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

#include <build2/bin/rule>

#include <build2/scope>
#include <build2/target>
#include <build2/algorithm>
#include <build2/diagnostics>

#include <build2/bin/target>

using namespace std;

namespace build2
{
  namespace bin
  {
    // obj
    //
    match_result obj_rule::
    match (action a, target& t, const std::string&) const
    {
      fail << diag_doing (a, t) << " target group" <<
        info << "explicitly select either obja{} or objso{} member";

      return nullptr;
    }

    recipe obj_rule::
    apply (action, target&, const match_result&) const {return empty_recipe;}

    // lib
    //
    // The whole logic is pretty much as if we had our two group
    // members as our prerequisites.
    //
    match_result lib_rule::
    match (action a, target& xt, const std::string&) const
    {
      lib& t (static_cast<lib&> (xt));

      // @@ We have to re-query it on each match_only()!

      // Get the library type to build. If not set for a target, this
      // should be configured at the project scope by init_lib().
      //
      const string& type (as<string> (*t["bin.lib"]));

      bool ar (type == "static" || type == "both");
      bool so (type == "shared" || type == "both");

      if (!ar && !so)
        fail << "unknown library type: " << type <<
          info << "'static', 'shared', or 'both' expected";

      // Search and pre-match the members. The pre-match here is part
      // of the "library meta-information protocol" that could be used
      // by the module that actually builds the members. The idea is
      // that pre-matching members may populate our prerequisite_targets
      // with prerequisite libraries from which others can extract the
      // meta-information about the library, such as the options to use
      // when linking it, etc.
      //
      if (ar)
      {
        if (t.a == nullptr)
          t.a = &search<liba> (t.dir, t.name, t.ext, nullptr);

        match_only (a, *t.a);
      }

      if (so)
      {
        if (t.so == nullptr)
          t.so = &search<libso> (t.dir, t.name, t.ext, nullptr);

        match_only (a, *t.so);
      }

      match_result mr (t, &type);

      // If there is an outer operation, indicate that we match
      // unconditionally so that we don't override ourselves.
      //
      if (a.outer_operation () != 0)
        mr.recipe_action = action (a.meta_operation (), a.operation ());

      return mr;
    }

    recipe lib_rule::
    apply (action a, target& xt, const match_result& mr) const
    {
      lib& t (static_cast<lib&> (xt));

      const string& type (*static_cast<const string*> (mr.cpvalue));

      bool ar (type == "static" || type == "both");
      bool so (type == "shared" || type == "both");

      // Now we do full match.
      //
      if (ar)
        build2::match (a, *t.a);

      if (so)
        build2::match (a, *t.so);

      return &perform;
    }

    target_state lib_rule::
    perform (action a, target& xt)
    {
      lib& t (static_cast<lib&> (xt));

      //@@ Not cool we have to do this again. Looks like we need
      //   some kind of a cache vs resolved pointer, like in
      //   prerequisite vs prerequisite_target.
      //
      //
      const string& type (as<string> (*t["bin.lib"]));
      bool ar (type == "static" || type == "both");
      bool so (type == "shared" || type == "both");

      target* m1 (ar ? t.a : nullptr);
      target* m2 (so ? t.so : nullptr);

      if (current_mode == execution_mode::last)
        swap (m1, m2);

      target_state r (target_state::unchanged);

      if (m1 != nullptr)
        r |= execute (a, *m1);

      if (m2 != nullptr)
        r |= execute (a, *m2);

      return r;
    }
  }
}