/*
 * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved. 
 * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
 *
 * This file is part of LVM2.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License v.2.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "tools.h"
#include "lv_alloc.h"

static int _remove_pv(struct volume_group *vg, struct pv_list *pvl)
{
	char uuid[64];

	if (vg->pv_count == 1) {
		log_error("Volume Groups must always contain at least one PV");
		return 0;
	}

	if (!id_write_format(&pvl->pv->id, uuid, sizeof(uuid))) {
		stack;
		return 0;
	}

	log_verbose("Removing PV with UUID %s from VG %s", uuid, vg->name);

	if (pvl->pv->pe_alloc_count) {
		log_error("LVs still present on PV with UUID %s: Can't remove "
			  "from VG %s", uuid, vg->name);
		return 0;
	}

	vg->free_count -= pvl->pv->pe_count;
	vg->extent_count -= pvl->pv->pe_count;
	vg->pv_count--;

	list_del(&pvl->list);

	return 1;
}

static int _remove_lv(struct cmd_context *cmd, struct logical_volume *lv,
		      int *list_unsafe, struct list *lvs_changed)
{
	struct lv_segment *snap_seg, *mirror_seg;
	struct list *snh, *snht;
	struct logical_volume *cow;
	struct lv_list *lvl;
	uint32_t extents;
	struct lvinfo info;
	int first = 1;

	log_verbose("%s/%s has missing extents: removing (including "
		    "dependencies)", lv->vg->name, lv->name);

	/* FIXME Cope properly with stacked devices & snapshots. */

	/* If snapshot device is missing, deactivate origin. */
	if (lv_is_cow(lv) && (snap_seg = find_cow(lv))) {
		log_verbose("Deactivating (if active) logical volume %s "
			    "(origin of %s)", snap_seg->origin->name, lv->name);

		if (!test_mode() && !deactivate_lv(cmd, snap_seg->origin)) {
			log_error("Failed to deactivate LV %s",
				  snap_seg->origin->name);
			return 0;
		}

		/* Use the origin LV */
		lv = snap_seg->origin;
	}

	/* Remove snapshot dependencies */
	list_iterate_safe(snh, snht, &lv->snapshot_segs) {
		snap_seg = list_struct_base(snh, struct lv_segment,
					    origin_list);
		cow = snap_seg->cow;

		if (first && !test_mode() &&
		    !deactivate_lv(cmd, snap_seg->origin)) {
			log_error("Failed to deactivate LV %s",
				  snap_seg->origin->name);
			return 0;
		}

		*list_unsafe = 1;	/* May remove caller's lvht! */
		if (!vg_remove_snapshot(cow)) {
			stack;
			return 0;
		}
		log_verbose("Removing LV %s from VG %s", cow->name,
			    lv->vg->name);
		if (!lv_remove(cow)) {
			stack;
			return 0;
		}

		first = 0;
	}

	/*
	 * If LV is active, replace it with error segment 
	 * and add to list of LVs to be removed later.
	 * Doesn't apply to snapshots/origins yet - they're already deactivated.
	 */
	if (lv_info(cmd, lv, &info, 0) && info.exists) {
		extents = lv->le_count;
		mirror_seg = first_seg(lv)->mirror_seg;
		if (!lv_empty(lv)) {
			stack;
			return 0;
		}
		if (!lv_add_virtual_segment(lv, 0, extents,
					    get_segtype_from_string(cmd,
								    "error"))) {
			stack;
			return 0;
		}
		if (mirror_seg) {
			first_seg(lv)->status |= MIRROR_IMAGE;
			first_seg(lv)->mirror_seg = mirror_seg;
		}

		if (!(lvl = dm_pool_alloc(cmd->mem, sizeof(*lvl)))) {
			log_error("lv_list alloc failed");
			return 0;
		}
		lvl->lv = lv;
		list_add(lvs_changed, &lvl->list);
	} else {
		/* Remove LV immediately. */
		log_verbose("Removing LV %s from VG %s", lv->name, lv->vg->name);
		if (!lv_remove(lv)) {
			stack;
			return 0;
		}
	}

	return 1;
}

static int _make_vg_consistent(struct cmd_context *cmd, struct volume_group *vg)
{
	struct list *pvh, *pvht;
	struct list *lvh, *lvht;
	struct pv_list *pvl;
	struct lv_list *lvl, *lvl2, *lvlt;
	struct logical_volume *lv;
	struct physical_volume *pv;
	struct lv_segment *seg, *mirrored_seg;
	struct lv_segment_area area;
	unsigned int s;
	uint32_t mimages;
	int list_unsafe, only_mirror_images_found;
	LIST_INIT(lvs_changed);
	only_mirror_images_found = 1;

	/* Deactivate & remove necessary LVs */
      restart_loop:
	list_unsafe = 0;	/* Set if we delete a different list-member */

	list_iterate_safe(lvh, lvht, &vg->lvs) {
		lv = list_item(lvh, struct lv_list)->lv;

		/* Are any segments of this LV on missing PVs? */
		list_iterate_items(seg, &lv->segments) {
			for (s = 0; s < seg->area_count; s++) {
				if (seg_type(seg, s) != AREA_PV)
					continue;

				/* FIXME Also check for segs on deleted LVs */

				pv = seg_pv(seg, s);
				if (!pv || !pv->dev) {
					if (arg_count(cmd, mirrorsonly_ARG) &&
					    !(lv->status & MIRROR_IMAGE)) {
						log_error("Non-mirror-image LV %s found: can't remove.", lv->name);
						only_mirror_images_found = 0;
						continue;
					}
					if (!_remove_lv(cmd, lv, &list_unsafe, &lvs_changed)) {
						stack;
						return 0;
					}
					if (list_unsafe)
						goto restart_loop;
				}
			}
		}
	}

	if (!only_mirror_images_found) {
		log_error("Aborting because --mirrorsonly was specified.");
		return 0;
	}

	/* Remove missing PVs */
	list_iterate_safe(pvh, pvht, &vg->pvs) {
		pvl = list_item(pvh, struct pv_list);
		if (pvl->pv->dev)
			continue;
		if (!_remove_pv(vg, pvl)) {
			stack;
			return 0;
		}
	}

	/* VG is now consistent */
	vg->status &= ~PARTIAL_VG;
	vg->status |= LVM_WRITE;

	init_partial(0);

	/* FIXME Recovery.  For now people must clean up by hand. */

	if (!list_empty(&lvs_changed)) {
		if (!vg_write(vg)) {
			log_error("Failed to write out a consistent VG for %s",
				  vg->name);
			return 0;
		}

		if (!test_mode()) {
			/* Suspend lvs_changed */
			init_partial(1);
			if (!suspend_lvs(cmd, &lvs_changed)) {
				stack;
				init_partial(0);
				vg_revert(vg);
				return 0;
			}
			init_partial(0);
		}

		if (!vg_commit(vg)) {
			log_error("Failed to commit consistent VG for %s",
				  vg->name);
			vg_revert(vg);
			return 0;
		}

		if (!test_mode()) {
			if (!resume_lvs(cmd, &lvs_changed)) {
				log_error("Failed to resume LVs using error segments.");
				return 0;
			}
		}

		/* Remove lost mirror images from mirrors */
		list_iterate_items(lvl, &vg->lvs) {
			mirrored_seg = first_seg(lvl->lv);
			if (!seg_is_mirrored(mirrored_seg))
				continue;
			mimages = mirrored_seg->area_count;
			for (s = 0; s < mirrored_seg->area_count; s++) {
				list_iterate_items_safe(lvl2, lvlt, &lvs_changed) {
					if (seg_type(mirrored_seg, s) != AREA_LV ||
					    lvl2->lv != seg_lv(mirrored_seg, s))
						continue;
					list_del(&lvl2->list);
					area = mirrored_seg->areas[mimages - 1];
					mirrored_seg->areas[mimages - 1] = mirrored_seg->areas[s];
					mirrored_seg->areas[s] = area;
					mimages--;	/* FIXME Assumes uniqueness */
				}
			}
			if (mimages != mirrored_seg->area_count) {
				if (!remove_mirror_images(mirrored_seg, mimages, NULL, 0)) {
					stack;
					return 0;
				}

				if (!vg_write(vg)) {
					log_error("Failed to write out updated "
						  "VG for %s", vg->name);
					return 0;
				}
		
				if (!vg_commit(vg)) {
					log_error("Failed to commit updated VG "
						  "for %s", vg->name);
					vg_revert(vg);
					return 0;
				}
			}
		}

		/* Deactivate error LVs */
		if (!test_mode()) {
			list_iterate_items(lvl, &lvs_changed) {
				log_verbose("Deactivating (if active) logical volume %s",
					    lvl->lv->name);

				if (!deactivate_lv(cmd, lvl->lv)) {
					log_error("Failed to deactivate LV %s",
						  lvl->lv->name);
					return 0;
				}
			}
		}

		/* Remove remaining LVs */
		list_iterate_items(lvl, &lvs_changed) {
			log_verbose("Removing LV %s from VG %s", lvl->lv->name,
				    lvl->lv->vg->name);
			if (!lv_remove(lvl->lv)) {
				stack;
				return 0;
			}
		}
	}

	return 1;
}

/* Or take pv_name instead? */
static int _vgreduce_single(struct cmd_context *cmd, struct volume_group *vg,
			    struct physical_volume *pv, void *handle)
{
	struct pv_list *pvl;
	const char *name = dev_name(pv->dev);

	if (pv->pe_alloc_count) {
		log_error("Physical volume \"%s\" still in use", name);
		return ECMD_FAILED;
	}

	if (vg->pv_count == 1) {
		log_error("Can't remove final physical volume \"%s\" from "
			  "volume group \"%s\"", name, vg->name);
		return ECMD_FAILED;
	}

	pvl = find_pv_in_vg(vg, name);

	if (!archive(vg))
		return ECMD_FAILED;

	log_verbose("Removing \"%s\" from volume group \"%s\"", name, vg->name);

	if (pvl)
		list_del(&pvl->list);

	pv->vg_name = ORPHAN;
	pv->status = ALLOCATABLE_PV;

	if (!dev_get_size(pv->dev, &pv->size)) {
		log_error("%s: Couldn't get size.", dev_name(pv->dev));
		return ECMD_FAILED;
	}

	vg->pv_count--;
	vg->free_count -= pv->pe_count - pv->pe_alloc_count;
	vg->extent_count -= pv->pe_count;

	if (!vg_write(vg) || !vg_commit(vg)) {
		log_error("Removal of physical volume \"%s\" from "
			  "\"%s\" failed", name, vg->name);
		return ECMD_FAILED;
	}

	if (!pv_write(cmd, pv, NULL, INT64_C(-1))) {
		log_error("Failed to clear metadata from physical "
			  "volume \"%s\" "
			  "after removal from \"%s\"", name, vg->name);
		return ECMD_FAILED;
	}

	backup(vg);

	log_print("Removed \"%s\" from volume group \"%s\"", name, vg->name);

	return ECMD_PROCESSED;
}

int vgreduce(struct cmd_context *cmd, int argc, char **argv)
{
	struct volume_group *vg;
	char *vg_name;
	int ret = 1;
	int consistent = 1;

	if (!argc & !arg_count(cmd, removemissing_ARG)) {
		log_error("Please give volume group name and "
			  "physical volume paths");
		return EINVALID_CMD_LINE;
	}

	if (!argc & arg_count(cmd, removemissing_ARG)) {
		log_error("Please give volume group name");
		return EINVALID_CMD_LINE;
	}

	if (arg_count(cmd, mirrorsonly_ARG) &&
	    !arg_count(cmd, removemissing_ARG)) {
		log_error("--mirrorsonly requires --removemissing");
		return EINVALID_CMD_LINE;
	}

	if (argc == 1 && !arg_count(cmd, all_ARG)
	    && !arg_count(cmd, removemissing_ARG)) {
		log_error("Please enter physical volume paths or option -a");
		return EINVALID_CMD_LINE;
	}

	if (argc > 1 && arg_count(cmd, all_ARG)) {
		log_error("Option -a and physical volume paths mutually "
			  "exclusive");
		return EINVALID_CMD_LINE;
	}

	if (argc > 1 && arg_count(cmd, removemissing_ARG)) {
		log_error("Please only specify the volume group");
		return EINVALID_CMD_LINE;
	}

	vg_name = argv[0];
	argv++;
	argc--;

	log_verbose("Finding volume group \"%s\"", vg_name);
	if (!lock_vol(cmd, vg_name, LCK_VG_WRITE)) {
		log_error("Can't get lock for %s", vg_name);
		return ECMD_FAILED;
	}

	if ((!(vg = vg_read(cmd, vg_name, &consistent)) || !consistent) &&
	    !arg_count(cmd, removemissing_ARG)) {
		log_error("Volume group \"%s\" doesn't exist", vg_name);
		unlock_vg(cmd, vg_name);
		return ECMD_FAILED;
	}

	if (arg_count(cmd, removemissing_ARG)) {
		if (vg && consistent) {
			log_error("Volume group \"%s\" is already consistent",
				  vg_name);
			unlock_vg(cmd, vg_name);
			return ECMD_FAILED;
		}

		init_partial(1);
		consistent = 0;
		if (!(vg = vg_read(cmd, vg_name, &consistent))) {
			log_error("Volume group \"%s\" not found", vg_name);
			unlock_vg(cmd, vg_name);
			return ECMD_FAILED;
		}
		if (!archive(vg)) {
			init_partial(0);
			unlock_vg(cmd, vg_name);
			return ECMD_FAILED;
		}

		if (!_make_vg_consistent(cmd, vg)) {
			init_partial(0);
			unlock_vg(cmd, vg_name);
			return ECMD_FAILED;
		}

		if (!vg_write(vg) || !vg_commit(vg)) {
			log_error("Failed to write out a consistent VG for %s",
				  vg_name);
			unlock_vg(cmd, vg_name);
			return ECMD_FAILED;
		}

		backup(vg);

		log_print("Wrote out consistent volume group %s", vg_name);

	} else {
		if (vg->status & EXPORTED_VG) {
			log_error("Volume group \"%s\" is exported", vg->name);
			unlock_vg(cmd, vg_name);
			return ECMD_FAILED;
		}

		if (!(vg->status & LVM_WRITE)) {
			log_error("Volume group \"%s\" is read-only", vg_name);
			unlock_vg(cmd, vg_name);
			return ECMD_FAILED;
		}

		if (!(vg->status & RESIZEABLE_VG)) {
			log_error("Volume group \"%s\" is not reducible",
				  vg_name);
			unlock_vg(cmd, vg_name);
			return ECMD_FAILED;
		}

		/* FIXME: Pass private struct through to all these functions */
		/* and update in batch here? */
		ret = process_each_pv(cmd, argc, argv, vg, NULL,
				      _vgreduce_single);

	}

	unlock_vg(cmd, vg_name);

	return ret;

/******* FIXME
	log_error ("no empty physical volumes found in volume group \"%s\"", vg_name);

	log_verbose
	    ("volume group \"%s\" will be reduced by %d physical volume%s",
	     vg_name, np, np > 1 ? "s" : "");
	log_verbose ("reducing volume group \"%s\" by physical volume \"%s\"",
		     vg_name, pv_names[p]);

	log_print
	    ("volume group \"%s\" %ssuccessfully reduced by physical volume%s:",
	     vg_name, error > 0 ? "NOT " : "", p > 1 ? "s" : "");
		log_print("%s", pv_this[p]->pv_name);
********/

}