/*
 * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
 * 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
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "server.h"
#include <math.h> /* isnan(), isinf() */

/*-----------------------------------------------------------------------------
 * String Commands
 *----------------------------------------------------------------------------*/

static int checkStringLength(client *c, PORT_LONGLONG size) {
 if (size > 512*1024*1024) {
 addReplyError(c,"string exceeds maximum allowed size (512MB)");
 return C_ERR;
 }
 return C_OK;
}

/* The setGenericCommand() function implements the SET operation with different
 * options and variants. This function is called in order to implement the
 * following commands: SET, SETEX, PSETEX, SETNX.
 *
 * 'flags' changes the behavior of the command (NX or XX, see belove).
 *
 * 'expire' represents an expire to set in form of a Redis object as passed
 * by the user. It is interpreted according to the specified 'unit'.
 *
 * 'ok_reply' and 'abort_reply' is what the function will reply to the client
 * if the operation is performed, or when it is not because of NX or
 * XX flags.
 *
 * If ok_reply is NULL "+OK" is used.
 * If abort_reply is NULL, "$-1" is used. */

#define OBJ_SET_NO_FLAGS 0
#define OBJ_SET_NX (1<<0) /* Set if key not exists. */
#define OBJ_SET_XX (1<<1) /* Set if key exists. */
#define OBJ_SET_EX (1<<2) /* Set if time in seconds is given */
#define OBJ_SET_PX (1<<3) /* Set if time in ms in given */

void setGenericCommand(client *c, int flags, robj *key, robj *val, robj *expire, int unit, robj *ok_reply, robj *abort_reply) {
 PORT_LONGLONG milliseconds = 0; /* initialized to avoid any harmness warning */

 if (expire) {
 if (getLongLongFromObjectOrReply(c, expire, &milliseconds, NULL) != C_OK)
 return;
 if (milliseconds <= 0) {
 addReplyErrorFormat(c,"invalid expire time in %s",c->cmd->name);
 return;
 }
 if (unit == UNIT_SECONDS) milliseconds *= 1000;
 }

 if ((flags & OBJ_SET_NX && lookupKeyWrite(c->db,key) != NULL) ||
 (flags & OBJ_SET_XX && lookupKeyWrite(c->db,key) == NULL))
 {
 addReply(c, abort_reply ? abort_reply : shared.nullbulk);
 return;
 }
 setKey(c->db,key,val);
 server.dirty++;
 if (expire) setExpire(c,c->db,key,mstime()+milliseconds);
 notifyKeyspaceEvent(NOTIFY_STRING,"set",key,c->db->id);
 if (expire) notifyKeyspaceEvent(NOTIFY_GENERIC,
 "expire",key,c->db->id);
 addReply(c, ok_reply ? ok_reply : shared.ok);
}

/* SET key value [NX] [XX] [EX <seconds>] [PX <milliseconds>] */
void setCommand(client *c) {
 int j;
 robj *expire = NULL;
 int unit = UNIT_SECONDS;
 int flags = OBJ_SET_NO_FLAGS;

 for (j = 3; j < c->argc; j++) {
 char *a = c->argv[j]->ptr;
 robj *next = (j == c->argc-1) ? NULL : c->argv[j+1];

 if ((a[0] == 'n' || a[0] == 'N') &&
 (a[1] == 'x' || a[1] == 'X') && a[2] == '0円' &&
 !(flags & OBJ_SET_XX))
 {
 flags |= OBJ_SET_NX;
 } else if ((a[0] == 'x' || a[0] == 'X') &&
 (a[1] == 'x' || a[1] == 'X') && a[2] == '0円' &&
 !(flags & OBJ_SET_NX))
 {
 flags |= OBJ_SET_XX;
 } else if ((a[0] == 'e' || a[0] == 'E') &&
 (a[1] == 'x' || a[1] == 'X') && a[2] == '0円' &&
 !(flags & OBJ_SET_PX) && next)
 {
 flags |= OBJ_SET_EX;
 unit = UNIT_SECONDS;
 expire = next;
 j++;
 } else if ((a[0] == 'p' || a[0] == 'P') &&
 (a[1] == 'x' || a[1] == 'X') && a[2] == '0円' &&
 !(flags & OBJ_SET_EX) && next)
 {
 flags |= OBJ_SET_PX;
 unit = UNIT_MILLISECONDS;
 expire = next;
 j++;
 } else {
 addReply(c,shared.syntaxerr);
 return;
 }
 }

 c->argv[2] = tryObjectEncoding(c->argv[2]);
 setGenericCommand(c,flags,c->argv[1],c->argv[2],expire,unit,NULL,NULL);
}

void setnxCommand(client *c) {
 c->argv[2] = tryObjectEncoding(c->argv[2]);
 setGenericCommand(c,OBJ_SET_NX,c->argv[1],c->argv[2],NULL,0,shared.cone,shared.czero);
}

void setexCommand(client *c) {
 c->argv[3] = tryObjectEncoding(c->argv[3]);
 setGenericCommand(c,OBJ_SET_NO_FLAGS,c->argv[1],c->argv[3],c->argv[2],UNIT_SECONDS,NULL,NULL);
}

void psetexCommand(client *c) {
 c->argv[3] = tryObjectEncoding(c->argv[3]);
 setGenericCommand(c,OBJ_SET_NO_FLAGS,c->argv[1],c->argv[3],c->argv[2],UNIT_MILLISECONDS,NULL,NULL);
}

int getGenericCommand(client *c) {
 robj *o;

 if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.nullbulk)) == NULL)
 return C_OK;

 if (o->type != OBJ_STRING) {
 addReply(c,shared.wrongtypeerr);
 return C_ERR;
 } else {
 addReplyBulk(c,o);
 return C_OK;
 }
}

void getCommand(client *c) {
 getGenericCommand(c);
}

void getsetCommand(client *c) {
 if (getGenericCommand(c) == C_ERR) return;
 c->argv[2] = tryObjectEncoding(c->argv[2]);
 setKey(c->db,c->argv[1],c->argv[2]);
 notifyKeyspaceEvent(NOTIFY_STRING,"set",c->argv[1],c->db->id);
 server.dirty++;
}

void setrangeCommand(client *c) {
 robj *o;
 PORT_LONG offset;
 sds value = c->argv[3]->ptr;

 if (getLongFromObjectOrReply(c,c->argv[2],&offset,NULL) != C_OK)
 return;

 if (offset < 0) {
 addReplyError(c,"offset is out of range");
 return;
 }

 o = lookupKeyWrite(c->db,c->argv[1]);
 if (o == NULL) {
 /* Return 0 when setting nothing on a non-existing string */
 if (sdslen(value) == 0) {
 addReply(c,shared.czero);
 return;
 }

 /* Return when the resulting string exceeds allowed size */
 if (checkStringLength(c,offset+sdslen(value)) != C_OK)
 return;

 o = createObject(OBJ_STRING,sdsnewlen(NULL, offset+sdslen(value)));
 dbAdd(c->db,c->argv[1],o);
 } else {
 size_t olen;

 /* Key exists, check type */
 if (checkType(c,o,OBJ_STRING))
 return;

 /* Return existing string length when setting nothing */
 olen = stringObjectLen(o);
 if (sdslen(value) == 0) {
 addReplyLongLong(c,olen);
 return;
 }

 /* Return when the resulting string exceeds allowed size */
 if (checkStringLength(c,offset+sdslen(value)) != C_OK)
 return;

 /* Create a copy when the object is shared or encoded. */
 o = dbUnshareStringValue(c->db,c->argv[1],o);
 }

 if (sdslen(value) > 0) {
 o->ptr = sdsgrowzero(o->ptr,offset+sdslen(value));
 memcpy((char*)o->ptr+offset,value,sdslen(value));
 signalModifiedKey(c->db,c->argv[1]);
 notifyKeyspaceEvent(NOTIFY_STRING,
 "setrange",c->argv[1],c->db->id);
 server.dirty++;
 }
 addReplyLongLong(c,sdslen(o->ptr));
}

void getrangeCommand(client *c) {
 robj *o;
 PORT_LONGLONG start, end;
 char *str, llbuf[32];
 size_t strlen;

 if (getLongLongFromObjectOrReply(c,c->argv[2],&start,NULL) != C_OK)
 return;
 if (getLongLongFromObjectOrReply(c,c->argv[3],&end,NULL) != C_OK)
 return;
 if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptybulk)) == NULL ||
 checkType(c,o,OBJ_STRING)) return;

 if (o->encoding == OBJ_ENCODING_INT) {
 str = llbuf;
 strlen = ll2string(llbuf,sizeof(llbuf),(PORT_LONG)o->ptr);
 } else {
 str = o->ptr;
 strlen = sdslen(str);
 }

 /* Convert negative indexes */
 if (start < 0 && end < 0 && start > end) {
 addReply(c,shared.emptybulk);
 return;
 }
 if (start < 0) start = strlen+start;
 if (end < 0) end = strlen+end;
 if (start < 0) start = 0;
 if (end < 0) end = 0;
 if ((PORT_ULONGLONG)end >= strlen) end = strlen-1;

 /* Precondition: end >= 0 && end < strlen, so the only condition where
 * nothing can be returned is: start > end. */
 if (start > end || strlen == 0) {
 addReply(c,shared.emptybulk);
 } else {
 addReplyBulkCBuffer(c,(char*)str+start,end-start+1);
 }
}

void mgetCommand(client *c) {
 int j;

 addReplyMultiBulkLen(c,c->argc-1);
 for (j = 1; j < c->argc; j++) {
 robj *o = lookupKeyRead(c->db,c->argv[j]);
 if (o == NULL) {
 addReply(c,shared.nullbulk);
 } else {
 if (o->type != OBJ_STRING) {
 addReply(c,shared.nullbulk);
 } else {
 addReplyBulk(c,o);
 }
 }
 }
}

void msetGenericCommand(client *c, int nx) {
 int j;

 if ((c->argc % 2) == 0) {
 addReplyError(c,"wrong number of arguments for MSET");
 return;
 }

 /* Handle the NX flag. The MSETNX semantic is to return zero and don't
 * set anything if at least one key alerady exists. */
 if (nx) {
 for (j = 1; j < c->argc; j += 2) {
 if (lookupKeyWrite(c->db,c->argv[j]) != NULL) {
 addReply(c, shared.czero);
 return;
 }
 }
 }

 for (j = 1; j < c->argc; j += 2) {
 c->argv[j+1] = tryObjectEncoding(c->argv[j+1]);
 setKey(c->db,c->argv[j],c->argv[j+1]);
 notifyKeyspaceEvent(NOTIFY_STRING,"set",c->argv[j],c->db->id);
 }
 server.dirty += (c->argc-1)/2;
 addReply(c, nx ? shared.cone : shared.ok);
}

void msetCommand(client *c) {
 msetGenericCommand(c,0);
}

void msetnxCommand(client *c) {
 msetGenericCommand(c,1);
}

void incrDecrCommand(client *c, PORT_LONGLONG incr) {
 PORT_LONGLONG value, oldvalue;
 robj *o, *new;

 o = lookupKeyWrite(c->db,c->argv[1]);
 if (o != NULL && checkType(c,o,OBJ_STRING)) return;
 if (getLongLongFromObjectOrReply(c,o,&value,NULL) != C_OK) return;

 oldvalue = value;
 if ((incr < 0 && oldvalue < 0 && incr < (LLONG_MIN-oldvalue)) ||
 (incr > 0 && oldvalue > 0 && incr > (LLONG_MAX-oldvalue))) {
 addReplyError(c,"increment or decrement would overflow");
 return;
 }
 value += incr;

 if (o && o->refcount == 1 && o->encoding == OBJ_ENCODING_INT &&
 (value < 0 || value >= OBJ_SHARED_INTEGERS) &&
 value >= LONG_MIN && value <= LONG_MAX)
 {
 new = o;
 o->ptr = (void*)((PORT_LONG)value);
 } else {
 new = createStringObjectFromLongLongForValue(value);
 if (o) {
 dbOverwrite(c->db,c->argv[1],new);
 } else {
 dbAdd(c->db,c->argv[1],new);
 }
 }
 signalModifiedKey(c->db,c->argv[1]);
 notifyKeyspaceEvent(NOTIFY_STRING,"incrby",c->argv[1],c->db->id);
 server.dirty++;
 addReply(c,shared.colon);
 addReply(c,new);
 addReply(c,shared.crlf);
}

void incrCommand(client *c) {
 incrDecrCommand(c,1);
}

void decrCommand(client *c) {
 incrDecrCommand(c,-1);
}

void incrbyCommand(client *c) {
 PORT_LONGLONG incr;

 if (getLongLongFromObjectOrReply(c, c->argv[2], &incr, NULL) != C_OK) return;
 incrDecrCommand(c,incr);
}

void decrbyCommand(client *c) {
 PORT_LONGLONG incr;

 if (getLongLongFromObjectOrReply(c, c->argv[2], &incr, NULL) != C_OK) return;
 incrDecrCommand(c,-incr);
}

void incrbyfloatCommand(client *c) {
 PORT_LONGDOUBLE incr, value;
 robj *o, *new, *aux;

 o = lookupKeyWrite(c->db,c->argv[1]);
 if (o != NULL && checkType(c,o,OBJ_STRING)) return;
 if (getLongDoubleFromObjectOrReply(c,o,&value,NULL) != C_OK ||
 getLongDoubleFromObjectOrReply(c,c->argv[2],&incr,NULL) != C_OK)
 return;

 value += incr;
 if (isnan(value) || isinf(value)) {
 addReplyError(c,"increment would produce NaN or Infinity");
 return;
 }
 new = createStringObjectFromLongDouble(value,1);
 if (o)
 dbOverwrite(c->db,c->argv[1],new);
 else
 dbAdd(c->db,c->argv[1],new);
 signalModifiedKey(c->db,c->argv[1]);
 notifyKeyspaceEvent(NOTIFY_STRING,"incrbyfloat",c->argv[1],c->db->id);
 server.dirty++;
 addReplyBulk(c,new);

 /* Always replicate INCRBYFLOAT as a SET command with the final value
 * in order to make sure that differences in float precision or formatting
 * will not create differences in replicas or after an AOF restart. */
 aux = createStringObject("SET",3);
 rewriteClientCommandArgument(c,0,aux);
 decrRefCount(aux);
 rewriteClientCommandArgument(c,2,new);
}

void appendCommand(client *c) {
 size_t totlen;
 robj *o, *append;

 o = lookupKeyWrite(c->db,c->argv[1]);
 if (o == NULL) {
 /* Create the key */
 c->argv[2] = tryObjectEncoding(c->argv[2]);
 dbAdd(c->db,c->argv[1],c->argv[2]);
 incrRefCount(c->argv[2]);
 totlen = stringObjectLen(c->argv[2]);
 } else {
 /* Key exists, check type */
 if (checkType(c,o,OBJ_STRING))
 return;

 /* "append" is an argument, so always an sds */
 append = c->argv[2];
 totlen = stringObjectLen(o)+sdslen(append->ptr);
 if (checkStringLength(c,totlen) != C_OK)
 return;

 /* Append the value */
 o = dbUnshareStringValue(c->db,c->argv[1],o);
 o->ptr = sdscatlen(o->ptr,append->ptr,sdslen(append->ptr));
 totlen = sdslen(o->ptr);
 }
 signalModifiedKey(c->db,c->argv[1]);
 notifyKeyspaceEvent(NOTIFY_STRING,"append",c->argv[1],c->db->id);
 server.dirty++;
 addReplyLongLong(c,totlen);
}

void strlenCommand(client *c) {
 robj *o;
 if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
 checkType(c,o,OBJ_STRING)) return;
 addReplyLongLong(c,stringObjectLen(o));
}