// file      : build2/context.txx -*- C++ -*-
// copyright : Copyright (c) 2014-2016 Code Synthesis Ltd
// license   : MIT; see accompanying LICENSE file

namespace build2
{
  template <typename K>
  basic_path<char, K>
  relative (const basic_path<char, K>& p)
  {
    typedef basic_path<char, K> path;

    const dir_path& b (*relative_base);

    if (p.simple () || b.empty ())
      return p;

    if (p.sub (b))
      return p.leaf (b);

    // If base is a sub-path of {src,out}_root and this path is also a
    // sub-path of it, then use '..' to form a relative path.
    //
    // Don't think this is a good heuristic. For example, why shouldn't
    // we display paths from imported projects as relative if they are
    // more readable than absolute?
    //
    /*
    if ((work.sub (src_root) && p.sub (src_root)) ||
        (work.sub (out_root) && p.sub (out_root)))
      return p.relative (work);
    */

    if (p.root_directory () == b.root_directory ())
    {
      path r (p.relative (b));

      if (r.string ().size () < p.string ().size ())
        return r;
    }

    return p;
  }
}