universe@50: /*
universe@50:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@50:  *
universe@55:  * Copyright 2016 Mike Becker. All rights reserved.
universe@50:  *
universe@50:  * Redistribution and use in source and binary forms, with or without
universe@50:  * modification, are permitted provided that the following conditions are met:
universe@50:  *
universe@50:  *   1. Redistributions of source code must retain the above copyright
universe@50:  *      notice, this list of conditions and the following disclaimer.
universe@50:  *
universe@50:  *   2. Redistributions in binary form must reproduce the above copyright
universe@50:  *      notice, this list of conditions and the following disclaimer in the
universe@50:  *      documentation and/or other materials provided with the distribution.
universe@50:  *
universe@50:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@50:  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@50:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@50:  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@50:  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@50:  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@50:  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@50:  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@50:  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@50:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@50:  * POSSIBILITY OF SUCH DAMAGE.
universe@50:  *
universe@50:  */
universe@50: 
universe@50: #include "pgn.h"
universe@50: #include <ctype.h>
universe@50: #include <stdlib.h>
universe@50: #include <string.h>
universe@50: 
universe@60: enum {
universe@60:     pgn_error_missing_quote = 1,
universe@60:     pgn_error_missing_bracket,
universe@60:     pgn_error_missing_dot,
universe@60:     pgn_error_move_syntax,
universe@60:     pgn_error_move_semantics
universe@60: };
universe@60: 
universe@60: static const char* pgn_error_strings[] = {
universe@60:     "No Error.",
universe@60:     "Tag values must be enclosed in double-quotes.",
universe@60:     "Tags must be enclosed in square brackets: '[Key \"Value\"]'.",
universe@60:     "Move numbers must be terminated with a dot (e.g. '13.' - not '13').",
universe@60:     "Move is syntactically incorrect.",
universe@60:     "Move is not valid according to chess rules."
universe@60: };
universe@60: 
universe@60: const char* pgn_error_str(int code) {
universe@60:     return pgn_error_strings[code];
universe@60: }
universe@60: 
universe@50: int read_pgn(FILE* stream, GameState *gamestate, GameInfo *gameinfo) {
universe@50:     int c, i;
universe@50:     
universe@50:     char result[8];
universe@50:     
universe@50:     char tagkey[32];
universe@50:     char tagvalue[128];
universe@50:     
universe@64:     /* read tag pairs */
universe@50:     _Bool readmoves = 0;
universe@50:     while (!readmoves) {
universe@50:         while (isspace(c = fgetc(stream)));
universe@50:         if (c == '1') {
universe@50:             readmoves = 1;
universe@50:             break;
universe@50:         }
universe@50:         if (c != '[') {
universe@60:             return pgn_error_missing_bracket;
universe@50:         }
universe@50:         while (isspace(c = fgetc(stream)));
universe@50:         i = 0;
universe@50:         do {
universe@50:             tagkey[i++] = c;
universe@50:         } while (!isspace(c = fgetc(stream)));
universe@50:         tagkey[i] = '\0';
universe@50:         while (isspace(c = fgetc(stream)));
universe@50:         if (c != '"') {
universe@60:             return pgn_error_missing_quote;
universe@50:         }
universe@50:         i = 0;
universe@50:         while ((c = fgetc(stream)) != '"') {
universe@60:             if (c == '\n' || c == EOF) {
universe@60:                 return pgn_error_missing_quote;
universe@50:             }
universe@50:             tagvalue[i++] = c;
universe@50:         }
universe@50:         tagvalue[i] = '\0';
universe@50:         if (fgetc(stream) != ']') {
universe@60:             return pgn_error_missing_bracket;
universe@50:         }
universe@50: 
universe@50:         if (strcmp("Result", tagkey) == 0) {
universe@50:             memcpy(result, tagvalue, 8);
universe@50:         }
universe@50:     }
universe@50:     
universe@64:     /* read moves */
universe@50:     if (fgetc(stream) != '.') {
universe@60:         return pgn_error_missing_dot;
universe@50:     }
universe@50:     
universe@50:     char movestr[10];
universe@50:     Move move;
universe@50:     uint8_t curcol = WHITE;
universe@50:     
universe@50:     while (readmoves) {
universe@64:         /* move */
universe@50:         while (isspace(c = fgetc(stream)));
universe@50:         i = 0;
universe@50:         do {
universe@50:             movestr[i++] = c;
universe@50:             if (i >= 10) {
universe@59:                 return 1;
universe@50:             }
universe@50:         } while (!isspace(c = fgetc(stream)));
universe@50:         movestr[i] = '\0';
universe@50:         if (eval_move(gamestate, movestr, &move, curcol)
universe@50:                 != VALID_MOVE_SYNTAX) {
universe@60:             return pgn_error_move_syntax;
universe@50:         }
universe@50:         if (validate_move(gamestate, &move) != VALID_MOVE_SEMANTICS) {
universe@60:             return pgn_error_move_semantics;
universe@50:         }
universe@50:         apply_move(gamestate, &move);
universe@50:         
universe@50:         // TODO: parse comments
universe@50:         while (isspace(c = fgetc(stream)));
universe@50:         
universe@64:         /* end of game data encountered */
universe@50:         if (c == EOF) {
universe@50:             break;
universe@50:         }
universe@50:         if (c == '1' || c == '0') {
universe@50:             c = fgetc(stream);
universe@50:             if (c == '-') {
universe@50:                 gamestate->resign = !gamestate->checkmate;
universe@50:                 break;
universe@50:             } else if (c == '/') {
universe@50:                 gamestate->remis = !gamestate->stalemate;
universe@50:                 break;
universe@50:             } else {
universe@64:                 /* oops, it was a move number, go back! */
universe@50:                 fseek(stream, -1, SEEK_CUR);
universe@50:             }
universe@50:         }
universe@50:         
universe@64:         /* we have eaten the next valuable byte, so go back */
universe@50:         fseek(stream, -1, SEEK_CUR);
universe@50:         
universe@64:         /* skip move number after black move */
universe@50:         if (curcol == BLACK) {
universe@50:             while (isdigit(c = fgetc(stream)));
universe@50:             if (c != '.') {
universe@60:                 return pgn_error_missing_dot;
universe@50:             }
universe@50:         }
universe@50:         curcol = opponent_color(curcol);
universe@50:     }
universe@50:     
universe@59:     return 0;
universe@50: }
universe@50: 
universe@50: size_t write_pgn(FILE* stream, GameState *gamestate, GameInfo *gameinfo) {
universe@50:     // TODO: tag pairs
universe@50:     size_t bytes = 0;
universe@50:     
universe@64:     /* Result */
universe@50:     char *result;
universe@50:     if (gamestate->stalemate || gamestate->remis) {
universe@50:         result = "1/2-1/2";
universe@50:     } else if (gamestate->checkmate || gamestate->resign) {
universe@50:         if (gamestate->lastmove) {
universe@50:             result = (gamestate->lastmove->move.piece & COLOR_MASK) == WHITE ?
universe@50:                 "1-0" : "0-1";
universe@50:         } else {
universe@50:             result = "0-1";
universe@50:         }
universe@50:     } else {
universe@50:         result = "*";
universe@50:     }
universe@50:     fprintf(stream, "[Result \"%s\"]\n\n", result);
universe@50:     
universe@64:     /* moves */
universe@50:     int i = 1;
universe@50:     for (MoveList *movelist = gamestate->movelist ;
universe@50:         movelist ; movelist = movelist->next) {
universe@50:         
universe@50:         if (++i % 2 == 0) {
universe@50:             fprintf(stream, "%d. %s", i/2, movelist->move.string);
universe@50:         } else {
universe@50:             fprintf(stream, " %s", movelist->move.string);
universe@50:         }
universe@50:         
universe@50:         // TODO: move time and maybe other comments
universe@50:         
universe@64:         /* line break every 10 moves */
universe@65:         if ((i-1) % 20)  {
universe@50:             fputc(' ', stream);
universe@50:         } else {
universe@50:             fputc('\n', stream);
universe@50:         }
universe@50:     }
universe@50:     
universe@50:     if (result[0] == '*') {
universe@50:         fputc('\n', stream);
universe@50:     } else {
universe@50:         fprintf(stream, "%s\n", result);
universe@50:     }
universe@50:     
universe@50:     
universe@50:     return bytes;
universe@50: }
universe@54: 
universe@54: static size_t fen_pieces(char *str, GameState *gamestate) {
universe@54:     size_t i = 0;
universe@54:     for (int row = 7 ; row >= 0 ; row--) {
universe@54:         unsigned int skip = 0;
universe@54:         for (int file = 0 ; file < 8 ; file++) {
universe@54:             if (gamestate->board[row][file]) {
universe@54:                 if (skip > 0) {
universe@54:                     str[i++] = '0'+skip;
universe@54:                     skip = 0;
universe@54:                 }
universe@54:                 switch (gamestate->board[row][file] & ~ENPASSANT_THREAT) {
universe@54:                 case WHITE|KING: str[i++] = 'K'; break;
universe@54:                 case WHITE|QUEEN: str[i++] = 'Q'; break;
universe@54:                 case WHITE|BISHOP: str[i++] = 'B'; break;
universe@54:                 case WHITE|KNIGHT: str[i++] = 'N'; break;
universe@54:                 case WHITE|ROOK: str[i++] = 'R'; break;
universe@54:                 case WHITE|PAWN: str[i++] = 'P'; break;
universe@54:                 case BLACK|KING: str[i++] = 'k'; break;
universe@54:                 case BLACK|QUEEN: str[i++] = 'q'; break;
universe@54:                 case BLACK|BISHOP: str[i++] = 'b'; break;
universe@54:                 case BLACK|KNIGHT: str[i++] = 'n'; break;
universe@54:                 case BLACK|ROOK: str[i++] = 'r'; break;
universe@54:                 case BLACK|PAWN: str[i++] = 'p'; break;
universe@54:                 }
universe@54:             } else {
universe@54:                 skip++;
universe@54:             }
universe@54:         }
universe@54:         if (skip > 0) {
universe@54:             str[i++] = '0'+skip;
universe@54:         }
universe@54:         if (row > 0) {
universe@54:             str[i++] = '/';
universe@54:         }
universe@54:     }
universe@54:     
universe@54:     return i;
universe@54: }
universe@54: 
universe@54: static size_t fen_color(char *str, GameState *gamestate) {
universe@54:     uint8_t color = opponent_color(gamestate->lastmove ?
universe@54:         (gamestate->lastmove->move.piece & COLOR_MASK) : BLACK);
universe@54:     
universe@54:     str[0] = color == WHITE ? 'w' : 'b';
universe@54:     
universe@54:     return 1;
universe@54: }
universe@54: 
universe@54: static _Bool fen_castling_chkmoved(GameState *gamestate,
universe@54:     uint8_t row, uint8_t file) {
universe@54:     
universe@54:     MoveList *ml = gamestate->movelist;
universe@54:     while (ml) {
universe@54:         if (ml->move.fromfile == file && ml->move.fromrow == row) {
universe@54:             return 1;
universe@54:         }
universe@54:         ml = ml->next;
universe@54:     }
universe@54:     
universe@54:     return 0;
universe@54: }
universe@54: 
universe@54: static size_t fen_castling(char *str, GameState *gamestate) {
universe@54:     _Bool K, Q, k, q;
universe@54:     
universe@54:     if (fen_castling_chkmoved(gamestate, rowidx('1'), fileidx('e'))) {
universe@54:         K = Q = 0;
universe@54:     } else {
universe@54:         K = !fen_castling_chkmoved(gamestate, rowidx('1'), fileidx('h'));
universe@54:         Q = !fen_castling_chkmoved(gamestate, rowidx('1'), fileidx('a'));
universe@54:     }
universe@54:     if (fen_castling_chkmoved(gamestate, rowidx('8'), fileidx('e'))) {
universe@54:         k = q = 0;
universe@54:     } else {
universe@54:         k = !fen_castling_chkmoved(gamestate, rowidx('8'), fileidx('h'));
universe@54:         q = !fen_castling_chkmoved(gamestate, rowidx('8'), fileidx('a'));
universe@54:     }
universe@54:     
universe@54:     size_t i = 0;
universe@54:     if (K) str[i++] = 'K';
universe@54:     if (Q) str[i++] = 'Q';
universe@54:     if (k) str[i++] = 'k';
universe@54:     if (q) str[i++] = 'q';
universe@54:     if (!i) str[i++] = '-';
universe@54:     
universe@54:     return i;
universe@54: }
universe@54: 
universe@54: static size_t fen_enpassant(char *str, GameState *gamestate) {
universe@54:     
universe@54:     str[0] = '-'; str[1] = '\0';
universe@54:     
universe@54:     for (int file = 0 ; file < 8 ; file++) {
universe@54:         if (gamestate->board[3][file] & ENPASSANT_THREAT) {
universe@54:             str[0] = filechr(file);
universe@54:             str[1] = rowchr(2);
universe@54:         }
universe@54:         if (gamestate->board[4][file] & ENPASSANT_THREAT) {
universe@54:             str[0] = filechr(file);
universe@54:             str[1] = rowchr(5);
universe@54:         }
universe@54:     }
universe@54:     
universe@54:     return str[0] == '-' ? 1 : 2;
universe@54: }
universe@54: 
universe@54: static size_t fen_halfmove(char *str, GameState *gamestate) {
universe@54:     
universe@54:     unsigned int i = 0;
universe@54:     for (MoveList *move = gamestate->movelist ; move ; move = move->next) {
universe@54:         if (move->move.capture || (move->move.piece & PIECE_MASK) == PAWN) {
universe@54:             i = 0;
universe@54:         } else {
universe@54:             i++;
universe@54:         }
universe@54:     }
universe@54:     
universe@54:     char m[8];
universe@54:     size_t len = sprintf(m, "%u", i);
universe@54:     memcpy(str, m, len);
universe@54:     
universe@54:     return len;
universe@54: }
universe@54: 
universe@54: static size_t fen_movenr(char *str, GameState *gamestate) {
universe@54:     
universe@54:     MoveList *move = gamestate->movelist;
universe@54:     unsigned int i = 1;
universe@54:     while (move) {
universe@54:         i++;
universe@54:         move = move->next;
universe@54:     }
universe@54:     
universe@54:     char m[8];
universe@54:     size_t len = sprintf(m, "%u", i);
universe@54:     memcpy(str, m, len);
universe@54:     
universe@54:     return len;
universe@54: }
universe@54: 
universe@54: void compute_fen(char *str, GameState *gamestate) {
universe@54:     str += fen_pieces(str, gamestate);
universe@54:     *str = ' '; str++;
universe@54:     str += fen_color(str, gamestate);
universe@54:     *str = ' '; str++;
universe@54:     str += fen_castling(str, gamestate);
universe@54:     *str = ' '; str++;
universe@54:     str += fen_enpassant(str, gamestate);
universe@54:     *str = ' '; str++;
universe@54:     str += fen_halfmove(str, gamestate);
universe@54:     *str = ' '; str++;
universe@54:     str += fen_movenr(str, gamestate);
universe@54:     str[0] = '\0';
universe@54: }