package pl.edu.agh.jsonrpc;

import java.io.IOException;
import java.io.UnsupportedEncodingException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.ProtocolVersion;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.apache.http.params.HttpProtocolParams;
import org.apache.http.util.EntityUtils;
import org.json.JSONException;
import org.json.JSONObject;

/**
 * Implementation of JSON-RPC over HTTP/POST
 */
public class JSONRPCHttpClient extends JSONRPCClient {

	/*
	 * HttpClient to issue the HTTP/POST request
	 */
	private HttpClient httpClient;
	/*
	 * Service URI
	 */
	private String serviceUri;

	// HTTP 1.0
	private static final ProtocolVersion PROTOCOL_VERSION = new ProtocolVersion("HTTP", 1, 0);

	/**
	 * Construct a JsonRPCClient with the given service uri
	 * 
	 * @param uri
	 *            uri of the service
	 */
	public JSONRPCHttpClient(String uri) {
		httpClient = new DefaultHttpClient();
		serviceUri = uri;
	}

	protected JSONObject doJSONRequest(JSONObject jsonRequest) throws JSONRPCException {
		// Create HTTP/POST request with a JSON entity containing the request
		HttpPost request = new HttpPost(serviceUri);
		HttpParams params = new BasicHttpParams();
		HttpConnectionParams.setConnectionTimeout(params, getConnectionTimeout());
		HttpConnectionParams.setSoTimeout(params, getSoTimeout());
		HttpProtocolParams.setVersion(params, PROTOCOL_VERSION);
		request.setParams(params);

		HttpEntity entity;
		try {
			entity = new JSONEntity(jsonRequest);
		} catch (UnsupportedEncodingException e1) {
			throw new JSONRPCException("Unsupported encoding", e1);
		}
		request.setEntity(entity);

		try {
			// Execute the request and try to decode the JSON Response
			HttpResponse response = httpClient.execute(request);
			String responseString = EntityUtils.toString(response.getEntity());
			responseString = responseString.trim();
			System.out.println("Rozmiar odpowiedzi: " + responseString.length());
			System.out.println("Odzpowiedz : " + responseString); 
			JSONObject jsonResponse = new JSONObject(responseString);

			// Check for remote errors
			if (jsonResponse.has(JSONRPCConstants.ERROR_KEY)) {
				String jsonError = jsonResponse.getString(JSONRPCConstants.ERROR_KEY);
				throw new JSONRPCException(jsonError);
			} else {
				return jsonResponse; // JSON-RPC 2.0
			}
		}
		// Underlying errors are wrapped into a JSONRPCException instance
		catch (ClientProtocolException e) {
			throw new JSONRPCException("HTTP error", e);
		} catch (IOException e) {
			throw new JSONRPCException("Connection error", e);
		} catch (JSONException e) {
			throw new JSONRPCException("Invalid response", e);
		}
	}
}