha, dst);

  if (wpi->img != NULL) dst = ChunkEmit(wpi->img, dst);

  if (wpi->unknown != NULL) dst = ChunkListEmit(wpi->unknown, dst);

  return dst;

}

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

// Helper methods for mux.

int MuxHasAlpha(const WebPMuxImage* images) {

  while (images != NULL) {

    if (images->has_alpha) return 1;

    images = images->next;

  }

  return 0;

}

uint8_t* MuxEmitRiffHeader(uint8_t* const data, size_t size) {

  PutLE32(data + 0, MKFOURCC('R', 'I', 'F', 'F'));

  PutLE32(data + TAG_SIZE, (uint32_t)size - CHUNK_HEADER_SIZE);

  assert(size == (uint32_t)size);

  PutLE32(data + TAG_SIZE + CHUNK_SIZE_BYTES, MKFOURCC('W', 'E', 'B', 'P'));

  return data + RIFF_HEADER_SIZE;

}

WebPChunk** MuxGetChunkListFromId(const WebPMux* mux, WebPChunkId id) {

  assert(mux != NULL);

  switch (id) {

    case WEBP_CHUNK_VP8X:

      return (WebPChunk**)&mux->vp8x;

    case WEBP_CHUNK_ICCP:

      return (WebPChunk**)&mux->iccp;

    case WEBP_CHUNK_ANIM:

      return (WebPChunk**)&mux->anim;

    case WEBP_CHUNK_EXIF:

      return (WebPChunk**)&mux->exif;

    case WEBP_CHUNK_XMP:

      return (WebPChunk**)&mux->xmp;

    default:

      return (WebPChunk**)&mux->unknown;

  }

}

static int IsNotCompatible(int feature, int num_items) {

  return (feature != 0) != (num_items > 0);

}

#define NO_FLAG ((WebPFeatureFlags)0)

// Test basic constraints:

// retrieval, maximum number of chunks by index (use -1 to skip)

// and feature incompatibility (use NO_FLAG to skip).

// On success returns WEBP_MUX_OK and stores the chunk count in *num.

static WebPMuxError ValidateChunk(const WebPMux* const mux, CHUNK_INDEX idx,

                                  WebPFeatureFlags feature, uint32_t vp8x_flags,

                                  int max, int* num) {

  const WebPMuxError err = WebPMuxNumChunks(mux, kChunks[idx].id, num);

  if (err != WEBP_MUX_OK) return err;

  if (max > -1 && *num > max) return WEBP_MUX_INVALID_ARGUMENT;

  if (feature != NO_FLAG && IsNotCompatible(vp8x_flags & feature, *num)) {

    return WEBP_MUX_INVALID_ARGUMENT;

  }

  return WEBP_MUX_OK;

}

WebPMuxError MuxValidate(const WebPMux* const mux) {

  int num_iccp;

  int num_exif;

  int num_xmp;

  int num_anim;

  int num_frames;

  int num_vp8x;

  int num_images;

  int num_alpha;

  uint32_t flags;

  WebPMuxError err;

  // Verify mux is not NULL.

  if (mux == NULL) return WEBP_MUX_INVALID_ARGUMENT;

  // Verify mux has at least one image.

  if (mux->images == NULL) return WEBP_MUX_INVALID_ARGUMENT;

  err = WebPMuxGetFeatures(mux, &flags);

  if (err != WEBP_MUX_OK) return err;

  // At most one color profile chunk.

  err = ValidateChunk(mux, IDX_ICCP, ICCP_FLAG, flags, 1, &num_iccp);

  if (err != WEBP_MUX_OK) return err;

  // At most one EXIF metadata.

  err = ValidateChunk(mux, IDX_EXIF, EXIF_FLAG, flags, 1, &num_exif);

  if (err != WEBP_MUX_OK) return err;

  // At most one XMP metadata.

  err = ValidateChunk(mux, IDX_XMP, XMP_FLAG, flags, 1, &num_xmp);

  if (err != WEBP_MUX_OK) return err;

  // Verify either VP8X chunk is present OR there is only one elem in

  // mux->images.

  err = ValidateChunk(mux, IDX_VP8X, NO_FLAG, flags, 1, &num_vp8x);

  if (err != WEBP_MUX_OK) return err;

  err = ValidateChunk(mux, IDX_VP8, NO_FLAG, flags, -1, &num_images);

  if (err != WEBP_MUX_OK) return err;

  if (num_vp8x == 0 && num_images != 1) return WEBP_MUX_INVALID_ARGUMENT;

  // Animation: ANIMATION_FLAG, ANIM chunk and ANMF chunk(s) are consistent.

  // At most one ANIM chunk.

  err = ValidateChunk(mux, IDX_ANIM, NO_FLAG, flags, 1, &num_anim);

  if (err != WEBP_MUX_OK) return err;

  err = ValidateChunk(mux, IDX_ANMF, NO_FLAG, flags, -1, &num_frames);

  if (err != WEBP_MUX_OK) return err;

  {

    const int has_animation = !!(flags & ANIMATION_FLAG);

    // An ANIM chunk must be present when has_animation is true, and all images

    // must be contained in ANMF chunks.

    if (has_animation &&

        (num_anim == 0 || num_frames == 0 || num_frames != num_images)) {

      return WEBP_MUX_INVALID_ARGUMENT;

    }

    if (!has_animation && (num_anim == 1 || num_frames > 0)) {

      return WEBP_MUX_INVALID_ARGUMENT;

    }

    if (!has_animation) {

      const WebPMuxImage* images = mux->images;

      // There can be only one image.

      if (images == NULL || images->next != NULL) {

        return WEBP_MUX_INVALID_ARGUMENT;

      }

      // Size must match.

      if (mux->canvas_width > 0) {

        if (images->width != mux->canvas_width ||

            images->height != mux->canvas_height) {

          return WEBP_MUX_INVALID_ARGUMENT;

        }

      }

    }

  }

  // ALPHA_FLAG & alpha chunk(s) are consistent.

  // Note: ALPHA_FLAG can be set when there is actually no Alpha data present.

  if (MuxHasAlpha(mux->images)) {

    if (num_vp8x > 0) {

      // VP8X chunk is present, so it should contain ALPHA_FLAG.

      if (!(flags & ALPHA_FLAG)) return WEBP_MUX_INVALID_ARGUMENT;

    } else {

      // VP8X chunk is not present, so ALPH chunks should NOT be present either.

      err = WebPMuxNumChunks(mux, WEBP_CHUNK_ALPHA, &num_alpha);

      if (err != WEBP_MUX_OK) return err;

      if (num_alpha > 0) return WEBP_MUX_INVALID_ARGUMENT;

    }

  }

  return WEBP_MUX_OK;

}

#undef NO_FLAG

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