text: // 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 "public/fpdf_doc.h"
  
  #include <memory>
  #include <set>
  
  #include "core/fpdfapi/page/cpdf_page.h"
  #include "core/fpdfapi/parser/cpdf_array.h"
  #include "core/fpdfapi/parser/cpdf_document.h"
  #include "core/fpdfdoc/cpdf_bookmark.h"
  #include "core/fpdfdoc/cpdf_bookmarktree.h"
  #include "core/fpdfdoc/cpdf_dest.h"
  #include "core/fpdfdoc/cpdf_pagelabel.h"
  #include "fpdfsdk/fsdk_define.h"
  #include "third_party/base/ptr_util.h"
  #include "third_party/base/stl_util.h"
  
  namespace {
  
  CPDF_Bookmark FindBookmark(const CPDF_BookmarkTree& tree,
                             CPDF_Bookmark bookmark,
                             const CFX_WideString& title,
                             std::set<CPDF_Dictionary*>* visited) {
    // Return if already checked to avoid circular calling.
    if (pdfium::ContainsKey(*visited, bookmark.GetDict()))
      return CPDF_Bookmark();
    visited->insert(bookmark.GetDict());
  
    if (bookmark.GetDict() &&
        bookmark.GetTitle().CompareNoCase(title.c_str()) == 0) {
      // First check this item.
      return bookmark;
    }
  
    // Go into children items.
    CPDF_Bookmark child = tree.GetFirstChild(bookmark);
    while (child.GetDict() && !pdfium::ContainsKey(*visited, child.GetDict())) {
      // Check this item and its children.
      CPDF_Bookmark found = FindBookmark(tree, child, title, visited);
      if (found.GetDict())
        return found;
      child = tree.GetNextSibling(child);
    }
    return CPDF_Bookmark();
  }
  
  CPDF_LinkList* GetLinkList(CPDF_Page* page) {
    if (!page)
      return nullptr;
  
    CPDF_Document* pDoc = page->m_pDocument;
    std::unique_ptr<CPDF_LinkList>* pHolder = pDoc->LinksContext();
    if (!pHolder->get())
      *pHolder = pdfium::MakeUnique<CPDF_LinkList>();
    return pHolder->get();
  }
  
  unsigned long Utf16EncodeMaybeCopyAndReturnLength(const CFX_WideString& text,
                                                    void* buffer,
                                                    unsigned long buflen) {
    CFX_ByteString encodedText = text.UTF16LE_Encode();
    unsigned long len = encodedText.GetLength();
    if (buffer && len <= buflen)
      FXSYS_memcpy(buffer, encodedText.c_str(), len);
    return len;
  }
  
  }  // namespace
  
  DLLEXPORT FPDF_BOOKMARK STDCALL
  FPDFBookmark_GetFirstChild(FPDF_DOCUMENT document, FPDF_BOOKMARK pDict) {
    CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
    if (!pDoc)
      return nullptr;
    CPDF_BookmarkTree tree(pDoc);
    CPDF_Bookmark bookmark =
        CPDF_Bookmark(ToDictionary(static_cast<CPDF_Object*>(pDict)));
    return tree.GetFirstChild(bookmark).GetDict();
  }
  
  DLLEXPORT FPDF_BOOKMARK STDCALL
  FPDFBookmark_GetNextSibling(FPDF_DOCUMENT document, FPDF_BOOKMARK pDict) {
    if (!pDict)
      return nullptr;
    CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
    if (!pDoc)
      return nullptr;
    CPDF_BookmarkTree tree(pDoc);
    CPDF_Bookmark bookmark =
        CPDF_Bookmark(ToDictionary(static_cast<CPDF_Object*>(pDict)));
    return tree.GetNextSibling(bookmark).GetDict();
  }
  
  DLLEXPORT unsigned long STDCALL FPDFBookmark_GetTitle(FPDF_BOOKMARK pDict,
                                                        void* buffer,
                                                        unsigned long buflen) {
    if (!pDict)
      return 0;
    CPDF_Bookmark bookmark(ToDictionary(static_cast<CPDF_Object*>(pDict)));
    CFX_WideString title = bookmark.GetTitle();
    return Utf16EncodeMaybeCopyAndReturnLength(title, buffer, buflen);
  }
  
  DLLEXPORT FPDF_BOOKMARK STDCALL FPDFBookmark_Find(FPDF_DOCUMENT document,
                                                    FPDF_WIDESTRING title) {
    if (!title || title[0] == 0)
      return nullptr;
    CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
    if (!pDoc)
      return nullptr;
    CPDF_BookmarkTree tree(pDoc);
    FX_STRSIZE len = CFX_WideString::WStringLength(title);
    CFX_WideString encodedTitle = CFX_WideString::FromUTF16LE(title, len);
    std::set<CPDF_Dictionary*> visited;
    return FindBookmark(tree, CPDF_Bookmark(), encodedTitle, &visited).GetDict();
  }
  
  DLLEXPORT FPDF_DEST STDCALL FPDFBookmark_GetDest(FPDF_DOCUMENT document,
                                                   FPDF_BOOKMARK pDict) {
    if (!pDict)
      return nullptr;
    CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
    if (!pDoc)
      return nullptr;
    CPDF_Bookmark bookmark(ToDictionary(static_cast<CPDF_Object*>(pDict)));
    CPDF_Dest dest = bookmark.GetDest(pDoc);
    if (dest.GetObject())
      return dest.GetObject();
    // If this bookmark is not directly associated with a dest, we try to get
    // action
    CPDF_Action action = bookmark.GetAction();
    if (!action.GetDict())
      return nullptr;
    return action.GetDest(pDoc).GetObject();
  }
  
  DLLEXPORT FPDF_ACTION STDCALL FPDFBookmark_GetAction(FPDF_BOOKMARK pDict) {
    if (!pDict)
      return nullptr;
    CPDF_Bookmark bookmark(ToDictionary(static_cast<CPDF_Object*>(pDict)));
    return bookmark.GetAction().GetDict();
  }
  
  DLLEXPORT unsigned long STDCALL FPDFAction_GetType(FPDF_ACTION pDict) {
    if (!pDict)
      return PDFACTION_UNSUPPORTED;
  
    CPDF_Action action(ToDictionary(static_cast<CPDF_Object*>(pDict)));
    CPDF_Action::ActionType type = action.GetType();
    switch (type) {
      case CPDF_Action::GoTo:
        return PDFACTION_GOTO;
      case CPDF_Action::GoToR:
        return PDFACTION_REMOTEGOTO;
      case CPDF_Action::URI:
        return PDFACTION_URI;
      case CPDF_Action::Launch:
        return PDFACTION_LAUNCH;
      default:
        return PDFACTION_UNSUPPORTED;
    }
  }
  
  DLLEXPORT FPDF_DEST STDCALL FPDFAction_GetDest(FPDF_DOCUMENT document,
                                                 FPDF_ACTION pDict) {
    if (!pDict)
      return nullptr;
    CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
    if (!pDoc)
      return nullptr;
    CPDF_Action action(ToDictionary(static_cast<CPDF_Object*>(pDict)));
    return action.GetDest(pDoc).GetObject();
  }
  
  DLLEXPORT unsigned long STDCALL FPDFAction_GetFilePath(FPDF_ACTION pDict,
                                                         void* buffer,
                                                         unsigned long buflen) {
    unsigned long type = FPDFAction_GetType(pDict);
    if (type != PDFACTION_REMOTEGOTO && type != PDFACTION_LAUNCH)
      return 0;
  
    CPDF_Action action(ToDictionary(static_cast<CPDF_Object*>(pDict)));
    CFX_ByteString path = action.GetFilePath().UTF8Encode();
    unsigned long len = path.GetLength() + 1;
    if (buffer && len <= buflen)
      FXSYS_memcpy(buffer, path.c_str(), len);
    return len;
  }
  
  DLLEXPORT unsigned long STDCALL FPDFAction_GetURIPath(FPDF_DOCUMENT document,
                                                        FPDF_ACTION pDict,
                                                        void* buffer,
                                                        unsigned long buflen) {
    if (!pDict)
      return 0;
    CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
    if (!pDoc)
      return 0;
    CPDF_Action action(ToDictionary(static_cast<CPDF_Object*>(pDict)));
    CFX_ByteString path = action.GetURI(pDoc);
    unsigned long len = path.GetLength() + 1;
    if (buffer && len <= buflen)
      FXSYS_memcpy(buffer, path.c_str(), len);
    return len;
  }
  
  DLLEXPORT unsigned long STDCALL FPDFDest_GetPageIndex(FPDF_DOCUMENT document,
                                                        FPDF_DEST pDict) {
    if (!pDict)
      return 0;
    CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
    if (!pDoc)
      return 0;
    CPDF_Dest dest(static_cast<CPDF_Array*>(pDict));
    return dest.GetPageIndex(pDoc);
  }
  
  DLLEXPORT FPDF_BOOL STDCALL FPDFDest_GetLocationInPage(FPDF_DEST pDict,
                                                         FPDF_BOOL* hasXVal,
                                                         FPDF_BOOL* hasYVal,
                                                         FPDF_BOOL* hasZoomVal,
                                                         FS_FLOAT* x,
                                                         FS_FLOAT* y,
                                                         FS_FLOAT* zoom) {
    if (!pDict)
      return false;
  
    std::unique_ptr<CPDF_Dest> dest(
        new CPDF_Dest(static_cast<CPDF_Object*>(pDict)));
  
    // FPDF_BOOL is an int, GetXYZ expects bools.
    bool bHasX;
    bool bHasY;
    bool bHasZoom;
    if (!dest->GetXYZ(&bHasX, &bHasY, &bHasZoom, x, y, zoom))
      return false;
  
    *hasXVal = bHasX;
    *hasYVal = bHasY;
    *hasZoomVal = bHasZoom;
    return true;
  }
  
  DLLEXPORT FPDF_LINK STDCALL FPDFLink_GetLinkAtPoint(FPDF_PAGE page,
                                                      double x,
                                                      double y) {
    CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
    if (!pPage)
      return nullptr;
  
    CPDF_LinkList* pLinkList = GetLinkList(pPage);
    if (!pLinkList)
      return nullptr;
  
    return pLinkList->GetLinkAtPoint(pPage, (FX_FLOAT)x, (FX_FLOAT)y, nullptr)
        .GetDict();
  }
  
  DLLEXPORT int STDCALL FPDFLink_GetLinkZOrderAtPoint(FPDF_PAGE page,
                                                      double x,
                                                      double y) {
    CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
    if (!pPage)
      return -1;
  
    CPDF_LinkList* pLinkList = GetLinkList(pPage);
    if (!pLinkList)
      return -1;
  
    int z_order = -1;
    pLinkList->GetLinkAtPoint(pPage, (FX_FLOAT)x, (FX_FLOAT)y, &z_order);
    return z_order;
  }
  
  DLLEXPORT FPDF_DEST STDCALL FPDFLink_GetDest(FPDF_DOCUMENT document,
                                               FPDF_LINK pDict) {
    if (!pDict)
      return nullptr;
    CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
    if (!pDoc)
      return nullptr;
    CPDF_Link link(ToDictionary(static_cast<CPDF_Object*>(pDict)));
    FPDF_DEST dest = link.GetDest(pDoc).GetObject();
    if (dest)
      return dest;
    // If this link is not directly associated with a dest, we try to get action
    CPDF_Action action = link.GetAction();
    if (!action.GetDict())
      return nullptr;
    return action.GetDest(pDoc).GetObject();
  }
  
  DLLEXPORT FPDF_ACTION STDCALL FPDFLink_GetAction(FPDF_LINK pDict) {
    if (!pDict)
      return nullptr;
  
    CPDF_Link link(ToDictionary(static_cast<CPDF_Object*>(pDict)));
    return link.GetAction().GetDict();
  }
  
  DLLEXPORT FPDF_BOOL STDCALL FPDFLink_Enumerate(FPDF_PAGE page,
                                                 int* startPos,
                                                 FPDF_LINK* linkAnnot) {
    if (!startPos || !linkAnnot)
      return false;
    CPDF_Page* pPage = CPDFPageFromFPDFPage(page);
    if (!pPage || !pPage->m_pFormDict)
      return false;
    CPDF_Array* pAnnots = pPage->m_pFormDict->GetArrayFor("Annots");
    if (!pAnnots)
      return false;
    for (size_t i = *startPos; i < pAnnots->GetCount(); i++) {
      CPDF_Dictionary* pDict =
          ToDictionary(static_cast<CPDF_Object*>(pAnnots->GetDirectObjectAt(i)));
      if (!pDict)
        continue;
      if (pDict->GetStringFor("Subtype") == "Link") {
        *startPos = static_cast<int>(i + 1);
        *linkAnnot = static_cast<FPDF_LINK>(pDict);
        return true;
      }
    }
    return false;
  }
  
  DLLEXPORT FPDF_BOOL STDCALL FPDFLink_GetAnnotRect(FPDF_LINK linkAnnot,
                                                    FS_RECTF* rect) {
    if (!linkAnnot || !rect)
      return false;
    CPDF_Dictionary* pAnnotDict =
        ToDictionary(static_cast<CPDF_Object*>(linkAnnot));
    CFX_FloatRect rt = pAnnotDict->GetRectFor("Rect");
    rect->left = rt.left;
    rect->bottom = rt.bottom;
    rect->right = rt.right;
    rect->top = rt.top;
    return true;
  }
  
  DLLEXPORT int STDCALL FPDFLink_CountQuadPoints(FPDF_LINK linkAnnot) {
    if (!linkAnnot)
      return 0;
    CPDF_Dictionary* pAnnotDict =
        ToDictionary(static_cast<CPDF_Object*>(linkAnnot));
    CPDF_Array* pArray = pAnnotDict->GetArrayFor("QuadPoints");
    if (!pArray)
      return 0;
    return static_cast<int>(pArray->GetCount() / 8);
  }
  
  DLLEXPORT FPDF_BOOL STDCALL FPDFLink_GetQuadPoints(FPDF_LINK linkAnnot,
                                                     int quadIndex,
                                                     FS_QUADPOINTSF* quadPoints) {
    if (!linkAnnot || !quadPoints)
      return false;
    CPDF_Dictionary* pAnnotDict =
        ToDictionary(static_cast<CPDF_Object*>(linkAnnot));
    CPDF_Array* pArray = pAnnotDict->GetArrayFor("QuadPoints");
    if (!pArray)
      return false;
  
    if (quadIndex < 0 ||
        static_cast<size_t>(quadIndex) >= pArray->GetCount() / 8 ||
        (static_cast<size_t>(quadIndex * 8 + 7) >= pArray->GetCount())) {
      return false;
    }
  
    quadPoints->x1 = pArray->GetNumberAt(quadIndex * 8);
    quadPoints->y1 = pArray->GetNumberAt(quadIndex * 8 + 1);
    quadPoints->x2 = pArray->GetNumberAt(quadIndex * 8 + 2);
    quadPoints->y2 = pArray->GetNumberAt(quadIndex * 8 + 3);
    quadPoints->x3 = pArray->GetNumberAt(quadIndex * 8 + 4);
    quadPoints->y3 = pArray->GetNumberAt(quadIndex * 8 + 5);
    quadPoints->x4 = pArray->GetNumberAt(quadIndex * 8 + 6);
    quadPoints->y4 = pArray->GetNumberAt(quadIndex * 8 + 7);
    return true;
  }
  
  DLLEXPORT unsigned long STDCALL FPDF_GetMetaText(FPDF_DOCUMENT document,
                                                   FPDF_BYTESTRING tag,
                                                   void* buffer,
                                                   unsigned long buflen) {
    if (!tag)
      return 0;
    CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
    if (!pDoc)
      return 0;
    CPDF_Dictionary* pInfo = pDoc->GetInfo();
    if (!pInfo)
      return 0;
    CFX_WideString text = pInfo->GetUnicodeTextFor(tag);
    return Utf16EncodeMaybeCopyAndReturnLength(text, buffer, buflen);
  }
  
  DLLEXPORT unsigned long STDCALL FPDF_GetPageLabel(FPDF_DOCUMENT document,
                                                    int page_index,
                                                    void* buffer,
                                                    unsigned long buflen) {
    if (page_index < 0)
      return 0;
  
    // CPDF_PageLabel can deal with NULL |document|.
    CPDF_PageLabel label(CPDFDocumentFromFPDFDocument(document));
    CFX_WideString str;
    if (!label.GetLabel(page_index, &str))
      return 0;
    return Utf16EncodeMaybeCopyAndReturnLength(str, buffer, buflen);
  }
  