#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "chess.h"
#include "data.h"

/* last modified 08/12/97 */
/*
********************************************************************************
*                                                                              *
*   ResignOrDraw() is used to determine if the program should either resign    *
*   or offer a draw.  this decision is based on two criteria:  (1) current     *
*   search evaluation and (2) time remaining on opponent's clock.              *
*                                                                              *
*   the evaluation returned by the last search must be less than the resign    *
*   threshold to trigger the resign code, or else must be exactly equal to the *
*   draw score to trigger the draw code.                                       *
*                                                                              *
*   the opponent must have enough time to be able to win or draw the game if   *
*   were played out as well.                                                   *
*                                                                              *
********************************************************************************
*/
void ResignOrDraw(TREE *tree, int value, int wtm)
{
  int returnv=0;
/*
 ----------------------------------------------------------
|                                                          |
|   if the game is a forced draw (repetition, 50-moves,    |
|   insufficient material, etc.) then immediately claim a  |
|   draw, otherwise the search will "break" due to the     |
|   50-move rule kicking in for *all* moves.               |
|                                                          |
 ----------------------------------------------------------
*/
  if (RepetitionDraw(tree, ChangeSide(wtm)) || Drawn(tree,value)) returnv=2;
/*
 ----------------------------------------------------------
|                                                          |
|   first check to see if the increment is 2 seconds or    |
|   more.  if so, then the game is being played slowly     |
|   enough that a draw offer or resignation is worth       |
|   consideration.  otherwise, if the opponent has at      |
|   least 30 seconds left, he can probably play the draw   |
|   or win out.                                            |
|                                                          |
|   if the value is below the resignation threshold, and   |
|   then crafty should resign and get on to the next game. |
|   note that it is necessary to have a bad score for      |
|   <resign_count> moves in a row before resigning.        |
|                                                          |
 ----------------------------------------------------------
*/
  if ((tc_increment > 200) || (tc_time_remaining_opponent >= 3000)) {
    if (resign) {
      if (value < -(MATE-15)) {
        if (++resign_counter >= resign_count) returnv=1;
      }
      else if (value<-resign*100 && value>-(MATE-100)) {
        if (++resign_counter >= resign_count) returnv=1;
      }
      else resign_counter=0;
    }
  }
/*
 ----------------------------------------------------------
|                                                          |
|   if the value is exactly equal to the draw score, then  |
|   crafty should offer the opponent a draw.  note that  . |
|   it is necessary that the draw score occur on exactly   |
|   <draw_count> moves in a row before making the offer.   |
|   note also that the draw offer will be repeated every   |
|   <draw_count> moves so setting this value too low can   |
|   make the program behave "obnoxiously."                 |
|                                                          |
 ----------------------------------------------------------
*/
  if ((tc_increment > 200) || (tc_time_remaining_opponent >= 3000)) {
    if (value==DrawScore() && moves_out_of_book>3) {
      if (++draw_counter >= draw_count) {
        draw_counter=0;
        returnv=3;
      }
    }
    else draw_counter=0;
  }
/*
 ----------------------------------------------------------
|                                                          |
|   now print the draw offer or resignation if appropriate |
|   but be sure and do it in a form that ICC/FICS will     |
|   understand if the "ics" or "xboard" flag is set.       |
|                                                          |
 ----------------------------------------------------------
*/
  if (returnv == 1) {
    if (!ics && !xboard) Print(4095,"\nCrafty resigns.\n\n");
    else if (xboard) {
      Print(4095,"tellics resign\n");
      if (crafty_is_white) {
        Print(4095,"White resigns\n");
        strcpy(pgn_result,"0-1");
      }
      else {
        Print(4095,"Black resigns\n");
        strcpy(pgn_result,"1-0");
      }
    }
    else Print(4095,"\n*resign\n");
    if (learning&result_learning) LearnResult(tree,crafty_is_white);
  }
  if (returnv >= 2) {
    if (!ics && !xboard) Print(4095,"\nCrafty offers a draw.\n\n");
    else if (xboard) {
      Print(4095,"tellics draw\n");
      if (xboard && returnv==2) Print(4095,"Draw\n");
    }
    else Print(4095,"\n*draw\n");
  }
}