/*       cccc h   h eeeee  ssss  ssss 2222         cccc 
**      c     h   h e     s     s         2       c     
**      c     hhhhh eeee   sss   sss   222        c     
**      c     h   h e         s     s 2      ..   c     
**       cccc h   h eeeee ssss  ssss  22222  ..    cccc 
**
**      c h e s s 2 . c           dennette@wiz-worx.com
**
**      test of C compiler on various platforms
**      ... draws a chessboard
**
**      29-jun-76       FORTRAN - XDS Sigma 9 - original version
**      27-oct-79       FORTRAN - PDP 11/70
**      08-jul-82       C       - VAX 780
**      01-apr-83       Pascal  - IBM PC
**      04-dec-83       C       - DEC Rainbow (Aztec CII)
**      22-dec-83               - modified to read data from a file
**      30-may-84       C       - SAGE-IV (DRI CP/M-68K)
**      09-sep-84       C       - DEC Rainbow (CI-C86)
**      23-aug-93       C       - Microsoft (ANSI) Visual C++
**      01-aug-95       C       - changed default board
**      1997-03-17      C       - outputs "small" board
**      2009-04-18      C       - uses lower case for black instead of "-"
**      2009-04-20      C       - reads .FEN files
**
**      usage:  A>CHESS2 filename
**
**      reads data from named file to display chessboard - see files
**      CHESS*.FEN for examples
*/

#include <stdio.h>
#include <stdlib.h>

#define DARK    '*'
#define LIGHT   '.'

FILE    *in_fcb;
char    inbuf[80];      // "3r2kr/ppp2n1p/7B/5q1N/1bp5/2Pp4/PP2RPPP/R2Q2K1"
char    board[8][16], pcolor, sqcolor;
char    mask[7] = { ' ', 'P', 'B', 'N', 'R', 'Q', 'K' };
long    buffer;
int     bp=0;
int     bcol, brow, col, re, row, ua,
        sq[8][8] = {    /* default values */
                {  0,  0,  0, -4,  0,  0, -6, -4 },     /*   . * . r . * k r  */
                { -1, -1, -1,  0,  0, -3,  0, -1 },     /*   p p p . * n * p  */
                {  0,  0,  0,  0,  0,  0,  0,  2 },     /*   . * . * . * . B  */
                {  0,  0,  0,  0,  0, -5,  0,  3 },     /*   * . * . * q * N  */
                {  0, -2, -1,  0,  0,  0,  0,  0 },     /*   . b p * . * . *  */
                {  0,  0,  1, -1,  0,  0,  0,  0 },     /*   * . P p * . * .  */
                {  1,  1,  0,  0,  4,  1,  1,  1 },     /*   P P . * R P P P  */
                {  4,  0,  0,  5,  0,  0,  6,  0 }      /*   R . * Q * . K .  */
                };     /* "SHANNON'S SACRIFICE" - SCIENTIFIC AMERICAN, FEB'50 */

/////////////////////////////////////////////////////////////////

int nextok( void )
{
char    token;
int     val;

    if (inbuf[bp] == '/')       // skip seperator
        bp++;
    token = inbuf[bp];          // get next token
    switch (token) {
        case 'K':   val = 6;    bp++;   break;
        case 'k':   val = -6;   bp++;   break;
        case 'Q':   val = 5;    bp++;   break;
        case 'q':   val = -5;   bp++;   break;
        case 'R':   val = 4;    bp++;   break;
        case 'r':   val = -4;   bp++;   break;
        case 'N':   val = 3;    bp++;   break;
        case 'n':   val = -3;   bp++;   break;
        case 'B':   val = 2;    bp++;   break;
        case 'b':   val = -2;   bp++;   break;
        case 'P':   val = 1;    bp++;   break;
        case 'p':   val = -1;   bp++;   break;
        case '1':   val = 0;    bp++;   break;
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':   val = 0;    inbuf[bp]--; break; // decrement buffer
    }
    return (val);
}

/////////////////////////////////////////////////////////////////

void main( int argc, char **argv )   
{
/*  read chessboard data from named file
**  ... or use default if no file named
*/
    if (argc>1) {
        if ((in_fcb = fopen(argv[1],"r")) == NULL) {
            fprintf(stderr, "\007\nCannot open data file '%s'\007\n", argv[1]);
            exit(-1);                           /* barf on open error */
        }
        else {
            fscanf(in_fcb, "%s", &inbuf);       /* ... get string */
            fclose(in_fcb);
            for (ua=0 ; ua<8 ; ua++)            /* for each row ... */
                for (re=0 ; re<8 ; re++)        /* for each column ... */
                    sq[ua][re] = nextok();      /* ... get value */
        }
    }
/*
**  for each sq[ua][re] determine the kind of piece ('mask'),
**  the color of the piece ('pcolor'), and the color of the
**  square ('sqcolor').
*/
    for (ua=0 ; ua<8 ; ua++) {
        for (re=0 ; re<8 ; re++) {
            buffer = mask[(sq[ua][re]<0 ? abs(sq[ua][re]) : sq[ua][re])];
            if (sq[ua][re] < 0)             /* pcolor==BLACK */
                buffer = tolower(buffer);
            sqcolor = (((ua+re)%2)==0 ? LIGHT : DARK);
/*
**  now that you've got it, put it on paper
**  if the sq[ua][re] is empty (value 0), put the square color,
**  otherwise use the 'buffer' as the kind of piece 
*/
            printf(" %c", (sq[ua][re]==0 ? sqcolor : buffer));
        }
        printf("\n");
    }
}