/*
   Copyright (c) 2014 Anton Titov.

   Copyright (c) 2014 pCloud Ltd.  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.  Neither the name of pCloud Ltd 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 pCloud
   Ltd 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 <errno.h>
#include <fuse.h>
#include <string.h>

#include "pfsxattr.h"
#include "pfsfolder.h"
#include "pfstasks.h"
#include "psql.h"
#include "plibs.h"
#include "pmem.h"

// needed by pfs_xatr_set_thread_name
extern PSYNC_THREAD const char *psync_thread_name; 

#define pfs_xatr_set_thread_name()                                             \
  do {                                                                         \
    if (IS_DEBUG) psync_thread_name = __FUNCTION__;                            \
  } while (0)

// Value get from standard xattr.h
enum {
  XATTR_CREATE = 1, /* set value, fail if attr already exists.  */
#define XATTR_CREATE XATTR_CREATE
  XATTR_REPLACE = 2 /* set value, fail if attr does not exist.  */
#define XATTR_REPLACE XATTR_REPLACE
};

#ifndef ENODATA
#define ENODATA 61
#endif

#ifndef ENOATTR
#define ENOATTR ENODATA
#endif

#define OBJECT_MULTIPLIER 8
#define OBJECT_FOLDER 0
#define OBJECT_FILE 1
#define OBJECT_TASK 2
#define OBJECT_STATICFILE 3

#define folderid_to_objid(id) ((id) * OBJECT_MULTIPLIER + OBJECT_FOLDER)
#define fileid_to_objid(id) ((id) * OBJECT_MULTIPLIER + OBJECT_FILE)
#define taskid_to_objid(id) ((id) * OBJECT_MULTIPLIER + OBJECT_TASK)
#define static_taskid_to_objid(id)                                             \
  ((UINT64_MAX - id + 1) * OBJECT_MULTIPLIER + OBJECT_STATICFILE)

static void delete_object_id(uint64_t oid) {
  psync_sql_res *res;
  res = psql_prepare("DELETE FROM fsxattr WHERE objectid=?");
  psql_bind_uint(res, 1, oid);
  psql_run_free(res);
}

void pfs_xatr_file_deleted(psync_fileid_t fileid) {
  delete_object_id(fileid_to_objid(fileid));
}

void pfs_xatr_folder_deleted(psync_folderid_t folderid) {
  delete_object_id(folderid_to_objid(folderid));
}

void pfs_xatr_task_deleted(uint64_t taskid) {
  delete_object_id(taskid_to_objid(taskid));
}

static void update_object_id(uint64_t ooid, uint64_t noid) {
  psync_sql_res *res;
  res = psql_prepare(
      "UPDATE OR REPLACE fsxattr SET objectid=? WHERE objectid=?");
  psql_bind_uint(res, 1, noid);
  psql_bind_uint(res, 2, ooid);
  psql_run_free(res);
}

void pfs_xatr_task_to_file(uint64_t taskid, psync_fileid_t fileid) {
  update_object_id(taskid_to_objid(taskid), fileid_to_objid(fileid));
}

void pfs_xatr_task_to_folder(uint64_t taskid, psync_folderid_t folderid) {
  update_object_id(taskid_to_objid(taskid), folderid_to_objid(folderid));
}

void pfs_xatr_static_to_task(uint64_t statictaskid, uint64_t taskid) {
  update_object_id(static_taskid_to_objid(statictaskid),
                   taskid_to_objid(taskid));
}

void pfs_xatr_file_to_task(psync_fileid_t fileid, uint64_t taskid) {
  update_object_id(fileid_to_objid(fileid), taskid_to_objid(taskid));
}

static int64_t xattr_get_object_id_locked(const char *path) {
  psync_fspath_t *fspath;
  psync_fstask_folder_t *folder;
  psync_fstask_mkdir_t *mk;
  psync_fstask_creat_t *cr;
  psync_sql_res *res;
  psync_uint_row row;
  int64_t ret;
  int checkfile, checkfolder;
  if (path[1] == 0 && path[0] == '/')
    return 0;
  fspath = pfs_fldr_resolve_path(path);
  if (!fspath) {
    pdbg_logf(D_NOTICE, "path component of %s not found", path);
    return -1;
  }
  checkfile = 1;
  checkfolder = 1;
  folder = pfs_task_get_folder_tasks_rdlocked(fspath->folderid);
  if (folder) {
    mk = pfs_task_find_mkdir(folder, fspath->name, 0);
    if (mk) {
      pmem_free(PMEM_SUBSYS_OTHER, fspath);
      pdbg_assertw(mk->folderid != 0);
      if (mk->folderid > 0)
        return folderid_to_objid(mk->folderid);
      else
        return taskid_to_objid(-mk->folderid);
    }
    cr = pfs_task_find_creat(folder, fspath->name, 0);
    if (cr) {
      pmem_free(PMEM_SUBSYS_OTHER, fspath);
      if (cr->fileid > 0)
        return fileid_to_objid(cr->fileid);
      else if (cr->fileid == 0)
        return static_taskid_to_objid(cr->taskid);
      else {
        res = psql_query_nolock(
            "SELECT type, fileid FROM fstask WHERE id=?");
        psql_bind_uint(res, 1, -cr->fileid);
        if ((row = psql_fetch_int(res))) {
          if (row[0] == PSYNC_FS_TASK_CREAT)
            ret = taskid_to_objid(-cr->fileid);
          else {
            pdbg_assertw(row[0] == PSYNC_FS_TASK_MODIFY);
            ret = fileid_to_objid(row[1]);
          }
        } else {
          pdbg_logf(D_WARNING,
                "found temporary file for path %s but could not find task %lu",
                path, (unsigned long)(-cr->fileid));
          ret = -1;
        }
        psql_free(res);
        return ret;
      }
    }
    checkfolder = !pfs_task_find_rmdir(folder, fspath->name, 0);
    checkfile = !pfs_task_find_unlink(folder, fspath->name, 0);
  }
  if (fspath->folderid < 0) {
    pmem_free(PMEM_SUBSYS_OTHER, fspath);
    pdbg_logf(D_NOTICE, "path %s not found in temporary folder", path);
    return -1;
  }
  if (checkfolder) {
    res = psql_query_nolock(
        "SELECT id FROM folder WHERE parentfolderid=? AND name=?");
    psql_bind_uint(res, 1, fspath->folderid);
    psql_bind_str(res, 2, fspath->name);
    if ((row = psql_fetch_int(res)))
      ret = folderid_to_objid(row[0]);
    else
      ret = -1;
    psql_free(res);
    if (ret != -1) {
      pmem_free(PMEM_SUBSYS_OTHER, fspath);
      return ret;
    }
  }
  if (checkfile) {
    res = psql_query_nolock(
        "SELECT id FROM file WHERE parentfolderid=? AND name=?");
    psql_bind_uint(res, 1, fspath->folderid);
    psql_bind_str(res, 2, fspath->name);
    if ((row = psql_fetch_int(res)))
      ret = fileid_to_objid(row[0]);
    else
      ret = -1;
    psql_free(res);
    if (ret != -1) {
      pmem_free(PMEM_SUBSYS_OTHER, fspath);
      return ret;
    }
  }
  pmem_free(PMEM_SUBSYS_OTHER, fspath);
  pdbg_logf(D_NOTICE, "path %s not found", path);
  return -1;
}

#define LOCK_AND_LOOKUP()                                                      \
  do {                                                                         \
    psql_lock();                                                          \
    oid = xattr_get_object_id_locked(path);                                    \
    if (unlikely(oid == -1)) {                                                 \
      psql_unlock();                                                      \
      return -pdbg_return_const(ENOENT);                                      \
    }                                                                          \
  } while (0)

#define LOCK_AND_LOOKUPRD()                                                    \
  do {                                                                         \
    psql_rdlock();                                                        \
    oid = xattr_get_object_id_locked(path);                                    \
    if (unlikely(oid == -1)) {                                                 \
      psql_rdunlock();                                                    \
      return -pdbg_return_const(ENOENT);                                      \
    }                                                                          \
  } while (0)

int pfs_xatr_set(const char *path, const char *name, const char *value,
                      size_t size, int flags PFS_XATTR_IGN) {
  psync_sql_res *res;
  int64_t oid;
  int ret;
  pfs_xatr_set_thread_name();
  pdbg_logf(D_NOTICE, "setting attribute %s of %s", name, path);
  LOCK_AND_LOOKUP();
  if (flags & XATTR_CREATE) {
    res = psql_prepare("INSERT OR IGNORE INTO fsxattr (objectid, "
                                   "name, value) VALUES (?, ?, ?)");
    psql_bind_uint(res, 1, oid);
    psql_bind_str(res, 2, name);
    psql_bind_blob(res, 3, value, size);
    psql_run_free(res);
    if (psql_affected())
      ret = 0;
    else
      ret = -pdbg_return_const(EEXIST);
  } else if (flags & XATTR_REPLACE) {
    res = psql_prepare(
        "UPDATE fsxattr SET value=? WHERE objectid=? AND name=?");
    psql_bind_blob(res, 1, value, size);
    psql_bind_uint(res, 2, oid);
    psql_bind_str(res, 3, name);
    psql_run_free(res);
    if (psql_affected())
      ret = 0;
    else
      ret = -pdbg_return_const(ENOATTR);
  } else {
    res = psql_prepare(
        "REPLACE INTO fsxattr (objectid, name, value) VALUES (?, ?, ?)");
    psql_bind_uint(res, 1, oid);
    psql_bind_str(res, 2, name);
    psql_bind_blob(res, 3, value, size);
    psql_run_free(res);
    ret = 0;
  }
  psql_unlock();
  return ret;
}

int pfs_xatr_get(const char *path, const char *name, char *value,
                      size_t size PFS_XATTR_IGN) {
  psync_sql_res *res;
  int64_t oid;
  int ret;
  pfs_xatr_set_thread_name();
  LOCK_AND_LOOKUPRD();
  if (size && value) {
    psync_variant_row row;
    const char *str;
    size_t len;
    res = psql_query_nolock(
        "SELECT value FROM fsxattr WHERE objectid=? AND name=?");
    psql_bind_uint(res, 1, oid);
    psql_bind_str(res, 2, name);
    if ((row = psql_fetch(res))) {
      str = psync_get_lstring(row[0], &len);
      if (size >= len) {
        pdbg_logf(D_NOTICE, "returning attribute %s of %s", name, path);
        memcpy(value, str, len);
        ret = len;
      } else {
        pdbg_logf(D_NOTICE, "buffer too small for attribute %s of %s", name, path);
        ret = -ERANGE;
      }
    } else {
      ret = -ENOATTR;
      //      pdbg_logf(D_NOTICE, "attribute %s not found for %s", name, path);
    }
    psql_free(res);
  } else {
    psync_uint_row row;
    res = psql_query_nolock(
        "SELECT LENGTH(value) FROM fsxattr WHERE objectid=? AND name=?");
    psql_bind_uint(res, 1, oid);
    psql_bind_str(res, 2, name);
    if ((row = psql_fetch_int(res))) {
      ret = row[0];
      pdbg_logf(D_NOTICE, "returning length of attribute %s of %s = %d", name, path,
            ret);
    } else {
      ret = -ENOATTR;
      //      pdbg_logf(D_NOTICE, "attribute %s not found for %s", name, path);
    }
    psql_free(res);
  }
  psql_rdunlock();
  return ret;
}

int pfs_xatr_list(const char *path, char *list, size_t size) {
  psync_sql_res *res;
  int64_t oid;
  const char *str;
  size_t len;
  int ret;
  pfs_xatr_set_thread_name();
  LOCK_AND_LOOKUPRD();
  if (size && list) {
    psync_variant_row row;
    ret = 0;
    res = psql_query_nolock("SELECT name FROM fsxattr WHERE objectid=?");
    psql_bind_uint(res, 1, oid);
    while ((row = psql_fetch(res))) {
      str = psync_get_lstring(row[0], &len);
      len++;
      if (ret + len > size) {
        ret = -ERANGE;
        break;
      }
      memcpy(list + ret, str, len);
      ret += len;
    }
    psql_free(res);
    pdbg_logf(D_NOTICE, "returning list of attributes of %s = %d", path, ret);
  } else {
    psync_uint_row row;
    res = psql_query_nolock(
        "SELECT SUM(LENGTH(name)+1) FROM fsxattr WHERE objectid=?");
    psql_bind_uint(res, 1, oid);
    if ((row = psql_fetch_int(res)))
      ret = row[0];
    else
      ret = 0;
    psql_free(res);
    pdbg_logf(D_NOTICE, "returning length of attributes of %s = %d", path, ret);
  }
  psql_rdunlock();
  return ret;
}

int pfs_xatr_remove(const char *path, const char *name) {
  psync_sql_res *res;
  int64_t oid;
  uint32_t aff;
  pfs_xatr_set_thread_name();
  LOCK_AND_LOOKUP();
  res = psql_prepare(
      "DELETE FROM fsxattr WHERE objectid=? AND name=?");
  psql_bind_uint(res, 1, oid);
  psql_bind_str(res, 2, name);
  psql_run_free(res);
  aff = psql_affected();
  psql_unlock();
  if (aff) {
    pdbg_logf(D_NOTICE, "attribute %s deleted for %s", name, path);
    return 0;
  } else {
    pdbg_logf(D_NOTICE, "attribute %s not found for %s", name, path);
    return -ENOATTR;
  }
}