import jm.music.data.*;
import jm.JMC;
import jm.util.*;
import jm.music.tools.*;

/**
 * Class that represents elements of the song
 * amazing grace
 * @author Mark Guzdial
 * @author Barb Ericson
 */
public class AmazingGraceSongElement {
  
  /** the next element */
  private AmazingGraceSongElement next;
  /** my part in the song */
  private Part myPart;
  
  /**
   * When we make a new element, the next part is 
   * empty, and ours is a blank new part
   */
  public AmazingGraceSongElement() {
    this.next = null;
    this.myPart = new Part();
  }
  
  /** 
   * addPhrase1 puts the first part of AmazingGrace 
   * into our part of the song at the desired start 
   * time with the given instrument
   * @param startTime the time to start playing this element
   * @param instrument the instrument to use 
   */
  public void addPhrase1(double startTime, 
                         int instrument) {
    
    double[] phrase1Data = {
      JMC.G4, JMC.QN,
      JMC.C5, JMC.HN, JMC.E5,JMC.EN, JMC.C5,JMC.EN,
      JMC.E5,JMC.HN,JMC.D5,JMC.QN,
      JMC.C5,JMC.HN,JMC.A4,JMC.QN,
      JMC.G4,JMC.HN,JMC.G4,JMC.EN,JMC.A4,JMC.EN,
      JMC.C5,JMC.HN,JMC.E5,JMC.EN,JMC.C5,JMC.EN,
      JMC.E5,JMC.HN,JMC.D5,JMC.EN,JMC.E5,JMC.EN,
      JMC.G5,JMC.DHN
    };
    
    Phrase myPhrase = new Phrase(startTime);
    myPhrase.addNoteList(phrase1Data);
    this.myPart.addPhrase(myPhrase);
    // In MVAmazingGraceSong, we did this when we initialized
    // the part. But we CAN do it later
    this.myPart.setInstrument(instrument);
  }
  
  /**
   * Add the second phrase
   * @param startTime the time to start
   * @param instrument the instrument to use
   */
  public void addPhrase2(double startTime, 
                         int instrument) {
    double[] phrase2Data = {
      JMC.G5,JMC.HN,JMC.E5,JMC.EN,JMC.G5,JMC.EN,
      JMC.G5,JMC.HN,JMC.E5,JMC.EN,JMC.C5,JMC.EN,
      JMC.E5,JMC.HN,JMC.D5,JMC.QN,
      JMC.C5,JMC.HN,JMC.A4,JMC.QN,
      JMC.G4,JMC.HN,JMC.G4,JMC.EN,JMC.A4,JMC.EN,
      JMC.C5,JMC.HN,JMC.E5,JMC.EN,JMC.C5,JMC.EN,
      JMC.E5,JMC.HN,JMC.D5,JMC.QN,
      JMC.C5,JMC.DHN
    };
    
    Phrase myPhrase = new Phrase(startTime);
    myPhrase.addNoteList(phrase2Data);
    this.myPart.addPhrase(myPhrase);
    this.myPart.setInstrument(instrument);
  }
  
  /**
   * Set the next element
   * @param nextOne the one to use as the next
   */
  public void setNext(AmazingGraceSongElement nextOne) {
    this.next = nextOne;
  }
  
  /**
   * Method to get the next element
   * @return the next element 
   */
  public AmazingGraceSongElement getNext() {
    return this.next;
  }
  
  /** We could just access myPart directly
    * but we can CONTROL access by using a method
    * We'll use it in showFromMeOn
    * @return the part for this element
    */
  public Part getPart() {
    return this.myPart;
  }
  
  /** We could just access myPart directly
    * but we can CONTROL access by using a method
    * We'll use it in showFromMeOn
    * @return the part for this element
    */
  public Part part() {
    return this.myPart;
  }
  
  /**
   * Why do we need this?  If we want one piece to 
   * start after another, we need to know when the 
   * last one ends.  Notice: It's the phrase that knows the end time.
   * We have to ask the part for its phrase (assuming only one)
   * to get the end time.
   * @return the end time of this element
   */
  public double getEndTime() {
    return this.myPart.getPhrase(0).getEndTime();
  }
  
  /** We need setChannel because each part has to be in its
    * own channel if it has different start times.  So, 
    * we'll set the channel when we assemble the score.
    * (But if we only need it for showFromMeOn, we could
    * make it PRIVATE...)
    * @param channel the channel to use
    */
  public void setChannel(int channel) {
    myPart.setChannel(channel);
  }
  
  /**
   * Method to show from this element on 
   */
  public void showFromMeOn() {
    
    // Make the score that we'll assemble the elements into
    Score myScore = new Score("Amazing Grace");
    myScore.setTimeSignature(3,4);
    
    // Each element will be in its own channel
    int channelCount = 1;
    
    // Start from this element (this)
    AmazingGraceSongElement current = this;
    
    // While we're not through...
    while (current != null) {
      
      // Set the channel, increment the channel, then add it in.
      current.setChannel(channelCount);
      channelCount = channelCount + 1;
      myScore.addPart(current.part());
      
      /* Now, move on to the next element
       * which we already know isn't null */
      current = current.getNext();
    }
    
    // At the end, let's see it!
    View.notate(myScore);
  }
  
}