#include <stdio.h>
#include "ifrilc.h"

/*
 * test_emb.c - example showing use of the Fril emebedded foreign language
 * interface. The main program displays a menu, reads a numerical option and
 * switches to call the appropriate function(s) from the Fril interface. Note
 * that little error checking is performed - return values from the Fril
 * interface functions such as createlist, putatom, etc are ignored, and it
 * is assumed that options are chosen in the correct order.
 * Most of this could be achieved more elegantly using the high-level interface
 */

output_fn(mesg)
char* mesg;
{
	printf("%s", mesg);
	return(1);
}

main()
{
    int             listid;
    int             listid2;
    int             listid3;
    int             listid4;
    char            pred[256];
    char            arg[256];
	int	output_fn();
    int             fril_ans = 1;
    static char    *opts[] =	/* create a "menu" of options */
    {"initialise_fril",		/* 0 */
	"initialise_interface",	/* 1 */
	"run",			/* 2 */
	"re-run",		/* 3 */
	"append",		/* 4 */
	"reverse",		/* 5 */
	"other query",		/* 6 */
	"get results",		/* 7 */
	"share vars ?((sum 1 2 X)(pp X))"	/* 8 */
    };
    int             opt;

    while (fril_ans != FRIL_TERMINATE)
    {
	printf("\n");
					/* display the options */
	for (opt = 0; opt < 9; opt++)
	    printf("option %d : %s\n", opt, opts[opt]);

	if (scanf("%d", &opt) == EOF)
		fril_ans = -2;	/* read	a value and switch to the appropriate
				 * interface functions */
	else

	switch (opt)
	{
	case 0:		/* this must be called first */
	    if (initialise_fril() == 1)
			printf("initialised OK\n");
	    else
			printf("test_emb : warning - initialisation failed\n");
	    break;

	case 1:		/* call this before a new goal */
	    initialise_interface();
	    break;

	case 2:		/* call to execute or re-execute a goal */
	case 3:
	    for (fril_ans = FRIL_REQUEST_INPUT; fril_ans == FRIL_REQUEST_INPUT;)
	    {
	       // fril_ans = call_fril(arg, output_fn);	/* send the query to fril */
	        fril_ans = call_fril("pp (shut up)", output_fn);	/* send the query to fril */
	        fril_says(fril_ans);	/* report the return value */
	        if (fril_ans == FRIL_REQUEST_INPUT) 
	        {
			    if(fgets(arg, 255, stdin) == NULL)
					fril_ans = -2;
	        }
        }
	    break;

	case 4:		 		/* create goal (append X Y (a b c)) */

	    createlist(&listid, 4);	/* main list */
	    putatom(listid, 1, "append");
	    createlist(&listid2, 3);	/* create list (a b c) */
	    putatom(listid2, 1, "a");
	    putatom(listid2, 2, "b");
	    putatom(listid2, 3, "c");
	    putlist(listid, 4, listid2);/* install as last argument */
	    putgoal(listid);		/* note that arguments 2 and 3 are
					 * uninstantiated variables */
	    break;
	case 5:				/* create goal (reverse (a b c) X) */
	    createlist(&listid, 3);	/* main list */
	    putatom(listid, 1, "reverse");
	    createlist(&listid2, 3);	/* create list (a b c) */
	    putatom(listid2, 1, "a");
	    putatom(listid2, 2, "b");
	    putatom(listid2, 3, "c");
	    putlist(listid, 2, listid2);
	    putgoal(listid);		/* argument 3 is uninstantiated */
	    break;
	case 6:			/* simple goal of the form <const1> <const2> */
	    scanf("%s", pred);	/* read in the predicate */
	    scanf("%s", arg);	/* and a single constant argument */
	    createlist(&listid, 2);
	    putatom(listid, 1, pred);
	    putatom(listid, 2, arg);
	    putgoal(listid);
	    break;
	case 7:			/* print out the goal (with instantiations if
				 * appropriate) */
	    get_all_elements_in_list(listid, 0);
	    break;
	case 8:		/* test of putarg function */
	    createlist(&listid, 2);     /* main list */
            putatom(listid, 1, "?");
            createlist(&listid2, 2);    /* create list (goal1 goal2) */
            createlist(&listid3, 4);    /* create goal (sum 1 2 X)  */
            createlist(&listid4, 2);    /* create goal (pp X)  */
            putatom(listid3, 1, "sum");
            putint(listid3, 2, 1);
            putint(listid3, 3, 2);
            putatom(listid4, 1, "pp");
            putarg(listid3, 4, listid4, 2);
            putlist(listid2, 1, listid3);
            putlist(listid2, 2, listid4);
	    
            putlist(listid, 2, listid2);
            putgoal(listid);            /* argument 4 of list 3 = arg 2 of list 4is uninstantiated */
	break;
	default:
		printf("input %d ignored - terminating\n", opt);
		fril_ans = -2;
	}
    }
printf("main(test_emb): fril has terminated\n");
}

/*
 * get_all_elements_in_list(id, indent) displays all the elements in the list
 * referenced by "id", indenting each element by "indent" spaces. This can be
 * used to display a goal to be passed to Fril either before or after
 * execution.
 */

get_all_elements_in_list(id, indent)
    int             id;
    int             indent;
{
    int             i;		/* loop counter */
    int             len;	/* stores the length of the list */
    char            buff[256];	/* used by "getatom" */
    int             integ;	/* used by "getint" */
    float           flo;	/* used by "getfloat" */
    int             newid;	/* used by "getlist" */
    int             type;	/* used by "getitemtype" */
    int             ind;	/* loop counter for indenting */

    if (getlistlen(id, &len))	/* find out how many elements there are */
    {
	for (i = 1; i <= abs(len); i++)	/* negative length indicates an
					 * unterminated list (...|X) */
	{
	    printf("\n");	/* start on new line and indent appropriately */
	    for (ind = 0; ind++ < indent; putchar(' '));

	    printf("item %d is ", i);
	    if (getitemtype(id, i, &type))	/* execute appropriate "get"
						 * function, according to
						 * argument type */
	    {
		switch (type)
		{

		case 1:				/* constant */
		    if (getatom(id, i, buff))
			printf("atom : %s ", buff);
		    break;

		case 2:				/* integer */
		    if (getint(id, i, &integ))
			printf("integer : %d ", integ);
		    break;

		case 3:				/* float */
		    if (getfloat(id, i, &flo))
			printf("float : %g ", flo);
		    break;

		case 4:		/* list - recursively print elements at
				 * indent+2 */
		    if (getlist(id, i, &newid))
		    {
			printf("list");
			get_all_elements_in_list(newid, indent + 2);
		    }
		    break;

		case 5:				/* variable */
		    printf("uninstantiated variable ");
		    break;
		default:
		    printf("bad return value from getitemtype\n");
		}
	    }
	    else
		printf("couldn't get item type\n");
	}
	if (len < 0)
	    printf("\nlist terminated by | X\n");
    }
    else
	printf("couldn't get listlen\n");
}


fril_says(ans)			/* print message appropriate to return value
				 * from call_fril */
    int             ans;
{
    switch (ans)
    {
    case 1:
	printf("\nfril says yes\n");
	break;
    case 0:
	printf("\nfril says no\n");
	break;
    case -1:
	printf("\nfril says system reset\n");
	break;
    case -2:
	printf("\nfril says goodbye I'm tired\n");
	break;
    case -3:
	printf("\nfril says Actually I need input\n");
	break;
    default:
       printf("\nfril returned %d\n", ans);

    }
}