// file      : bbot/agent.cxx -*- C++ -*-
// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
// license   : MIT; see accompanying LICENSE file

#ifndef _WIN32
#  include <signal.h> // signal()
#else
#  include <stdlib.h> // getenv(), _putenv()
#endif

#include <iostream>

#include <butl/pager>

#include <bbot/types>
#include <bbot/utility>

#include <bbot/diagnostics>
#include <bbot/bbot-version>

#include <bbot/agent-options>

using namespace std;
using namespace butl;
using namespace bbot;

int
main (int argc, char* argv[])
try
{
  // This is a little hack to make out baseutils for Windows work when called
  // with absolute path. In a nutshell, MSYS2's exec*p() doesn't search in the
  // parent's executable directory, only in PATH. And since we are running
  // without a shell (that would read /etc/profile which sets PATH to some
  // sensible values), we are only getting Win32 PATH values. And MSYS2 /bin
  // is not one of them. So what we are going to do is add /bin at the end of
  // PATH (which will be passed as is by the MSYS2 machinery). This will make
  // MSYS2 search in /bin (where our baseutils live). And for everyone else
  // this should be harmless since it is not a valid Win32 path.
  //
#ifdef _WIN32
  {
    string mp ("PATH=");
    if (const char* p = getenv ("PATH"))
    {
      mp += p;
      mp += ';';
    }
    mp += "/bin";

    _putenv (mp.c_str ());
  }
#endif

  // On POSIX ignore SIGPIPE which is signaled to a pipe-writing process if
  // the pipe reading end is closed. Note that by default this signal
  // terminates a process. Also note that there is no way to disable this
  // behavior on a file descriptor basis or for the write() function call.
  //
#ifndef _WIN32
  if (signal (SIGPIPE, SIG_IGN) == SIG_ERR)
    fail << "unable to ignore broken pipe (SIGPIPE) signal: "
         << system_error (errno, generic_category ()); // Sanitize.
#endif

  cli::argv_scanner scan (argc, argv, true);
  agent_options ops (scan);

  // Version.
  //
  if (ops.version ())
  {
    cout << "bbot-agent " << BBOT_VERSION_STR << endl
         << "libbbot " << LIBBBOT_VERSION_STR << endl
         << "libbutl " << LIBBUTL_VERSION_STR << endl
         << "Copyright (c) 2014-2017 Code Synthesis Ltd" << endl
         << "MIT; see accompanying LICENSE file" << endl;

    return 0;
  }

  // Help.
  //
  if (ops.help ())
  {
    pager p ("bbot-agent help", false);
    print_bbot_agent_usage (p.stream ());

    // If the pager failed, assume it has issued some diagnostics.
    //
    return p.wait () ? 0 : 1;
  }
}
catch (const failed&)
{
  return 1; // Diagnostics has already been issued.
}
catch (const cli::exception& e)
{
  error << e;
  return 1;
}