/*	$OpenBSD: ex_usage.c,v 1.10 2018/07/13 09:02:07 krw Exp $	*/

/*-
 * Copyright (c) 1992, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1992, 1993, 1994, 1995, 1996
 *	Keith Bostic.  All rights reserved.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/time.h>

#include <bitstring.h>
#include <ctype.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "../common/common.h"
#include "../vi/vi.h"

/*
 * ex_help -- :help
 *	Display help message.
 *
 * PUBLIC: int ex_help(SCR *, EXCMD *);
 */
int
ex_help(SCR *sp, EXCMD *cmdp)
{
	(void)ex_puts(sp,
	    "To see the list of vi commands, enter \":viusage<CR>\"\n");
	(void)ex_puts(sp,
	    "To see the list of ex commands, enter \":exusage<CR>\"\n");
	(void)ex_puts(sp,
	    "For an ex command usage statement enter \":exusage [cmd]<CR>\"\n");
	(void)ex_puts(sp,
	    "For a vi key usage statement enter \":viusage [key]<CR>\"\n");
	(void)ex_puts(sp, "To exit, enter \":q!\"\n");
	return (0);
}

/*
 * ex_usage -- :exusage [cmd]
 *	Display ex usage strings.
 *
 * PUBLIC: int ex_usage(SCR *, EXCMD *);
 */
int
ex_usage(SCR *sp, EXCMD *cmdp)
{
	ARGS *ap;
	EXCMDLIST const *cp;
	int newscreen;

	switch (cmdp->argc) {
	case 1:
		ap = cmdp->argv[0];
		if (isupper(ap->bp[0])) {
			newscreen = 1;
			ap->bp[0] = tolower(ap->bp[0]);
		} else
			newscreen = 0;
		for (cp = cmds; cp->name != NULL &&
		    memcmp(ap->bp, cp->name, ap->len); ++cp);
		if (cp->name == NULL ||
		    (newscreen && !F_ISSET(cp, E_NEWSCREEN))) {
			if (newscreen)
				ap->bp[0] = toupper(ap->bp[0]);
			(void)ex_printf(sp, "The %.*s command is unknown\n",
			    (int)ap->len, ap->bp);
		} else {
			(void)ex_printf(sp,
			    "Command: %s\n  Usage: %s\n", cp->help, cp->usage);
			/*
			 * !!!
			 * The "visual" command has two modes, one from ex,
			 * one from the vi colon line.  Don't ask.
			 */
			if (cp != &cmds[C_VISUAL_EX] &&
			    cp != &cmds[C_VISUAL_VI])
				break;
			if (cp == &cmds[C_VISUAL_EX])
				cp = &cmds[C_VISUAL_VI];
			else
				cp = &cmds[C_VISUAL_EX];
			(void)ex_printf(sp,
			    "Command: %s\n  Usage: %s\n", cp->help, cp->usage);
		}
		break;
	case 0:
		for (cp = cmds; cp->name != NULL && !INTERRUPTED(sp); ++cp)
			(void)ex_printf(sp, "%*s: %s\n", MAXCMDNAMELEN,
			    /* The ^D command has an unprintable name. */
			    cp == &cmds[C_SCROLL] ? "^D" : cp->name,
			    cp->help);
		break;
	default:
		abort();
	}
	return (0);
}

/*
 * ex_viusage -- :viusage [key]
 *	Display vi usage strings.
 *
 * PUBLIC: int ex_viusage(SCR *, EXCMD *);
 */
int
ex_viusage(SCR *sp, EXCMD *cmdp)
{
	VIKEYS const *kp;
	int key;

	switch (cmdp->argc) {
	case 1:
		if (cmdp->argv[0]->len != 1) {
			ex_emsg(sp, cmdp->cmd->usage, EXM_USAGE);
			return (1);
		}
		key = cmdp->argv[0]->bp[0];
		if (key > MAXVIKEY)
			goto nokey;

		/* Special case: '[' and ']' commands. */
		if ((key == '[' || key == ']') && cmdp->argv[0]->bp[1] != key)
			goto nokey;

		/* Special case: ~ command. */
		if (key == '~' && O_ISSET(sp, O_TILDEOP))
			kp = &tmotion;
		else
			kp = &vikeys[key];

		if (kp->usage == NULL)
nokey:			(void)ex_printf(sp,
			    "The %s key has no current meaning\n",
			    KEY_NAME(sp, key));
		else
			(void)ex_printf(sp,
			    "  Key:%s%s\nUsage: %s\n",
			    isblank(*kp->help) ? "" : " ", kp->help, kp->usage);
		break;
	case 0:
		for (key = 0; key <= MAXVIKEY && !INTERRUPTED(sp); ++key) {
			/* Special case: ~ command. */
			if (key == '~' && O_ISSET(sp, O_TILDEOP))
				kp = &tmotion;
			else
				kp = &vikeys[key];
			if (kp->help != NULL)
				(void)ex_printf(sp, "%s\n", kp->help);
		}
		break;
	default:
		abort();
	}
	return (0);
}