#pragma once
#ifndef _MAXINFO_H
#define _MAXINFO_H
/*
 * Copyright (c) 2016 MariaDB Corporation Ab
 *
 * Use of this software is governed by the Business Source License included
 * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
 *
 * Change Date: 2023-11-12
 *
 * On the date above, in accordance with the Business Source License, use
 * of this software will be governed by version 2 or later of the General
 * Public License.
 */

/**
 * @file maxinfo.h The MaxScale information schema provider
 *
 * @verbatim
 * Revision History
 *
 * Date     Who             Description
 * 16/02/15 Mark Riddoch    Initial implementation
 *
 * @endverbatim
 */

#define MXS_MODULE_NAME "maxinfo"

#include <maxscale/ccdefs.hh>
#include <maxscale/service.hh>
#include <maxscale/session.hh>
#include <maxscale/resultset.hh>

struct maxinfo_session;

/**
 * The INFO_INSTANCE structure. There is one instane of the maxinfo "router" for
 * each service that uses the MaxScale information schema.
 */
typedef struct maxinfo_instance
{
    pthread_mutex_t lock;   /*< The instance spinlock */
    SERVICE*        service;/*< The debug cli service */
    struct maxinfo_session
    * sessions;     /*< Linked list of sessions within this instance */
    struct maxinfo_instance
    * next;         /*< The next pointer for the list of instances */
} INFO_INSTANCE;

/**
 * The INFO_SESSION structure. As INFO_SESSION is created for each user that logs into
 * the MaxScale information schema.
 */

typedef struct maxinfo_session
{
    MXS_SESSION* session;   /*< The MaxScale session */
    DCB*         dcb;       /*< DCB of the client side */
    GWBUF*       queue;     /*< Queue for building contiguous requests */
    struct maxinfo_session
    * next;         /*< The next pointer for the list of sessions */
} INFO_SESSION;

/**
 * The operators that can be in the parse tree
 */
typedef enum
{
    MAXOP_SHOW,
    MAXOP_SELECT,
    MAXOP_TABLE,
    MAXOP_COLUMNS,
    MAXOP_ALL_COLUMNS,
    MAXOP_LITERAL,
    MAXOP_PREDICATE,
    MAXOP_LIKE,
    MAXOP_EQUAL,
    MAXOP_FLUSH,
    MAXOP_SET,
    MAXOP_CLEAR,
    MAXOP_SHUTDOWN,
    MAXOP_RESTART
} MAXINFO_OPERATOR;

/**
 * The Parse tree nodes for the MaxInfo parser
 */
typedef struct maxinfo_tree
{
    MAXINFO_OPERATOR     op;    /*< The operator */
    char*                value; /*< The value */
    struct maxinfo_tree* left;  /*< The left hand side of the operator */
    struct maxinfo_tree* right; /*< The right hand side of the operator */
} MAXINFO_TREE;



#define MYSQL_COMMAND(buf) (*((uint8_t*)GWBUF_DATA(buf) + 4))

/**
 * Token values for the tokeniser used by the parser for maxinfo
 */
#define LT_STRING   1
#define LT_SHOW     2
#define LT_LIKE     3
#define LT_SELECT   4
#define LT_EQUAL    5
#define LT_COMMA    6
#define LT_FROM     7
#define LT_STAR     8
#define LT_VARIABLE 9
#define LT_FLUSH    10
#define LT_SET      11
#define LT_CLEAR    12
#define LT_SHUTDOWN 13
#define LT_RESTART  14


/**
 * Possible parse errors
 */
typedef enum
{
    PARSE_NOERROR,
    PARSE_MALFORMED_SHOW,
    PARSE_EXPECTED_LIKE,
    PARSE_SYNTAX_ERROR
} PARSE_ERROR;


extern MAXINFO_TREE*              maxinfo_parse(char*, PARSE_ERROR*);
extern void                       maxinfo_free_tree(MAXINFO_TREE*);
extern void                       maxinfo_execute(DCB*, MAXINFO_TREE*);
extern void                       maxinfo_send_error(DCB*, int, const char*);
extern void                       maxinfo_send_parse_error(DCB*, char*, PARSE_ERROR);
extern std::unique_ptr<ResultSet> maxinfo_variables();
extern std::unique_ptr<ResultSet> maxinfo_status();
extern int                        handle_url(INFO_INSTANCE* instance, INFO_SESSION* session, GWBUF* queue);

#endif