Utils.kt

import java.io.BufferedReader
import java.io.IOException
import java.io.InputStream
import java.io.InputStreamReader
import java.net.HttpURLConnection
import java.net.MalformedURLException
import java.net.URL
import java.nio.charset.Charset
import java.text.SimpleDateFormat
import java.util.Date

/**
 * Created by ahmad on 14/12/17.
 */
object Utils {

    /** content of :
     * readFromStream method
     * formatDate method
     * formatTime method
     * createUrl method
     * makeHttpRequest method
     */

    /**
     * Return the formatted date string (i.e. "Mar 3, 1984") from a Date object.
     */
    fun formatDate(dateObject: Date): String {
        val dateFormat = SimpleDateFormat("LLL dd, yyyy")
        return dateFormat.format(dateObject)
    }

    /**
     * Return the formatted date string (i.e. "4:30 PM") from a Date object.
     */
    fun formatTime(dateObject:Date):String {
        val timeFormat = SimpleDateFormat("h:mm a")
        return timeFormat.format(dateObject)
    }

    /**
     * Returns new URL object from the given string URL.
     */
    private fun createUrl(stringUrl: String): URL? {
        var url: URL? = null
        try {
            url = URL(stringUrl)
        } catch (e: MalformedURLException) {
            // TODO Handel the Exception.
        }catch (e :Exception){
            // TODO Handel the Exception.
        }

        return url
    }

    /**
     * Make an HTTP request to the given URL and return a String as the response.
     */
    private fun makeHttpRequest(url: URL?): String {
        var jsonResponse = ""

        // If the URL is null, then return early.
        if (url == null) {
            return jsonResponse
        }

        var urlConnection: HttpURLConnection? = null
        var inputStream: InputStream? = null
        try {
            urlConnection = url.openConnection() as HttpURLConnection
            urlConnection.setReadTimeout(10000 /* milliseconds */)
            urlConnection.setConnectTimeout(15000 /* milliseconds */)
            urlConnection.setRequestMethod("GET")
            urlConnection.connect()

            // If the request was successful (response code 200),
            // then read the input stream and parse the response.
            if (urlConnection.responseCode === 200) {
                inputStream = urlConnection.getInputStream()
                jsonResponse = readFromStream(inputStream)
            } else {
                // TODO : there is a problem with the response code 
            }
        } catch (e: IOException) {
            // TODO Handel the Exception.
        } catch (e :Exception){
            // TODO Handel the Exception.
        }finally {
            if (urlConnection != null) {
                urlConnection.disconnect()
            }
            if (inputStream != null) {
                // Closing the input stream could throw an IOException, which is why
                // the makeHttpRequest(URL url) method signature specifies than an IOException
                // could be thrown.
                inputStream.close()
            }
        }
        return jsonResponse
    }

    /**
     * Convert the [InputStream] into a String which contains the
     * whole JSON response from the server.
     */
    private fun readFromStream(inputStream: InputStream?): String {
        val output = StringBuilder()
        if (inputStream != null) {
            val inputStreamReader = InputStreamReader(inputStream, Charset.forName("UTF-8"))
            val reader = BufferedReader(inputStreamReader)
            var line = reader.readLine()
            while (line != null) {
                output.append(line)
                line = reader.readLine()
            }
        }
        return output.toString()
    }

}