/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
#pragma ident   "%Z%%M% %I%     %E% SMI"

#include <sys/promif.h>
#include <sys/salib.h>

#define MAX_CMDLINE     1600  /* from GRUB source */

char **titles;
char **datasets;

int     menu_entry_count;
int     menu_table_size;

int     in_menu_entry;

#define ENTRY_ALLOC_COUNT       10

extern void     set_default_fs(char *fsw_name);
extern int      mountroot(char *str);

void
init_table(void)
{

        menu_entry_count = 0;
        titles = (char **)calloc(ENTRY_ALLOC_COUNT, sizeof (char *));
        datasets = (char **)calloc(ENTRY_ALLOC_COUNT, sizeof (char *));
        if (titles == NULL || datasets == NULL)
                prom_panic("out of mem");
        menu_table_size = ENTRY_ALLOC_COUNT;
        in_menu_entry = 0;
}

void
add_title_entry(char *title_str)
{

        /* skip leading white space */
        while (isspace(*title_str))
                title_str++;

        if (menu_entry_count == menu_table_size) {
                printf("Reallocating at count %d\n", menu_table_size);
                titles = (char **)realloc(titles,
                    ENTRY_ALLOC_COUNT * sizeof (char *));
                datasets = (char **)realloc(datasets,
                    ENTRY_ALLOC_COUNT * sizeof (char *));
                if (titles == NULL || datasets == NULL)
                        prom_panic("out of mem");
                menu_table_size += ENTRY_ALLOC_COUNT;
        }

        if (in_menu_entry)
                free(titles[menu_entry_count]);
        if ((titles[menu_entry_count] = strdup(title_str)) == NULL)
                prom_panic("out of mem");
        in_menu_entry = 1;
}

void
add_dataset_entry(char *dataset_str)
{
        char    *cp;

        /* skip leading white space */
        while (isspace(*dataset_str))
                dataset_str++;

        /* if there is still any white space in the line, it's invalid */
        for (cp = dataset_str; *cp; cp++)
                if (isspace(*cp))
                        break;
        if (*cp)
                return;  /* dataset name was invalid */

        if (!in_menu_entry)
                return;  /* dataset line was not preceded by a title */

        if ((datasets[menu_entry_count] = strdup(dataset_str)) == NULL)
                prom_panic("out of mem");
        menu_entry_count++;
        in_menu_entry = 0;
}


char *
trim_white_space(char *cp)
{
        char    *ep;

        /* skip leading white space */
        while (isspace(*cp))
                cp++;

        /*
         *  if the string contained nothing but white space, return a
         *  null string.
         */
        if (*cp == '\0')
                return (cp);

        /* truncate trailing white space */
        for (ep = cp + strlen(cp) - 1; isspace(*ep); ep--)
                ;
        ep++;
        *ep = '\0';
        return (cp);
}

char *cons_gets(char *, int);

void
main(void *cif)
{
        char linebuf[MAX_CMDLINE];
        FILE    *file;
        char    *cp, *ep;
        int     n;
        unsigned long   choice;

        prom_init("bootlst", cif);
        set_default_fs("promfs");
        if (mountroot("bootfs") != 0)
                prom_panic("can't mount root");

        if ((file = fopen("/boot/menu.lst", "r")) == NULL)
                prom_panic("can't open menu.lst");
        init_table();

        while (fgets(linebuf, MAX_CMDLINE, file)) {
                cp = trim_white_space(linebuf);

                /* skip comments and blank lines */
                if (*cp == '#' || *cp == '\0')
                        continue;

                /* find end of first keyword on line */
                for (ep = cp; !isspace(*ep) && *ep; ep++)
                        ;

                /* if at the end of the line, the line had no arguments */
                if (*ep == '\0')
                        continue;

                *ep = '\0';

                if (strcmp(cp, "title") == 0) {
                        add_title_entry(ep + 1);
                        continue;
                }

                if (strcmp(cp, "bootfs") == 0) {
                        add_dataset_entry(ep + 1);
                        continue;
                }
        }

        if (menu_entry_count == 0)
                prom_panic("no menu entries found");

        for (n = 0; n < menu_entry_count; n++) {
                printf("%d %s\n", n + 1, titles[n]);
        }

        printf("Select environment to boot: [ 1 - %d ]: ", menu_entry_count);

        while (cons_gets(linebuf, MAX_CMDLINE)) {
                /* cut off leading and trailing white space */
                cp = trim_white_space(linebuf);
                choice = strtoul(cp, NULL, 0);

                /*
                 * If the input is totally invalid, the return value of
                 * strtoul() will be 0 or ULONG_MAX.  Either way, it's
                 * of the acceptable range.
                 */
                if (choice == 0 || choice > menu_entry_count) {
                        printf("Invalid entry.\n");
                        continue;
                }
                /* XXX here is the result */
                printf("\nTo boot the selected entry, invoke:\n");
                printf("boot [<root-device>] -Z %s\n\n", datasets[choice - 1]);
                prom_exit_to_mon();
        }
}