//===-- ClangIncludeFixer.cpp - Standalone change namespace ---------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// This tool can be used to change the surrounding namespaces of class/function
// definitions.
//
// Example: test.cc
//    namespace na {
//    class X {};
//    namespace nb {
//    class Y { X x; };
//    } // namespace nb
//    } // namespace na
// To move the definition of class Y from namespace "na::nb" to "x::y", run:
//    clang-change-namespace --old_namespace "na::nb" \
//      --new_namespace "x::y" --file_pattern "test.cc" test.cc --
// Output:
//    namespace na {
//    class X {};
//    } // namespace na
//    namespace x {
//    namespace y {
//    class Y { na::X x; };
//    } // namespace y
//    } // namespace x

#include "ChangeNamespace.h"
#include "clang/Frontend/FrontendActions.h"
#include "clang/Frontend/TextDiagnosticPrinter.h"
#include "clang/Rewrite/Core/Rewriter.h"
#include "clang/Tooling/CommonOptionsParser.h"
#include "clang/Tooling/Refactoring.h"
#include "clang/Tooling/Tooling.h"
#include "llvm/Support/CommandLine.h"

using namespace clang;
using namespace llvm;

namespace {

cl::OptionCategory ChangeNamespaceCategory("Change namespace.");

cl::opt<std::string> OldNamespace("old_namespace", cl::Required,
                                  cl::desc("Old namespace."),
                                  cl::cat(ChangeNamespaceCategory));

cl::opt<std::string> NewNamespace("new_namespace", cl::Required,
                                  cl::desc("New namespace."),
                                  cl::cat(ChangeNamespaceCategory));

cl::opt<std::string> FilePattern(
    "file_pattern", cl::Required,
    cl::desc("Only rename namespaces in files that match the given pattern."),
    cl::cat(ChangeNamespaceCategory));

cl::opt<bool> Inplace("i", cl::desc("Inplace edit <file>s, if specified."),
                      cl::cat(ChangeNamespaceCategory));

cl::opt<std::string> Style("style",
                           cl::desc("The style name used for reformatting."),
                           cl::init("LLVM"), cl::cat(ChangeNamespaceCategory));

} // anonymous namespace

int main(int argc, const char **argv) {
  tooling::CommonOptionsParser OptionsParser(argc, argv,
                                             ChangeNamespaceCategory);
  const auto &Files = OptionsParser.getSourcePathList();
  tooling::RefactoringTool Tool(OptionsParser.getCompilations(), Files);
  change_namespace::ChangeNamespaceTool NamespaceTool(
      OldNamespace, NewNamespace, FilePattern, &Tool.getReplacements());
  ast_matchers::MatchFinder Finder;
  NamespaceTool.registerMatchers(&Finder);
  std::unique_ptr<tooling::FrontendActionFactory> Factory =
      tooling::newFrontendActionFactory(&Finder);

  if (int Result = Tool.run(Factory.get()))
    return Result;
  LangOptions DefaultLangOptions;
  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
  clang::TextDiagnosticPrinter DiagnosticPrinter(errs(), &*DiagOpts);
  DiagnosticsEngine Diagnostics(
      IntrusiveRefCntPtr<DiagnosticIDs>(new DiagnosticIDs()), &*DiagOpts,
      &DiagnosticPrinter, false);
  auto &FileMgr = Tool.getFiles();
  SourceManager Sources(Diagnostics, FileMgr);
  Rewriter Rewrite(Sources, DefaultLangOptions);

  if (!formatAndApplyAllReplacements(Tool.getReplacements(), Rewrite, Style)) {
    llvm::errs() << "Failed applying all replacements.\n";
    return 1;
  }
  if (Inplace)
    return Rewrite.overwriteChangedFiles();

  for (const auto &File : Files) {
    const auto *Entry = FileMgr.getFile(File);

    auto ID = Sources.getOrCreateFileID(Entry, SrcMgr::C_User);
    // FIXME: print results in parsable format, e.g. JSON.
    outs() << "============== " << File << " ==============\n";
    Rewrite.getEditBuffer(ID).write(llvm::outs());
    outs() << "\n============================================\n";
  }
  return 0;
}