/*
 * Copyright (c) 2011 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Antonio Huete <tuxillo@quantumachine.net>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <unistd.h>

#include "libhammer.h"

libhammer_fsinfo_t
libhammer_get_fsinfo(const char *path)
{
        struct hammer_pseudofs_data *pfs_od;
        struct hammer_ioc_pseudofs_rw pfs;
        struct hammer_ioc_info info;
        libhammer_pfsinfo_t pip;
        libhammer_fsinfo_t fip;
        int error = 0;
        int fd;

        if ((fd = open(path, O_RDONLY)) < 0)
                return NULL;

        fip = _libhammer_malloc(sizeof(*fip));
        TAILQ_INIT(&fip->list_pseudo);
        if ((ioctl(fd, HAMMERIOC_GET_INFO, &info)) < 0) {
                libhammer_free_fsinfo(fip);
                close(fd);
                return NULL;
        }

        /* Fill filesystem information */
        snprintf(fip->vol_name, TXTLEN, "%s", info.vol_label);
        fip->vol_fsid = info.vol_fsid;
        fip->version = info.version;
        fip->nvolumes = info.nvolumes;
        fip->rootvol = info.rootvol;
        fip->inodes = info.inodes;
        fip->bigblocks = info.bigblocks;
        fip->freebigblocks = info.freebigblocks;
        fip->rsvbigblocks = info.rsvbigblocks;

        bzero(&pfs, sizeof(pfs));
        pfs.pfs_id = 0; /* start off with root PFS */
        pfs.ondisk = _libhammer_malloc(sizeof(*pfs_od));
        pfs.bytes = sizeof(struct hammer_pseudofs_data);

        while(error == 0) {
                error = ioctl(fd, HAMMERIOC_SCAN_PSEUDOFS, &pfs);
                if (error == 0 && !hammer_is_pfs_deleted(pfs.ondisk)) {
                        pip = _libhammer_malloc(sizeof(*pip));
                        pfs_od = pfs.ondisk;
                        pip->ismaster = hammer_is_pfs_master(pfs_od);

                        /*
                         * Fill in structs used in the library. We don't rely on
                         * HAMMER structs but we do fill our own.
                         */
                        pip->version = fip->version;
                        pip->pfs_id = pfs.pfs_id;
                        pip->mirror_flags = pfs_od->mirror_flags;
                        pip->beg_tid = pfs_od->sync_beg_tid;
                        pip->end_tid = pfs_od->sync_end_tid;
                        pip->mountedon =
                            libhammer_find_pfs_mount(&pfs_od->unique_uuid);
                        if (fip->version < 3) {
                                libhammer_compat_old_snapcount(pip);
                        } else {
                                TAILQ_INIT(&pip->list_snap);
                                if (libhammer_pfs_get_snapshots(fip, pip) < 0)
                                        pip->snapcount = 0;
                        }

                        /*
                         * PFS retrieval goes 0..n so inserting in the tail
                         * leaves the TAILQ sorted by pfs_id.
                         * This is important since quickly getting PFS #0 is
                         * required for some functions so *DO NOT CHANGE IT*.
                         */
                        TAILQ_INSERT_TAIL(&fip->list_pseudo, pip, entries);

                }
                pfs.pfs_id++;
        }
        free(pfs.ondisk);

        close (fd);

        return (fip);
}

void
libhammer_free_fsinfo(libhammer_fsinfo_t fip)
{
        struct libhammer_pfsinfo *pfstmp;

        while(!TAILQ_EMPTY(&fip->list_pseudo)) {
                pfstmp = TAILQ_FIRST(&fip->list_pseudo);
                libhammer_pfs_free_snapshots(pfstmp);
                if (pfstmp->mountedon)
                        free(pfstmp->mountedon);
                TAILQ_REMOVE(&fip->list_pseudo, pfstmp, entries);
                free(pfstmp);
        }
        free(fip);
}