/*
 * Copyright (c) 2009-2021, Redis Ltd.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   * Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *   * Neither the name of Redis nor the names of its contributors may be used
 *     to endorse or promote products derived from this software without
 *     specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef __SCRIPT_H_
#define __SCRIPT_H_

/*
 * Script.c unit provides an API for functions and eval
 * to interact with the server. Interaction includes mostly
 * executing commands, but also functionalities like calling
 * the server back on long scripts or check if the script was killed.
 *
 * The interaction is done using a scriptRunCtx object that
 * need to be created by the user and initialized using scriptPrepareForRun.
 *
 * Detailed list of functionalities expose by the unit:
 * 1. Calling commands (including all the validation checks such as
 *    acl, cluster, read only run, ...)
 * 2. Set Resp
 * 3. Set Replication method (AOF/REPLICATION/NONE)
 * 4. Call the server back to on long running scripts to allow the server reply
 *    to clients and perform script kill
 */

/*
 * scriptInterrupt function will return one of those value,
 *
 * - SCRIPT_KILL - kill the current running script.
 * - SCRIPT_CONTINUE - keep running the current script.
 */
#define SCRIPT_KILL 1
#define SCRIPT_CONTINUE 2

/* runCtx flags */
#define SCRIPT_WRITE_DIRTY (1ULL << 0)      /* indicate that the current script already performed a write command */
#define SCRIPT_TIMEDOUT (1ULL << 3)         /* indicate that the current script timedout */
#define SCRIPT_KILLED (1ULL << 4)           /* indicate that the current script was marked to be killed */
#define SCRIPT_READ_ONLY (1ULL << 5)        /* indicate that the current script should only perform read commands */
#define SCRIPT_ALLOW_OOM (1ULL << 6)        /* indicate to allow any command even if OOM reached */
#define SCRIPT_EVAL_MODE (1ULL << 7)        /* Indicate that the current script called from legacy Lua */
#define SCRIPT_ALLOW_CROSS_SLOT (1ULL << 8) /* Indicate that the current script may access keys from multiple slots */
typedef struct scriptRunCtx scriptRunCtx;

/* This struct stores the necessary information to manage the execution of
 * scripts using EVAL and FCALL. */
struct scriptRunCtx {
    const char *funcname;
    client *c;
    client *original_client;
    int flags;
    int repl_flags;
    monotime start_time;
    int slot;
};

/* Scripts flags */
#define SCRIPT_FLAG_NO_WRITES (1ULL << 0)
#define SCRIPT_FLAG_ALLOW_OOM (1ULL << 1)
#define SCRIPT_FLAG_ALLOW_STALE (1ULL << 2)
#define SCRIPT_FLAG_NO_CLUSTER (1ULL << 3)
#define SCRIPT_FLAG_EVAL_COMPAT_MODE (1ULL << 4) /* EVAL Script backwards compatible behavior, no shebang provided */
#define SCRIPT_FLAG_ALLOW_CROSS_SLOT (1ULL << 5)

/* Defines a script flags */
typedef struct scriptFlag {
    uint64_t flag;
    const char *str;
} scriptFlag;

extern scriptFlag scripts_flags_def[];

uint64_t scriptFlagsToCmdFlags(uint64_t cmd_flags, uint64_t script_flags);
int scriptPrepareForRun(scriptRunCtx *r_ctx,
                        client *engine_client,
                        client *caller,
                        const char *funcname,
                        uint64_t script_flags,
                        int ro);
void scriptResetRun(scriptRunCtx *r_ctx);
int scriptSetResp(scriptRunCtx *r_ctx, int resp);
int scriptSetRepl(scriptRunCtx *r_ctx, int repl);
void scriptCall(scriptRunCtx *r_ctx, sds *err);
int scriptInterrupt(scriptRunCtx *r_ctx);
void scriptKill(client *c, int is_eval);
int scriptIsRunning(void);
const char *scriptCurrFunction(void);
int scriptIsEval(void);
int scriptIsTimedout(void);
client *scriptGetClient(void);
client *scriptGetCaller(void);
long long scriptRunDuration(void);

#endif /* __SCRIPT_H_ */
