#include "os.h"
#include "tutil.h"

#include "tname.h"
#include "tstoken.h"
#include "ttokendef.h"

// todo refactor
__attribute__((unused)) static FORCE_INLINE const char* skipSegments(const char* input, char delim, int32_t num) {
  for (int32_t i = 0; i < num; ++i) {
    while (*input != 0 && *input++ != delim) {
    };
  }
  return input;
}

__attribute__((unused)) static FORCE_INLINE size_t copy(char* dst, const char* src, char delimiter) {
  size_t len = 0;
  while (*src != delimiter && *src != 0) {
    *dst++ = *src++;
    len++;
  }
  
  return len;
}

void extractTableName(const char* tableId, char* name) {
  size_t s1 = strcspn(tableId, &TS_PATH_DELIMITER[0]);
  size_t s2 = strcspn(&tableId[s1 + 1], &TS_PATH_DELIMITER[0]);
  
  tstrncpy(name, &tableId[s1 + s2 + 2], TSDB_TABLE_NAME_LEN);
}

char* extractDBName(const char* tableId, char* name) {
  size_t offset1 = strcspn(tableId, &TS_PATH_DELIMITER[0]);
  size_t len = strcspn(&tableId[offset1 + 1], &TS_PATH_DELIMITER[0]);
  
  return strncpy(name, &tableId[offset1 + 1], len);
}

SSchema tGetTableNameColumnSchema() {
  SSchema s = {0};
  s.bytes = TSDB_TABLE_NAME_LEN - 1 + VARSTR_HEADER_SIZE;
  s.type  = TSDB_DATA_TYPE_BINARY;
  s.colId = TSDB_TBNAME_COLUMN_INDEX;
  strncpy(s.name, TSQL_TBNAME_L, TSDB_COL_NAME_LEN);
  return s;
}

bool tscValidateTableNameLength(size_t len) {
  return len < TSDB_TABLE_NAME_LEN;
}

SColumnFilterInfo* tscFilterInfoClone(const SColumnFilterInfo* src, int32_t numOfFilters) {
  if (numOfFilters == 0) {
    assert(src == NULL);
    return NULL;
  }

  SColumnFilterInfo* pFilter = calloc(1, numOfFilters * sizeof(SColumnFilterInfo));

  memcpy(pFilter, src, sizeof(SColumnFilterInfo) * numOfFilters);
  for (int32_t j = 0; j < numOfFilters; ++j) {

    if (pFilter[j].filterstr) {
      size_t len = (size_t) pFilter[j].len + 1 * TSDB_NCHAR_SIZE;
      pFilter[j].pz = (int64_t) calloc(1, len);

      memcpy((char*)pFilter[j].pz, (char*)src[j].pz, (size_t)len);
    }
  }

  assert(src->filterstr == 0 || src->filterstr == 1);
  assert(!(src->lowerRelOptr == TSDB_RELATION_INVALID && src->upperRelOptr == TSDB_RELATION_INVALID));

  return pFilter;
}

int64_t taosGetIntervalStartTimestamp(int64_t startTime, int64_t slidingTime, int64_t intervalTime, char timeUnit, int16_t precision) {
  if (slidingTime == 0) {
    return startTime;
  }

  int64_t start = ((startTime - intervalTime) / slidingTime + 1) * slidingTime;
  if (!(timeUnit == 'u' || timeUnit == 'a' || timeUnit == 'm' || timeUnit == 's' || timeUnit == 'h')) {
    /*
     * here we revised the start time of day according to the local time zone,
     * but in case of DST, the start time of one day need to be dynamically decided.
     */
    // todo refactor to extract function that is available for Linux/Windows/Mac platform
#if defined(WINDOWS) && _MSC_VER >= 1900
    // see https://docs.microsoft.com/en-us/cpp/c-runtime-library/daylight-dstbias-timezone-and-tzname?view=vs-2019
    int64_t timezone = _timezone;
    int32_t daylight = _daylight;
    char**  tzname = _tzname;
#endif

    int64_t t = (precision == TSDB_TIME_PRECISION_MILLI) ? MILLISECOND_PER_SECOND : MILLISECOND_PER_SECOND * 1000L;
    start += timezone * t;
  }

  int64_t end = start + intervalTime - 1;
  if (end < startTime) {
    start += slidingTime;
  }
  return start;
}

/*
 * tablePrefix.columnName
 * extract table name and save it in pTable, with only column name in pToken
 */
void extractTableNameFromToken(SSQLToken* pToken, SSQLToken* pTable) {
  const char sep = TS_PATH_DELIMITER[0];

  if (pToken == pTable || pToken == NULL || pTable == NULL) {
    return;
  }

  char* r = strnchr(pToken->z, sep, pToken->n, false);

  if (r != NULL) {  // record the table name token
    pTable->n = r - pToken->z;
    pTable->z = pToken->z;

    r += 1;
    pToken->n -= (r - pToken->z);
    pToken->z = r;
  }
}
