// file      : bpkg/utility -*- C++ -*-
// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
// license   : MIT; see accompanying LICENSE file

#ifndef BPKG_UTILITY
#define BPKG_UTILITY

#include <memory>    // make_shared()
#include <cassert>
#include <utility>   // move()
#include <exception> // uncaught_exception()

#include <butl/filesystem>

#include <bpkg/types>

namespace bpkg
{
  using std::move;
  using std::make_shared;
  using std::to_string; // To complement bpkg::to_string().

  // Y/N prompt. The def argument, if specified, should be either 'y'
  // or 'no'. It is used as the default answer, in case the user just
  // hits enter. Issue diagnostics and throw failed if no answer could
  // be extracted from STDOUT (e.g., because it was closed).
  //
  bool
  yn_prompt (const char* prompt, char def = '\0');

  // Filesystem.
  //
  bool
  exists (const path&);

  bool
  exists (const dir_path&);

  bool
  empty (const dir_path&);

  void
  mk (const dir_path&);

  void
  mk_p (const dir_path&);

  void
  rm (const path&);

  void
  rm_r (const dir_path&, bool dir = true);

  using auto_rm = butl::auto_rmfile;
  using auto_rm_r = butl::auto_rmdir;

  // Process.
  //
  // The process command line is printed for verbosity >= 2 (essential
  // command lines).
  //
  void
  run (const char* const args[]);

  inline void
  run (const cstrings& args) {run (args.data ());}

  // Run build2, mapping verbosity levels. If quiet is true, then
  // run build2 quiet if our verbosity level is 1.
  //
  class common_options;

  void
  run_b (const common_options&,
         const string& buildspec,
         bool quiet = false,
         const strings& vars1 = strings (),
         const strings& vars2 = strings ());

  // Call a function if there is an exception.
  //

  // True means we are in the body of a destructor that is being
  // called as part of the exception stack unwindining. Used to
  // compensate for the deficiencies of uncaught_exception() until
  // C++17 uncaught_exceptions() becomes available.
  //
  // @@ MT: will have to be TLS.
  //
  extern bool exception_unwinding_dtor;

  template <typename F>
  struct exception_guard;

  template <typename F>
  inline exception_guard<F>
  make_exception_guard (F f)
  {
    return exception_guard<F> (std::move (f));
  }

  template <typename F>
  struct exception_guard
  {
    exception_guard (F f): f_ (std::move (f)) {}
    ~exception_guard ()
    {
      if (std::uncaught_exception ())
      {
        exception_unwinding_dtor = true;
        f_ ();
        exception_unwinding_dtor = false;
      }
    }

  private:
    F f_;
  };
}

#endif // BPKG_UTILITY