// Copyright 2014 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

#include "core/fxcrt/fx_basic.h"
#include "core/fxcrt/plex.h"

CFX_PtrList::CFX_PtrList(int nBlockSize)
    : m_pNodeHead(nullptr),
      m_pNodeTail(nullptr),
      m_nCount(0),
      m_pNodeFree(nullptr),
      m_pBlocks(nullptr),
      m_nBlockSize(nBlockSize) {}
FX_POSITION CFX_PtrList::AddTail(void* newElement) {
  CNode* pNewNode = NewNode(m_pNodeTail, nullptr);
  pNewNode->data = newElement;
  if (m_pNodeTail) {
    m_pNodeTail->pNext = pNewNode;
  } else {
    m_pNodeHead = pNewNode;
  }
  m_pNodeTail = pNewNode;
  return (FX_POSITION)pNewNode;
}
FX_POSITION CFX_PtrList::AddHead(void* newElement) {
  CNode* pNewNode = NewNode(nullptr, m_pNodeHead);
  pNewNode->data = newElement;
  if (m_pNodeHead) {
    m_pNodeHead->pPrev = pNewNode;
  } else {
    m_pNodeTail = pNewNode;
  }
  m_pNodeHead = pNewNode;
  return (FX_POSITION)pNewNode;
}
FX_POSITION CFX_PtrList::InsertAfter(FX_POSITION position, void* newElement) {
  if (!position) {
    return AddTail(newElement);
  }
  CNode* pOldNode = (CNode*)position;
  CNode* pNewNode = NewNode(pOldNode, pOldNode->pNext);
  pNewNode->data = newElement;
  if (pOldNode->pNext) {
    pOldNode->pNext->pPrev = pNewNode;
  } else {
    m_pNodeTail = pNewNode;
  }
  pOldNode->pNext = pNewNode;
  return (FX_POSITION)pNewNode;
}
void CFX_PtrList::RemoveAt(FX_POSITION position) {
  CNode* pOldNode = (CNode*)position;
  if (pOldNode == m_pNodeHead) {
    m_pNodeHead = pOldNode->pNext;
  } else {
    pOldNode->pPrev->pNext = pOldNode->pNext;
  }
  if (pOldNode == m_pNodeTail) {
    m_pNodeTail = pOldNode->pPrev;
  } else {
    pOldNode->pNext->pPrev = pOldNode->pPrev;
  }
  FreeNode(pOldNode);
}
void CFX_PtrList::FreeNode(CFX_PtrList::CNode* pNode) {
  pNode->pNext = m_pNodeFree;
  m_pNodeFree = pNode;
  m_nCount--;
  if (m_nCount == 0) {
    RemoveAll();
  }
}

void CFX_PtrList::RemoveAll() {
  m_nCount = 0;
  m_pNodeHead = nullptr;
  m_pNodeTail = nullptr;
  m_pNodeFree = nullptr;
  if (m_pBlocks) {
    m_pBlocks->FreeDataChain();
    m_pBlocks = nullptr;
  }
}

CFX_PtrList::CNode* CFX_PtrList::NewNode(CFX_PtrList::CNode* pPrev,
                                         CFX_PtrList::CNode* pNext) {
  if (!m_pNodeFree) {
    CFX_Plex* pNewBlock =
        CFX_Plex::Create(m_pBlocks, m_nBlockSize, sizeof(CNode));
    CNode* pNode = (CNode*)pNewBlock->data();
    pNode += m_nBlockSize - 1;
    for (int i = m_nBlockSize - 1; i >= 0; i--, pNode--) {
      pNode->pNext = m_pNodeFree;
      m_pNodeFree = pNode;
    }
  }
  CFX_PtrList::CNode* pNode = m_pNodeFree;
  m_pNodeFree = m_pNodeFree->pNext;
  pNode->pPrev = pPrev;
  pNode->pNext = pNext;
  m_nCount++;
  ASSERT(m_nCount > 0);
  pNode->data = 0;
  return pNode;
}
CFX_PtrList::~CFX_PtrList() {
  RemoveAll();
  ASSERT(m_nCount == 0);
}
FX_POSITION CFX_PtrList::FindIndex(int nIndex) const {
  if (nIndex >= m_nCount || nIndex < 0) {
    return nullptr;
  }
  CNode* pNode = m_pNodeHead;
  while (nIndex--) {
    pNode = pNode->pNext;
  }
  return (FX_POSITION)pNode;
}
FX_POSITION CFX_PtrList::Find(void* searchValue, FX_POSITION startAfter) const {
  CNode* pNode = (CNode*)startAfter;
  pNode = pNode ? pNode->pNext : m_pNodeHead;
  for (; pNode; pNode = pNode->pNext) {
    if (pNode->data == searchValue)
      return (FX_POSITION)pNode;
  }
  return nullptr;
}