// file      : build/parser -*- C++ -*-
// copyright : Copyright (c) 2014-2015 Code Synthesis Tools CC
// license   : MIT; see accompanying LICENSE file

#ifndef BUILD_PARSER
#define BUILD_PARSER

#include <string>
#include <iosfwd>
#include <unordered_set>

#include <build/path>
#include <build/token>
#include <build/name>
#include <build/diagnostics>

namespace build
{
  class scope;
  class target;
  class lexer;

  class parser
  {
  public:
    parser (): fail (&path_) {}

    // Issues diagnostics and throws failed in case of an error.
    //
    void
    parse (std::istream&, const path&, scope&);

    // Recursive descent parser.
    //
  private:
    typedef build::names names_type;

    void
    clause (token&, token_type&);

    void
    print (token&, token_type&);

    void
    source (token&, token_type&);

    void
    include (token&, token_type&);

    names_type
    names (token& t, token_type& tt)
    {
      names_type ns;
      names (t, tt, ns, nullptr, nullptr);
      return ns;
    }

    void
    names (token&, token_type&, names_type&,
           const path* dir, const std::string* type);

    // Utilities.
    //
  private:
    void
    process_default_target (token&);

    // Lexer.
    //
  private:
    token_type
    next (token&, token_type&);

    token_type
    peek ();

    const token&
    peeked () const
    {
      assert (peeked_);
      return peek_;
    }

    // Diagnostics.
    //
  private:
    const fail_mark<failed> fail;

  private:
    const std::string* path_; // Path processed by diagnostic_string().
    lexer* lexer_;
    scope* scope_;
    target* default_target_;

    token peek_ {token_type::eos, false, 0, 0};
    bool peeked_ {false};

    std::unordered_set<path> include_;
  };
}

#endif // BUILD_PARSER