/* Copyright (c) 2010, 2023, Oracle and/or its affiliates. All rights
   reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   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, version 2.0, 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 St, Fifth Floor, Boston, MA 02110-1301  USA */

#ifndef SQL_ALTER_TABLE_H
#define SQL_ALTER_TABLE_H

#include "sql_cmd.h"  // Sql_cmd
#include "sql_list.h" // List

class Create_field;
class Item;
class Key;
class String;
struct TABLE_LIST;

/**
  Class representing DROP COLUMN, DROP KEY and DROP FOREIGN KEY
  clauses in ALTER TABLE statement.
*/

class Alter_drop :public Sql_alloc {
public:
  enum drop_type {KEY, COLUMN, FOREIGN_KEY };
  const char *name;
  enum drop_type type;
  Alter_drop(enum drop_type par_type,const char *par_name)
    :name(par_name), type(par_type)
  {
    assert(par_name != NULL);
  }
  /**
    Used to make a clone of this object for ALTER/CREATE TABLE
    @sa comment for Key_part_spec::clone
  */
  Alter_drop *clone(MEM_ROOT *mem_root) const
    { return new (mem_root) Alter_drop(*this); }
};


/**
  Class representing SET DEFAULT and DROP DEFAULT clauses in
  ALTER TABLE statement.
*/

class Alter_column :public Sql_alloc {
public:
  const char *name;
  Item *def;
  Alter_column(const char *par_name,Item *literal)
    :name(par_name), def(literal) {}
  /**
    Used to make a clone of this object for ALTER/CREATE TABLE
    @sa comment for Key_part_spec::clone
  */
  Alter_column *clone(MEM_ROOT *mem_root) const
    { return new (mem_root) Alter_column(*this); }
};


/**
  Class which instances represent RENAME INDEX clauses in
  ALTER TABLE statement.
*/

class Alter_rename_key :public Sql_alloc {
public:
  const char *old_name;
  const char *new_name;

  Alter_rename_key(const char *old_name_arg, const char *new_name_arg)
    : old_name(old_name_arg), new_name(new_name_arg)
  { }

  /**
    Used to make a clone of this object for ALTER/CREATE TABLE
    @sa comment for Key_part_spec::clone
  */
  Alter_rename_key *clone(MEM_ROOT *mem_root) const
  { return new (mem_root) Alter_rename_key(*this); }
};


/**
  Data describing the table being created by CREATE TABLE or
  altered by ALTER TABLE.
*/

class Alter_info
{
public:
  /*
    These flags are set by the parser and describes the type of
    operation(s) specified by the ALTER TABLE statement.

    They do *not* describe the type operation(s) to be executed
    by the storage engine. For example, we don't yet know the
    type of index to be added/dropped.
  */

  // Set for ADD [COLUMN]
  static const uint ALTER_ADD_COLUMN            = 1L <<  0;

  // Set for DROP [COLUMN]
  static const uint ALTER_DROP_COLUMN           = 1L <<  1;

  // Set for CHANGE [COLUMN] | MODIFY [CHANGE]
  // Set by mysql_recreate_table()
  static const uint ALTER_CHANGE_COLUMN         = 1L <<  2;

  // Set for ADD INDEX | ADD KEY | ADD PRIMARY KEY | ADD UNIQUE KEY |
  //         ADD UNIQUE INDEX | ALTER ADD [COLUMN]
  static const uint ALTER_ADD_INDEX             = 1L <<  3;

  // Set for DROP PRIMARY KEY | DROP FOREIGN KEY | DROP KEY | DROP INDEX
  static const uint ALTER_DROP_INDEX            = 1L <<  4;

  // Set for RENAME [TO]
  static const uint ALTER_RENAME                = 1L <<  5;

  // Set for ORDER BY
  static const uint ALTER_ORDER                 = 1L <<  6;

  // Set for table_options
  static const uint ALTER_OPTIONS               = 1L <<  7;

  // Set for ALTER [COLUMN] ... SET DEFAULT ... | DROP DEFAULT
  static const uint ALTER_CHANGE_COLUMN_DEFAULT = 1L <<  8;

  // Set for DISABLE KEYS | ENABLE KEYS
  static const uint ALTER_KEYS_ONOFF            = 1L <<  9;

  // Set for FORCE
  // Set for ENGINE(same engine)
  // Set by mysql_recreate_table()
  static const uint ALTER_RECREATE              = 1L << 10;

  // Set for ADD PARTITION
  static const uint ALTER_ADD_PARTITION         = 1L << 11;

  // Set for DROP PARTITION
  static const uint ALTER_DROP_PARTITION        = 1L << 12;

  // Set for COALESCE PARTITION
  static const uint ALTER_COALESCE_PARTITION    = 1L << 13;

  // Set for REORGANIZE PARTITION ... INTO
  static const uint ALTER_REORGANIZE_PARTITION  = 1L << 14;

  // Set for partition_options
  static const uint ALTER_PARTITION             = 1L << 15;

  // Set for LOAD INDEX INTO CACHE ... PARTITION
  // Set for CACHE INDEX ... PARTITION
  static const uint ALTER_ADMIN_PARTITION       = 1L << 16;

  // Set for REORGANIZE PARTITION
  static const uint ALTER_TABLE_REORG           = 1L << 17;

  // Set for REBUILD PARTITION
  static const uint ALTER_REBUILD_PARTITION     = 1L << 18;

  // Set for partitioning operations specifying ALL keyword
  static const uint ALTER_ALL_PARTITION         = 1L << 19;

  // Set for REMOVE PARTITIONING
  static const uint ALTER_REMOVE_PARTITIONING   = 1L << 20;

  // Set for ADD FOREIGN KEY
  static const uint ADD_FOREIGN_KEY             = 1L << 21;

  // Set for DROP FOREIGN KEY
  static const uint DROP_FOREIGN_KEY            = 1L << 22;

  // Set for EXCHANGE PARITION
  static const uint ALTER_EXCHANGE_PARTITION    = 1L << 23;

  // Set by Sql_cmd_alter_table_truncate_partition::execute()
  static const uint ALTER_TRUNCATE_PARTITION    = 1L << 24;

  // Set for ADD [COLUMN] FIRST | AFTER
  static const uint ALTER_COLUMN_ORDER          = 1L << 25;

  // Set for RENAME INDEX
  static const uint ALTER_RENAME_INDEX          = 1L << 26;

  // Set for UPGRADE PARTITIONING
  static const uint ALTER_UPGRADE_PARTITIONING  = 1L << 27;

  enum enum_enable_or_disable { LEAVE_AS_IS, ENABLE, DISABLE };

  /**
     The different values of the ALGORITHM clause.
     Describes which algorithm to use when altering the table.
  */
  enum enum_alter_table_algorithm
  {
    // In-place if supported, copy otherwise.
    ALTER_TABLE_ALGORITHM_DEFAULT,

    // In-place if supported, error otherwise.
    ALTER_TABLE_ALGORITHM_INPLACE,

    // Copy if supported, error otherwise.
    ALTER_TABLE_ALGORITHM_COPY
  };


  /**
     The different values of the LOCK clause.
     Describes the level of concurrency during ALTER TABLE.
  */
  enum enum_alter_table_lock
  {
    // Maximum supported level of concurency for the given operation.
    ALTER_TABLE_LOCK_DEFAULT,

    // Allow concurrent reads & writes. If not supported, give erorr.
    ALTER_TABLE_LOCK_NONE,

    // Allow concurrent reads only. If not supported, give error.
    ALTER_TABLE_LOCK_SHARED,

    // Block reads and writes.
    ALTER_TABLE_LOCK_EXCLUSIVE
  };


  /**
    Status of validation clause in ALTER TABLE statement. Used during
    partitions and GC alterations.
  */
  enum enum_with_validation
  {
    /**
      Default value, used when it's not specified in the statement.
      Means WITH VALIDATION for partitions alterations and WITHOUT VALIDATION
      for altering virtual GC.
    */
    ALTER_VALIDATION_DEFAULT,
    ALTER_WITH_VALIDATION,
    ALTER_WITHOUT_VALIDATION
  };


  /**
     Columns and keys to be dropped.
     After mysql_prepare_alter_table() it contains only foreign keys and
     virtual generated columns to be dropped. This information is necessary
     for the storage engine to do in-place alter.
  */
  List<Alter_drop>              drop_list;
  // Columns for ALTER_COLUMN_CHANGE_DEFAULT.
  List<Alter_column>            alter_list;
  // List of keys, used by both CREATE and ALTER TABLE.
  List<Key>                     key_list;
  // Keys to be renamed.
  List<Alter_rename_key>        alter_rename_key_list;
  // List of columns, used by both CREATE and ALTER TABLE.
  List<Create_field>            create_list;
  // Type of ALTER TABLE operation.
  uint                          flags;
  // Enable or disable keys.
  enum_enable_or_disable        keys_onoff;
  // List of partitions.
  List<String>                  partition_names;
  // Number of partitions.
  uint                          num_parts;
  // Type of ALTER TABLE algorithm.
  enum_alter_table_algorithm    requested_algorithm;
  // Type of ALTER TABLE lock.
  enum_alter_table_lock         requested_lock;
  /*
    Whether VALIDATION is asked for an operation. Used during virtual GC and
    partitions alterations.
  */
  enum_with_validation          with_validation;

  Alter_info() :
    flags(0),
    keys_onoff(LEAVE_AS_IS),
    num_parts(0),
    requested_algorithm(ALTER_TABLE_ALGORITHM_DEFAULT),
    requested_lock(ALTER_TABLE_LOCK_DEFAULT),
    with_validation(ALTER_VALIDATION_DEFAULT)
  {}

  void reset()
  {
    drop_list.empty();
    alter_list.empty();
    key_list.empty();
    alter_rename_key_list.empty();
    create_list.empty();
    flags= 0;
    keys_onoff= LEAVE_AS_IS;
    num_parts= 0;
    partition_names.empty();
    requested_algorithm= ALTER_TABLE_ALGORITHM_DEFAULT;
    requested_lock= ALTER_TABLE_LOCK_DEFAULT;
    with_validation= ALTER_VALIDATION_DEFAULT;
  }


  /**
    Construct a copy of this object to be used for mysql_alter_table
    and mysql_create_table.

    Historically, these two functions modify their Alter_info
    arguments. This behaviour breaks re-execution of prepared
    statements and stored procedures and is compensated by always
    supplying a copy of Alter_info to these functions.

    @param  rhs       Alter_info to make copy of
    @param  mem_root  Mem_root for new Alter_info

    @note You need to use check the error in THD for out
    of memory condition after calling this function.
  */
  Alter_info(const Alter_info &rhs, MEM_ROOT *mem_root);


  /**
     Parses the given string and sets requested_algorithm
     if the string value matches a supported value.
     Supported values: INPLACE, COPY, DEFAULT

     @param  str    String containing the supplied value
     @retval false  Supported value found, state updated
     @retval true   Not supported value, no changes made
  */
  bool set_requested_algorithm(const LEX_STRING *str);


  /**
     Parses the given string and sets requested_lock
     if the string value matches a supported value.
     Supported values: NONE, SHARED, EXCLUSIVE, DEFAULT

     @param  str    String containing the supplied value
     @retval false  Supported value found, state updated
     @retval true   Not supported value, no changes made
  */

  bool set_requested_lock(const LEX_STRING *str);

private:
  Alter_info &operator=(const Alter_info &rhs); // not implemented
  Alter_info(const Alter_info &rhs);            // not implemented
};


/** Runtime context for ALTER TABLE. */
class Alter_table_ctx
{
public:
  Alter_table_ctx();

  Alter_table_ctx(THD *thd, TABLE_LIST *table_list, uint tables_opened_arg,
                  const char *new_db_arg, const char *new_name_arg);

  /**
     @return true if the table is moved to another database, false otherwise.
  */
  bool is_database_changed() const
  { return (new_db != db); };

  /**
     @return true if the table is renamed, false otherwise.
  */
  bool is_table_renamed() const
  { return (is_database_changed() || new_name != table_name); };

  /**
     @return filename (including .frm) for the new table.
  */
  const char *get_new_filename() const
  {
    assert(!tmp_table);
    return new_filename;
  }

  /**
     @return path to the original table.
  */
  const char *get_path() const
  {
    assert(!tmp_table);
    return path;
  }

  /**
     @return path to the new table.
  */
  const char *get_new_path() const
  {
    assert(!tmp_table);
    return new_path;
  }

  /**
     @return path to the temporary table created during ALTER TABLE.
  */
  const char *get_tmp_path() const
  { return tmp_path; }

public:
  typedef uint error_if_not_empty_mask;
  static const error_if_not_empty_mask DATETIME_WITHOUT_DEFAULT= 1 << 0;
  static const error_if_not_empty_mask GEOMETRY_WITHOUT_DEFAULT= 1 << 1;

  Create_field *datetime_field;
  error_if_not_empty_mask error_if_not_empty;
  uint         tables_opened;
  const char   *db;
  const char   *table_name;
  const char   *alias;
  const char   *new_db;
  const char   *new_name;
  const char   *new_alias;
  char         tmp_name[80];

private:
  char new_filename[FN_REFLEN + 1];
  char new_alias_buff[FN_REFLEN + 1];
  char path[FN_REFLEN + 1];
  char new_path[FN_REFLEN + 1];
  char tmp_path[FN_REFLEN + 1];

#ifndef NDEBUG
  /** Indicates that we are altering temporary table. Used only in asserts. */
  bool tmp_table;
#endif

  Alter_table_ctx &operator=(const Alter_table_ctx &rhs); // not implemented
  Alter_table_ctx(const Alter_table_ctx &rhs);            // not implemented
};


/**
  Sql_cmd_common_alter_table represents the common properties of the ALTER TABLE
  statements.
  @todo move Alter_info and other ALTER generic structures from Lex here.
*/
class Sql_cmd_common_alter_table : public Sql_cmd
{
protected:
  /**
    Constructor.
  */
  Sql_cmd_common_alter_table()
  {}

  virtual ~Sql_cmd_common_alter_table()
  {}

  virtual enum_sql_command sql_command_code() const
  {
    return SQLCOM_ALTER_TABLE;
  }
};

/**
  Sql_cmd_alter_table represents the generic ALTER TABLE statement.
  @todo move Alter_info and other ALTER specific structures from Lex here.
*/
class Sql_cmd_alter_table : public Sql_cmd_common_alter_table
{
public:
  /**
    Constructor, used to represent a ALTER TABLE statement.
  */
  Sql_cmd_alter_table()
  {}

  ~Sql_cmd_alter_table()
  {}

  bool execute(THD *thd);
};


/**
  Sql_cmd_alter_table_tablespace represents ALTER TABLE
  IMPORT/DISCARD TABLESPACE statements.
*/
class Sql_cmd_discard_import_tablespace : public Sql_cmd_common_alter_table
{
public:
  enum enum_tablespace_op_type
  {
    DISCARD_TABLESPACE, IMPORT_TABLESPACE
  };

  Sql_cmd_discard_import_tablespace(enum_tablespace_op_type tablespace_op_arg)
    : m_tablespace_op(tablespace_op_arg)
  {}

  bool execute(THD *thd);

private:
  const enum_tablespace_op_type m_tablespace_op;
};

#endif