{
    This file is part of the Free Component Library

    Pascal tree source file writer
    Copyright (c) 2003 by
      Areca Systems GmbH / Sebastian Guenther, sg@freepascal.org

    See the file COPYING.FPC, included in this distribution,
    for details about the copyright.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 **********************************************************************}

{$mode objfpc}
{$h+}

unit PasWrite;

interface

uses Classes, PasTree;

type
  TPasWriter = class
  private
    FStream: TStream;
    IsStartOfLine: Boolean;
    Indent, CurDeclSection: string;
    DeclSectionStack: TList;
    procedure IncIndent;
    procedure DecIndent;
    procedure IncDeclSectionLevel;
    procedure DecDeclSectionLevel;
    procedure PrepareDeclSection(const ADeclSection: string);
  public
    constructor Create(AStream: TStream);
    destructor Destroy; override;
    procedure wrt(const s: string);
    procedure wrtln(const s: string);overload;
    procedure wrtln;overload;

    procedure WriteElement(AElement: TPasElement);
    procedure WriteType(AType: TPasType);
    procedure WriteModule(AModule: TPasModule);
    procedure WriteSection(ASection: TPasSection);
    procedure WriteClass(AClass: TPasClassType);
    procedure WriteVariable(AVar: TPasVariable);
    procedure WriteProcDecl(AProc: TPasProcedure);
    procedure WriteProcImpl(AProc: TPasProcedureImpl);
    procedure WriteProperty(AProp: TPasProperty);
    procedure WriteImplBlock(ABlock: TPasImplBlock);
    procedure WriteImplElement(AElement: TPasImplElement;
      AAutoInsertBeginEnd: Boolean);
    procedure WriteImplCommand(ACommand: TPasImplCommand);
    procedure WriteImplCommands(ACommands: TPasImplCommands);
    procedure WriteImplIfElse(AIfElse: TPasImplIfElse);
    procedure WriteImplForLoop(AForLoop: TPasImplForLoop);
    property Stream: TStream read FStream;
  end;


procedure WritePasFile(AElement: TPasElement; const AFilename: string);overload;
procedure WritePasFile(AElement: TPasElement; AStream: TStream);overload;



implementation

uses SysUtils;

type
  PDeclSectionStackElement = ^TDeclSectionStackElement;
  TDeclSectionStackElement = record
    LastDeclSection, LastIndent: string;
  end;

constructor TPasWriter.Create(AStream: TStream);
begin
  FStream := AStream;
  IsStartOfLine := True;
  DeclSectionStack := TList.Create;
end;

destructor TPasWriter.Destroy;
var
  i: Integer;
  El: PDeclSectionStackElement;
begin
  for i := 0 to DeclSectionStack.Count - 1 do
  begin
    El := PDeclSectionStackElement(DeclSectionStack[i]);
    Dispose(El);
  end;
  DeclSectionStack.Free;
  inherited Destroy;
end;

procedure TPasWriter.wrt(const s: string);
begin
  if IsStartOfLine then
  begin
    if Length(Indent) > 0 then
      Stream.Write(Indent[1], Length(Indent));
    IsStartOfLine := False;
  end;
  Stream.Write(s[1], Length(s));
end;

const
  LF: string = #10;

procedure TPasWriter.wrtln(const s: string);
begin
  wrt(s);
  Stream.Write(LF[1], 1);
  IsStartOfLine := True;
end;

procedure TPasWriter.wrtln;
begin
  Stream.Write(LF[1], 1);
  IsStartOfLine := True;
end;

procedure TPasWriter.WriteElement(AElement: TPasElement);
begin
  if AElement.InheritsFrom(TPasModule) then
    WriteModule(TPasModule(AElement))
  else if AElement.InheritsFrom(TPasSection) then
    WriteSection(TPasSection(AElement))
  else if AElement.InheritsFrom(TPasVariable) then
    WriteVariable(TPasVariable(AElement))
  else if AElement.InheritsFrom(TPasType) then
    WriteType(TPasType(AElement))
  else if AElement.InheritsFrom(TPasProcedure) then
    WriteProcDecl(TPasProcedure(AElement))
  else if AElement.InheritsFrom(TPasProcedureImpl) then
    WriteProcImpl(TPasProcedureImpl(AElement))
  else if AElement.ClassType = TPasProperty then
    WriteProperty(TPasProperty(AElement))
  else
    raise Exception.Create('Writing not implemented for ' +
      AElement.ElementTypeName + ' nodes');
end;

procedure TPasWriter.WriteType(AType: TPasType);
begin
  if AType.ClassType = TPasUnresolvedTypeRef then
    wrt(AType.Name)
  else if AType.ClassType = TPasClassType then
    WriteClass(TPasClassType(AType))
  else
    raise Exception.Create('Writing not implemented for ' +
      AType.ElementTypeName + ' nodes');
end;


procedure TPasWriter.WriteModule(AModule: TPasModule);
begin
  wrtln('unit ' + AModule.Name + ';');
  wrtln;
  wrtln('interface');
  wrtln;
  WriteSection(AModule.InterfaceSection);
  Indent := '';
  wrtln;
  wrtln;
  wrtln('implementation');
  if Assigned(AModule.ImplementationSection) then
  begin
    wrtln;
    WriteSection(AModule.ImplementationSection);
  end;
  wrtln;
  wrtln('end.');
end;

procedure TPasWriter.WriteSection(ASection: TPasSection);
var
  i: Integer;
begin
  if ASection.UsesList.Count > 0 then
  begin
    wrt('uses ');
    for i := 0 to ASection.UsesList.Count - 1 do
    begin
      if i > 0 then
        wrt(', ');
      wrt(TPasElement(ASection.UsesList[i]).Name);
    end;
    wrtln(';');
    wrtln;
  end;

  CurDeclSection := '';

  for i := 0 to ASection.Declarations.Count - 1 do
    WriteElement(TPasElement(ASection.Declarations[i]));
end;

procedure TPasWriter.WriteClass(AClass: TPasClassType);
var
  i: Integer;
  Member: TPasElement;
  LastVisibility, CurVisibility: TPasMemberVisibility;
begin
  PrepareDeclSection('type');
  wrt(AClass.Name + ' = ');
  if AClass.IsPacked then
     wrt('packed ');                      // 12/04/04 - Dave - Added
  case AClass.ObjKind of
    okObject: wrt('object');
    okClass: wrt('class');
    okInterface: wrt('interface');
  end;
  if Assigned(AClass.AncestorType) then
    wrtln('(' + AClass.AncestorType.Name + ')')
  else
    wrtln;
  IncIndent;
  LastVisibility := visDefault;
  for i := 0 to AClass.Members.Count - 1 do
  begin
    Member := TPasElement(AClass.Members[i]);
    CurVisibility := Member.Visibility;
    if CurVisibility <> LastVisibility then
    begin
      DecIndent;
      case CurVisibility of
        visPrivate: wrtln('private');
        visProtected: wrtln('protected');
        visPublic: wrtln('public');
        visPublished: wrtln('published');
        visAutomated: wrtln('automated');
      end;
      IncIndent;
      LastVisibility := CurVisibility;
    end;
    WriteElement(Member);
  end;
  DecIndent;
  wrtln('end;');
  wrtln;
end;

procedure TPasWriter.WriteVariable(AVar: TPasVariable);
begin
  if (AVar.Parent.ClassType <> TPasClassType) and
    (AVar.Parent.ClassType <> TPasRecordType) then
    PrepareDeclSection('var');
  wrt(AVar.Name + ': ');
  WriteType(AVar.VarType);
  wrtln(';');
end;

procedure TPasWriter.WriteProcDecl(AProc: TPasProcedure);
var
  i: Integer;
begin
  wrt(AProc.TypeName + ' ' + AProc.Name);

  if Assigned(AProc.ProcType) and (AProc.ProcType.Args.Count > 0) then
  begin
    wrt('(');
    for i := 0 to AProc.ProcType.Args.Count - 1 do
      with TPasArgument(AProc.ProcType.Args[i]) do
      begin
        if i > 0 then
          wrt('; ');
        case Access of
          argConst: wrt('const ');
          argVar: wrt('var ');
        end;
        wrt(Name);
        if Assigned(ArgType) then
        begin
          wrt(': ');
          WriteElement(ArgType);
        end;
        if Value <> '' then
          wrt(' = ' + Value);
      end;
    wrt(')');
  end;

  if Assigned(AProc.ProcType) and
    (AProc.ProcType.ClassType = TPasFunctionType) then
  begin
    wrt(': ');
    WriteElement(TPasFunctionType(AProc.ProcType).ResultEl.ResultType);
  end;

  wrt(';');

  if AProc.IsVirtual then
    wrt(' virtual;');
  if AProc.IsDynamic then
    wrt(' dynamic;');
  if AProc.IsAbstract then
    wrt(' abstract;');
  if AProc.IsOverride then
    wrt(' override;');
  if AProc.IsOverload then
    wrt(' overload;');
  if AProc.IsReintroduced then
    wrt(' reintroduce;');
  if AProc.IsStatic then
    wrt(' static;');


  // !!!: Not handled: Message, calling conventions

  wrtln;
end;

procedure TPasWriter.WriteProcImpl(AProc: TPasProcedureImpl);
var
  i: Integer;
begin
  PrepareDeclSection('');
  wrt(AProc.TypeName + ' ');

  if AProc.Parent.ClassType = TPasClassType then
    wrt(AProc.Parent.Name + '.');

  wrt(AProc.Name);

  if Assigned(AProc.ProcType) and (AProc.ProcType.Args.Count > 0) then
  begin
    wrt('(');
    for i := 0 to AProc.ProcType.Args.Count - 1 do
      with TPasArgument(AProc.ProcType.Args[i]) do
      begin
        if i > 0 then
          wrt('; ');
        case Access of
          argConst: wrt('const ');
          argVar: wrt('var ');
        end;
        wrt(Name);
        if Assigned(ArgType) then
        begin
          wrt(': ');
          WriteElement(ArgType);
        end;
        if Value <> '' then
          wrt(' = ' + Value);
      end;
    wrt(')');
  end;

  if Assigned(AProc.ProcType) and
    (AProc.ProcType.ClassType = TPasFunctionType) then
  begin
    wrt(': ');
    WriteElement(TPasFunctionType(AProc.ProcType).ResultEl.ResultType);
  end;

  wrtln(';');
  IncDeclSectionLevel;
  for i := 0 to AProc.Locals.Count - 1 do
  begin
    if TPasElement(AProc.Locals[i]).InheritsFrom(TPasProcedureImpl) then
    begin
      IncIndent;
      if (i = 0) or not
        TPasElement(AProc.Locals[i - 1]).InheritsFrom(TPasProcedureImpl) then
        wrtln;
    end;

    WriteElement(TPasElement(AProc.Locals[i]));

    if TPasElement(AProc.Locals[i]).InheritsFrom(TPasProcedureImpl) then
      DecIndent;
  end;
  DecDeclSectionLevel;

  wrtln('begin');
  IncIndent;
  if Assigned(AProc.Body) then
    WriteImplBlock(AProc.Body);
  DecIndent;
  wrtln('end;');
  wrtln;
end;

procedure TPasWriter.WriteProperty(AProp: TPasProperty);
var
  i: Integer;
begin
  wrt('property ' + AProp.Name);
  if AProp.Args.Count > 0 then
  begin
    wrt('[');
    for i := 0 to AProp.Args.Count - 1 do;
      // !!!: Create WriteArgument method and call it here
    wrt(']');
  end;
  if Assigned(AProp.VarType) then
  begin
    wrt(': ');
    WriteType(AProp.VarType);
  end;
  if AProp.IndexValue <> '' then
    wrt(' index ' + AProp.IndexValue); 
  if AProp.ReadAccessorName <> '' then
    wrt(' read ' + AProp.ReadAccessorName);
  if AProp.WriteAccessorName <> '' then
    wrt(' write ' + AProp.WriteAccessorName);
  if AProp.StoredAccessorName <> '' then
    wrt(' stored ' + AProp.StoredAccessorName);
  if AProp.DefaultValue <> '' then
    wrt(' default ' + AProp.DefaultValue);
  if AProp.IsNodefault then
    wrt(' nodefault');
  if AProp.IsDefault then
    wrt('; default');
  wrtln(';');
end;

procedure TPasWriter.WriteImplBlock(ABlock: TPasImplBlock);
var
  i: Integer;
begin
  for i := 0 to ABlock.Elements.Count - 1 do
  begin
    WriteImplElement(TPasImplElement(ABlock.Elements[i]), False);
    if TPasImplElement(ABlock.Elements[i]).ClassType = TPasImplCommand then
      wrtln(';');
  end;
end;

procedure TPasWriter.WriteImplElement(AElement: TPasImplElement;
  AAutoInsertBeginEnd: Boolean);
begin
  if AElement.ClassType = TPasImplCommand then
    WriteImplCommand(TPasImplCommand(AElement))
  else if AElement.ClassType = TPasImplCommands then
  begin
    DecIndent;
    if AAutoInsertBeginEnd then
      wrtln('begin');
    IncIndent;
    WriteImplCommands(TPasImplCommands(AElement));
    DecIndent;
    if AAutoInsertBeginEnd then
      wrtln('end;');
    IncIndent;
  end else if AElement.ClassType = TPasImplBlock then
  begin
    DecIndent;
    if AAutoInsertBeginEnd then
      wrtln('begin');
    IncIndent;
    WriteImplBlock(TPasImplBlock(AElement));
    DecIndent;
    if AAutoInsertBeginEnd then
      wrtln('end;');
    IncIndent;
  end else if AElement.ClassType = TPasImplIfElse then
    WriteImplIfElse(TPasImplIfElse(AElement))
  else if AElement.ClassType = TPasImplForLoop then
    WriteImplForLoop(TPasImplForLoop(AElement))
  else
    raise Exception.Create('Writing not yet implemented for ' +
      AElement.ClassName + ' implementation elements');
end;

procedure TPasWriter.WriteImplCommand(ACommand: TPasImplCommand);
begin
  wrt(ACommand.Command);
end;

procedure TPasWriter.WriteImplCommands(ACommands: TPasImplCommands);
var
  i: Integer;
  s: string;
begin
  for i := 0 to ACommands.Commands.Count - 1 do
  begin
    s := ACommands.Commands[i];
    if Length(s) > 0 then
      if (Length(s) >= 2) and (s[1] = '/') and (s[2] = '/') then
        wrtln(s)
      else
        wrtln(s + ';');
  end;
end;

procedure TPasWriter.WriteImplIfElse(AIfElse: TPasImplIfElse);
begin
  wrt('if ' + AIfElse.Condition + ' then');
  if Assigned(AIfElse.IfBranch) then
  begin
    wrtln;
    if (AIfElse.IfBranch.ClassType = TPasImplCommands) or
      (AIfElse.IfBranch.ClassType = TPasImplBlock) then
      wrtln('begin');
    IncIndent;
    WriteImplElement(AIfElse.IfBranch, False);
    DecIndent;
    if (AIfElse.IfBranch.ClassType = TPasImplCommands) or
      (AIfElse.IfBranch.ClassType = TPasImplBlock) then
      if Assigned(AIfElse.ElseBranch) then
        wrt('end ')
      else
        wrtln('end;')
    else
      if Assigned(AIfElse.ElseBranch) then
        wrtln;
  end else
    if not Assigned(AIfElse.ElseBranch) then
      wrtln(';')
    else
      wrtln;

  if Assigned(AIfElse.ElseBranch) then
    if AIfElse.ElseBranch.ClassType = TPasImplIfElse then
    begin
      wrt('else ');
      WriteImplElement(AIfElse.ElseBranch, True);
    end else
    begin
      wrtln('else');
      IncIndent;
      WriteImplElement(AIfElse.ElseBranch, True);
      if (not Assigned(AIfElse.Parent)) or
        (AIfElse.Parent.ClassType <> TPasImplIfElse) or
        (TPasImplIfElse(AIfElse.Parent).IfBranch <> AIfElse) then
        wrtln(';');
      DecIndent;
    end;
end;

procedure TPasWriter.WriteImplForLoop(AForLoop: TPasImplForLoop);
begin
  wrtln('for ' + AForLoop.Variable.Name + ' := ' + AForLoop.StartValue +
    ' to ' + AForLoop.EndValue + ' do');
  IncIndent;
  WriteImplElement(AForLoop.Body, True);
  DecIndent;
  if (AForLoop.Body.ClassType <> TPasImplBlock) and
    (AForLoop.Body.ClassType <> TPasImplCommands) then
      wrtln(';');
end;

procedure TPasWriter.IncIndent;
begin
  Indent := Indent + '  ';
end;

procedure TPasWriter.DecIndent;
begin
  if Indent = '' then
    raise Exception.Create('Internal indent error');
  SetLength(Indent, Length(Indent) - 2);
end;

procedure TPasWriter.IncDeclSectionLevel;
var
  El: PDeclSectionStackElement;
begin
  New(El);
  DeclSectionStack.Add(El);
  El^.LastDeclSection := CurDeclSection;
  El^.LastIndent := Indent;
  CurDeclSection := '';
end;

procedure TPasWriter.DecDeclSectionLevel;
var
  El: PDeclSectionStackElement;
begin
  El := PDeclSectionStackElement(DeclSectionStack[DeclSectionStack.Count - 1]);
  DeclSectionStack.Delete(DeclSectionStack.Count - 1);
  CurDeclSection := El^.LastDeclSection;
  Indent := El^.LastIndent;
  Dispose(El);
end;

procedure TPasWriter.PrepareDeclSection(const ADeclSection: string);
begin
  if ADeclSection <> CurDeclSection then
  begin
    if CurDeclsection <> '' then
      DecIndent;
    if ADeclSection <> '' then
    begin
      wrtln(ADeclSection);
      IncIndent;
    end;
    CurDeclSection := ADeclSection;
  end;
end;


procedure WritePasFile(AElement: TPasElement; const AFilename: string);
var
  Stream: TFileStream;
begin
  Stream := TFileStream.Create(AFilename, fmCreate);
  try
    WritePasFile(AElement, Stream);
  finally
    Stream.Free;
  end;
end;

procedure WritePasFile(AElement: TPasElement; AStream: TStream);
var
  Writer: TPasWriter;
begin
  Writer := TPasWriter.Create(AStream);
  try
    Writer.WriteElement(AElement);
  finally
    Writer.Free;
  end;
end;

end.