package config;

/**
 * The session identifier generator use to create unused Redis key, this is used by cookie system
 * @author Deisss (LGPLv3)
 * @version 0.1
 */
public class SessionIdentifierGenerator{
    /**
     * This function generate a unique -not used- key for Redis database storage.
     * The function is mostly used during cookie creation. Use generate instead if you just
     * need a unique string
     * @return The key ready to be sended to Redis database
     */
    public static String create(){
        Redis rd = Redis.getInstance();

        String key = SessionIdentifierGenerator.generate(32);
        while(rd.getJedis().get(key) != null){
            key = SessionIdentifierGenerator.generate(32);
        }

        return key;
    }

    /**
     * This generate a random string of the given size
     * @param length The output length to retrieve
     * @return The generated string
     */
    public static String generate(int length){
        String chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
        int charLength = chars.length();
        String pass = "";
        for(int x=0; x<length; x++){
            int i = (int) Math.floor(Math.random() * charLength);
            pass += chars.charAt(i);
        }
        return pass;
    }
}