#include <limits.h>
#include "redis.h"

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

void setGenericCommand(redisClient *c, int nx, robj *key, robj *val, robj *expire) {
    int retval;
    long seconds = 0; /* initialized to avoid an harmness warning */

    if (expire) {
        if (getLongFromObjectOrReply(c, expire, &seconds, NULL) != REDIS_OK)
            return;
        if (seconds <= 0) {
            addReplyError(c,"invalid expire time in SETEX");
            return;
        }
    }

    retval = dbAdd(c->db,key,val);
    if (retval == REDIS_ERR) {
        if (!nx) {
            dbReplace(c->db,key,val);
            incrRefCount(val);
        } else {
            addReply(c,shared.czero);
            return;
        }
    } else {
        incrRefCount(val);
    }
    touchWatchedKey(c->db,key);
    server.dirty++;
    removeExpire(c->db,key);
    if (expire) setExpire(c->db,key,time(NULL)+seconds);
    addReply(c, nx ? shared.cone : shared.ok);
}

void setCommand(redisClient *c) {
    c->argv[2] = tryObjectEncoding(c->argv[2]);
    setGenericCommand(c,0,c->argv[1],c->argv[2],NULL);
}

void setnxCommand(redisClient *c) {
    c->argv[2] = tryObjectEncoding(c->argv[2]);
    setGenericCommand(c,1,c->argv[1],c->argv[2],NULL);
}

void setexCommand(redisClient *c) {
    c->argv[3] = tryObjectEncoding(c->argv[3]);
    setGenericCommand(c,0,c->argv[1],c->argv[3],c->argv[2]);
}

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

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

    if (o->type != REDIS_STRING) {
        addReply(c,shared.wrongtypeerr);
        return REDIS_ERR;
    } else {
        addReplyBulk(c,o);
        return REDIS_OK;
    }
}

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

void getsetCommand(redisClient *c) {
    if (getGenericCommand(c) == REDIS_ERR) return;
    c->argv[2] = tryObjectEncoding(c->argv[2]);
    dbReplace(c->db,c->argv[1],c->argv[2]);
    incrRefCount(c->argv[2]);
    touchWatchedKey(c->db,c->argv[1]);
    server.dirty++;
    removeExpire(c->db,c->argv[1]);
}

static int getBitOffsetFromArgument(redisClient *c, robj *o, size_t *offset) {
    long long loffset;
    char *err = "bit offset is not an integer or out of range";

    if (getLongLongFromObjectOrReply(c,o,&loffset,err) != REDIS_OK)
        return REDIS_ERR;

    /* Limit offset to SIZE_T_MAX or 512MB in bytes */
    if ((loffset < 0) ||
        ((unsigned long long)loffset >= (unsigned)SIZE_T_MAX) ||
        ((unsigned long long)loffset >> 3) >= (512*1024*1024))
    {
        addReplyError(c,err);
        return REDIS_ERR;
    }

    *offset = (size_t)loffset;
    return REDIS_OK;
}

void setbitCommand(redisClient *c) {
    robj *o;
    char *err = "bit is not an integer or out of range";
    size_t bitoffset;
    long long bitvalue;
    int byte, bit, on;

    if (getBitOffsetFromArgument(c,c->argv[2],&bitoffset) != REDIS_OK)
        return;

    if (getLongLongFromObjectOrReply(c,c->argv[3],&bitvalue,err) != REDIS_OK)
        return;

    /* A bit can only be set to be on or off... */
    if (bitvalue & ~1) {
        addReplyError(c,err);
        return;
    }

    o = lookupKeyWrite(c->db,c->argv[1]);
    if (o == NULL) {
        o = createObject(REDIS_STRING,sdsempty());
        dbAdd(c->db,c->argv[1],o);
    } else {
        if (checkType(c,o,REDIS_STRING)) return;

        /* Create a copy when the object is shared or encoded. */
        if (o->refcount != 1 || o->encoding != REDIS_ENCODING_RAW) {
            robj *decoded = getDecodedObject(o);
            o = createStringObject(decoded->ptr, sdslen(decoded->ptr));
            decrRefCount(decoded);
            dbReplace(c->db,c->argv[1],o);
        }
    }

    byte = bitoffset >> 3;
    bit = 7 - (bitoffset & 0x7);
    on = bitvalue & 0x1;
    o->ptr = sdsgrowzero(o->ptr,byte+1);
    ((char*)o->ptr)[byte] |= on << bit;
    ((char*)o->ptr)[byte] &= ~((!on) << bit);

    touchWatchedKey(c->db,c->argv[1]);
    server.dirty++;
    addReply(c,shared.cone);
}

void getbitCommand(redisClient *c) {
    robj *o;
    size_t bitoffset, byte, bitmask;
    int on = 0;
    char llbuf[32];

    if (getBitOffsetFromArgument(c,c->argv[2],&bitoffset) != REDIS_OK)
        return;

    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
        checkType(c,o,REDIS_STRING)) return;

    byte = bitoffset >> 3;
    bitmask = 1 << (7 - (bitoffset & 0x7));
    if (o->encoding != REDIS_ENCODING_RAW) {
        if (byte < (size_t)ll2string(llbuf,sizeof(llbuf),(long)o->ptr))
            on = llbuf[byte] & bitmask;
    } else {
        if (byte < sdslen(o->ptr))
            on = ((sds)o->ptr)[byte] & bitmask;
    }
    addReply(c, on ? shared.cone : shared.czero);
}

void mgetCommand(redisClient *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 != REDIS_STRING) {
                addReply(c,shared.nullbulk);
            } else {
                addReplyBulk(c,o);
            }
        }
    }
}

void msetGenericCommand(redisClient *c, int nx) {
    int j, busykeys = 0;

    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 nothing at all if at least one already key exists. */
    if (nx) {
        for (j = 1; j < c->argc; j += 2) {
            if (lookupKeyWrite(c->db,c->argv[j]) != NULL) {
                busykeys++;
            }
        }
    }
    if (busykeys) {
        addReply(c, shared.czero);
        return;
    }

    for (j = 1; j < c->argc; j += 2) {
        c->argv[j+1] = tryObjectEncoding(c->argv[j+1]);
        dbReplace(c->db,c->argv[j],c->argv[j+1]);
        incrRefCount(c->argv[j+1]);
        removeExpire(c->db,c->argv[j]);
        touchWatchedKey(c->db,c->argv[j]);
    }
    server.dirty += (c->argc-1)/2;
    addReply(c, nx ? shared.cone : shared.ok);
}

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

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

void incrDecrCommand(redisClient *c, long long incr) {
    long long value;
    robj *o;

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

    value += incr;
    o = createStringObjectFromLongLong(value);
    dbReplace(c->db,c->argv[1],o);
    touchWatchedKey(c->db,c->argv[1]);
    server.dirty++;
    addReply(c,shared.colon);
    addReply(c,o);
    addReply(c,shared.crlf);
}

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

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

void incrbyCommand(redisClient *c) {
    long long incr;

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

void decrbyCommand(redisClient *c) {
    long long incr;

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

void appendCommand(redisClient *c) {
    int retval;
    size_t totlen;
    robj *o, *append;

    o = lookupKeyWrite(c->db,c->argv[1]);
    c->argv[2] = tryObjectEncoding(c->argv[2]);
    if (o == NULL) {
        /* Create the key */
        retval = dbAdd(c->db,c->argv[1],c->argv[2]);
        incrRefCount(c->argv[2]);
        totlen = stringObjectLen(c->argv[2]);
    } else {
        if (o->type != REDIS_STRING) {
            addReply(c,shared.wrongtypeerr);
            return;
        }

        append = getDecodedObject(c->argv[2]);
        if (o->encoding == REDIS_ENCODING_RAW &&
            (sdslen(o->ptr) + sdslen(append->ptr)) > 512*1024*1024)
        {
            addReplyError(c,"string exceeds maximum allowed size (512MB)");
            decrRefCount(append);
            return;
        }

        /* If the object is shared or encoded, we have to make a copy */
        if (o->refcount != 1 || o->encoding != REDIS_ENCODING_RAW) {
            robj *decoded = getDecodedObject(o);
            o = createStringObject(decoded->ptr, sdslen(decoded->ptr));
            decrRefCount(decoded);
            dbReplace(c->db,c->argv[1],o);
        }

        /* Append the value */
        o->ptr = sdscatlen(o->ptr,append->ptr,sdslen(append->ptr));
        decrRefCount(append);
        totlen = sdslen(o->ptr);
    }
    touchWatchedKey(c->db,c->argv[1]);
    server.dirty++;
    addReplyLongLong(c,totlen);
}

void substrCommand(redisClient *c) {
    robj *o;
    long start = atoi(c->argv[2]->ptr);
    long end = atoi(c->argv[3]->ptr);
    size_t rangelen, strlen;
    sds range;

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

    o = getDecodedObject(o);
    strlen = sdslen(o->ptr);

    /* convert negative indexes */
    if (start < 0) start = strlen+start;
    if (end < 0) end = strlen+end;
    if (start < 0) start = 0;
    if (end < 0) end = 0;

    /* indexes sanity checks */
    if (start > end || (size_t)start >= strlen) {
        /* Out of range start or start > end result in null reply */
        addReply(c,shared.nullbulk);
        decrRefCount(o);
        return;
    }
    if ((size_t)end >= strlen) end = strlen-1;
    rangelen = (end-start)+1;

    /* Return the result */
    addReplySds(c,sdscatprintf(sdsempty(),"$%zu\r\n",rangelen));
    range = sdsnewlen((char*)o->ptr+start,rangelen);
    addReplySds(c,range);
    addReply(c,shared.crlf);
    decrRefCount(o);
}

void strlenCommand(redisClient *c) {
    robj *o;

    if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.czero)) == NULL ||
        checkType(c,o,REDIS_STRING)) return;

    if (o->encoding == REDIS_ENCODING_RAW) {
        addReplyLongLong(c,sdslen(o->ptr));
    } else if (o->encoding == REDIS_ENCODING_INT) {
        char llbuf[32];
        int len = ll2string(llbuf,sizeof(llbuf),(long)o->ptr);
        addReplyLongLong(c,len);
    } else {
        redisPanic("Unknown string encoding");
    }
}