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package Parser;

import java.util.HashMap;
import javax.swing.JOptionPane;

/**
 *
 * @author sven
 */
public class UrlAnalyzer {
    public static final String PROTOCOL_HTTP = "http";
    public static final String PROTOCOL_HTTPS = "https";
    public static final String PROTOCOL_FTP = "ftp";
    public static final String PROTOCOL_FILE = "file";
    public static final String NO_PROTOCOL = "NO_PROTOCOL";
    public static final String NO_HOST = "NO_HOST";
    public static final String NO_VALID_PATH = "NO_VALID_PATH";
    public static final String NO_VALID_FILE = "NO_VALID_FILE";
    public static final String PROTOCOL_SEPARATOR = "://";
    public static final String PATH_SEPARATOR = "/";
    public static final String PARAMS_INDICATOR = "?";
    public static final String ANCHOR = "#";
    public static final String PARAMS_SEPARATOR = "&";
    public static final String PARAMS_ASSIGN = "=";
    public static final String[] VALID_PROTOCOLS =
        {PROTOCOL_HTTP,PROTOCOL_HTTPS,PROTOCOL_FTP,PROTOCOL_FILE};
    public static final String NO_ANCHOR = "NO_ANCHOR";

    public static HashMap<String, String> getParams(String url) {
        HashMap<String,String> result = new HashMap<String,String>();
        
        if(url!=null) {
            String paramStr = url.substring(url.indexOf(PARAMS_INDICATOR)+1);
            String[] params = paramStr.split(PARAMS_SEPARATOR);
            for(String param : params) {
                String[] paramKeyValue = param.split(PARAMS_ASSIGN);
                if (paramKeyValue.length > 1) {
                    result.put(paramKeyValue[0], paramKeyValue[1]);
                } else {
                    result.put(paramKeyValue[0],null);
                }
            }
        }
        return result;
    }

    public static final String getProtocol(final String url) {
        if(url==null)
            return NO_PROTOCOL;
        
        for (String proto : VALID_PROTOCOLS) {
            if (url.startsWith(proto)) {
                return proto;
            }
        }
        return new String(NO_PROTOCOL);
    }
    public static final String getHostname(final String url) {
        if(url==null)
            return NO_HOST;
        
        if (!url.contains(PROTOCOL_SEPARATOR)) {
            return NO_HOST;
        }
        int hostStart = url.indexOf(PROTOCOL_SEPARATOR)+PROTOCOL_SEPARATOR.length();
        int hostEnd = url.indexOf(PATH_SEPARATOR, hostStart);
        if ( hostEnd <= 1 ) {
            return NO_HOST;
        }
        return url.substring(hostStart, hostEnd);
    }
    public static final String getFilename(final String url) {
        if(url==null)
            return "";
        
        String rest = url;
        if (url.contains(PROTOCOL_SEPARATOR)) {
            int protoEnd = url.indexOf(PROTOCOL_SEPARATOR)+PROTOCOL_SEPARATOR.length();
            rest = url.substring(protoEnd);
            if ( (rest.indexOf(PATH_SEPARATOR)) == -1) {
                return NO_VALID_FILE;
            }
            rest = url.substring(protoEnd);
        }
        int fileStart = rest.lastIndexOf(PATH_SEPARATOR);
        String res = (fileStart != -1) ? rest.substring(fileStart+1) : rest;
        if (hasParams(res)) {
            res = res.substring(0, res.indexOf(PARAMS_INDICATOR));
        }
        if (hasAnchor(res)) {
            res = res.substring(0, res.indexOf(ANCHOR));
        }
        return res;
    }
    public static final String getPath(String url) {
        if(url==null)
            return NO_VALID_PATH;
        
        int pathStart = 0;
        int pathEnd = url.lastIndexOf(PATH_SEPARATOR);

        if (pathEnd < 1) {
            // item at root level
            // e. g. foobar.html oder cool.gifv
            return PATH_SEPARATOR;
        }
        if (url.contains(PROTOCOL_SEPARATOR)) {
            // we have a full url 
            // e.g. http://foo.bar.com/dir/subdir/index.html
            pathStart = url.indexOf(PATH_SEPARATOR,url.indexOf(PROTOCOL_SEPARATOR)+PROTOCOL_SEPARATOR.length());
            if (pathStart < 0) {
                return NO_VALID_PATH;
            }
        } else {
            // we have a relative path on site
            // e. g.: img/coolimg.jpg
            //  or res/img/anotherimg.gif
            pathStart = 0;
            pathEnd = url.lastIndexOf(PATH_SEPARATOR);
        }
        return url.substring(pathStart,pathEnd)+PATH_SEPARATOR;
    }
    public static final String getAnchor(String url) {
        if(url==null)
            return NO_ANCHOR;
        
        return (hasAnchor(url)) ? url.substring(url.indexOf(ANCHOR)+1) : null;
    }
    public static final boolean hasParams(String url) {
        if(url==null)
            return false;
        
        return url.contains(PARAMS_INDICATOR);
    }
    public static final boolean hasAnchor(String url) {
        if(url==null)
            return false;
        
        return url.contains(ANCHOR);
    }
    public static final String stripProtocol(String url) {
        return url.substring(url.indexOf(PROTOCOL_SEPARATOR)+PROTOCOL_SEPARATOR.length());
    }
    
    public static final boolean validateURL(String url)
    {
        if( url.contains(PROTOCOL_HTTP) || url.contains(PROTOCOL_HTTPS) || url.contains(PROTOCOL_FTP) || url.contains(PROTOCOL_FILE) )
            if(url.contains(PROTOCOL_SEPARATOR))
                if(url.contains("."))
                    return true;
        
        JOptionPane.showMessageDialog(null, "Falsche Url. Bitte geben Sie eine korrekte Url ein!");

        return false;
    }
}