/* c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil
 * vi: set shiftwidth=4 tabstop=4 expandtab:
 *  :indentSize=4:tabSize=4:noTabs=true:
 *
 * Copyright (C) 2016 MariaDB Corporation
 *
 * This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 2 of
 * the License.
 *
 * 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.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 */

#define PREFER_MY_CONFIG_H
#include "idb_mysql.h"
#include <vector>
#include <limits>

#include "dbrm.h"
#include "objectidmanager.h"
#include "is_columnstore.h"
#include "mcs_decimal.h"
#include "dataconvert.h"

// Required declaration as it isn't in a MairaDB include
bool schema_table_store_record(THD* thd, TABLE* table);

ST_FIELD_INFO is_columnstore_extents_fields[] = {
    Show::Column("OBJECT_ID", Show::ULong(0), NOT_NULL),                // 0
    Show::Column("OBJECT_TYPE", Show::Varchar(64), NOT_NULL),           // 1
    Show::Column("LOGICAL_BLOCK_START", Show::SLonglong(0), NOT_NULL),  // 2
    Show::Column("LOGICAL_BLOCK_END", Show::SLonglong(0), NOT_NULL),    // 3
    // length=3800 here because sql/sql_i_s.h sets
    // decimal_precision() as (length / 100) % 100). Not sure why.
    Show::Column("MIN_VALUE", Show::Decimal(3800), NULLABLE),   // 4
    Show::Column("MAX_VALUE", Show::Decimal(3800), NULLABLE),   // 5
    Show::Column("WIDTH", Show::ULong(0), NOT_NULL),            // 6
    Show::Column("DBROOT", Show::ULong(0), NOT_NULL),           // 7
    Show::Column("PARTITION_ID", Show::ULong(0), NOT_NULL),     // 8
    Show::Column("SEGMENT_ID", Show::ULong(0), NOT_NULL),       // 9
    Show::Column("BLOCK_OFFSET", Show::ULong(0), NOT_NULL),     // 10
    Show::Column("MAX_BLOCKS", Show::ULong(0), NOT_NULL),       // 11
    Show::Column("HIGH_WATER_MARK", Show::ULong(0), NOT_NULL),  // 12
    Show::Column("STATE", Show::Varchar(64), NOT_NULL),         // 13
    Show::Column("STATUS", Show::Varchar(64), NOT_NULL),        // 14
    Show::Column("DATA_SIZE", Show::ULonglong(0), NOT_NULL),    // 15
    Show::CEnd()};

static int generate_result(BRM::OID_t oid, BRM::DBRM* emp, TABLE* table, THD* thd)
{
  CHARSET_INFO* cs = system_charset_info;
  std::vector<struct BRM::EMEntry> entries;
  std::vector<struct BRM::EMEntry>::iterator iter;
  std::vector<struct BRM::EMEntry>::iterator end;

  emp->getExtents(oid, entries, false, false, true);

  if (entries.size() == 0)
    return 0;

  iter = entries.begin();
  end = entries.end();

  while (iter != end)
  {
    table->field[0]->store(oid);

    if (iter->colWid > 0)
    {
      table->field[1]->store("Column", strlen("Column"), cs);

      if (iter->colWid != datatypes::MAXDECIMALWIDTH)
      {
        if (iter->partition.cprange.loVal == std::numeric_limits<int64_t>::max() ||
            iter->partition.cprange.loVal <= (std::numeric_limits<int64_t>::min() + 1))
        {
          table->field[4]->set_null();
        }
        else
        {
          table->field[4]->set_notnull();
          table->field[4]->store((longlong)iter->partition.cprange.loVal, false);
        }

        if (iter->partition.cprange.hiVal <= (std::numeric_limits<int64_t>::min() + 1))
        {
          table->field[5]->set_null();
        }
        else
        {
          table->field[5]->set_notnull();
          table->field[5]->store((longlong)iter->partition.cprange.hiVal, false);
        }
      }
      else
      {
        if (iter->partition.cprange.bigLoVal == utils::maxInt128 ||
            iter->partition.cprange.bigLoVal <= (utils::minInt128 + 1))
        {
          table->field[4]->set_null();
        }
        else
        {
          table->field[4]->set_notnull();
          std::string decAsAStr = datatypes::TSInt128(iter->partition.cprange.bigLoVal).toString();
          table->field[4]->store(decAsAStr.c_str(), decAsAStr.length(), table->field[4]->charset());
        }

        if (iter->partition.cprange.bigHiVal <= (utils::minInt128 + 1))
        {
          table->field[5]->set_null();
        }
        else
        {
          table->field[5]->set_notnull();
          std::string decAsAStr = datatypes::TSInt128(iter->partition.cprange.bigHiVal).toString();
          table->field[5]->store(decAsAStr.c_str(), decAsAStr.length(), table->field[5]->charset());
        }
      }

      table->field[6]->store(iter->colWid);
    }
    else
    {
      table->field[1]->store("Dictionary", strlen("Dictionary"), cs);
      table->field[4]->set_null();
      table->field[5]->set_null();
      table->field[6]->store(8192);
    }

    table->field[2]->store(iter->range.start);
    table->field[3]->store(iter->range.start + (iter->range.size * 1024) - 1);

    table->field[7]->store(iter->dbRoot);
    table->field[8]->store(iter->partitionNum);
    table->field[9]->store(iter->segmentNum);
    table->field[10]->store(iter->blockOffset);
    table->field[11]->store(iter->range.size * 1024);
    table->field[12]->store(iter->HWM);

    switch (iter->partition.cprange.isValid)
    {
      case 0: table->field[13]->store("Invalid", strlen("Invalid"), cs); break;

      case 1: table->field[13]->store("Updating", strlen("Updating"), cs); break;

      case 2: table->field[13]->store("Valid", strlen("Valid"), cs); break;

      default: table->field[13]->store("Unknown", strlen("Unknown"), cs); break;
    }

    switch (iter->status)
    {
      case BRM::EXTENTAVAILABLE: table->field[14]->store("Available", strlen("Available"), cs); break;

      case BRM::EXTENTUNAVAILABLE: table->field[14]->store("Unavailable", strlen("Unavailable"), cs); break;

      case BRM::EXTENTOUTOFSERVICE:
        table->field[14]->store("Out of service", strlen("Out of service"), cs);
        break;

      default: table->field[14]->store("Unknown", strlen("Unknown"), cs);
    }

    // MCOL-1016: on multiple segments HWM is set to 0 on the lower
    // segments, we don't want these to show as 8KB. The down side is
    // if the column has less than 1 block it will show as 0 bytes.
    // We have no lookahead without it getting messy so this is the
    // best compromise.
    if (iter->HWM == 0)
    {
      table->field[15]->store(0);
    }
    else
    {
      table->field[15]->store((iter->HWM + 1) * 8192);
    }

    if (schema_table_store_record(thd, table))
    {
      delete emp;
      return 1;
    }

    iter++;
  }

  return 0;
}

static int is_columnstore_extents_fill(THD* thd, TABLE_LIST* tables, COND* cond)
{
  BRM::OID_t cond_oid = 0;
  TABLE* table = tables->table;

  BRM::DBRM::refreshShm();
  BRM::DBRM* emp = new BRM::DBRM();

  if (!emp || !emp->isDBRMReady())
  {
    return 1;
  }

  if (cond && cond->type() == Item::FUNC_ITEM)
  {
    Item_func* fitem = (Item_func*)cond;

    if ((fitem->functype() == Item_func::EQ_FUNC) && (fitem->argument_count() == 2))
    {
      if (fitem->arguments()[0]->real_item()->type() == Item::FIELD_ITEM &&
          fitem->arguments()[1]->const_item())
      {
        // WHERE object_id = value
        Item_field* item_field = (Item_field*)fitem->arguments()[0]->real_item();

        if (strcasecmp(item_field->field_name.str, "object_id") == 0)
        {
          cond_oid = fitem->arguments()[1]->val_int();
          return generate_result(cond_oid, emp, table, thd);
        }
      }
      else if (fitem->arguments()[1]->real_item()->type() == Item::FIELD_ITEM &&
               fitem->arguments()[0]->const_item())
      {
        // WHERE value = object_id
        Item_field* item_field = (Item_field*)fitem->arguments()[1]->real_item();

        if (strcasecmp(item_field->field_name.str, "object_id") == 0)
        {
          cond_oid = fitem->arguments()[0]->val_int();
          return generate_result(cond_oid, emp, table, thd);
        }
      }
    }
    else if (fitem->functype() == Item_func::IN_FUNC)
    {
      // WHERE object_id in (value1, value2)
      Item_field* item_field = (Item_field*)fitem->arguments()[0]->real_item();

      if (strcasecmp(item_field->field_name.str, "object_id") == 0)
      {
        for (unsigned int i = 1; i < fitem->argument_count(); i++)
        {
          cond_oid = fitem->arguments()[i]->val_int();
          int result = generate_result(cond_oid, emp, table, thd);

          if (result)
            return 1;
        }
      }
    }
    else if (fitem->functype() == Item_func::UNKNOWN_FUNC &&
             strcasecmp(fitem->func_name(), "find_in_set") == 0)
    {
      // WHERE FIND_IN_SET(object_id, values)
      String* tmp_var = fitem->arguments()[1]->val_str();
      std::stringstream ss(tmp_var->ptr());

      while (ss >> cond_oid)
      {
        int ret = generate_result(cond_oid, emp, table, thd);

        if (ret)
          return 1;

        if (ss.peek() == ',')
          ss.ignore();
      }
    }
  }

  execplan::ObjectIDManager oidm;
  BRM::OID_t MaxOID = oidm.size();

  for (BRM::OID_t oid = 3000; oid <= MaxOID; oid++)
  {
    int result = generate_result(oid, emp, table, thd);

    if (result)
      return 1;
  }

  delete emp;
  return 0;
}

int is_columnstore_extents_plugin_init(void* p)
{
  ST_SCHEMA_TABLE* schema = (ST_SCHEMA_TABLE*)p;
  schema->fields_info = is_columnstore_extents_fields;
  schema->fill_table = is_columnstore_extents_fill;
  return 0;
}