/vqdr/trunk

using Gee;

using VQDR.Common;

namespace VQDR.Expression {

  public class Context : GLib.Object{

    private bool changed;

    private Gee.TreeMap<string, Variable?> values;

    construct {

      changed = false;

      values = new Gee.TreeMap<string, Variable?>

                              (Common.Utils.str_cmp, null);

    }

    public Context () {

    }

    public void set_value (string name, 

                           int min_val,

                           int max_val,

                           int current_val) {

      set_variable (name, Variable (min_val, max_val, current_val));

    }

    public Variable get_variable (string name) throws ArgError {

    throw_name (name);

    return values.@get (name.down ());

    }

    public void set_variable (string name, Variable? variable) {

      string new_name = name.down ();

    if (!(values.has_key (new_name)) ||

          !(values.get(new_name).equals(variable))) {

          values.set (new_name, variable);

          changed = true;

      }

    }

    private void throw_name (string name) throws ArgError {

      if (! (values.has_key (name.down ()))) {

         throw new ArgError.INVALID_ARGUMENT ("Name \"" +

                                               name.down () +

                                               "\" not defined.");

       }

    }

    public int get_value (string name) throws ArgError {

      throw_name (name);

      return values.@get (name.down ()).current_val;

    }

    public int get_min_value (string name) throws ArgError {

      throw_name (name);

      return values.@get (name.down ()).min_val;

    }

    public int get_max_value (string name) throws ArgError {

      throw_name (name);

      return values.@get (name.down ()).max_val;

    }

    public int get_current_value (string name) throws ArgError {

      throw_name (name);

      return values.@get (name.down ()).current_val;

    }

    public bool has_name (string name) {

      return values.has_key (name.down ());

    }

    protected void reset () {

      changed = false;

    }

  }

}