/*
 * This file implements the API used in the PC version.
 */

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

#include "spint.h"
#include "api.h"
#include "../general.h"


/*
 * Supervisor Services.
 */

static void
name_resolve(regs, sregs)
union REGS *regs;
struct SREGS *sregs;
{
}

/*
 * Session Information Services.
 */

static void
query_session_id(regs, sregs)
union REGS *regs;
struct SREGS *sregs;
{
}

static void
query_session_parameters(regs, sregs)
union REGS *regs;
struct SREGS *sregs;
{
}

static void
query_session_cursor(regs, sregs)
union REGS *regs;
struct SREGS *sregs;
{
}

/*
 * Keyboard Services.
 */


static void
connect_to_keyboard(regs, sregs)
union REGS *regs;
struct SREGS *sregs;
{
}

static void
disable_input(regs, sregs)
union REGS *regs;
struct SREGS *sregs;
{
}

static void
write_keystroke(regs, sregs)
union REGS *regs;
struct SREGS *sregs;
{
}

static void
enable_input(regs, sregs)
union REGS *regs;
struct SREGS *sregs;
{
}

/*
 * Copy Services.
 */

static void
disconnect_from_keyboard(regs, sregs)
union REGS *regs;
struct SREGS *sregs;
{
}

/*
 * Operator Information Area Services.
 */

static void
read_oia_group(regs, sregs)
union REGS *regs;
struct SREGS *sregs;
{
}

static void
unknown_op(regs, sregs)
union REGS *regs;
struct SREGS *sregs;
{
    regs->h.ch = 0x12;
    regs->h.cl = 0x05;
}


handle_api(regs, sregs)
union REGS *regs;
struct SREGS *sregs;
{
    if (regs->h.ah == NAME_RESOLUTION) {
	name_resolution(regs, sregs);
    } else {
	switch (regs->x.dx) {
	case GATE_SESSMGR:
	    switch (regs->h.al) {
	    case QUERY_SESSION_ID:
		query_session_id(regs, sregs);
		break;
	    case QUERY_SESSION_PARMS:
		query_session_parms(regs, sregs);
		break;
	    case QUERY_SESSION_CURSOR:
		query_session_cursor(regs, sregs);
		break;
	    default:
		unknown_op(regs, sregs);
		break;
	    }
	    break;
	case GATE_KEYBOARD:
	    switch (regs->h.al) {
	    case CONNECT_TO_KEYBOARD:
		connect_to_keyboard(regs, sregs);
		break;
	    case DISABLE_INPUT:
		disable_input(regs, sregs);
		break;
	    case WRITE_KEYSTROKE:
		write_keystroke(regs, sregs);
		break;
	    case ENABLE_INPUT:
		enable_input(regs, sregs);
		break;
	    case DISCONNECT_FROM_KEYBOARD:
		disconnect_from_keyboard(regs, sregs);
		break;
	    default:
		unknown_op(regs, sregs);
		break;
	    }
	    break;
	case GATE_COPY:
	    switch (regs->h.al) {
	    case COPY_STRING:
		copy_string(regs, sregs);
		break;
	    default:
		unknown_op(regs, sregs);
		break;
	    }
	    break;
	case GATE_OIAM:
	    switch (regs->h.al) {
	    case READ_OIA_GROUP:
		read_oia_group(regs, sregs);
		break;
	    default:
		unknown_op(regs, sregs);
		break;
	    }
	    break;
	default:
	    unknown_op(regs, sregs);
	    break;
	}
    }
}


/*
 * Called from telnet.c to fork a lower command.com.  We
 * use the spint... routines so that we can pick up
 * interrupts generated by application programs.
 */


int
shell(argc,argv)
int	argc;
char	*argv[];
{
    Spint spinted;
    static char command[256];

    ClearElement(spinted);
    spinted.int_no = API_INTERRUPT_NUMBER;
    if (argc == 1) {
	command[0] = 0;
    } else {
	char *cmdptr;
	int length;

	argc--;
	argv++;
	strcpy(command, " /c");
	cmdptr = command+strlen(command);
	while (argc) {
	    if ((cmdptr+strlen(*argv)) >= (command+sizeof command)) {
		fprintf(stderr, "Argument list too long at argument *%s*.\n",
			    *argv);
		return 0;
	    }
	    *cmdptr++ = ' ';		/* Blank separators */
	    strcpy(cmdptr, *argv);
	    cmdptr += strlen(cmdptr);
	    argc--;
	    argv++;
	}
	length = strlen(command)-1;
	if (length < 0) {
	    length = 0;
	}
	command[0] = length;
    }

    /*
     * spint_start() returns when either the command has finished, or when
     * the required interrupt comes in.  In the latter case, the appropriate
     * thing to do is to process the interrupt, and then return to
     * the interrupt issuer by calling spint_continue().
     */
    spint_start(command, &spinted);
    while (spinted.done == 0) {
	/* Process request */
	handle_api(&spinted.regs, &spinted.sregs);
	spint_continue(&spinted);
    }
    if (spinted.rc != 0) {
	fprintf(stderr, "Process generated a return code of 0x%x.\n",
								spinted.rc);
    }
    return 0;
}