/*
 * 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 "tsdb.h"

typedef struct {
  STsdb *pTsdb;
  /* commit data */
  int32_t minutes;
  int8_t  precision;
  int32_t minRow;
  int32_t maxRow;
  // --------------
  TSKEY   nextKey;  // need to be reset by each table commit
  int32_t commitFid;
  TSKEY   minKey;
  TSKEY   maxKey;
  // commit file data
  SDataFReader *pReader;
  SMapData      oBlockIdx;  // SMapData<SBlockIdx>, read from reader
  SMapData      oBlock;     // SMapData<SBlock>, read from reader
  SDataFWriter *pWriter;
  SMapData      nBlockIdx;  // SMapData<SBlockIdx>, build by committer
  SMapData      nBlock;     // SMapData<SBlock>
  /* commit del */
  SDelFReader *pDelFReader;
  SMapData     oDelIdxMap;   // SMapData<SDelIdx>, old
  SMapData     oDelDataMap;  // SMapData<SDelData>, old
  SDelFWriter *pDelFWriter;
  SMapData     nDelIdxMap;   // SMapData<SDelIdx>, new
  SMapData     nDelDataMap;  // SMapData<SDelData>, new
} SCommitter;

static int32_t tsdbStartCommit(STsdb *pTsdb, SCommitter *pCommitter);
static int32_t tsdbCommitData(SCommitter *pCommitter);
static int32_t tsdbCommitDel(SCommitter *pCommitter);
static int32_t tsdbCommitCache(SCommitter *pCommitter);
static int32_t tsdbEndCommit(SCommitter *pCommitter, int32_t eno);

int32_t tsdbBegin(STsdb *pTsdb) {
  int32_t code = 0;

  code = tsdbMemTableCreate(pTsdb, &pTsdb->mem);
  if (code) {
    goto _err;
  }

  return code;

_err:
  return code;
}

int32_t tsdbCommit(STsdb *pTsdb) {
  if (!pTsdb) return 0;

  int32_t    code = 0;
  SCommitter commith;
  SMemTable *pMemTable = pTsdb->mem;

  // check
  if (pMemTable->nRow == 0 && pMemTable->nDel == 0) {  // TODO
    pTsdb->mem = NULL;
    tsdbMemTableDestroy(pMemTable);
    goto _exit;
  }

  // start commit
  code = tsdbStartCommit(pTsdb, &commith);
  if (code) {
    goto _err;
  }

  // commit impl
  code = tsdbCommitData(&commith);
  if (code) {
    goto _err;
  }

  code = tsdbCommitDel(&commith);
  if (code) {
    goto _err;
  }

  code = tsdbCommitCache(&commith);
  if (code) {
    goto _err;
  }

  // end commit
  code = tsdbEndCommit(&commith, 0);
  if (code) {
    goto _err;
  }

_exit:
  return code;

_err:
  tsdbEndCommit(&commith, code);
  tsdbError("vgId:%d, failed to commit since %s", TD_VID(pTsdb->pVnode), tstrerror(code));
  return code;
}

static int32_t tsdbCommitDelStart(SCommitter *pCommitter) {
  int32_t    code = 0;
  STsdb     *pTsdb = pCommitter->pTsdb;
  SMemTable *pMemTable = pTsdb->imem;
  SDelFile  *pDelFileR = NULL;  // TODO
  SDelFile  *pDelFileW = NULL;  // TODO

  tMapDataReset(&pCommitter->oDelIdxMap);
  tMapDataReset(&pCommitter->nDelIdxMap);

  // load old
  if (pDelFileR) {
    code = tsdbDelFReaderOpen(&pCommitter->pDelFReader, pDelFileR, pTsdb, NULL);
    if (code) goto _err;

    code = tsdbReadDelIdx(pCommitter->pDelFReader, &pCommitter->oDelIdxMap, NULL);
    if (code) goto _err;
  }

  // prepare new
  code = tsdbDelFWriterOpen(&pCommitter->pDelFWriter, pDelFileW, pTsdb);
  if (code) goto _err;

_exit:
  tsdbDebug("vgId:%d commit del start", TD_VID(pTsdb->pVnode));
  return code;

_err:
  tsdbError("vgId:%d commit del start failed since %s", TD_VID(pTsdb->pVnode), tstrerror(code));
  return code;
}

static int32_t tsdbCommitTableDel(SCommitter *pCommitter, STbData *pTbData, SDelIdx *pDelIdx) {
  int32_t  code = 0;
  SDelData delData;
  SDelOp  *pDelOp;
  tb_uid_t suid;
  tb_uid_t uid;
  SDelIdx  delIdx;  // TODO

  // check no del data, just return
  if (pTbData && pTbData->pHead == NULL) {
    pTbData = NULL;
  }
  if (pTbData == NULL && pDelIdx == NULL) goto _exit;

  // prepare
  if (pTbData) {
    delIdx.suid = pTbData->suid;
    delIdx.uid = pTbData->uid;
  } else {
    delIdx.suid = pDelIdx->suid;
    delIdx.uid = pDelIdx->uid;
  }
  delIdx.minKey = TSKEY_MAX;
  delIdx.maxKey = TSKEY_MIN;
  delIdx.minVersion = INT64_MAX;
  delIdx.maxVersion = -1;

  // start
  tMapDataReset(&pCommitter->oDelDataMap);
  tMapDataReset(&pCommitter->nDelDataMap);

  if (pDelIdx) {
    code = tsdbReadDelData(pCommitter->pDelFReader, pDelIdx, &pCommitter->oDelDataMap, NULL);
    if (code) goto _err;
  }

  // disk
  for (int32_t iDelData = 0; iDelData < pCommitter->oDelDataMap.nItem; iDelData++) {
    code = tMapDataGetItemByIdx(&pCommitter->oDelDataMap, iDelData, &delData, tGetDelData);
    if (code) goto _err;

    code = tMapDataPutItem(&pCommitter->nDelDataMap, &delData, tPutDelData);
    if (code) goto _err;

    if (delIdx.minKey > delData.sKey) delIdx.minKey = delData.sKey;
    if (delIdx.maxKey < delData.eKey) delIdx.maxKey = delData.eKey;
    if (delIdx.minVersion > delData.version) delIdx.minVersion = delData.version;
    if (delIdx.maxVersion < delData.version) delIdx.maxVersion = delData.version;
  }

  // memory
  pDelOp = pTbData ? pTbData->pHead : NULL;
  for (; pDelOp; pDelOp = pDelOp->pNext) {
    delData.version = pDelOp->version;
    delData.sKey = pDelOp->sKey;
    delData.eKey = pDelOp->eKey;

    code = tMapDataPutItem(&pCommitter->nDelDataMap, &delData, tPutDelData);
    if (code) goto _err;

    if (delIdx.minKey > delData.sKey) delIdx.minKey = delData.sKey;
    if (delIdx.maxKey < delData.eKey) delIdx.maxKey = delData.eKey;
    if (delIdx.minVersion > delData.version) delIdx.minVersion = delData.version;
    if (delIdx.maxVersion < delData.version) delIdx.maxVersion = delData.version;
  }

  ASSERT(pCommitter->nDelDataMap.nItem > 0);

  // write
  code = tsdbWriteDelData(pCommitter->pDelFWriter, &pCommitter->nDelDataMap, NULL, &delIdx);
  if (code) goto _err;

  // put delIdx
  code = tMapDataPutItem(&pCommitter->nDelIdxMap, &delIdx, tPutDelIdx);
  if (code) goto _err;

_exit:
  return code;

_err:
  tsdbError("vgId:%d commit table del failed since %s", TD_VID(pCommitter->pTsdb->pVnode), tstrerror(code));
  return code;
}

static int32_t tsdbCommitDelImpl(SCommitter *pCommitter) {
  int32_t    code = 0;
  STsdb     *pTsdb = pCommitter->pTsdb;
  SMemTable *pMemTable = pTsdb->imem;
  int32_t    iDelIdx = 0;
  int32_t    nDelIdx = pCommitter->oDelIdxMap.nItem;
  int32_t    iTbData = 0;
  int32_t    nTbData = taosArrayGetSize(pMemTable->aTbData);
  STbData   *pTbData;
  SDelIdx   *pDelIdx;
  SDelIdx    delIdx;
  int32_t    c;

  ASSERT(nTbData > 0);

  pTbData = (STbData *)taosArrayGetP(pMemTable->aTbData, iTbData);
  if (iDelIdx < nDelIdx) {
    code = tMapDataGetItemByIdx(&pCommitter->oDelIdxMap, iDelIdx, &delIdx, tGetDelIdx);
    if (code) goto _err;
    pDelIdx = &delIdx;
  } else {
    pDelIdx = NULL;
  }

  while (true) {
    if (pTbData == NULL && pDelIdx == NULL) break;

    if (pTbData && pDelIdx) {
      c = tTABLEIDCmprFn(pTbData, pDelIdx);
      if (c == 0) {
        goto _commit_mem_and_disk_del;
      } else if (c < 0) {
        goto _commit_mem_del;
      } else {
        goto _commit_disk_del;
      }
    } else {
      if (pTbData) goto _commit_mem_del;
      if (pDelIdx) goto _commit_disk_del;
    }

  _commit_mem_del:
    code = tsdbCommitTableDel(pCommitter, pTbData, NULL);
    if (code) goto _err;
    iTbData++;
    if (iTbData < nTbData) {
      pTbData = (STbData *)taosArrayGetP(pMemTable->aTbData, iTbData);
    } else {
      pTbData = NULL;
    }
    continue;

  _commit_disk_del:
    code = tsdbCommitTableDel(pCommitter, NULL, pDelIdx);
    if (code) goto _err;
    iDelIdx++;
    if (iDelIdx < nDelIdx) {
      code = tMapDataGetItemByIdx(&pCommitter->oDelIdxMap, iDelIdx, &delIdx, tGetDelIdx);
      if (code) goto _err;
      pDelIdx = &delIdx;
    } else {
      pDelIdx = NULL;
    }
    continue;

  _commit_mem_and_disk_del:
    code = tsdbCommitTableDel(pCommitter, pTbData, pDelIdx);
    if (code) goto _err;
    iTbData++;
    iDelIdx++;
    if (iTbData < nTbData) {
      pTbData = (STbData *)taosArrayGetP(pMemTable->aTbData, iTbData);
    } else {
      pTbData = NULL;
    }
    if (iDelIdx < nDelIdx) {
      code = tMapDataGetItemByIdx(&pCommitter->oDelIdxMap, iDelIdx, &delIdx, tGetDelIdx);
      if (code) goto _err;
      pDelIdx = &delIdx;
    } else {
      pDelIdx = NULL;
    }
    continue;
  }

  return code;

_err:
  tsdbError("vgId:%d commit del impl failed since %s", TD_VID(pTsdb->pVnode), tstrerror(code));
  return code;
}

static int32_t tsdbCommitDelEnd(SCommitter *pCommitter) {
  int32_t code = 0;

  code = tsdbWriteDelIdx(pCommitter->pDelFWriter, &pCommitter->nDelIdxMap, NULL);
  if (code) goto _err;

  code = tsdbUpdateDelFileHdr(pCommitter->pDelFWriter, NULL);
  if (code) goto _err;

  code = tsdbDelFWriterClose(pCommitter->pDelFWriter, 1);
  if (code) goto _err;

  if (pCommitter->pDelFReader) {
    code = tsdbDelFReaderClose(pCommitter->pDelFReader);
    if (code) goto _err;
  }

  return code;

_err:
  tsdbError("vgId:%d commit del end failed since %s", TD_VID(pCommitter->pTsdb->pVnode), tstrerror(code));
  return code;
}

#define ROW_END(pRow, maxKey) (((pRow) == NULL) || ((pRow)->pTSRow->ts > (maxKey)))

static int32_t tsdbMergeCommit(SCommitter *pCommitter, STbDataIter *pIter, SBlock *pBlock) {
  int32_t code = 0;
  // TODO
  return code;
}

static int32_t tsdbCommitTableData(SCommitter *pCommitter, STbData *pTbData, SBlockIdx *pBlockIdx) {
  int32_t      code = 0;
  STbDataIter  iter;
  STbDataIter *pIter = &iter;
  TSDBROW     *pRow;
  SBlockIdx    blockIdx;  // TODO

  // create iter
  if (pTbData) {
    tsdbTbDataIterOpen(pTbData, &(TSDBKEY){.ts = pCommitter->minKey, .version = 0}, 0, pIter);
  } else {
    pIter = NULL;
  }

  // check
  pRow = tsdbTbDataIterGet(pIter);
  if (ROW_END(pRow, pCommitter->maxKey) && pBlockIdx == NULL) goto _exit;

  // start ================================
  tMapDataReset(&pCommitter->oBlock);
  tMapDataReset(&pCommitter->nBlock);
  if (pBlockIdx) {
    code = tsdbReadBlock(pCommitter->pReader, pBlockIdx, &pCommitter->oBlock, NULL);
    if (code) goto _err;
  }

  // impl ===============================
  SBlock  block;
  SBlock *pBlock = &block;
  int32_t iBlock = 0;
  int32_t nBlock = pCommitter->oBlock.nItem;

  // merge
  pRow = tsdbTbDataIterGet(pIter);
  while (!ROW_END(pRow, pCommitter->maxKey) && iBlock < nBlock) {
    tMapDataGetItemByIdx(&pCommitter->oBlock, iBlock, pBlock, tGetBlock);
    code = tsdbMergeCommit(pCommitter, pIter, pBlock);
    if (code) goto _err;

    pRow = tsdbTbDataIterGet(pIter);
    iBlock++;
  }

  // mem
  pRow = tsdbTbDataIterGet(pIter);
  while (!ROW_END(pRow, pCommitter->maxKey)) {
    code = tsdbMergeCommit(pCommitter, pIter, NULL);
    if (code) goto _err;

    pRow = tsdbTbDataIterGet(pIter);
  }

  // disk
  while (iBlock < nBlock) {
    tMapDataGetItemByIdx(&pCommitter->oBlock, iBlock, pBlock, tGetBlock);

    code = tsdbMergeCommit(pCommitter, NULL, pBlock);
    if (code) goto _err;

    iBlock++;
  }

  // end ===============================
  code = tsdbWriteBlock(pCommitter->pWriter, &pCommitter->nBlock, NULL, &blockIdx);
  if (code) goto _err;

  code = tMapDataPutItem(&pCommitter->nBlockIdx, &blockIdx, tPutBlockIdx);
  if (code) goto _err;

_exit:
  pRow = tsdbTbDataIterGet(pIter);
  if (pRow) {
    ASSERT(pRow->pTSRow->ts > pCommitter->maxKey);
    if (pCommitter->nextKey > pRow->pTSRow->ts) {
      pCommitter->nextKey = pRow->pTSRow->ts;
    }
  }

  return code;

_err:
  tsdbError("vgId:%d commit Table data failed since %s", TD_VID(pCommitter->pTsdb->pVnode), tstrerror(code));
  return code;
}

static int32_t tsdbCommitFileDataStart(SCommitter *pCommitter) {
  int32_t    code = 0;
  STsdb     *pTsdb = pCommitter->pTsdb;
  SDFileSet *pRSet = NULL;  // TODO
  SDFileSet *pWSet = NULL;  // TODO

  // memory
  pCommitter->nextKey = TSKEY_MAX;
  tMapDataReset(&pCommitter->oBlockIdx);
  tMapDataReset(&pCommitter->oBlock);
  tMapDataReset(&pCommitter->nBlockIdx);
  tMapDataReset(&pCommitter->nBlock);

  // load old
  if (pRSet) {
    code = tsdbDataFReaderOpen(&pCommitter->pReader, pTsdb, pRSet);
    if (code) goto _err;

    code = tsdbReadBlockIdx(pCommitter->pReader, &pCommitter->oBlockIdx, NULL);
    if (code) goto _err;
  }

  // create new
  code = tsdbDataFWriterOpen(&pCommitter->pWriter, pTsdb, pWSet);
  if (code) goto _err;

_exit:
  return code;

_err:
  tsdbError("vgId:%d commit file data start failed since %s", TD_VID(pTsdb->pVnode), tstrerror(code));
  return code;
}

static int32_t tsdbCommitFileDataImpl(SCommitter *pCommitter) {
  int32_t    code = 0;
  int32_t    c;
  STsdb     *pTsdb = pCommitter->pTsdb;
  SMemTable *pMemTable = pTsdb->imem;
  int32_t    iTbData = 0;
  int32_t    nTbData = taosArrayGetSize(pMemTable->aTbData);
  int32_t    iBlockIdx = 0;
  int32_t    nBlockIdx = pCommitter->oBlockIdx.nItem;
  STbData   *pTbData;
  SBlockIdx *pBlockIdx;
  SBlockIdx  blockIdx;

  ASSERT(nTbData > 0);

  pTbData = (STbData *)taosArrayGetP(pMemTable->aTbData, iTbData);
  if (iBlockIdx < nBlockIdx) {
    pBlockIdx = &blockIdx;
    code = tMapDataGetItemByIdx(&pCommitter->oBlockIdx, iBlockIdx, pBlockIdx, tGetBlockIdx);
    if (code) goto _err;
  } else {
    pBlockIdx = NULL;
  }

  while (true) {
    if (pTbData == NULL && pBlockIdx == NULL) break;

    if (pTbData && pBlockIdx) {
      c = tTABLEIDCmprFn(pTbData, pBlockIdx);

      if (c == 0) {
        goto _commit_mem_and_disk_data;
      } else if (c < 0) {
        goto _commit_mem_data;
      } else {
        goto _commit_disk_data;
      }
    } else if (pTbData) {
      goto _commit_mem_data;
    } else {
      goto _commit_disk_data;
    }

  _commit_mem_data:
    code = tsdbCommitTableData(pCommitter, pTbData, NULL);
    if (code) goto _err;

    iTbData++;
    if (iTbData < nTbData) {
      pTbData = (STbData *)taosArrayGetP(pMemTable->aTbData, iTbData);
    } else {
      pTbData = NULL;
    }
    continue;

  _commit_disk_data:
    code = tsdbCommitTableData(pCommitter, NULL, pBlockIdx);
    if (code) goto _err;

    iBlockIdx++;
    if (iBlockIdx < nBlockIdx) {
      pBlockIdx = &blockIdx;
      code = tMapDataGetItemByIdx(&pCommitter->oBlockIdx, iBlockIdx, pBlockIdx, tGetBlockIdx);
      if (code) goto _err;
    } else {
      pBlockIdx = NULL;
    }
    continue;

  _commit_mem_and_disk_data:
    code = tsdbCommitTableData(pCommitter, pTbData, pBlockIdx);
    if (code) goto _err;

    iTbData++;
    iBlockIdx++;
    if (iTbData < nTbData) {
      pTbData = (STbData *)taosArrayGetP(pMemTable->aTbData, iTbData);
    } else {
      pTbData = NULL;
    }
    if (iBlockIdx < nBlockIdx) {
      pBlockIdx = &blockIdx;
      code = tMapDataGetItemByIdx(&pCommitter->oBlockIdx, iBlockIdx, pBlockIdx, tGetBlockIdx);
      if (code) goto _err;
    } else {
      pBlockIdx = NULL;
    }
    continue;
  }

  return code;

_err:
  tsdbError("vgId:%d commit file data impl failed since %s", TD_VID(pTsdb->pVnode), tstrerror(code));
  return code;
}

static int32_t tsdbCommitFileDataEnd(SCommitter *pCommitter) {
  int32_t code = 0;

  // write blockIdx
  code = tsdbWriteBlockIdx(pCommitter->pWriter, &pCommitter->nBlockIdx, NULL);
  if (code) goto _err;

  // update file header
  code = tsdbUpdateDFileSetHeader(pCommitter->pWriter, NULL);
  if (code) goto _err;

  // close and sync
  code = tsdbDataFWriterClose(pCommitter->pWriter, 1);
  if (code) goto _err;

  if (pCommitter->pReader) {
    code = tsdbDataFReaderClose(pCommitter->pReader);
    goto _err;
  }

_exit:
  return code;

_err:
  tsdbError("vgId:%d commit file data end failed since %s", TD_VID(pCommitter->pTsdb->pVnode), tstrerror(code));
  return code;
}

static int32_t tsdbCommitFileData(SCommitter *pCommitter) {
  int32_t code = 0;

  // commit file data start
  code = tsdbCommitFileDataStart(pCommitter);
  if (code) {
    goto _err;
  }

  // commit file data impl
  code = tsdbCommitFileDataImpl(pCommitter);
  if (code) {
    goto _err;
  }

  // commit file data end
  code = tsdbCommitFileDataEnd(pCommitter);
  if (code) {
    goto _err;
  }

  return code;

_err:
  return code;
}

// ----------------------------------------------------------------------------
static int32_t tsdbStartCommit(STsdb *pTsdb, SCommitter *pCommitter) {
  int32_t code = 0;

  memset(pCommitter, 0, sizeof(*pCommitter));
  ASSERT(pTsdb->mem && pTsdb->imem == NULL);
  // lock();
  pTsdb->imem = pTsdb->mem;
  pTsdb->mem = NULL;
  // unlock();

  pCommitter->pTsdb = pTsdb;

  return code;
}

static int32_t tsdbCommitData(SCommitter *pCommitter) {
  int32_t    code = 0;
  STsdb     *pTsdb = pCommitter->pTsdb;
  SMemTable *pMemTable = pTsdb->imem;

  // check
  if (pMemTable->nRow == 0) goto _exit;

  // loop
  pCommitter->nextKey = pMemTable->minKey.ts;
  while (pCommitter->nextKey < TSKEY_MAX) {
    pCommitter->commitFid = tsdbKeyFid(pCommitter->nextKey, pCommitter->minutes, pCommitter->precision);
    tsdbFidKeyRange(pCommitter->commitFid, pCommitter->minutes, pCommitter->precision, &pCommitter->minKey,
                    &pCommitter->maxKey);
    code = tsdbCommitFileData(pCommitter);
    if (code) goto _err;
  }

_exit:
  tsdbDebug("vgId:%d commit data done, nRow:%" PRId64, TD_VID(pTsdb->pVnode), pMemTable->nRow);
  return code;

_err:
  tsdbError("vgId:%d commit data failed since %s", TD_VID(pTsdb->pVnode), tstrerror(code));
  return code;
}

static int32_t tsdbCommitDel(SCommitter *pCommitter) {
  int32_t    code = 0;
  STsdb     *pTsdb = pCommitter->pTsdb;
  SMemTable *pMemTable = pTsdb->imem;

  if (pMemTable->nDel == 0) {
    goto _exit;
  }

  // start
  code = tsdbCommitDelStart(pCommitter);
  if (code) {
    goto _err;
  }

  // impl
  code = tsdbCommitDelImpl(pCommitter);
  if (code) {
    goto _err;
  }

  // end
  code = tsdbCommitDelEnd(pCommitter);
  if (code) {
    goto _err;
  }

_exit:
  tsdbDebug("vgId:%d commit del done, nDel:%" PRId64, TD_VID(pTsdb->pVnode), pMemTable->nDel);
  return code;

_err:
  tsdbError("vgId:%d commit del failed since %s", TD_VID(pTsdb->pVnode), tstrerror(code));
  return code;
}

static int32_t tsdbCommitCache(SCommitter *pCommitter) {
  int32_t code = 0;
  // TODO
  return code;
}

static int32_t tsdbEndCommit(SCommitter *pCommitter, int32_t eno) {
  int32_t code = 0;
  // TODO
  return code;
}