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

#include <build2/cxx/module>

#include <butl/process>
#include <butl/triplet>
#include <butl/fdstream>

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

#include <build2/config/utility>
#include <build2/install/utility>

#include <build2/bin/target>

#include <build2/cxx/link>
#include <build2/cxx/guess>
#include <build2/cxx/target>
#include <build2/cxx/compile>
#include <build2/cxx/install>
#include <build2/cxx/utility>

using namespace std;
using namespace butl;

namespace build2
{
  namespace cxx
  {
    extern "C" bool
    cxx_init (scope& r,
              scope& b,
              const location& loc,
              unique_ptr<module>&,
              bool first,
              bool)
    {
      tracer trace ("cxx::init");
      l5 ([&]{trace << "for " << b.out_path ();});

      // Initialize the bin module. Only do this if it hasn't already
      // been loaded so that we don't overwrite user's bin.* settings.
      //
      {
        auto l (b["bin.loaded"]);

        if (!l || !as<bool> (*l))
          load_module (false, "bin", r, b, loc);
      }

      // Enter module variables.
      //
      // @@ Probably should only be done on load; make sure reset() unloads
      //    modules.
      //
      // @@ Should probably cache the variable pointers so we don't have
      //    to keep looking them up.
      //
      if (first)
      {
        auto& v (var_pool);

        v.find ("config.cxx", string_type); //@@ VAR type

        v.find ("config.cxx.poptions", strings_type);
        v.find ("config.cxx.coptions", strings_type);
        v.find ("config.cxx.loptions", strings_type);
        v.find ("config.cxx.libs", strings_type);

        v.find ("cxx.poptions", strings_type);
        v.find ("cxx.coptions", strings_type);
        v.find ("cxx.loptions", strings_type);
        v.find ("cxx.libs", strings_type);

        v.find ("cxx.export.poptions", strings_type);
        v.find ("cxx.export.coptions", strings_type);
        v.find ("cxx.export.loptions", strings_type);
        v.find ("cxx.export.libs", strings_type);

        v.find ("cxx.std", string_type);
      }

      // Register target types.
      //
      {
        auto& t (b.target_types);

        t.insert<h> ();
        t.insert<c> ();

        t.insert<cxx> ();
        t.insert<hxx> ();
        t.insert<ixx> ();
        t.insert<txx> ();
      }

      // Register rules.
      //
      {
        using namespace bin;

        auto& r (b.rules);

        r.insert<obja> (perform_update_id, "cxx.compile", compile::instance);

        r.insert<obja> (perform_update_id, "cxx.compile", compile::instance);
        r.insert<obja> (perform_clean_id, "cxx.compile", compile::instance);

        r.insert<objso> (perform_update_id, "cxx.compile", compile::instance);
        r.insert<objso> (perform_clean_id, "cxx.compile", compile::instance);

        r.insert<exe> (perform_update_id, "cxx.link", link::instance);
        r.insert<exe> (perform_clean_id, "cxx.link", link::instance);

        r.insert<liba> (perform_update_id, "cxx.link", link::instance);
        r.insert<liba> (perform_clean_id, "cxx.link", link::instance);

        r.insert<libso> (perform_update_id, "cxx.link", link::instance);
        r.insert<libso> (perform_clean_id, "cxx.link", link::instance);

        // Register for configure so that we detect unresolved imports
        // during configuration rather that later, e.g., during update.
        //
        r.insert<obja> (configure_update_id, "cxx.compile", compile::instance);
        r.insert<objso> (configure_update_id, "cxx.compile", compile::instance);

        r.insert<exe> (configure_update_id, "cxx.link", link::instance);
        r.insert<liba> (configure_update_id, "cxx.link", link::instance);
        r.insert<libso> (configure_update_id, "cxx.link", link::instance);

        //@@ Should we check if install module was loaded (see bin)?
        //
        r.insert<exe> (perform_install_id, "cxx.install", install::instance);
        r.insert<liba> (perform_install_id, "cxx.install", install::instance);
        r.insert<libso> (perform_install_id, "cxx.install", install::instance);
      }

      // Configure.
      //

      // config.cxx.{p,c,l}options
      // config.cxx.libs
      //
      // These are optional. We also merge them into the corresponding
      // cxx.* variables.
      //
      // The merging part gets a bit tricky if this module has already
      // been loaded in one of the outer scopes. By doing the straight
      // append we would just be repeating the same options over and
      // over. So what we are going to do is only append to a value if
      // it came from this scope. Then the usage for merging becomes:
      //
      // cxx.coptions = <overridable options> # Note: '='.
      // using cxx
      // cxx.coptions += <overriding options> # Note: '+='.
      //
      if (const value& v = config::optional (r, "config.cxx.poptions"))
        b.assign ("cxx.poptions") += as<strings> (v);

      if (const value& v = config::optional (r, "config.cxx.coptions"))
        b.assign ("cxx.coptions") += as<strings> (v);

      if (const value& v = config::optional (r, "config.cxx.loptions"))
        b.assign ("cxx.loptions") += as<strings> (v);

      if (const value& v = config::optional (r, "config.cxx.libs"))
        b.assign ("cxx.libs") += as<strings> (v);

      // config.cxx
      //
      if (first)
      {
        auto p (config::required (r, "config.cxx", "g++"));

        // Figure out which compiler we are dealing with, its target, etc.
        //
        const path& cxx (path (as<string> (p.first))); // @@ VAR
        compiler_info ci (guess (cxx, r["cxx.coptions"]));

        // If this is a new value (e.g., we are configuring), then print the
        // report at verbosity level 2 and up (-v).
        //
        if (verb >= (p.second ? 2 : 3))
        {
          //@@ Print project out root or name? Don't print if unnamed?

          text << cxx << ":\n"
               << "  id         " << ci.id << "\n"
               << "  major      " << ci.version.major << "\n"
               << "  minor      " << ci.version.minor << "\n"
               << "  patch      " << ci.version.patch << "\n"
               << "  build      " << ci.version.build << "\n"
               << "  signature  " << ci.signature << "\n"
               << "  checksum   " << ci.checksum << "\n"
               << "  target     " << ci.target << "";
        }

        r.assign ("cxx.id", string_type) = ci.id.string ();
        r.assign ("cxx.id.type", string_type) = move (ci.id.type);
        r.assign ("cxx.id.variant", string_type) = move (ci.id.variant);

        r.assign ("cxx.version", string_type) = ci.version.string ();
        r.assign ("cxx.version.major", string_type) = move (ci.version.major);
        r.assign ("cxx.version.minor", string_type) = move (ci.version.minor);
        r.assign ("cxx.version.patch", string_type) = move (ci.version.patch);
        r.assign ("cxx.version.build", string_type) = move (ci.version.build);

        r.assign ("cxx.signature", string_type) = move (ci.signature);
        r.assign ("cxx.checksum", string_type) = move (ci.checksum);

        // Split/canonicalize the target.
        //
        try
        {
          string canon;
          triplet t (ci.target, canon);

          l5 ([&]{trace << "canonical target: '" << canon << "'; "
                        << "class: " << t.class_;});

          // Enter as cxx.target.{cpu,vendor,system,version,class}.
          //
          r.assign ("cxx.target", string_type) = move (canon);
          r.assign ("cxx.target.cpu", string_type) = move (t.cpu);
          r.assign ("cxx.target.vendor", string_type) = move (t.vendor);
          r.assign ("cxx.target.system", string_type) = move (t.system);
          r.assign ("cxx.target.version", string_type) = move (t.version);
          r.assign ("cxx.target.class", string_type) = move (t.class_);
        }
        catch (const invalid_argument& e)
        {
          // This is where we could suggest that the user specifies
          // --config-sub to help us out.
          //
          fail << "unable to parse compiler target '" << ci.target << "': "
               << e.what ();
        }
      }

      // Configure "installability" of our target types.
      //
      {
        using build2::install::path;

        path<hxx> (b, dir_path ("include")); // Install into install.include.
        path<ixx> (b, dir_path ("include"));
        path<txx> (b, dir_path ("include"));
        path<h>   (b, dir_path ("include"));
      }

      return true;
    }
  }
}