package redis.clients.jedis;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import redis.clients.jedis.exceptions.JedisConnectionException;
import redis.clients.jedis.exceptions.JedisDataException;
import redis.clients.util.RedisInputStream;
import redis.clients.util.RedisOutputStream;
import redis.clients.util.SafeEncoder;

public final class Protocol {

    public static final int DEFAULT_PORT = 6379;
    public static final int DEFAULT_TIMEOUT = 2000;

    public static final String CHARSET = "UTF-8";

    public static final byte DOLLAR_BYTE = '$';
    public static final byte ASTERISK_BYTE = '*';
    public static final byte PLUS_BYTE = '+';
    public static final byte MINUS_BYTE = '-';
    public static final byte COLON_BYTE = ':';

    public void sendCommand(final RedisOutputStream os, final Command command,
            final byte[]... args) {
        sendCommand(os, command.raw, args);
    }

    private void sendCommand(final RedisOutputStream os, final byte[] command,
            final byte[]... args) {
        try {
            os.write(ASTERISK_BYTE);
            os.writeIntCrLf(args.length + 1);
            os.write(DOLLAR_BYTE);
            os.writeIntCrLf(command.length);
            os.write(command);
            os.writeCrLf();

            for (final byte[] arg : args) {
                os.write(DOLLAR_BYTE);
                os.writeIntCrLf(arg.length);
                os.write(arg);
                os.writeCrLf();
            }
            os.flush();
        } catch (IOException e) {
            throw new JedisConnectionException(e);
        }
    }

    private void processError(final RedisInputStream is) {
        String message = is.readLine();
        throw new JedisDataException(message);
    }

    private Object process(final RedisInputStream is) {
        try {
            byte b = is.readByte();
            if (b == MINUS_BYTE) {
                processError(is);
            } else if (b == ASTERISK_BYTE) {
                return processMultiBulkReply(is);
            } else if (b == COLON_BYTE) {
                return processInteger(is);
            } else if (b == DOLLAR_BYTE) {
                return processBulkReply(is);
            } else if (b == PLUS_BYTE) {
                return processStatusCodeReply(is);
            } else {
                throw new JedisConnectionException("Unknown reply: " + (char) b);
            }
        } catch (IOException e) {
            throw new JedisConnectionException(e);
        }
        return null;
    }

    private byte[] processStatusCodeReply(final RedisInputStream is) {
        return SafeEncoder.encode(is.readLine());
    }

    private byte[] processBulkReply(final RedisInputStream is) {
        int len = Integer.parseInt(is.readLine());
        if (len == -1) {
            return null;
        }
        byte[] read = new byte[len];
        int offset = 0;
        try {
            while (offset < len) {
                offset += is.read(read, offset, (len - offset));
            }
            // read 2 more bytes for the command delimiter
            is.readByte();
            is.readByte();
        } catch (IOException e) {
            throw new JedisConnectionException(e);
        }

        return read;
    }

    private Long processInteger(final RedisInputStream is) {
        String num = is.readLine();
        return Long.valueOf(num);
    }

    private List<Object> processMultiBulkReply(final RedisInputStream is) {
        int num = Integer.parseInt(is.readLine());
        if (num == -1) {
            return null;
        }
        List<Object> ret = new ArrayList<Object>(num);
        for (int i = 0; i < num; i++) {
            ret.add(process(is));
        }
        return ret;
    }

    public Object read(final RedisInputStream is) {
        return process(is);
    }

    public static final byte[] toByteArray(final int value) {
        return SafeEncoder.encode(String.valueOf(value));
    }

    public static final byte[] toByteArray(final long value) {
        return SafeEncoder.encode(String.valueOf(value));
    }

    public static final byte[] toByteArray(final double value) {
        return SafeEncoder.encode(String.valueOf(value));
    }

    public static enum Command {
        PING, SET, GET, QUIT, EXISTS, DEL, TYPE, FLUSHDB, KEYS, RANDOMKEY, RENAME, RENAMENX, RENAMEX, DBSIZE, EXPIRE, EXPIREAT, TTL, SELECT, MOVE, FLUSHALL, GETSET, MGET, SETNX, SETEX, MSET, MSETNX, DECRBY, DECR, INCRBY, INCR, APPEND, SUBSTR, HSET, HGET, HSETNX, HMSET, HMGET, HINCRBY, HEXISTS, HDEL, HLEN, HKEYS, HVALS, HGETALL, RPUSH, LPUSH, LLEN, LRANGE, LTRIM, LINDEX, LSET, LREM, LPOP, RPOP, RPOPLPUSH, SADD, SMEMBERS, SREM, SPOP, SMOVE, SCARD, SISMEMBER, SINTER, SINTERSTORE, SUNION, SUNIONSTORE, SDIFF, SDIFFSTORE, SRANDMEMBER, ZADD, ZRANGE, ZREM, ZINCRBY, ZRANK, ZREVRANK, ZREVRANGE, ZCARD, ZSCORE, MULTI, DISCARD, EXEC, WATCH, UNWATCH, SORT, BLPOP, BRPOP, AUTH, SUBSCRIBE, PUBLISH, UNSUBSCRIBE, PSUBSCRIBE, PUNSUBSCRIBE, ZCOUNT, ZRANGEBYSCORE, ZREMRANGEBYRANK, ZREMRANGEBYSCORE, ZUNIONSTORE, ZINTERSTORE, SAVE, BGSAVE, BGREWRITEAOF, LASTSAVE, SHUTDOWN, INFO, MONITOR, SLAVEOF, CONFIG, STRLEN, SYNC, LPUSHX, PERSIST, RPUSHX, ECHO, LINSERT, DEBUG, BRPOPLPUSH, SETBIT, GETBIT, SETRANGE, GETRANGE;

        public final byte[] raw;

        Command() {
            raw = SafeEncoder.encode(this.name());
        }
    }

    public static enum Keyword {
        AGGREGATE, ALPHA, ASC, BY, DESC, GET, LIMIT, MESSAGE, NO, NOSORT, PMESSAGE, PSUBSCRIBE, PUNSUBSCRIBE, OK, ONE, QUEUED, SET, STORE, SUBSCRIBE, UNSUBSCRIBE, WEIGHTS, WITHSCORES, RESETSTAT;
        public final byte[] raw;

        Keyword() {
            raw = SafeEncoder.encode(this.name().toLowerCase());
        }

    }
}