// Copyright 2017 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_ZUCCHINI_ZUCCHINI_H_
#define COMPONENTS_ZUCCHINI_ZUCCHINI_H_

#include <string>

#include "components/zucchini/buffer_view.h"
#include "components/zucchini/patch_reader.h"
#include "components/zucchini/patch_writer.h"

// Core Zucchini library, consisting of:
// - Global constants.
// - Patch gen and apply functions, where "old" and "new" data are represented
//   as buffers, and patch data represented as EnsemblePatchWriter or
//   EnsemblePatchReader.

namespace zucchini {

namespace status {

// Zucchini status code, which can also be used as process exit code. Therefore
// success is explicitly 0.
enum Code {
  kStatusSuccess = 0,
  kStatusInvalidParam = 1,
  kStatusFileReadError = 2,
  kStatusFileWriteError = 3,
  kStatusPatchReadError = 4,
  kStatusPatchWriteError = 5,
  kStatusInvalidOldImage = 6,
  kStatusInvalidNewImage = 7,
  kStatusFatal = 8,
};

}  // namespace status

// Generates ensemble patch from |old_image| to |new_image| using the default
// element detection and matching heuristics, writes the results to
// |patch_writer|, and returns a status::Code.
status::Code GenerateBuffer(ConstBufferView old_image,
                            ConstBufferView new_image,
                            EnsemblePatchWriter* patch_writer);

// Same as GenerateEnsemble(), but if |imposed_matches| is non-empty, then
// overrides default element detection and matching heuristics with custom
// element matching encoded in |imposed_matches|, which should be formatted as:
//   "#+#=#+#,#+#=#+#,..."  (e.g., "1+2=3+4", "1+2=3+4,5+6=7+8"),
// where "#+#=#+#" encodes a match as 4 unsigned integers:
//   [offset in "old", size in "old", offset in "new", size in "new"].
status::Code GenerateBufferImposed(ConstBufferView old_image,
                                   ConstBufferView new_image,
                                   std::string imposed_matches,
                                   EnsemblePatchWriter* patch_writer);

// Generates raw patch from |old_image| to |new_image|, and writes it to
// |patch_writer|.
status::Code GenerateBufferRaw(ConstBufferView old_image,
                               ConstBufferView new_image,
                               EnsemblePatchWriter* patch_writer);

// Applies |patch_reader| to |old_image| to build |new_image|, which refers to
// preallocated memory of sufficient size.
status::Code ApplyBuffer(ConstBufferView old_image,
                         const EnsemblePatchReader& patch_reader,
                         MutableBufferView new_image);

}  // namespace zucchini

#endif  // COMPONENTS_ZUCCHINI_ZUCCHINI_H_