/*
 * 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"

#define TSDB_FHDR_SIZE 512
#define TSDB_FILE_DLMT ((uint32_t)0xF00AFA0F)

// SDelFWriter ====================================================
struct SDelFWriter {
  STsdb    *pTsdb;
  SDelFile *pFile;
  TdFilePtr pWriteH;
};

int32_t tsdbDelFWriterOpen(SDelFWriter **ppWriter, SDelFile *pFile, STsdb *pTsdb) {
  int32_t      code = 0;
  char        *fname = NULL;  // TODO
  SDelFWriter *pDelFWriter;

  pDelFWriter = (SDelFWriter *)taosMemoryCalloc(1, sizeof(*pDelFWriter));
  if (pDelFWriter == NULL) {
    code = TSDB_CODE_OUT_OF_MEMORY;
    goto _err;
  }

  pDelFWriter->pTsdb = pTsdb;
  pDelFWriter->pFile = pFile;
  pDelFWriter->pWriteH = taosOpenFile(fname, TD_FILE_WRITE | TD_FILE_CREATE);
  if (pDelFWriter->pWriteH == NULL) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  if (taosLSeekFile(pDelFWriter->pWriteH, TSDB_FHDR_SIZE, SEEK_SET) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  pDelFWriter->pFile->size = TSDB_FHDR_SIZE;
  pDelFWriter->pFile->offset = 0;

  return code;

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

int32_t tsdbDelFWriterClose(SDelFWriter *pWriter, int8_t sync) {
  int32_t code = 0;

  // sync
  if (sync && taosFsyncFile(pWriter->pWriteH) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  // close
  if (taosCloseFile(&pWriter->pWriteH) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  return code;

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

int32_t tsdbWriteDelData(SDelFWriter *pWriter, SMapData *pDelDataMap, uint8_t **ppBuf, SDelIdx *pDelIdx) {
  int32_t  code = 0;
  uint8_t *pBuf = NULL;
  int64_t  size = 0;
  int64_t  n = 0;

  // prepare
  size += tPutU32(NULL, TSDB_FILE_DLMT);
  size += tPutI64(NULL, pDelIdx->suid);
  size += tPutI64(NULL, pDelIdx->uid);
  size = size + tPutMapData(NULL, pDelDataMap) + sizeof(TSCKSUM);

  // alloc
  if (!ppBuf) ppBuf = &pBuf;
  code = tsdbRealloc(ppBuf, size);
  if (code) goto _err;

  // build
  n += tPutU32(*ppBuf + n, TSDB_FILE_DLMT);
  n += tPutI64(*ppBuf + n, pDelIdx->suid);
  n += tPutI64(*ppBuf + n, pDelIdx->uid);
  n += tPutMapData(*ppBuf + n, pDelDataMap);
  taosCalcChecksumAppend(0, *ppBuf, size);

  ASSERT(n + sizeof(TSCKSUM) == size);

  // write
  n = taosWriteFile(pWriter->pWriteH, *ppBuf, size);
  if (n < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  ASSERT(n == size);

  // update
  pDelIdx->offset = pWriter->pFile->size;
  pDelIdx->size = size;
  pWriter->pFile->offset = pWriter->pFile->size;
  pWriter->pFile->size += size;

  tsdbFree(pBuf);
  return code;

_err:
  tsdbError("vgId:%d failed to write del data since %s", TD_VID(pWriter->pTsdb->pVnode), tstrerror(code));
  tsdbFree(pBuf);
  return code;
}

int32_t tsdbWriteDelIdx(SDelFWriter *pWriter, SMapData *pDelIdxMap, uint8_t **ppBuf) {
  int32_t  code = 0;
  int64_t  size = 0;
  int64_t  n = 0;
  uint8_t *pBuf = NULL;

  // prepare
  size += tPutU32(NULL, TSDB_FILE_DLMT);
  size = size + tPutMapData(NULL, pDelIdxMap) + sizeof(TSCKSUM);

  // alloc
  if (!ppBuf) ppBuf = &pBuf;
  code = tsdbRealloc(ppBuf, size);
  if (code) goto _err;

  // build
  n += tPutU32(*ppBuf + n, TSDB_FILE_DLMT);
  n += tPutMapData(*ppBuf + n, pDelIdxMap);
  taosCalcChecksumAppend(0, *ppBuf, size);

  ASSERT(n + sizeof(TSCKSUM) == size);

  // write
  n = taosWriteFile(pWriter->pWriteH, *ppBuf, size);
  if (n < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  ASSERT(n == size);

  // update
  pWriter->pFile->offset = pWriter->pFile->size;
  pWriter->pFile->size += size;

  tsdbFree(pBuf);
  return code;

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

int32_t tsdbUpdateDelFileHdr(SDelFWriter *pWriter, uint8_t **ppBuf) {
  int32_t  code = 0;
  uint8_t *pBuf = NULL;
  int64_t  size = TSDB_FHDR_SIZE;
  int64_t  n;

  // alloc
  if (!ppBuf) ppBuf = &pBuf;
  code = tsdbRealloc(ppBuf, size);
  if (code) goto _err;

  // build
  memset(*ppBuf, 0, size);
  n = tPutDelFileHdr(*ppBuf, pWriter->pFile);
  taosCalcChecksumAppend(0, *ppBuf, size);

  ASSERT(n <= size - sizeof(TSCKSUM));

  // seek
  if (taosLSeekFile(pWriter->pWriteH, 0, SEEK_SET) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  // write
  if (taosWriteFile(pWriter->pWriteH, *ppBuf, size) < size) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  tsdbFree(pBuf);
  return code;

_err:
  tsdbError("vgId:%d update del file hdr failed since %s", TD_VID(pWriter->pTsdb->pVnode), tstrerror(code));
  tsdbFree(pBuf);
  return code;
}

// SDelFReader ====================================================
struct SDelFReader {
  STsdb    *pTsdb;
  SDelFile *pFile;
  TdFilePtr pReadH;
};

int32_t tsdbDelFReaderOpen(SDelFReader **ppReader, SDelFile *pFile, STsdb *pTsdb, uint8_t **ppBuf) {
  int32_t      code = 0;
  char        *fname = NULL;  // todo
  SDelFReader *pDelFReader;
  int64_t      n;

  // alloc
  pDelFReader = (SDelFReader *)taosMemoryCalloc(1, sizeof(*pDelFReader));
  if (pDelFReader == NULL) {
    code = TSDB_CODE_OUT_OF_MEMORY;
    goto _err;
  }

  // open impl
  pDelFReader->pTsdb = pTsdb;
  pDelFReader->pFile = pFile;
  pDelFReader->pReadH = taosOpenFile(fname, TD_FILE_READ);
  if (pDelFReader == NULL) {
    code = TAOS_SYSTEM_ERROR(errno);
    taosMemoryFree(pDelFReader);
    goto _err;
  }

  // load and check hdr if buffer is given
  if (ppBuf) {
    code = tsdbRealloc(ppBuf, TSDB_FHDR_SIZE);
    if (code) {
      goto _err;
    }

    n = taosReadFile(pDelFReader->pReadH, *ppBuf, TSDB_FHDR_SIZE);
    if (n < 0) {
      code = TAOS_SYSTEM_ERROR(errno);
      goto _err;
    } else if (n < TSDB_FHDR_SIZE) {
      code = TSDB_CODE_FILE_CORRUPTED;
      goto _err;
    }

    if (!taosCheckChecksumWhole(*ppBuf, TSDB_FHDR_SIZE)) {
      code = TSDB_CODE_FILE_CORRUPTED;
      goto _err;
    }

    // TODO: check the content
  }

_exit:
  *ppReader = pDelFReader;
  return code;

_err:
  tsdbError("vgId:%d del file reader open failed since %s", TD_VID(pTsdb->pVnode), tstrerror(code));
  *ppReader = NULL;
  return code;
}

int32_t tsdbDelFReaderClose(SDelFReader *pReader) {
  int32_t code = 0;

  if (pReader) {
    if (taosCloseFile(&pReader->pReadH) < 0) {
      code = TAOS_SYSTEM_ERROR(errno);
      goto _exit;
    }
    taosMemoryFree(pReader);
  }

_exit:
  return code;
}

int32_t tsdbReadDelData(SDelFReader *pReader, SDelIdx *pDelIdx, SMapData *pDelDataMap, uint8_t **ppBuf) {
  int32_t  code = 0;
  int64_t  n;
  uint32_t delimiter;
  tb_uid_t suid;
  tb_uid_t uid;

  // seek
  if (taosLSeekFile(pReader->pReadH, pDelIdx->offset, SEEK_SET) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  // alloc
  if (!ppBuf) ppBuf = &pDelDataMap->pBuf;
  code = tsdbRealloc(ppBuf, pDelIdx->size);
  if (code) goto _err;

  // read
  n = taosReadFile(pReader->pReadH, *ppBuf, pDelIdx->size);
  if (n < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  } else if (n < pDelIdx->size) {
    code = TSDB_CODE_FILE_CORRUPTED;
    goto _err;
  }

  // check
  if (!taosCheckChecksumWhole(*ppBuf, pDelIdx->size)) {
    code = TSDB_CODE_FILE_CORRUPTED;
    goto _err;
  }

  // // decode
  n = 0;
  n += tGetU32(*ppBuf + n, &delimiter);
  ASSERT(delimiter == TSDB_FILE_DLMT);
  n += tGetI64(*ppBuf + n, &suid);
  ASSERT(suid == pDelIdx->suid);
  n += tGetI64(*ppBuf + n, &uid);
  ASSERT(uid == pDelIdx->uid);
  n += tGetMapData(*ppBuf + n, pDelDataMap);
  ASSERT(n + sizeof(TSCKSUM) == pDelIdx->size);

  return code;

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

int32_t tsdbReadDelIdx(SDelFReader *pReader, SMapData *pDelIdxMap, uint8_t **ppBuf) {
  int32_t  code = 0;
  int32_t  n;
  int64_t  offset = pReader->pFile->offset;
  int64_t  size = pReader->pFile->size - offset;
  uint32_t delimiter;

  ASSERT(ppBuf && *ppBuf);

  // seek
  if (taosLSeekFile(pReader->pReadH, offset, SEEK_SET) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  // alloc
  if (!ppBuf) ppBuf = &pDelIdxMap->pBuf;
  code = tsdbRealloc(ppBuf, size);
  if (code) goto _err;

  // read
  n = taosReadFile(pReader->pReadH, *ppBuf, size);
  if (n < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  } else if (n < size) {
    code = TSDB_CODE_FILE_CORRUPTED;
    goto _err;
  }

  // check
  if (!taosCheckChecksumWhole(*ppBuf, size)) {
    code = TSDB_CODE_FILE_CORRUPTED;
    goto _err;
  }

  // decode
  n = 0;
  n += tGetU32(*ppBuf + n, &delimiter);
  ASSERT(delimiter == TSDB_FILE_DLMT);
  n += tGetMapData(*ppBuf + n, pDelIdxMap);
  ASSERT(n + sizeof(TSCKSUM) == size);

  return code;

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

// SDataFReader ====================================================
struct SDataFReader {
  STsdb     *pTsdb;
  SDFileSet *pSet;
  TdFilePtr  pHeadFD;
  TdFilePtr  pDataFD;
  TdFilePtr  pLastFD;
  TdFilePtr  pSmaFD;
};

int32_t tsdbDataFReaderOpen(SDataFReader **ppReader, STsdb *pTsdb, SDFileSet *pSet) {
  int32_t code = 0;
  // TODO
  return code;
}

int32_t tsdbDataFReaderClose(SDataFReader *pReader) {
  int32_t code = 0;

  if (taosCloseFile(&pReader->pHeadFD) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  if (taosCloseFile(&pReader->pDataFD) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  if (taosCloseFile(&pReader->pLastFD) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  if (taosCloseFile(&pReader->pSmaFD) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  return code;

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

int32_t tsdbReadBlockIdx(SDataFReader *pReader, SMapData *pMapData, uint8_t **ppBuf) {
  int32_t  code = 0;
  int64_t  offset = -1;  // TODO
  int64_t  size = -1;    // TODO
  int64_t  n;
  uint32_t delimiter;

  // alloc
  if (!ppBuf) ppBuf = &pMapData->pBuf;
  code = tsdbRealloc(ppBuf, size);
  if (code) goto _err;

  // seek
  if (taosLSeekFile(pReader->pHeadFD, offset, SEEK_SET) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  // read
  n = taosReadFile(pReader->pHeadFD, *ppBuf, size);
  if (n < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  } else if (n < size) {
    code = TSDB_CODE_FILE_CORRUPTED;
    goto _err;
  }

  // check
  if (!taosCheckChecksumWhole(*ppBuf, size)) {
    code = TSDB_CODE_FILE_CORRUPTED;
    goto _err;
  }

  // decode
  n = 0;
  n += tGetU32(*ppBuf + n, &delimiter);
  ASSERT(delimiter == TSDB_FILE_DLMT);
  n += tGetMapData(*ppBuf + n, pMapData);
  ASSERT(n + sizeof(TSCKSUM) == size);

  return code;

_err:
  tsdbError("vgId:%d read block idx failed since %s", TD_VID(pReader->pTsdb->pVnode), tstrerror(code));
  return code;
}

int32_t tsdbReadBlock(SDataFReader *pReader, SBlockIdx *pBlockIdx, SMapData *pMapData, uint8_t **ppBuf) {
  int32_t  code = 0;
  int64_t  offset = pBlockIdx->offset;
  int64_t  size = pBlockIdx->size;
  int64_t  n;
  uint32_t delimiter;
  tb_uid_t suid;
  tb_uid_t uid;

  // alloc
  if (!ppBuf) ppBuf = &pMapData->pBuf;
  code = tsdbRealloc(ppBuf, size);
  if (code) goto _err;

  // seek
  if (taosLSeekFile(pReader->pHeadFD, offset, SEEK_SET) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  // read
  n = taosReadFile(pReader->pHeadFD, *ppBuf, size);
  if (n < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  } else if (n < size) {
    code = TSDB_CODE_FILE_CORRUPTED;
    goto _err;
  }

  // check
  if (!taosCheckChecksumWhole(*ppBuf, size)) {
    code = TSDB_CODE_FILE_CORRUPTED;
    goto _err;
  }

  // decode
  n = 0;
  n += tGetU32(*ppBuf + n, &delimiter);
  ASSERT(delimiter == TSDB_FILE_DLMT);
  n += tGetI64(*ppBuf + n, &suid);
  ASSERT(suid == pBlockIdx->suid);
  n += tGetI64(*ppBuf + n, &uid);
  ASSERT(uid == pBlockIdx->uid);
  n += tGetMapData(*ppBuf + n, pMapData);
  ASSERT(n + sizeof(TSCKSUM) == size);

  return code;

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

int32_t tsdbReadBlockData(SDataFReader *pReader, SBlock *pBlock, SColDataBlock *pBlockData, uint8_t **ppBuf) {
  int32_t code = 0;
  // TODO
  return code;
}

int32_t tsdbReadBlockSMA(SDataFReader *pReader, SBlockSMA *pBlkSMA) {
  int32_t code = 0;
  // TODO
  return code;
}

// SDataFWriter ====================================================
struct SDataFWriter {
  STsdb     *pTsdb;
  SDFileSet *pSet;
  TdFilePtr  pHeadFD;
  TdFilePtr  pDataFD;
  TdFilePtr  pLastFD;
  TdFilePtr  pSmaFD;
};

int32_t tsdbDataFWriterOpen(SDataFWriter **ppWriter, STsdb *pTsdb, SDFileSet *pSet) {
  int32_t code = 0;
  // TODO
  return code;
}

int32_t tsdbDataFWriterClose(SDataFWriter *pWriter, int8_t sync) {
  int32_t code = 0;

  if (sync) {
    if (taosFsyncFile(pWriter->pHeadFD) < 0) {
      code = TAOS_SYSTEM_ERROR(errno);
      goto _err;
    }

    if (taosFsyncFile(pWriter->pDataFD) < 0) {
      code = TAOS_SYSTEM_ERROR(errno);
      goto _err;
    }

    if (taosFsyncFile(pWriter->pLastFD) < 0) {
      code = TAOS_SYSTEM_ERROR(errno);
      goto _err;
    }

    if (taosFsyncFile(pWriter->pSmaFD) < 0) {
      code = TAOS_SYSTEM_ERROR(errno);
      goto _err;
    }
  }

  if (taosCloseFile(&pWriter->pHeadFD) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  if (taosCloseFile(&pWriter->pDataFD) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  if (taosCloseFile(&pWriter->pLastFD) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  if (taosCloseFile(&pWriter->pSmaFD) < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  return code;

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

int32_t tsdbUpdateDFileSetHeader(SDataFWriter *pWriter, uint8_t **ppBuf) {
  int32_t code = 0;
  // TODO
  return code;
}

int32_t tsdbWriteBlockIdx(SDataFWriter *pWriter, SMapData *pBlockIdxMap, uint8_t **ppBuf) {
  int32_t  code = 0;
  int64_t  size = 0;
  int64_t  n = 0;
  uint8_t *pBuf = NULL;

  // prepare
  size += tPutU32(NULL, TSDB_FILE_DLMT);
  size = size + tPutMapData(NULL, pBlockIdxMap) + sizeof(TSCKSUM);

  // alloc
  if (!ppBuf) ppBuf = &pBuf;
  code = tsdbRealloc(ppBuf, size);
  if (code) goto _err;

  // build
  n += tPutU32(*ppBuf + n, TSDB_FILE_DLMT);
  n += tPutMapData(*ppBuf, pBlockIdxMap);
  taosCalcChecksumAppend(0, *ppBuf, size);

  ASSERT(n + sizeof(TSCKSUM) == size);

  // write
  n = taosWriteFile(pWriter->pHeadFD, *ppBuf, size);
  if (n < 0) {
    code = TAOS_SYSTEM_ERROR(errno);
    goto _err;
  }

  // update (todo)

  tsdbFree(pBuf);
  return code;

_err:
  tsdbError("vgId:%d write block idx failed since %s", TD_VID(pWriter->pTsdb->pVnode), tstrerror(code));
  tsdbFree(pBuf);
  return code;
}

int32_t tsdbWriteBlock(SDataFWriter *pWriter, SMapData *pMapData, uint8_t **ppBuf, SBlockIdx *pBlockIdx) {
  int32_t code = 0;
  // TODO
  return code;
}

int32_t tsdbWriteBlockData(SDataFWriter *pWriter, SColDataBlock *pBlockData, uint8_t **ppBuf, int64_t *rOffset,
                           int64_t *rSize) {
  int32_t code = 0;
  // TODO
  return code;
}

int32_t tsdbWriteBlockSMA(SDataFWriter *pWriter, SBlockSMA *pBlockSMA, int64_t *rOffset, int64_t *rSize) {
  int32_t code = 0;
  // TODO
  return code;
}