/vqdr/trunk

using Gee;

using VQDR.Expression;

namespace VQDR.Expression {

  public abstract class FunctionToken : Token {

    protected FunctionToken () {

      base (0);

    }

    // We only store the type, as that is what is important.

    private static Gee.HashMap<string, Type?> _allowed_functions;

    protected const long UNDEFINED = long.MIN + 1; //+1 so that I can still use Long.MIN_VALUE.

    /** Right arrow */

    protected const string CH_RARR = "\u2192";

    /** Left arrow */

    protected const string CH_LARR = "\u2190";

    /** Round up open bracket */

    protected const string CH_RUP_OP = "\u2308";

    /** Round up closed bracket */

    protected const string CH_RUP_CL = "\u2309";

    /** Round down open bracket */

    protected const string CH_RDN_OP = "\u230a";

    /** Round down closed bracket */

    protected const string CH_RDN_CL = "\u230b";

    /** Absolute open bracket */

    protected const string CH_ABS_OP = "|";

    /** Absolute closed bracket */

    protected const string CH_ABS_CL = "|";

    /** Greater than */

    protected const string CH_GT = ">";

    /** Lower than */

    protected const string CH_LT = "<";

    /** Equal */

    protected const string CH_EQUAL = "=";

    /** Begin of a complex result */

    protected const string SYM_BEGIN = "[";

    /** End of a complex result */

    protected const string SYM_END = "]";

    /** Begin of a complex result, alternative */

    protected const string SYM_BEGIN_ALT = "{";

    /** End of a complex result, alternative */

    protected const string SYM_END_ALT = "}";

    /** Separator for different roll result */

    protected const string SYM_SEP = ",";

    /** Separator for different value of same roll */

    protected const string SYM_SEP_SAME = ":";

    /** Separator for  overall (fumble, critical, botch, glitch) */

    protected const string SYM_SEP_ = "\u2261"; //"=" (with 3 lines)

    /** Denotes a success */

    protected const string SYM_SUCCESS = "!";

    /** Denotes a failure */

    protected const string SYM_FAILURE = "*";

    /** Denotes an extra result */

    protected const string SYM_EXTRA = "!";

    /** Denotes a selected result */

    protected const string SYM_SELECTED = "!";

    /** Separator for exploding rolls */

    protected const string SYM_EXPLODE = "\u00bb"; //">>"

    /** Truncated output: ellipsis */

    protected const string SYM_TRUNK_PART_ELLIPSIS = "\u2026"; //"..."

    /** Truncated output: equal */

    protected const string SYM_TRUNK_PART_EQUAL = CH_EQUAL; //"="

    /** Truncated output: begin */

    protected const string SYM_TRUNK_BEGIN = SYM_BEGIN + SYM_TRUNK_PART_ELLIPSIS + SYM_TRUNK_PART_EQUAL; //"[...="

    /** Truncated output: end */

    protected const string SYM_TRUNK_END = SYM_END; //"]"

    construct {

      _allowed_functions = new Gee.HashMap<string, Type?> ();

      this.priority = PRIO_FUNCTION;

    }

    /**

     * Ititialise the right functon token by it's name.

     * 

     * @param token Token of the Function.

     * @param position Token position.

     * @return An instance representing the function, or @c null if not found.

     */

    public static FunctionToken? init_token (string token, int position) {

      FunctionToken? retval = null;

      // We get the token type.

      Type? t = _allowed_functions.@get (token.down ());

      if (t != null) {

          // Construct a new instance of the token.

          retval = (FunctionToken) GLib.Object.@new (t, null, null);

      }

      return retval;

    }

    /**

     * Add a FunctionToken Type to the list of allowed functions.

     * 

     * Note: The Type must be derived from FunctionToken, as there is an

     *        assert that chkecks.

     */

    public static void add_function (string token, Type t) {

      assert (t.is_a (typeof (FunctionToken)) == true);

      _allowed_functions.@set (token, t);

    }

    public static string get_function_name (Type t) {

      assert (t.is_a (typeof (FunctionToken)) == true);

      string ret_val = null;

      _allowed_functions.map_iterator ().@foreach ((k,v) => {

        if (v == t) {

          ret_val = k;

          return false;

        }

        return true;

      });

      return ret_val;

    }

    protected long get_optional_child_raw_result (Context instance,

                                                  int index,

                                                  long default_result)

                                                  throws GLib.Error {

     Token? tmp_roll = get_child (index);

     if (tmp_roll != null) {

         tmp_roll.evaluate (instance);

         return tmp_roll.result_value;

     } else {

       return default_result;

     }

    }

  }

}