/*
 * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
 *
 * This program is free software: you can use, redistribute, and/or modify
 * it under the terms of the GNU Affero General Public License, version 3
 * or later ("AGPL"), as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "metaTtl.h"
#include "meta.h"

typedef struct {
  TTB   *pNewTtlIdx;
  SMeta *pMeta;
} SConvertData;

static void    ttlMgrBuildKey(STtlIdxKeyV1 *pTtlKey, int64_t ttlDays, int64_t changeTimeMs, tb_uid_t uid);
static int     ttlIdxKeyCmpr(const void *pKey1, int kLen1, const void *pKey2, int kLen2);
static int     ttlIdxKeyV1Cmpr(const void *pKey1, int kLen1, const void *pKey2, int kLen2);
static int     ttlMgrFillCache(STtlManger *pTtlMgr);
static int32_t ttlMgrFillCacheOneEntry(const void *pKey, int keyLen, const void *pVal, int valLen, void *pTtlCache);
static int32_t ttlMgrConvertOneEntry(const void *pKey, int keyLen, const void *pVal, int valLen, void *pConvertData);

static int32_t ttlMgrWLock(STtlManger *pTtlMgr);
static int32_t ttlMgrRLock(STtlManger *pTtlMgr);
static int32_t ttlMgrULock(STtlManger *pTtlMgr);

const char *ttlTbname = "ttl.idx";
const char *ttlV1Tbname = "ttlv1.idx";

int ttlMgrOpen(STtlManger **ppTtlMgr, TDB *pEnv, int8_t rollback) {
  int ret;

  *ppTtlMgr = NULL;

  STtlManger *pTtlMgr = (STtlManger *)tdbOsCalloc(1, sizeof(*pTtlMgr));
  if (pTtlMgr == NULL) {
    return -1;
  }

  if (tdbTbExist(ttlTbname, pEnv)) {
    ret = tdbTbOpen(ttlTbname, sizeof(STtlIdxKey), 0, ttlIdxKeyCmpr, pEnv, &pTtlMgr->pOldTtlIdx, rollback);
    if (ret < 0) {
      metaError("failed to open %s index since %s", ttlTbname, tstrerror(terrno));
      return ret;
    }
  }

  ret = tdbTbOpen(ttlV1Tbname, TDB_VARIANT_LEN, TDB_VARIANT_LEN, ttlIdxKeyV1Cmpr, pEnv, &pTtlMgr->pTtlIdx, rollback);
  if (ret < 0) {
    metaError("failed to open %s since %s", ttlV1Tbname, tstrerror(terrno));

    tdbOsFree(pTtlMgr);
    return ret;
  }

  pTtlMgr->pTtlCache = taosHashInit(8192, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), true, HASH_NO_LOCK);
  pTtlMgr->pDirtyUids = taosHashInit(8192, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), true, HASH_NO_LOCK);

  taosThreadRwlockInit(&pTtlMgr->lock, NULL);

  *ppTtlMgr = pTtlMgr;
  return 0;
}

int ttlMgrClose(STtlManger *pTtlMgr) {
  taosHashCleanup(pTtlMgr->pTtlCache);
  taosHashCleanup(pTtlMgr->pDirtyUids);
  tdbTbClose(pTtlMgr->pTtlIdx);
  taosThreadRwlockDestroy(&pTtlMgr->lock);
  tdbOsFree(pTtlMgr);
  return 0;
}

int ttlMgrBegin(STtlManger *pTtlMgr, void *pMeta) {
  metaInfo("ttl mgr start open");
  int ret;

  int64_t startNs = taosGetTimestampNs();

  SMeta *meta = (SMeta *)pMeta;

  if (pTtlMgr->pOldTtlIdx) {
    ret = ttlMgrConvert(pTtlMgr->pOldTtlIdx, pTtlMgr->pTtlIdx, pMeta);
    if (ret < 0) {
      metaError("failed to convert ttl index since %s", tstrerror(terrno));
      goto _out;
    }

    ret = tdbTbDropByName(ttlTbname, meta->pEnv, meta->txn);
    if (ret < 0) {
      metaError("failed to drop old ttl index since %s", tstrerror(terrno));
      goto _out;
    }

    tdbTbClose(pTtlMgr->pOldTtlIdx);
    pTtlMgr->pOldTtlIdx = NULL;
  }

  ret = ttlMgrFillCache(pTtlMgr);
  if (ret < 0) {
    metaError("failed to fill hash since %s", tstrerror(terrno));
    goto _out;
  }

  int64_t endNs = taosGetTimestampNs();

  metaInfo("ttl mgr open end, hash size: %d, time consumed: %" PRId64 " ns", taosHashGetSize(pTtlMgr->pTtlCache),
           endNs - startNs);
_out:
  return ret;
}

static void ttlMgrBuildKey(STtlIdxKeyV1 *pTtlKey, int64_t ttlDays, int64_t changeTimeMs, tb_uid_t uid) {
  if (ttlDays <= 0) return;

  pTtlKey->deleteTimeMs = changeTimeMs + ttlDays * tsTtlUnit * 1000;
  pTtlKey->uid = uid;
}

static int ttlIdxKeyCmpr(const void *pKey1, int kLen1, const void *pKey2, int kLen2) {
  STtlIdxKey *pTtlIdxKey1 = (STtlIdxKey *)pKey1;
  STtlIdxKey *pTtlIdxKey2 = (STtlIdxKey *)pKey2;

  if (pTtlIdxKey1->deleteTimeSec > pTtlIdxKey2->deleteTimeSec) {
    return 1;
  } else if (pTtlIdxKey1->deleteTimeSec < pTtlIdxKey2->deleteTimeSec) {
    return -1;
  }

  if (pTtlIdxKey1->uid > pTtlIdxKey2->uid) {
    return 1;
  } else if (pTtlIdxKey1->uid < pTtlIdxKey2->uid) {
    return -1;
  }

  return 0;
}

static int ttlIdxKeyV1Cmpr(const void *pKey1, int kLen1, const void *pKey2, int kLen2) {
  STtlIdxKeyV1 *pTtlIdxKey1 = (STtlIdxKeyV1 *)pKey1;
  STtlIdxKeyV1 *pTtlIdxKey2 = (STtlIdxKeyV1 *)pKey2;

  if (pTtlIdxKey1->deleteTimeMs > pTtlIdxKey2->deleteTimeMs) {
    return 1;
  } else if (pTtlIdxKey1->deleteTimeMs < pTtlIdxKey2->deleteTimeMs) {
    return -1;
  }

  if (pTtlIdxKey1->uid > pTtlIdxKey2->uid) {
    return 1;
  } else if (pTtlIdxKey1->uid < pTtlIdxKey2->uid) {
    return -1;
  }

  return 0;
}

static int ttlMgrFillCache(STtlManger *pTtlMgr) {
  return tdbTbTraversal(pTtlMgr->pTtlIdx, pTtlMgr->pTtlCache, ttlMgrFillCacheOneEntry);
}

static int32_t ttlMgrFillCacheOneEntry(const void *pKey, int keyLen, const void *pVal, int valLen, void *pTtlCache) {
  SHashObj *pCache = (SHashObj *)pTtlCache;

  STtlIdxKeyV1 *ttlKey = (STtlIdxKeyV1 *)pKey;
  tb_uid_t      uid = ttlKey->uid;
  int64_t       ttlDays = *(int64_t *)pVal;
  int64_t       changeTimeMs = ttlKey->deleteTimeMs - ttlDays * tsTtlUnit * 1000;

  STtlCacheEntry data = {.ttlDays = ttlDays, .changeTimeMs = changeTimeMs};

  return taosHashPut(pCache, &uid, sizeof(uid), &data, sizeof(data));
}

static int ttlMgrConvertOneEntry(const void *pKey, int keyLen, const void *pVal, int valLen, void *pConvertData) {
  SConvertData *pData = (SConvertData *)pConvertData;

  STtlIdxKey *ttlKey = (STtlIdxKey *)pKey;
  tb_uid_t    uid = ttlKey->uid;
  int64_t     ttlDays = 0;

  int ret = metaGetTableTtlByUid(pData->pMeta, uid, &ttlDays);
  if (ret < 0) {
    metaError("ttlMgr convert failed to get ttl since %s", tstrerror(terrno));
    goto _out;
  }

  STtlIdxKeyV1 ttlKeyV1 = {.deleteTimeMs = ttlKey->deleteTimeSec * 1000, .uid = uid};
  ret = tdbTbUpsert(pData->pNewTtlIdx, &ttlKeyV1, sizeof(ttlKeyV1), &ttlDays, sizeof(ttlDays), pData->pMeta->txn);
  if (ret < 0) {
    metaError("ttlMgr convert failed to upsert since %s", tstrerror(terrno));
    goto _out;
  }

  ret = 0;
_out:
  return ret;
}

int ttlMgrConvert(TTB *pOldTtlIdx, TTB *pNewTtlIdx, void *pMeta) {
  SMeta *meta = pMeta;

  metaInfo("ttlMgr convert ttl start.");

  SConvertData cvData = {.pNewTtlIdx = pNewTtlIdx, .pMeta = meta};

  int ret = tdbTbTraversal(pOldTtlIdx, &cvData, ttlMgrConvertOneEntry);
  if (ret < 0) {
    metaError("failed to convert ttl since %s", tstrerror(terrno));
  }

  metaInfo("ttlMgr convert ttl end.");
  return ret;
}

int ttlMgrInsertTtl(STtlManger *pTtlMgr, const STtlUpdTtlCtx *updCtx) {
  if (updCtx->ttlDays == 0) return 0;

  STtlCacheEntry cacheEntry = {.ttlDays = updCtx->ttlDays, .changeTimeMs = updCtx->changeTimeMs};
  STtlDirtyEntry dirtryEntry = {.type = ENTRY_TYPE_UPSERT};

  ttlMgrWLock(pTtlMgr);

  int ret = taosHashPut(pTtlMgr->pTtlCache, &updCtx->uid, sizeof(updCtx->uid), &cacheEntry, sizeof(cacheEntry));
  if (ret < 0) {
    metaError("ttlMgr insert failed to update ttl cache since %s", tstrerror(terrno));
    goto _out;
  }

  ret = taosHashPut(pTtlMgr->pDirtyUids, &updCtx->uid, sizeof(updCtx->uid), &dirtryEntry, sizeof(dirtryEntry));
  if (ret < 0) {
    metaError("ttlMgr insert failed to update ttl dirty uids since %s", tstrerror(terrno));
    goto _out;
  }

  ret = 0;
_out:
  ttlMgrULock(pTtlMgr);

  metaDebug("ttl mgr insert ttl, uid: %" PRId64 ", ctime: %" PRId64 ", ttlDays: %" PRId64, updCtx->uid,
            updCtx->changeTimeMs, updCtx->ttlDays);

  return ret;
}

int ttlMgrDeleteTtl(STtlManger *pTtlMgr, const STtlDelTtlCtx *delCtx) {
  ttlMgrWLock(pTtlMgr);

  STtlDirtyEntry dirtryEntry = {.type = ENTRY_TYPE_DEL};

  int ret = taosHashPut(pTtlMgr->pDirtyUids, &delCtx->uid, sizeof(delCtx->uid), &dirtryEntry, sizeof(dirtryEntry));
  if (ret < 0) {
    metaError("ttlMgr del failed to update ttl dirty uids since %s", tstrerror(terrno));
    goto _out;
  }

  ret = 0;
_out:
  ttlMgrULock(pTtlMgr);

  metaDebug("ttl mgr delete ttl, uid: %" PRId64, delCtx->uid);

  return ret;
}

int ttlMgrUpdateChangeTime(STtlManger *pTtlMgr, const STtlUpdCtimeCtx *pUpdCtimeCtx) {
  ttlMgrWLock(pTtlMgr);

  STtlCacheEntry *oldData = taosHashGet(pTtlMgr->pTtlCache, &pUpdCtimeCtx->uid, sizeof(pUpdCtimeCtx->uid));
  if (oldData == NULL) {
    goto _out;
  }

  STtlCacheEntry cacheEntry = {.ttlDays = oldData->ttlDays, .changeTimeMs = pUpdCtimeCtx->changeTimeMs};
  STtlDirtyEntry dirtryEntry = {.type = ENTRY_TYPE_UPSERT};

  int ret =
      taosHashPut(pTtlMgr->pTtlCache, &pUpdCtimeCtx->uid, sizeof(pUpdCtimeCtx->uid), &cacheEntry, sizeof(cacheEntry));
  if (ret < 0) {
    metaError("ttlMgr update ctime failed to update ttl cache since %s", tstrerror(terrno));
    goto _out;
  }

  ret = taosHashPut(pTtlMgr->pDirtyUids, &pUpdCtimeCtx->uid, sizeof(pUpdCtimeCtx->uid), &dirtryEntry,
                    sizeof(dirtryEntry));
  if (ret < 0) {
    metaError("ttlMgr update ctime failed to update ttl dirty uids since %s", tstrerror(terrno));
    goto _out;
  }

  ret = 0;
_out:
  ttlMgrULock(pTtlMgr);

  metaDebug("ttl mgr update ctime, uid: %" PRId64 ", ctime: %" PRId64, pUpdCtimeCtx->uid, pUpdCtimeCtx->changeTimeMs);

  return ret;
}

int ttlMgrFindExpired(STtlManger *pTtlMgr, int64_t timePointMs, SArray *pTbUids) {
  ttlMgrRLock(pTtlMgr);

  TBC *pCur;
  int  ret = tdbTbcOpen(pTtlMgr->pTtlIdx, &pCur, NULL);
  if (ret < 0) {
    goto _out;
  }

  STtlIdxKeyV1 ttlKey = {0};
  ttlKey.deleteTimeMs = timePointMs;
  ttlKey.uid = INT64_MAX;
  int c = 0;
  tdbTbcMoveTo(pCur, &ttlKey, sizeof(ttlKey), &c);
  if (c < 0) {
    tdbTbcMoveToPrev(pCur);
  }

  void *pKey = NULL;
  int   kLen = 0;
  while (1) {
    ret = tdbTbcPrev(pCur, &pKey, &kLen, NULL, NULL);
    if (ret < 0) {
      ret = 0;
      break;
    }
    ttlKey = *(STtlIdxKeyV1 *)pKey;
    taosArrayPush(pTbUids, &ttlKey.uid);
  }

  tdbFree(pKey);
  tdbTbcClose(pCur);

  ret = 0;
_out:
  ttlMgrULock(pTtlMgr);
  return ret;
}

int ttlMgrFlush(STtlManger *pTtlMgr, TXN *pTxn) {
  ttlMgrWLock(pTtlMgr);

  metaInfo("ttl mgr flush start.");

  int ret = -1;

  void *pIter = taosHashIterate(pTtlMgr->pDirtyUids, NULL);
  while (pIter != NULL) {
    STtlDirtyEntry *pEntry = (STtlDirtyEntry *)pIter;
    tb_uid_t       *pUid = taosHashGetKey(pIter, NULL);

    STtlCacheEntry *cacheEntry = taosHashGet(pTtlMgr->pTtlCache, pUid, sizeof(*pUid));
    if (cacheEntry == NULL) {
      metaError("ttlMgr flush failed to get ttl cache since %s, uid: %" PRId64 ", type: %d", tstrerror(terrno), *pUid,
                pEntry->type);
      goto _out;
    }

    STtlIdxKeyV1 ttlKey;
    ttlMgrBuildKey(&ttlKey, cacheEntry->ttlDays, cacheEntry->changeTimeMs, *pUid);

    if (pEntry->type == ENTRY_TYPE_UPSERT) {
      ret = tdbTbUpsert(pTtlMgr->pTtlIdx, &ttlKey, sizeof(ttlKey), &cacheEntry->ttlDays, sizeof(cacheEntry->ttlDays),
                        pTxn);
      if (ret < 0) {
        metaError("ttlMgr flush failed to flush ttl cache upsert since %s", tstrerror(terrno));
        goto _out;
      }
    } else if (pEntry->type == ENTRY_TYPE_DEL) {
      ret = tdbTbDelete(pTtlMgr->pTtlIdx, &ttlKey, sizeof(ttlKey), pTxn);
      if (ret < 0) {
        metaError("ttlMgr flush failed to flush ttl cache del since %s", tstrerror(terrno));
        goto _out;
      }

      ret = taosHashRemove(pTtlMgr->pTtlCache, pUid, sizeof(*pUid));
      if (ret < 0) {
        metaError("ttlMgr flush failed to delete ttl cache since %s", tstrerror(terrno));
        goto _out;
      }
    } else {
      metaError("ttlMgr flush failed to flush ttl cache, unknown type: %d", pEntry->type);
      goto _out;
    }

    pIter = taosHashIterate(pTtlMgr->pDirtyUids, pIter);
  }

  taosHashClear(pTtlMgr->pDirtyUids);

  ret = 0;
_out:
  ttlMgrULock(pTtlMgr);

  metaInfo("ttl mgr flush end.");

  return ret;
}

static int32_t ttlMgrRLock(STtlManger *pTtlMgr) {
  int32_t ret = 0;

  metaTrace("ttlMgr rlock %p", &pTtlMgr->lock);

  ret = taosThreadRwlockRdlock(&pTtlMgr->lock);

  return ret;
}

static int32_t ttlMgrWLock(STtlManger *pTtlMgr) {
  int32_t ret = 0;

  metaTrace("ttlMgr wlock %p", &pTtlMgr->lock);

  ret = taosThreadRwlockWrlock(&pTtlMgr->lock);

  return ret;
}

static int32_t ttlMgrULock(STtlManger *pTtlMgr) {
  int32_t ret = 0;

  metaTrace("ttlMgr ulock %p", &pTtlMgr->lock);

  ret = taosThreadRwlockUnlock(&pTtlMgr->lock);

  return ret;
}