//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
/** @author  John Miller
 *  @version 1.0
 *  @date    Mon Jan 26 14:56:24 EST 2015
 *  @see     LICENSE (MIT style license file).
 */

import java.io.{IOException, StringWriter}
import java.nio.file.Files
import java.nio.file.Paths

import com.fasterxml.jackson.core.`type`.TypeReference
import com.fasterxml.jackson.databind.JsonNode
import com.fasterxml.jackson.databind.ObjectMapper
import com.fasterxml.jackson.databind.SerializationFeature
import com.fasterxml.jackson.databind.node.ObjectNode

//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
/** The `ReadWrite2` class provides methods for reading a Json stream into a Scala Bean
 *  and writing a Scala Bean into a Json stream.
 *  @see http://www.journaldev.com/2324/jackson-json-processing-api-in-java-example-tutorial
 */
object ReadWriteJson2
{
    private val objectMapper = new ObjectMapper ()     // create ObjectMapper instance

    //::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
    /** Read a file containing Json data into a Scala Bean.
     *  @param fname  the name of Json file 
     */
    @throws (classOf [IOException])
    def read (fname: String): Employee =
    {
        val jsonData = Files.readAllBytes (Paths.get (fname))
        objectMapper.readValue (jsonData, classOf [Employee])       // convert Json string to object
    } // read

    //::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
    /** Write a Scala Bean into a stream (in this case a string).
     *  @param emp  the Employee Scala Bean to write
     */
    @throws (classOf [IOException])
    def write (emp: Employee): StringWriter =
    {
        // configure Object mapper for pretty print
        objectMapper.configure (SerializationFeature.INDENT_OUTPUT, true)
         
        val stringEmp = new StringWriter ()                   // create string stream
        objectMapper.writeValue (stringEmp, emp)                       // write into string stream
        stringEmp
    } // write

    //::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
    /** Run the program via the main method.
     *  @param args  the command-line arguments
     */
    @throws (classOf [IOException])
    def main (args: Array [String])
    {
        println ("Read a Json stream/file into a Scala Bean")
        val emp = read ("employee.txt")
        println ("Employee Object:\n" + emp)
         
        println ("Write a Scala Bean into a Json stream")
        val stringEmp = write (emp)
        println ("Employee Json:\n" + stringEmp)
    } // main

} // ReadJson2 object