// Copyright 2016 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com

#ifndef CORE_FPDFAPI_PARSER_CPDF_ARRAY_H_
#define CORE_FPDFAPI_PARSER_CPDF_ARRAY_H_

#include <set>
#include <type_traits>
#include <utility>
#include <vector>

#include "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
#include "core/fpdfapi/parser/cpdf_object.h"
#include "core/fxcrt/fx_coordinates.h"
#include "core/fxcrt/retain_ptr.h"
#include "third_party/base/check.h"

class CPDF_Array final : public CPDF_Object {
 public:
  using const_iterator = std::vector<RetainPtr<CPDF_Object>>::const_iterator;

  CONSTRUCT_VIA_MAKE_RETAIN;

  // CPDF_Object:
  Type GetType() const override;
  RetainPtr<CPDF_Object> Clone() const override;
  bool IsArray() const override;
  CPDF_Array* AsArray() override;
  const CPDF_Array* AsArray() const override;
  bool WriteTo(IFX_ArchiveStream* archive,
               const CPDF_Encryptor* encryptor) const override;

  bool IsEmpty() const { return m_Objects.empty(); }
  size_t size() const { return m_Objects.size(); }
  CPDF_Object* GetObjectAt(size_t index);
  const CPDF_Object* GetObjectAt(size_t index) const;
  CPDF_Object* GetDirectObjectAt(size_t index);
  const CPDF_Object* GetDirectObjectAt(size_t index) const;
  ByteString GetStringAt(size_t index) const;
  WideString GetUnicodeTextAt(size_t index) const;
  bool GetBooleanAt(size_t index, bool bDefault) const;
  int GetIntegerAt(size_t index) const;
  float GetNumberAt(size_t index) const;
  CPDF_Dictionary* GetDictAt(size_t index);
  const CPDF_Dictionary* GetDictAt(size_t index) const;
  CPDF_Stream* GetStreamAt(size_t index);
  const CPDF_Stream* GetStreamAt(size_t index) const;
  CPDF_Array* GetArrayAt(size_t index);
  const CPDF_Array* GetArrayAt(size_t index) const;
  CFX_Matrix GetMatrix() const;
  CFX_FloatRect GetRect() const;

  // Creates object owned by the array, returns unowned pointer to it.
  // We have special cases for objects that can intern strings from
  // a ByteStringPool. Prefer using these templates over direct calls
  // to Append()/SetAt()/InsertAt() since by creating a new object with no
  // previous references, they ensure cycles can not be introduced.
  template <typename T, typename... Args>
  typename std::enable_if<!CanInternStrings<T>::value, T*>::type AppendNew(
      Args&&... args) {
    return static_cast<T*>(
        Append(pdfium::MakeRetain<T>(std::forward<Args>(args)...)));
  }
  template <typename T, typename... Args>
  typename std::enable_if<CanInternStrings<T>::value, T*>::type AppendNew(
      Args&&... args) {
    return static_cast<T*>(
        Append(pdfium::MakeRetain<T>(m_pPool, std::forward<Args>(args)...)));
  }
  template <typename T, typename... Args>
  typename std::enable_if<!CanInternStrings<T>::value, T*>::type SetNewAt(
      size_t index,
      Args&&... args) {
    return static_cast<T*>(
        SetAt(index, pdfium::MakeRetain<T>(std::forward<Args>(args)...)));
  }
  template <typename T, typename... Args>
  typename std::enable_if<CanInternStrings<T>::value, T*>::type SetNewAt(
      size_t index,
      Args&&... args) {
    return static_cast<T*>(SetAt(
        index, pdfium::MakeRetain<T>(m_pPool, std::forward<Args>(args)...)));
  }
  template <typename T, typename... Args>
  typename std::enable_if<!CanInternStrings<T>::value, T*>::type InsertNewAt(
      size_t index,
      Args&&... args) {
    return static_cast<T*>(
        InsertAt(index, pdfium::MakeRetain<T>(std::forward<Args>(args)...)));
  }
  template <typename T, typename... Args>
  typename std::enable_if<CanInternStrings<T>::value, T*>::type InsertNewAt(
      size_t index,
      Args&&... args) {
    return static_cast<T*>(InsertAt(
        index, pdfium::MakeRetain<T>(m_pPool, std::forward<Args>(args)...)));
  }

  // Retains reference to `pObj`, returns raw pointer to it.
  CPDF_Object* Append(RetainPtr<CPDF_Object> pObj);
  // Overwrites the object at `index`. `index` must be less than the array size.
  CPDF_Object* SetAt(size_t index, RetainPtr<CPDF_Object> pObj);
  // Inserts `pObj` and shifts existing objects starting at `index` over, like
  // std::vector::insert(). Unlike std::vector::insert(), where
  // std::vector::end() is the last possible position, `index` can be greater
  // than or equal to the array size. In which case, the array will be resized
  // such that `index` is the last object.
  CPDF_Object* InsertAt(size_t index, RetainPtr<CPDF_Object> pObj);

  void Clear();
  void RemoveAt(size_t index);
  void ConvertToIndirectObjectAt(size_t index,
                                 CPDF_IndirectObjectHolder* pHolder);
  bool IsLocked() const { return !!m_LockCount; }

 private:
  friend class CPDF_ArrayLocker;

  CPDF_Array();
  explicit CPDF_Array(const WeakPtr<ByteStringPool>& pPool);
  ~CPDF_Array() override;

  RetainPtr<CPDF_Object> CloneNonCyclic(
      bool bDirect,
      std::set<const CPDF_Object*>* pVisited) const override;

  std::vector<RetainPtr<CPDF_Object>> m_Objects;
  WeakPtr<ByteStringPool> m_pPool;
  mutable uint32_t m_LockCount = 0;
};

class CPDF_ArrayLocker {
 public:
  using const_iterator = CPDF_Array::const_iterator;

  explicit CPDF_ArrayLocker(const CPDF_Array* pArray);
  ~CPDF_ArrayLocker();

  const_iterator begin() const {
    CHECK(m_pArray->IsLocked());
    return m_pArray->m_Objects.begin();
  }
  const_iterator end() const {
    CHECK(m_pArray->IsLocked());
    return m_pArray->m_Objects.end();
  }

 private:
  RetainPtr<const CPDF_Array> const m_pArray;
};

inline CPDF_Array* ToArray(CPDF_Object* obj) {
  return obj ? obj->AsArray() : nullptr;
}

inline const CPDF_Array* ToArray(const CPDF_Object* obj) {
  return obj ? obj->AsArray() : nullptr;
}

inline RetainPtr<CPDF_Array> ToArray(RetainPtr<CPDF_Object> obj) {
  return RetainPtr<CPDF_Array>(ToArray(obj.Get()));
}

#endif  // CORE_FPDFAPI_PARSER_CPDF_ARRAY_H_