// file      : odb/mysql/schema.cxx
// author    : Boris Kolpackov <boris@codesynthesis.com>
// copyright : Copyright (c) 2009-2010 Code Synthesis Tools CC
// license   : GNU GPL v3; see accompanying LICENSE file

#include <set>
#include <odb/mysql/schema.hxx>

namespace mysql
{
  namespace
  {
    struct data_member: traversal::data_member, context
    {
      data_member (context& c)
          : context (c), first_ (true)
      {
      }

      virtual void
      traverse (type& m)
      {
        if (m.count ("transient"))
          return;

        if (first_)
          first_ = false;
        else
          os << "," << endl;

        os << "  `" << column_name (m) << "` " << column_type (m);

        if (m.count ("id"))
          os << " PRIMARY KEY";
      }

    private:
      bool first_;
    };

    struct class_create: traversal::class_, context
    {
      class_create (context& c)
          : context (c)
      {
      }

      virtual void
      traverse (type& c)
      {
        if (c.file () != unit.file ())
          return;

        if (!c.count ("object"))
          return;

        string const& name (table_name (c));

        // If the table with this name was already created, assume the
        // user knows what they are doing and skip it.
        //
        if (tables_.count (name))
          return;

        os << "CREATE TABLE `" << name << "` (" << endl;

        {
          data_member m (*this);
          traversal::names n (m);
          names (c, n);
        }

        os << ")";

        string const& engine (options.mysql_engine ());

        if (engine != "default")
          os << endl
             << "  ENGINE=" << engine;

        os << ";" << endl
           << endl;

        tables_.insert (name);
      }

    private:
      std::set<string> tables_;
    };

    struct class_drop: traversal::class_, context
    {
      class_drop (context& c)
          : context (c)
      {
      }

      virtual void
      traverse (type& c)
      {
        if (c.file () != unit.file ())
          return;

        if (!c.count ("object"))
          return;

        string const& name (table_name (c));

        if (tables_.count (name))
          return;

        os << "DROP TABLE IF EXISTS `" << name << "`;" << endl;

        tables_.insert (name);
      }

    private:
      std::set<string> tables_;
    };

    static char const file_header[] =
    "/* This file was generated by ODB, object-relational mapping (ORM)\n"
    " * compiler for C++.\n"
    " */\n\n";
  }

  void
  generate_schema (context& ctx)
  {
    ctx.os << file_header;

    // Drop.
    //
    {
      traversal::unit unit;
      traversal::defines unit_defines;
      traversal::namespace_ ns;
      class_drop c (ctx);

      unit >> unit_defines >> ns;
      unit_defines >> c;

      traversal::defines ns_defines;

      ns >> ns_defines >> ns;
      ns_defines >> c;
      unit.dispatch (ctx.unit);
    }

    ctx.os << endl;

    // Create.
    //
    {
      traversal::unit unit;
      traversal::defines unit_defines;
      traversal::namespace_ ns;
      class_create c (ctx);

      unit >> unit_defines >> ns;
      unit_defines >> c;

      traversal::defines ns_defines;

      ns >> ns_defines >> ns;
      ns_defines >> c;
      unit.dispatch (ctx.unit);
    }
  }
}