/*
 * Copyright (c) 2025 Miroslav Cimerman
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/** @addtogroup hr
 * @{
 */
/**
 * @file
 */

#include <adt/list.h>
#include <block.h>
#include <errno.h>
#include <fibril_synch.h>
#include <hr.h>
#include <io/log.h>
#include <loc.h>
#include <stdlib.h>
#include <stdio.h>
#include <str_error.h>

#include "util.h"
#include "var.h"

#define HR_RL_LIST_LOCK(vol) (fibril_mutex_lock(&vol->range_lock_list_lock))
#define HR_RL_LIST_UNLOCK(vol) \
    (fibril_mutex_unlock(&vol->range_lock_list_lock))

static bool hr_range_lock_overlap(hr_range_lock_t *, hr_range_lock_t *);

extern loc_srv_t *hr_srv;

errno_t hr_init_devs(hr_volume_t *vol)
{
	HR_DEBUG("hr_init_devs()\n");

	errno_t rc;
	size_t i;
	hr_extent_t *extent;

	for (i = 0; i < vol->extent_no; i++) {
		extent = &vol->extents[i];
		if (extent->svc_id == 0) {
			extent->status = HR_EXT_MISSING;
			continue;
		}

		HR_DEBUG("hr_init_devs(): block_init() on (%lu)\n",
		    extent->svc_id);
		rc = block_init(extent->svc_id);
		extent->status = HR_EXT_ONLINE;

		if (rc != EOK) {
			HR_ERROR("hr_init_devs(): initing (%lu) failed, "
			    "aborting\n", extent->svc_id);
			break;
		}
	}

	return rc;
}

void hr_fini_devs(hr_volume_t *vol)
{
	HR_DEBUG("hr_fini_devs()\n");

	size_t i;

	for (i = 0; i < vol->extent_no; i++) {
		if (vol->extents[i].svc_id != 0) {
			HR_DEBUG("hr_fini_devs(): block_fini() on (%lu)\n",
			    vol->extents[i].svc_id);
			block_fini(vol->extents[i].svc_id);
		}
	}
}

errno_t hr_register_volume(hr_volume_t *vol)
{
	HR_DEBUG("hr_register_volume()\n");

	errno_t rc;
	service_id_t new_id;
	category_id_t cat_id;
	char *fullname = NULL;
	char *devname = vol->devname;

	if (asprintf(&fullname, "devices/%s", devname) < 0)
		return ENOMEM;

	rc = loc_service_register(hr_srv, fullname, &new_id);
	if (rc != EOK) {
		HR_ERROR("unable to register device \"%s\": %s\n",
		    fullname, str_error(rc));
		goto error;
	}

	rc = loc_category_get_id("raid", &cat_id, IPC_FLAG_BLOCKING);
	if (rc != EOK) {
		HR_ERROR("failed resolving category \"raid\": %s\n",
		    str_error(rc));
		goto error;
	}

	rc = loc_service_add_to_cat(hr_srv, new_id, cat_id);
	if (rc != EOK) {
		HR_ERROR("failed adding \"%s\" to category \"raid\": %s\n",
		    fullname, str_error(rc));
		goto error;
	}

	vol->svc_id = new_id;
error:
	free(fullname);
	return rc;
}

errno_t hr_check_devs(hr_volume_t *vol, uint64_t *rblkno, size_t *rbsize)
{
	HR_DEBUG("hr_check_devs()\n");

	errno_t rc;
	size_t i, bsize;
	uint64_t nblocks;
	size_t last_bsize = 0;
	uint64_t last_nblocks = 0;
	uint64_t total_blocks = 0;
	hr_extent_t *extent;

	for (i = 0; i < vol->extent_no; i++) {
		extent = &vol->extents[i];
		if (extent->status == HR_EXT_MISSING)
			continue;
		rc = block_get_nblocks(extent->svc_id, &nblocks);
		if (rc != EOK)
			goto error;
		if (last_nblocks != 0 && nblocks != last_nblocks) {
			HR_ERROR("number of blocks differs\n");
			rc = EINVAL;
			goto error;
		}

		total_blocks += nblocks;
		last_nblocks = nblocks;
	}

	for (i = 0; i < vol->extent_no; i++) {
		extent = &vol->extents[i];
		if (extent->status == HR_EXT_MISSING)
			continue;
		rc = block_get_bsize(extent->svc_id, &bsize);
		if (rc != EOK)
			goto error;
		if (last_bsize != 0 && bsize != last_bsize) {
			HR_ERROR("block sizes differ\n");
			rc = EINVAL;
			goto error;
		}

		last_bsize = bsize;
	}

	if ((bsize % 512) != 0) {
		HR_ERROR("block size not multiple of 512\n");
		return EINVAL;
	}

	if (rblkno != NULL)
		*rblkno = total_blocks;
	if (rbsize != NULL)
		*rbsize = bsize;
error:
	return rc;
}

errno_t hr_check_ba_range(hr_volume_t *vol, size_t cnt, uint64_t ba)
{
	if (ba + cnt > vol->data_blkno)
		return ERANGE;
	return EOK;
}

void hr_add_ba_offset(hr_volume_t *vol, uint64_t *ba)
{
	*ba = *ba + vol->data_offset;
}

void hr_update_ext_status(hr_volume_t *vol, size_t extent, hr_ext_status_t s)
{
	if (vol->level != HR_LVL_0)
		assert(fibril_rwlock_is_locked(&vol->extents_lock));

	assert(fibril_rwlock_is_write_locked(&vol->states_lock));

	assert(extent < vol->extent_no);

	hr_ext_status_t old = vol->extents[extent].status;
	HR_WARN("\"%s\": changing extent %lu state: %s -> %s\n",
	    vol->devname, extent, hr_get_ext_status_msg(old),
	    hr_get_ext_status_msg(s));
	vol->extents[extent].status = s;
}

void hr_update_hotspare_status(hr_volume_t *vol, size_t hs, hr_ext_status_t s)
{
	assert(fibril_mutex_is_locked(&vol->hotspare_lock));

	assert(hs < vol->hotspare_no);

	hr_ext_status_t old = vol->hotspares[hs].status;
	HR_WARN("\"%s\": changing hotspare %lu state: %s -> %s\n",
	    vol->devname, hs, hr_get_ext_status_msg(old),
	    hr_get_ext_status_msg(s));
	vol->hotspares[hs].status = s;
}

void hr_update_vol_status(hr_volume_t *vol, hr_vol_status_t new)
{
	assert(fibril_rwlock_is_write_locked(&vol->states_lock));

	HR_WARN("\"%s\": changing volume state: %s -> %s\n", vol->devname,
	    hr_get_vol_status_msg(vol->status), hr_get_vol_status_msg(new));
	vol->status = new;
}

void hr_update_ext_svc_id(hr_volume_t *vol, size_t extent, service_id_t new)
{
	if (vol->level != HR_LVL_0)
		assert(fibril_rwlock_is_write_locked(&vol->extents_lock));

	assert(extent < vol->extent_no);

	service_id_t old = vol->extents[extent].svc_id;
	HR_WARN("\"%s\": changing extent no. %lu svc_id: (%lu) -> (%lu)\n",
	    vol->devname, extent, old, new);
	vol->extents[extent].svc_id = new;
}

void hr_update_hotspare_svc_id(hr_volume_t *vol, size_t hs, service_id_t new)
{
	assert(fibril_mutex_is_locked(&vol->hotspare_lock));

	assert(hs < vol->hotspare_no);

	service_id_t old = vol->hotspares[hs].svc_id;
	HR_WARN("\"%s\": changing hotspare no. %lu svc_id: (%lu) -> (%lu)\n",
	    vol->devname, hs, old, new);
	vol->hotspares[hs].svc_id = new;
}

/*
 * Do a whole sync (ba = 0, cnt = 0) across all extents,
 * and update extent status. *For now*, the caller has to
 * update volume status after the syncs.
 *
 * TODO: add update_vol_status fcn ptr for each raid
 */
void hr_sync_all_extents(hr_volume_t *vol)
{
	errno_t rc;

	fibril_mutex_lock(&vol->lock);
	for (size_t i = 0; i < vol->extent_no; i++) {
		if (vol->extents[i].status != HR_EXT_ONLINE)
			continue;
		rc = block_sync_cache(vol->extents[i].svc_id, 0, 0);
		if (rc == ENOMEM || rc == ENOTSUP)
			continue;
		if (rc != EOK) {
			if (rc == ENOENT)
				hr_update_ext_status(vol, i, HR_EXT_MISSING);
			else if (rc != EOK)
				hr_update_ext_status(vol, i, HR_EXT_FAILED);
		}
	}
	fibril_mutex_unlock(&vol->lock);
}

size_t hr_count_extents(hr_volume_t *vol, hr_ext_status_t status)
{
	if (vol->level != HR_LVL_0)
		assert(fibril_rwlock_is_locked(&vol->extents_lock));
	assert(fibril_rwlock_is_locked(&vol->states_lock));

	size_t count = 0;
	for (size_t i = 0; i < vol->extent_no; i++)
		if (vol->extents[i].status == status)
			count++;

	return count;
}

hr_range_lock_t *hr_range_lock_acquire(hr_volume_t *vol, uint64_t ba,
    uint64_t cnt)
{
	hr_range_lock_t *rl = malloc(sizeof(hr_range_lock_t));
	if (rl == NULL)
		return NULL;

	rl->vol = vol;
	rl->off = ba;
	rl->len = cnt;

	rl->pending = 1;
	rl->ignore = false;

	link_initialize(&rl->link);
	fibril_mutex_initialize(&rl->lock);

	fibril_mutex_lock(&rl->lock);

again:
	HR_RL_LIST_LOCK(vol);
	list_foreach(vol->range_lock_list, link, hr_range_lock_t, rlp) {
		if (rlp->ignore)
			continue;
		if (hr_range_lock_overlap(rlp, rl)) {
			rlp->pending++;

			HR_RL_LIST_UNLOCK(vol);

			fibril_mutex_lock(&rlp->lock);

			HR_RL_LIST_LOCK(vol);

			rlp->pending--;

			/*
			 * when ignore is set, after HR_RL_LIST_UNLOCK(),
			 * noone new is going to be able to start sleeping
			 * on the ignored range lock, only already waiting
			 * IOs will come through here
			 */
			rlp->ignore = true;

			fibril_mutex_unlock(&rlp->lock);

			if (rlp->pending == 0) {
				list_remove(&rlp->link);
				free(rlp);
			}

			HR_RL_LIST_UNLOCK(vol);
			goto again;
		}
	}

	list_append(&rl->link, &vol->range_lock_list);

	HR_RL_LIST_UNLOCK(vol);
	return rl;
}

void hr_range_lock_release(hr_range_lock_t *rl)
{
	if (rl == NULL)
		return;

	HR_RL_LIST_LOCK(rl->vol);

	rl->pending--;

	fibril_mutex_unlock(&rl->lock);

	if (rl->pending == 0) {
		list_remove(&rl->link);
		free(rl);
	}

	HR_RL_LIST_UNLOCK(rl->vol);
}

static bool hr_range_lock_overlap(hr_range_lock_t *rl1, hr_range_lock_t *rl2)
{
	uint64_t rl1_start = rl1->off;
	uint64_t rl1_end = rl1->off + rl1->len - 1;
	uint64_t rl2_start = rl2->off;
	uint64_t rl2_end = rl2->off + rl2->len - 1;

	/* one ends before the other starts */
	if (rl1_end < rl2_start || rl2_end < rl1_start)
		return false;

	return true;
}

void hr_process_deferred_invalidations(hr_volume_t *vol)
{
	HR_DEBUG("hr_raid1_update_vol_status(): deferred invalidations\n");

	fibril_mutex_lock(&vol->halt_lock);
	vol->halt_please = true;
	fibril_rwlock_write_lock(&vol->extents_lock);
	fibril_rwlock_write_lock(&vol->states_lock);
	fibril_mutex_lock(&vol->hotspare_lock);

	list_foreach(vol->deferred_invalidations_list, link,
	    hr_deferred_invalidation_t, di) {
		assert(vol->extents[di->index].status == HR_EXT_INVALID);

		HR_DEBUG("moving invalidated extent no. %lu to hotspares\n",
		    di->index);

		block_fini(di->svc_id);

		size_t hs_idx = vol->hotspare_no;

		vol->hotspare_no++;

		hr_update_hotspare_svc_id(vol, hs_idx, di->svc_id);
		hr_update_hotspare_status(vol, hs_idx, HR_EXT_HOTSPARE);

		hr_update_ext_svc_id(vol, di->index, 0);
		hr_update_ext_status(vol, di->index, HR_EXT_MISSING);

		assert(vol->hotspare_no < HR_MAX_HOTSPARES + HR_MAX_EXTENTS);
	}

	for (size_t i = 0; i < HR_MAX_EXTENTS; i++) {
		hr_deferred_invalidation_t *di = &vol->deferred_inval[i];
		if (di->svc_id != 0) {
			list_remove(&di->link);
			di->svc_id = 0;
		}
	}

	fibril_mutex_unlock(&vol->hotspare_lock);
	fibril_rwlock_write_unlock(&vol->states_lock);
	fibril_rwlock_write_unlock(&vol->extents_lock);
	vol->halt_please = false;
	fibril_mutex_unlock(&vol->halt_lock);
}

/** @}
 */