///
// Copyright (C) 2003, 2004, Fredrik Arnerup & Rasmus Kaj, See COPYING
///
#include "tempfile.h"
#include "warning.h"
#include "filesys.h"
#include "os.h"
#include <stdexcept>
#include <unistd.h>

namespace {
  std::string get_tmplate(std::string base) {
    base += "XXXXXX";
    if(base[0] != '/') {
      const std::string tmpdir(os::get_env("TMPDIR"));
      if(tmpdir != "") {
	base = tmpdir + '/' + base;
      } else {
	base = "/tmp/" + base;
      }
    }
    /// \todo verbose is not initialized when the constructor is executed
    verbose << "Temp file base is " << base << std::endl;
    return base;
  }
}

std::string Tempfile::tmplate;

// Note: This method creates the temp file with suitable permissions, but then
// it closes it for anything to reopen rather than using the actual fd where
// the file is open.
/// \todo Create and use a new version
// tmpfile() is said to be more portable
std::string Tempfile::find_new_name() {
  // in case the tmplate has not been initialized:
  if(tmplate.empty())
    tmplate = get_tmplate("foo");
  char* templ = strdup(tmplate.c_str());
  /// \todo possible security problem - change umask
  int fd = mkstemp(templ);
  if(fd == -1)
    throw std::runtime_error("Failed to create temp file.");
  close(fd);
  std::string result(templ);
  free(templ);
  return result;
}

void Tempfile::set_prefix(const std::string &prefix) {
  tmplate = get_tmplate(prefix);
}

Tempfile::Tempfile(): filename(find_new_name()) {}

Tempfile::~Tempfile() {
  // delete the temp file
  try {
    unlink(filename);
  } catch(std::exception& err) {
    warning << "Failed to delete " << filename 
	    << ", " << err.what() << std::endl;
  }
}