package it.test;
 
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.net.HttpURLConnection;
import java.net.ProtocolException;
import java.net.URL;
import java.net.URLConnection;
 
public class InvokeDataMinerViaPost {
 
	static String dataMinerUrl = "https://dataminer-prototypes.d4science.org/wps/WebProcessingService?request=Execute&service=WPS&Version=1.0.0";
	static String token = "your-token-here";
 
	private static void pipe(Reader reader, Writer writer) throws IOException {
		char[] buf = new char[1024];
		int read = 0;
		while ((read = reader.read(buf)) >= 0) {
			writer.write(buf, 0, read);
		}
		writer.flush();
	}
 
	public static void postData(Reader data, URL endpoint, Writer output) throws Exception {
		HttpURLConnection urlc = null;
		try {
			urlc = (HttpURLConnection) endpoint.openConnection();
			try {
				urlc.setRequestMethod("POST");
			} catch (ProtocolException e) {
				throw new Exception("Shouldn't happen: HttpURLConnection doesn't support POST??", e);
			}
			urlc.setDoOutput(true);
			urlc.setDoInput(true);
			urlc.setUseCaches(false);
			urlc.setAllowUserInteraction(false);
			urlc.setRequestProperty("Content-type", "text/xml; charset=" + "UTF-8");
 
			OutputStream out = urlc.getOutputStream();
 
			try {
				Writer writer = new OutputStreamWriter(out, "UTF-8");
				pipe(data, writer);
				writer.close();
			} catch (IOException e) {
				throw new Exception("IOException while posting data", e);
			} finally {
				if (out != null)
					out.close();
			}
 
			InputStream in = urlc.getInputStream();
			try {
				Reader reader = new InputStreamReader(in);
				pipe(reader, output);
				reader.close();
			} catch (IOException e) {
				throw new Exception("IOException while reading response", e);
			} finally {
				if (in != null)
					in.close();
			}
 
		} catch (IOException e) {
			throw new Exception("Connection error (is server running at " + endpoint + " ?): " + e);
		} finally {
			if (urlc != null)
				urlc.disconnect();
		}
	}
 
	public static String getStatus(String endpoint) {
		String result = null;
 
			// Send a GET request to the servlet
			try {
				// Send data
				String urlStr = endpoint;
 
				URL url = new URL(urlStr);
				URLConnection conn = url.openConnection();
				conn.setConnectTimeout(120000);
				conn.setReadTimeout(120000);
 
				// Get the response
				BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
				StringBuffer sb = new StringBuffer();
				String line;
				while ((line = rd.readLine()) != null) {
					sb.append(line);
				}
				rd.close();
				result = sb.toString();
			} catch (Exception e) {
				e.printStackTrace();
			}
 
		return result;
	}
 
 
 
	public static void main(String args[]) throws Exception{
		String template = "templateDBScan.txt";
//		String template = "templateNOV_QRA.txt";
 
		StringWriter sw = new StringWriter();
		FileReader fr = new FileReader(new File(template));
 
		postData(fr , new URL(dataMinerUrl+"&gcube-token="+token), sw);
 
		fr.close();
 
		String answer = sw.toString();
 
		String statusLocation = answer.substring(answer.indexOf("statusLocation=\"")+"statusLocation=\"".length(), answer.indexOf("\">")); 
 
		System.out.println(sw.toString());
		System.out.println(statusLocation);
 
		String status = getStatus(statusLocation+"&gcube-token="+token);
 
		while (!(status.contains("wps:ProcessSucceeded") || status.contains("wps:ProcessFailed"))){
			System.out.println(status);
			status = getStatus(statusLocation+"&gcube-token="+token);
			Thread.sleep(5000);
		}
 
 
		System.out.println(status);
 
		if (status.contains("wps:ProcessFailed"))
			System.out.println("Process Failed!");
		else{
			String UrlToOutput = status.substring(status.lastIndexOf("<d4science:Data>")+"<d4science:Data>".length(), status.lastIndexOf("</d4science:Data>"));
			System.out.println("Url to output:"+UrlToOutput);
		}
	}
}