package dk.thoerup.checkupdates;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.DialogInterface.OnClickListener;
import android.content.SharedPreferences.Editor;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.net.Uri;
import android.os.AsyncTask;
import android.util.Log;

public class CheckUpdates {
	public static long TIMESPAN_DAY = 24*60*60*1000; // one day
	final static String PREFS = "CheckUpdate";
	
	int versionCode;
	String versionName;
	String packageName;
	String phone_model;
	String androidVersion;
	
	String title;
	
	
	Context context;	

	public void checkForUpdates(Context context, String url, String title) {
		this.context = context;
		this.title = title;
		
		SharedPreferences prefs = context.getSharedPreferences(PREFS, Context.MODE_PRIVATE);
		long lastCheck = prefs.getLong("lastcheck", 0);

		long now = System.currentTimeMillis(); //should i use  android.os.SystemClock.elapsedRealtime() instead ?
		
		if ( (now+TIMESPAN_DAY) > lastCheck ){

			PackageManager pm = context.getPackageManager();
			try {
				PackageInfo pi;

				pi = pm.getPackageInfo(context.getPackageName(), 0);

				versionCode = pi.versionCode;
				versionName = pi.versionName;
				packageName = pi.packageName;
				phone_model = android.os.Build.MODEL;
				androidVersion = android.os.Build.VERSION.RELEASE;
				
	
				UpdateTask task = new UpdateTask();
				task.execute(url);
				


			} catch (NameNotFoundException e) {
				e.printStackTrace();
			}

		}
	}
	
	class UpdateTask extends AsyncTask<String,Void,Void> {
		boolean result = false;
		int newestVersion = 0;

		@Override
		protected Void doInBackground(String... arg0) {
			String requestUrl = arg0[0] + "?version=" + versionName + "&phone=" + phone_model + "&android=" + androidVersion;
			try {
				URL url = new URL(requestUrl);
				URLConnection conn = url.openConnection();
				conn.setConnectTimeout(5);
								
				String resultStr = readIOStream( conn.getInputStream() );
				resultStr = resultStr.trim();
				newestVersion = Integer.parseInt(resultStr);
				
				result = true;
				
			} catch (Exception e) {
				Log.e("CheckUpdates", "Check for " + packageName + " failed!", e);
			}
						
			return null;
		}
		
		private String readIOStream(InputStream in) throws IOException {
			ByteArrayOutputStream baos = new ByteArrayOutputStream();
			
			byte buf[] = new byte[1024];
			int len;
			
			while ( (len=in.read(buf)) != -1) {
				baos.write(buf, 0, len);
			}
			
			return baos.toString(); 
		}

		@Override
		protected void onPostExecute(Void r) {
			super.onPostExecute(r);
			
			Log.i("CheckUpdates", "result=" + result + ", newestVersion" + newestVersion + ", versionCode=" + versionCode);
			
			if (result == true) {
				if (newestVersion > versionCode) {
					AlertDialog.Builder builder = new AlertDialog.Builder(context);
					builder.setTitle(title);
					builder.setMessage("This application has an a newer version available. Update now?");
					
					builder.setPositiveButton("Yes", new OnClickListener() {						
						public void onClick(DialogInterface dialog, int which) {
							Intent i = new Intent(Intent.ACTION_VIEW, Uri.parse("market://search?q=pname:" + packageName) );
							try {
								context.startActivity(i);
							} catch (Exception e) {
								Log.e("CheckUpdates", "Activity launch failed", e);
							}
							context = null;
							
						}
					});
					builder.setNegativeButton("No", new OnClickListener() {
						public void onClick(DialogInterface dialog, int which) {
							context = null;
						}
					});
					
					try {
						builder.show();
					} catch (Exception e) {
						Log.e("CheckUpdates", "Builder.show failed", e);
					}
					
					
				}
				
				long now = System.currentTimeMillis();
				SharedPreferences prefs = context.getSharedPreferences(PREFS, Context.MODE_PRIVATE);
				//when done write 
				Editor edit = prefs.edit();
				edit.putLong("lastCheck", now);
				edit.commit();
			}
			
		}
		
	}
	
	
}