#!/usr/bin/env instantfpc
{$mode objfpc}{$H+}{$ASSERTIONS ON}
uses
  Classes, SysUtils, StrUtils, DateUtils,
  Classes, SysUtils, StrUtils,
  fgl, Regexpr;

type
  TStringArray = array of string;

function Join(const Strings: TStringArray; const Separator: string = sLineBreak): string;
var
  i: integer;
begin
  if Length(Strings) = 0 then
    Exit;
  Result := Strings[Low(Strings)];
  for i := Low(Strings) + 1 to High(Strings) do begin
    Result := Result + Separator + Strings[i];
  end;
end {Join};

function IndexOfText(const S: string; const Strings: TStringArray): integer;
var
  i: integer;
begin
  Result := -1;
  for i := Low(Strings) to High(Strings) do begin
    if SameText(Strings[i], S) then begin
      Result := i;
      Exit;
    end;
  end;
end {IndexOfText};



type
  TFolder = class;

  { TEntry }

  TEntry = class

  TContentEntry = class(TEntry)
  private
    FAdded: TDateTime;
    FDescription: string;
    FModified: TDateTime;
    FName: string;
    FAttributes: TStringList;
  protected
    procedure DoSetProperty(const Key, Value: string; var HasBeenSet: boolean); virtual;
    function  GetHTMLAttributes: string; virtual;
  public
    constructor Create(const AParent: TFolder; const LineNumber: cardinal); override;
    destructor  Destroy; override;

    procedure ReadProperties(HtmlAttributes: string);

    property Name: string             read FName        write FName;
    property Added: TDateTime         read FAdded       write FAdded;
    property LastModified: TDateTime  read FModified    write FModified;
    property Description: string      read FDescription write FDescription;
    property Attributes: TStringList  read FAttributes;
  end;

  { TFolder }

  TFolder = class(TContentEntry)
  private
    FEntries: TEntries;
    FToolbar: boolean;
  protected
    procedure DoSetProperty(const Key, Value: string; var HasBeenSet: boolean); override;
    function  GetHTMLAttributes: string; override;
  public
    constructor Create(const AParent: TFolder; const LineNumber: cardinal); override;
    destructor  Destroy; override;

    function ToString: AnsiString; override;
    procedure SaveToStrings(const Strings: TStrings); override;

    property Entries: TEntries        read FEntries;
    property IsToolbarFolder: boolean read FToolbar;
    property IsToolbarFolder: boolean read FToolbar write FToolbar;
  end;

  { TBookmark }

  TBookmark = class(TContentEntry)
  private
    FURL: string;
    FFeedURL: string;
    FKeyword: string;
    FURL: string;
    FTags: TStringList;
  protected
    procedure DoSetProperty(const Key, Value: string; var HasBeenSet: boolean); override;
    function  GetHTMLAttributes: string; override;
  public
    constructor Create(const AParent: TFolder; const LineNumber: cardinal); override;
    destructor  Destroy; override;

    procedure SaveToStrings(const Strings: TStrings); override;

    property URL: string      read FURL     write FURL;
    property FeedURL: string  read FFeedURL write FFeedURL;
    property Keyword: string  read FKeyword write FKeyword;
    property URL: string        read FURL     write FURL;
    property FeedURL: string    read FFeedURL write FFeedURL;
    property Keyword: string    read FKeyword write FKeyword;
    property Tags: TStringList  read FTags;
  end;


const // for use both in HTMLDecode and HTMLEncode
  cEntities: array[0..9] of string = ('amp', '&', 'lt', '<', 'gt', '>', 'quot', '"', 'apos', '''');

function HTMLDecode(const HTML: string): string;
var
  i, ei: integer;
  i: integer;
  c: char;
  InEntity, Found: boolean;
  InEntity: boolean;
  Entity: string;
  { - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - }
  procedure ProcessEntity(const FoundSemicolon: boolean);
  var
    ei: integer;
  CharCode: integer;
begin
    CharCode: integer;
    Found: boolean;
  begin
    Found := False;
    if Length(Entity) > 1 then begin
      if Entity[1] = '#' then begin
        CharCode := 0;
        if Entity[2] = 'x' then begin
          Found := TryStrToInt('$' + Copy(Entity, 3, Length(Entity)), CharCode);
        end else begin
          Found := TryStrToInt(Copy(Entity, 2, Length(Entity)), CharCode);
        end;
        if Found then
          Entity := Char(CharCode);
      end else begin
        for ei := Low(cEntities) to High(cEntities) do begin
          if (ei mod 2) = 0 then begin
            if Entity = cEntities[ei] then begin
              Entity := cEntities[ei + 1];
              Found := True;
              Break;
            end;
          end;
        end {for};
      end;
    end;
    if Found then
      Result := Result + Entity
    else begin
      Result := Result + '&' + Entity;
      if FoundSemicolon then
        Result := Result + ';';
    end;
    InEntity := False;
    Entity := '';
  end {ProcessEntity};
  { - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - }
begin
  Result := '';
  Entity := '';
  InEntity := False;
  for i := 1 to Length(HTML) do begin
    if InEntity and (Length(Entity) > 6) then
      ProcessEntity(False);
    c := HTML[i];
    if InEntity then begin
      if c = ';' then begin
        Found := False;
      if c = '&' then begin
        ProcessEntity(False);
        if Length(Entity) > 1 then begin
          if Entity[1] = '#' then begin
            CharCode := 0;
            if Entity[2] = 'x' then begin
              Found := TryStrToInt('$' + Copy(Entity, 3, Length(Entity)), CharCode);
            end else begin
              Found := TryStrToInt(Copy(Entity, 2, Length(Entity)), CharCode);
            end;
            if Found then
              Entity := Char(CharCode);
          end else begin
        InEntity := True;
      end else if c = ';' then begin
            for ei := Low(cEntities) to High(cEntities) do begin
              if (ei mod 2) = 0 then begin
                if Entity = cEntities[ei] then begin
                  Entity := cEntities[ei + 1];
                  Found := True;
                  Break;
                end;
              end;
            end {for};
          end;
        end;
        if Found then
          Result := Result + Entity
        else
          Result := Result + '&' + Entity + ';';
        InEntity := False;
        Entity := '';
        ProcessEntity(True);
      end else begin
        Entity := Entity + c;
      end;
    end else begin
      if c = '&' then begin
        InEntity := True;
        Entity := '';
      end else begin
        Result := Result + c;
      end;
    end;
  end;
  if InEntity then
    ProcessEntity(False);
end {HTMLDecode};

type
  THTMLEncodingContext = (hecText, hecAttribute);
  THTMLEncodingContext = (hecText, hecAttribute, hecURI);

function HTMLEncode(const Text: string; const Context: THTMLEncodingContext = hecText): string;
var
  i: integer;
  { - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - }
  procedure ReplaceEntity;
  var

    Result[i] := '&';
  end {ReplaceEntity};
  { - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - }
begin
  Result := Text;
  for i := Length(Result) downto 1 do begin
    case Result[i] of
      '&', '<', '>', #0:
      '<', '>', #0:
        ReplaceEntity;
      '&':
        if Context <> hecURI then
          ReplaceEntity;
      '"':
        if Context = hecAttribute then
        if Context in [hecAttribute, hecURI] then
          ReplaceEntity;
    end {case};
  end;
end {HTMLEncode};


{ TDivider }

  // Then, check if Self is not already in the new parent; if not, add Self
  if Assigned(FParent) and (FParent.Entries.IndexOf(Self) = -1) then
    FParent.Entries.Add(Self);
end {TEntry.SetParent};


{ TBookmark }

constructor TBookmark.Create(const AParent: TFolder; const LineNumber: cardinal);
begin
  inherited Create(AParent, LineNumber);
  FTags := TStringList.Create;
  FTags.Delimiter := ',';
  FTags.StrictDelimiter := True;
  FTags.Sorted := True;
  FTags.Duplicates := dupIgnore;
end {TBookmark.Create};

destructor TBookmark.Destroy;
begin
  FTags.Free;
  inherited Destroy;
end {TBookmark.Destroy};

procedure TBookmark.DoSetProperty(const Key, Value: string; var HasBeenSet: boolean);
begin
  inherited DoSetProperty(Key, Value, HasBeenSet);

  if SameText(Key, 'HREF') then begin
    FURL := Value;
    HasBeenSet := True;
  end else if SameText(Key, 'FEEDURL') then begin
    FFeedURL := Value;
    HasBeenSet := True;
  end else if SameText(Key, 'SHORTCUTURL') then begin
    FKeyword := Value;
    HasBeenSet := True;
  end else if SameText(Key, 'TAGS') then begin
    FTags.DelimitedText := Value;
    HasBeenSet := True;
  end;
end {TBookmark.DoSetProperty};

function TBookmark.GetHTMLAttributes: string;
begin
  Result := '';
  if FURL <> '' then
    Result := ' HREF="' + HTMLEncode(FURL, hecAttribute) + '"';
    Result := Result + ' HREF="' + HTMLEncode(FURL, hecURI) + '"';
  if FFeedURL <> '' then
    Result := Result + ' FEEDURL="' + HTMLEncode(FFeedURL, hecAttribute) + '"';
    Result := Result + ' FEEDURL="' + HTMLEncode(FFeedURL, hecURI) + '"';
  if FKeyword <> '' then
    Result := Result + ' SHORTCUTURL="' + HTMLEncode(FKeyword, hecAttribute) + '"';
  Result := Result + inherited GetHTMLAttributes;
  if FTags.Count > 0 then
    Result := Result + ' TAGS="' + HTMLEncode(FTags.DelimitedText, hecAttribute) + '"';
end {TBookmark.GetHTMLAttributes};

procedure TBookmark.SaveToStrings(const Strings: TStrings);
begin
  Strings.Add(StringOfChar(' ', 4 * Level) + '<DT><A' + GetHTMLAttributes + '>'
            + HTMLEncode(Name)
            + '</A>');

    FToolbar := SameText(Value, 'TRUE');
    HasBeenSet := True;
  end;
end {TFolder.DoSetProperty};

function TFolder.GetHTMLAttributes: string;
begin
  Result := inherited GetHTMLAttributes;
  if FToolbar then
    Result := ' PERSONAL_TOOLBAR_FOLDER="TRUE"';
    Result := Result + ' PERSONAL_TOOLBAR_FOLDER="TRUE"';
  Result := inherited GetHTMLAttributes + Result;
end {TFolder.GetHTMLAttributes};

procedure TFolder.SaveToStrings(const Strings: TStrings);
var
  Indent: string;
  i: integer;
begin
  Indent := StringOfChar(' ', 4 * Level);
  if Level > 0 then
    Strings.Add(Indent+'<DT><H3' + GetHTMLAttributes +'>' + HTMLEncode(Name) + '</H3>');
  Strings.Add(Indent+'<DL><p>');
  for i := 0 to Entries.Count - 1 do begin
    Entries[i].SaveToStrings(Strings);
  end;
  Strings.Add(Indent+'</DL><p>');
end {TFolder.SaveToStrings};


{ TContentEntry }

constructor TContentEntry.Create(const AParent: TFolder; const LineNumber: cardinal);
begin
  inherited Create(AParent, LineNumber);
  FAttributes := TStringList.Create;
  FAttributes.NameValueSeparator := '=';
end {TContentEntry.Create};

destructor TContentEntry.Destroy;
begin
  FAttributes.Free;
  inherited Destroy;
end;

procedure TContentEntry.ReadProperties(HtmlAttributes: string);
const
  cKnownKeys: array[0..4] of string = ('ICON', 'ICON_URI', 'WEB_PANEL', 'UNFILED_BOOKMARKS_FOLDER', 'LAST_CHARSET');
var
  rxAttr: TRegExpr;
  Matches: boolean;
  Key, Value: string;
  HasBeenSet: boolean;
begin
  FAttributes.Clear;
  HtmlAttributes := TrimLeft(HtmlAttributes);
  rxAttr := TRegExpr.Create;
  rxAttr.Expression := '(\S+?)\s*=\s*"([^"]*)"';
  rxAttr.Compile;
  Matches := rxAttr.Exec(HtmlAttributes);
  while Matches do begin
    Key := HTMLDecode(LowerCase(rxAttr.Match[1]));
    Key := HTMLDecode(rxAttr.Match[1]);
    Value := HTMLDecode(rxAttr.Match[2]);
    HasBeenSet := False;
    DoSetProperty(Key, Value, HasBeenSet);
    if not HasBeenSet then
      WriteLn(ErrOutput, '!!! Unprocessed property "', Key, '" in line ', Self.Line,' !!!');
    if not HasBeenSet then begin
      if IndexOfText(Key, cKnownKeys) = -1 then
        WriteLn(ErrOutput, '!!! Unprocessed property "', Key, '" in line ', Self.Line,' !!!');
      FAttributes.Add(Key + FAttributes.NameValueSeparator + Value);
    end;
    Matches := rxAttr.ExecNext;
  end;
end {TContentEntry.ReadProperties};

function TContentEntry.GetHTMLAttributes: string;
var
  i: integer;
  hec: THTMLEncodingContext;
begin
  Result := '';
  if FAdded > 0 then
    Result := ' ADD_DATE="' + IntToStr(SecondsBetween(FAdded, EncodeDate(1970, 1, 1))) + '"';
    Result := Result + ' ADD_DATE="' + IntToStr(Round((FAdded - EncodeDate(1970, 1, 1)) * SecsPerDay)) + '"';
  if FModified > 0 then
    Result := ' LAST_MODIFIED="' + IntToStr(SecondsBetween(FModified, EncodeDate(1970, 1, 1))) + '"';
    Result := Result + ' LAST_MODIFIED="' + IntToStr(Round((FModified - EncodeDate(1970, 1, 1)) * SecsPerDay)) + '"';
  for i := 0 to FAttributes.Count - 1 do begin
    if AnsiContainsText(FAttributes.Names[i], 'URL') or AnsiContainsText(FAttributes.Names[i], 'HREF') or AnsiContainsText(FAttributes.Names[i], 'SRC') then
      hec := hecURI
    else
      hec := hecAttribute;
    Result := Result + ' ' + HTMLEncode(FAttributes.Names[i]) + '="' + HTMLEncode(FAttributes.ValueFromIndex[i], hec) + '"';
  end;
end {TContentEntry.GetHTMLAttributes};

procedure TContentEntry.DoSetProperty(const Key, Value: string; var HasBeenSet: boolean);
var
  Seconds: Integer;
begin
  if SameText(Key, 'ADD_DATE') then begin
    if TryStrToInt(Value, Seconds) then
      FAdded := EncodeDate(1970, 1, 1) + (Seconds / 86400)
      FAdded := EncodeDate(1970, 1, 1) + (Seconds / SecsPerDay)
    else
      FAdded := 0;
    HasBeenSet := True;
  end else if SameText(Key, 'LAST_MODIFIED') then begin
    if TryStrToInt(Value, Seconds) then
      FModified := EncodeDate(1970, 1, 1) + (Seconds / 86400)
      FModified := EncodeDate(1970, 1, 1) + (Seconds / SecsPerDay)
    else
      FModified := 0;
    HasBeenSet := True;
  end;
end {TContentEntry.DoSetProperty};

type
  TStringArray = array of string;

function Join(const Strings: TStringArray; const Separator: string = sLineBreak): string;
var
  i: integer;
begin
  if Length(Strings) = 0 then
    Exit;
  Result := Strings[Low(Strings)];
  for i := Low(Strings) + 1 to High(Strings) do begin
    Result := Result + Separator + Strings[i];
  end;
end {Join};

type
  { TDuplicateSet }

  TDuplicateSet = class(specialize TFPGObjectList<TBookmark>)
  TDuplicateSet = class(specialize TFPGObjectList<TContentEntry>)
  private
    FNames: TStringArray;
    FAdded: TDateTime;
    FLastModified: TDateTime;
    FMinLevel: cardinal;
    FMaxLevel: cardinal;
    FDescriptions: TStringArray;
    FAttributes: TStringList;
    FTags: TStringList;

    function AddStringIfUnique(const NewString: string; var Strings: TStringArray): boolean;
  public
    constructor Create(const Initial: TBookmark);
    function Add(const Bookmark: TBookmark): integer;
    constructor Create(const Initial: TContentEntry);
    destructor  Destroy; override;
    function Add(const Entry: TContentEntry): integer;
    property Names: TStringArray        read FNames;
    property Added: TDateTime           read FAdded;
    property LastModified: TDateTime    read FLastModified;
    property Descriptions: TStringArray read FDescriptions;
    property MinLevel: cardinal         read FMinLevel;
    property MaxLevel: cardinal         read FMaxLevel;
    property Attributes: TStringList    read FAttributes;
    property Tags: TStringList          read FTags;
  end;

constructor TDuplicateSet.Create(const Initial: TBookmark);
constructor TDuplicateSet.Create(const Initial: TContentEntry);
begin
  inherited Create(False);
  FAdded := 0;
  FLastModified := 0;
  SetLength(FNames, 1);
  FNames[0] := Initial.Name;
  SetLength(FDescriptions, 0);
  FMinLevel := High(FMinLevel);
  FMaxLevel := Low(FMaxLevel);
  FAttributes := TStringList.Create;
  FAttributes.NameValueSeparator := '=';
  FTags := TStringList.Create;
  FTags.Delimiter := ',';
  FTags.StrictDelimiter := True;
  FTags.Sorted := True;
  FTags.Duplicates := dupIgnore;
  Add(Initial);
end {TDuplicateSet.Create};

destructor TDuplicateSet.Destroy;
begin
  FTags.Free;
  FAttributes.Free;
  inherited Destroy;
end {TDuplicateSet.Destroy};

function TDuplicateSet.Add(const Bookmark: TBookmark): integer;
function TDuplicateSet.Add(const Entry: TContentEntry): integer;
var
  Bookmark: TBookmark;
  AddName, AddDescription: boolean;
  D: TDateTime;
  L: integer;
  IsNewer: boolean;
  i: integer;
begin
  Result := inherited Add(Bookmark);
  Result := inherited Add(Entry);

  AddName := True;
  AddDescription := (Length(Entry.Description) > 0) and (Pos(Entry.Description, Entry.Name) = 0);
  if Entry is TBookmark then begin
    Bookmark := TBookmark(Entry);
  if Pos(Bookmark.Name, Bookmark.URL) = 0 then
    AddStringIfUnique(Bookmark.Name, FNames);
  if (Length(Bookmark.Description) > 0) and (Pos(Bookmark.Description, Bookmark.Name) = 0) and (Pos(Bookmark.Description, Bookmark.URL) <> 1) then
    AddStringIfUnique(Bookmark.Description, FDescriptions);
    AddName := Pos(Bookmark.Name, Bookmark.URL) = 0;
    AddDescription := AddDescription and (Pos(Bookmark.Description, Bookmark.URL) <> 1);
    FTags.AddStrings(Bookmark.Tags);
  end;
  if AddName then
    AddStringIfUnique(Entry.Name, FNames);
  if AddDescription then
    AddStringIfUnique(Entry.Description, FDescriptions);

  IsNewer := (Entry.LastModified > 0) and ((FLastModified = 0) or (Entry.LastModified > FLastModified));
  for i := 0 to Entry.Attributes.Count - 1 do begin
    if IsNewer or (FAttributes.IndexOfName(Entry.Attributes.Names[i]) = -1) then
      FAttributes.Values[Entry.Attributes.Names[i]] := Entry.Attributes.ValueFromIndex[i];
  end;

  D := Bookmark.Added;
  D := Entry.Added;
  if (D > 0) and ((FAdded = 0) or (D < FAdded)) then
    FAdded := D;

  D := Bookmark.LastModified;
  D := Entry.LastModified;
  if (D > 0) and (D > FLastModified) then
    FLastModified := D;

  L := Bookmark.Level;
  L := Entry.Level;
  if L < FMinLevel then
    FMinLevel := L;
  if L > FMaxLevel then
    FMaxLevel := L;
end {TDuplicateSet.Add};

function TDuplicateSet.AddStringIfUnique(const NewString: string; var Strings: TStringArray): boolean;

          if Trim(Copy(Line, 1, P - 1)) <> '' then begin
            Assert(Entry is TContentEntry);
            TContentEntry(Entry).Description := TContentEntry(Entry).Description + sLineBreak + HTMLDecode(Copy(Line, 1, P - 1));
            //WriteLn(StringOfChar(#9, Entry.Level - 1), ' "', TContentEntry(Entry).Description, '"');
          end;
          ReadingDescription := False;
        end;

        Line := Copy(Line, P + 1, Length(Line));
        if AnsiStartsText('HR>', Line) then begin
        while AnsiStartsText('HR>', Line) do begin
          Entry := TDivider.Create(Folder, i);
          Bookmarks.Add(Entry);
          //WriteLn(StringOfChar(#9, Entry.Level - 1), '---- ---- ---- ---- ---- ');
          Line := Copy(Line, 4, Length(Line));
          P := Pos('<', Line);
          if P = 0 then
            Continue;
          Line := Copy(Line, P + 1, Length(Line));
        end;

        end else if AnsiStartsText('DT><A', Line) then begin
        if AnsiStartsText('DT><A', Line) then begin
          Entry := TBookmark.Create(Folder, i);
          Bookmarks.Add(Entry);

          P := PosEx('>', Line, 6);
          TContentEntry(Entry).ReadProperties(Copy(Line, 6, P - 6));
          Pe := PosEx('</A>', Line, P);
          TContentEntry(Entry).Name := HTMLDecode(Copy(Line, P + 1, Pe - P - 1));

function TBookmarkManager.FindDupesByURL(const AllEntries: TEntries; const StartIndex: integer; const DupeSet: TDuplicateSet): cardinal;
var
  URL: string;
  i: integer;
  Bookmark: TBookmark;
begin
  Result := 0;
  URL := DupeSet.Items[0].URL;
  URL := TBookmark(DupeSet.Items[0]).URL;
  for i := StartIndex to AllEntries.Count - 1 do begin
    if (AllEntries[i] is TBookmark) then begin
      Bookmark := TBookmark(AllEntries[i]);
      if SameText(Bookmark.URL, URL) then begin
        DupeSet.Add(Bookmark);
        Inc(Result);
      end;

          Dupeset.Free;
      end;
    end {if TBookmark};
  end {for i};
end {TBookmarkManager.FindDupes};

function TBookmarkManager.RemoveDuplicates(const AllEntries: TEntries): TEntries;
  function IsInToolbar(const Bookmark: TContentEntry): boolean;
  var
    Folder: TFolder;
  begin
    Result := False;
    Folder := Bookmark.Parent;
    while Assigned(Folder) do begin
      Result := Folder.IsToolbarFolder;
      if Result then
        Exit;
      Folder := Folder.Parent;
    end;
  end {IsInToolbar};
var
  NumDupes: integer;
  Dupes: TDuplicateSet;
  di, bi: integer;
  di, bi, ni: integer;
  Bookmark: TBookmark;
  Names: TStringArray;
begin
  // Walk through all bookmarks; for each bookmark, walk through the entire list again, and gather all bookmarks with the same URL;
  //  keeping track of the earliest add date, and the latest modify date.
  //  Keep the names and descriptions in a list each, only adding them if they're not already in there.
  //  Also keep track of the highest level.
  NumDupes := FindDupesets(AllEntries);
  WriteLn(NumDupes, ' duplicates found. Marking for deletion...');

  Result := TEntries.Create(False);
  for di := FDupeSets.Count - 1 downto 0 do begin
    Bookmark := nil;
    Dupes := FDupeSets.Data[di];

    // Identify which bookmark should be kept. By default, if there's one on the toolbar, we keep
    //  that one. Otherwise, we keep the one with the deepest level, on the assumption that nested
    //  deeper means better organised.
    for bi := 0 to Dupes.Count - 1 do begin
      if Assigned(Dupes[bi].Parent) and Dupes[bi].Parent.IsToolbarFolder then begin
        Bookmark := Dupes[bi];
      if IsInToolbar(Dupes[bi]) then begin
        Bookmark := TBookmark(Dupes[bi]);
        Break;
      end else if not Assigned(Bookmark) and (Dupes[bi].Level = Dupes.MaxLevel) then
        Bookmark := Dupes[bi];
      end else if (not Assigned(Bookmark)) and (Dupes[bi].Level = Dupes.MaxLevel) then
        Bookmark := TBookmark(Dupes[bi]);
    end {for bi};
    Assert(Assigned(Bookmark));

    //   apply the earliest add date and the latest modify date,
    //   apply the combined names and descriptions,
    Bookmark.Added := Dupes.Added;
    Bookmark.LastModified := Dupes.LastModified;
    if Length(Dupes.Descriptions) > 0 then
      Bookmark.Description := Join(Dupes.Descriptions);
    if Length(Dupes.Names) > 1 then begin
      SetLength(Names, Length(Dupes.Names));
      bi := 0; // offset due to deleted name(s)
      for ni := Low(Names) to High(Names) do begin
        if SameText(Bookmark.Name, Dupes.Names[ni]) then
          Inc(bi)
        else
          Names[ni - bi] := Dupes.Names[ni];
      end;
      if bi > 0 then
        SetLength(Names, Length(Names) - bi);
      Bookmark.Description := IfThen(Bookmark.Description <> '', Bookmark.Description + sLineBreak, '')
                            + 'Alternative names:' + sLineBreak
                            + Join(Dupes.Names);
                            + 'Alternative name' + IfThen(Length(Names) = 1, ': ', 's:' + sLineBreak)
                            + Join(Names);
    end;
    Bookmark.Attributes.Assign(Dupes.Attributes);
    Bookmark.Tags.AddStrings(Dupes.Tags);

    // Instead of deleting them right now, move them to the result set of entries. The calling party can then free them.
    for bi := Dupes.Count - 1 downto 0 do begin
      if Dupes[bi] <> Bookmark then begin
        Result.Add(Dupes[bi]);
      end;
    end;

function TBookmarkManager.MergeFolders(const RootEntries: TEntries): TEntries;
var
  fi, i, Index: integer;
  Folder, Preceding: TFolder;
  Entry: TEntry;
  Merged: TEntries;
  FolderIsMoreRecent: boolean;
begin
  Result := TEntries.Create(False);
  for fi := RootEntries.Count - 1 downto 0 do begin
    Entry := RootEntries[fi];
    //WriteLn(StringOfChar('.', Entry.Level), Entry.ToString);
    if Entry is TFolder then begin
      Folder := TFolder(Entry);

      // Look for a preceding folder with the same name
      Preceding := nil;
      for i := 0 to fi - 1 do begin
        if (RootEntries[i] is TFolder) and SameText(Folder.Name, TFolder(RootEntries[i]).Name) then begin
          Preceding := TFolder(RootEntries[i]);
          Break;
        end;
      end;

      if Assigned(Preceding) then begin
        // merge the attributes of both folders
        if Folder.IsToolbarFolder then
          Preceding.IsToolbarFolder := True;
        if (Folder.Added > 0) and ((Preceding.Added = 0) or (Folder.Added < Preceding.Added)) then
          Preceding.Added := Folder.Added;
        FolderIsMoreRecent := (Folder.LastModified > 0) and (Folder.LastModified > Preceding.LastModified);
        if FolderIsMoreRecent then
          Preceding.LastModified := Folder.LastModified;
        for i := 0 to Folder.Attributes.Count - 1 do begin
          if FolderIsMoreRecent or (Preceding.Attributes.IndexOfName(Folder.Attributes.Names[i]) = -1) then
            Preceding.Attributes.Values[Folder.Attributes.Names[i]] := Folder.Attributes.ValueFromIndex[i];
        end;

        //WriteLn(#9, 'Moving ', Folder.Entries.Count ,' entries to preceding ', Preceding.ToString);
        // move all its RootEntries to the Preceding folder
        // move all its entries to the Preceding folder
        Index := Preceding.Entries.Count;
        for i := Folder.Entries.Count - 1 downto 0 do begin
          Entry := Folder.Entries[i];
          Preceding.Entries.Insert(Index, Entry);
          Entry.Parent := Preceding;
        end;
      end else begin

begin
  try
    Mgr := TBookmarkManager.Create;
    try

      Mgr.LoadFromFile(ParamStr(1));
      WriteLn(Mgr.Bookmarks.Count, ' entries loaded.');
      Mgr.SaveToFile(ChangeFileExt(ParamStr(1), '-out-1' + ExtractFileExt(ParamStr(1))));
      //Mgr.SaveToFile(ChangeFileExt(ParamStr(1), '-out-1' + ExtractFileExt(ParamStr(1))));
      WriteLn;

      // REMOVE DUPLICATES
      WriteLn('Looking for duplicate bookmarks...');
      Mgr.RemoveDuplicates;
      WriteLn(Mgr.Bookmarks.Count, ' entries left.');
      Mgr.SaveToFile(ChangeFileExt(ParamStr(1), '-out-2' + ExtractFileExt(ParamStr(1))));
      //Mgr.SaveToFile(ChangeFileExt(ParamStr(1), '-out-2' + ExtractFileExt(ParamStr(1))));
      WriteLn;

      // MERGE DUPLICATE FOLDERS AND PRUNE EMPTY ONES
      WriteLn('Merging duplicate folders and pruning empty ones...');
      Mgr.MergeFolders;
      WriteLn(Mgr.Bookmarks.Count, ' entries left.');
      Mgr.SaveToFile(ChangeFileExt(ParamStr(1), '-out-3' + ExtractFileExt(ParamStr(1))));
      //Mgr.SaveToFile(ChangeFileExt(ParamStr(1), '-out-3' + ExtractFileExt(ParamStr(1))));
      WriteLn;

      // MERGE CONSECUTIVE SEPARATORS
      WriteLn('Sanitizing dividers...');
      Mgr.SanitizeDividers;
      WriteLn(Mgr.Bookmarks.Count, ' entries left.');
      Mgr.SaveToFile(ChangeFileExt(ParamStr(1), '-out-4' + ExtractFileExt(ParamStr(1))));
      //Mgr.SaveToFile(ChangeFileExt(ParamStr(1), '-out-4' + ExtractFileExt(ParamStr(1))));
      WriteLn;

      Mgr.SaveToFile(ChangeFileExt(ParamStr(1), '-new' + ExtractFileExt(ParamStr(1))));
    finally
      Mgr.Free;
    end;
  except
    Beep;
    ShowException(ExceptObject, ExceptAddr);
    //Readln;
  end;
end.