#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/DiagnosticOptions.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/IdentifierTable.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TokenKinds.h"
#include "clang/Frontend/CompilerInstance.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/Refactoring/Rename/RenamingAction.h"
#include "clang/Tooling/Refactoring/Rename/USRFindingAction.h"
#include "clang/Tooling/ReplacementsYaml.h"
#include "clang/Tooling/Tooling.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/InitLLVM.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/YAMLTraits.h"
#include "llvm/Support/raw_ostream.h"

#include <string>
#include <system_error>
#include <memory>

using namespace llvm;
using namespace clang;

static cl::OptionCategory
    ClangASTRenameOptions("clang-ast-rewrite common options");

static cl::opt<std::string> Input("input", cl::desc("Input .ast file"),
                                  cl::Required, cl::cat(ClangASTRenameOptions));

static cl::opt<std::string> Output("output", cl::desc("Output .ast file"),
                                   cl::Required,
                                   cl::cat(ClangASTRenameOptions));

static cl::opt<std::string>
    FindPath("find", cl::desc("The path to be replaced with `replace` value"),
             cl::Required, cl::cat(ClangASTRenameOptions));

static cl::opt<std::string>
    ReplacePath("replace", cl::desc("The path which will replace `find` value"),
                cl::Required, cl::cat(ClangASTRenameOptions));

static cl::opt<bool> Help("h", cl::desc("Alias for -help"), cl::Hidden);

int main(int argc, const char **argv) {
  llvm::InitLLVM X(argc, argv);

  cl::HideUnrelatedOptions(ClangASTRenameOptions);

  cl::ParseCommandLineOptions(
      argc, argv, "A tool to modify the absolute path(s) inside a .ast file");

  if (Help) {
    cl::PrintHelpMessage();
    return 0;
  }

  // remove leading and trailing spaces
  StringRef refInput(Input);
  refInput = refInput.ltrim().rtrim();

  StringRef refOutput(Output);
  refOutput = refOutput.ltrim().rtrim();

  StringRef refFindPath(FindPath);
  refFindPath = refFindPath.ltrim().rtrim();

  StringRef refReplacePath(ReplacePath);
  refReplacePath = refReplacePath.ltrim().rtrim();

  // check the sanity of arguments
  if (refInput.empty()) {
    errs() << "clang-ast-rename: valid --input must be specified.\n\n";
    return 1;
  }
  if (refOutput.empty()) {
    errs() << "clang-ast-rename: valid --output must be specified.\n\n";
    return 1;
  }

  if (refFindPath.empty()) {
    errs() << "clang-ast-rename: valid --find must be specified.\n\n";
    return 1;
  }
  if (refReplacePath.empty()) {
    errs() << "clang-ast-rename: valid --replace must be specified.\n\n";
    return 1;
  }

  CompilerInstance ci;
  IntrusiveRefCntPtr<DiagnosticOptions> DiagOpts = new DiagnosticOptions();
  TextDiagnosticPrinter *DiagClient =
      new TextDiagnosticPrinter(llvm::errs(), &*DiagOpts);
  ci.createDiagnostics(DiagClient,false);
  IntrusiveRefCntPtr<DiagnosticIDs> DiagID(new DiagnosticIDs());
  IntrusiveRefCntPtr<DiagnosticsEngine> Diags(
      new DiagnosticsEngine(DiagID, &*DiagOpts, DiagClient));

  auto to = std::make_shared<clang::TargetOptions>();
  to->Triple = llvm::sys::getDefaultTargetTriple();
  TargetInfo *pti = TargetInfo::CreateTargetInfo(ci.getDiagnostics(), to);
  ci.setTarget(pti);
  auto FileMan = ci.createFileManager();
  ci.createSourceManager(ci.getFileManager());
  ci.createPreprocessor(TranslationUnitKind::TU_Complete);

  auto AU = ASTUnit::LoadFromASTFile(
      std::string(refInput.str()),
      ci.getPCHContainerOperations()->getRawReader(), ASTUnit::LoadEverything,
      Diags, ci.getFileSystemOpts());

  return 0;
}