Track.java

package MusicLandscape.entities;

import java.util.Objects;

/**
 * represents a piece of music that has been released on some kind of media (CD, vinyl, video, ...)
 *
 * @author Jonas Altrock (ew20b126@technikum-wien.at)
 * @version 1
 * @since ExcerciseSheet01
 */
public class Track {
    /**
     * the duration of this track in seconds the duration is a non-negative number, duration 0 (zero) represents unknown duration
     */
    private int duration = 0;

    /**
     * the artist who performs this track the performer cannot be null
     */
    private Artist performer = new Artist();

    /**
     * the title of this track.
     */
    private String title;

    /**
     * the artist who wrote this track the writer cannot be null
     */
    private Artist writer = new Artist();

    /**
     * the year in which the Track was or will be produced valid years are between 1900-2999
     */
    private int year = 0;

    /**
     * gets the duration of this track
     *
     * @return the duration
     */
    public int getDuration() {
        return duration;
    }

    /**
     * returns the performer of this track
     *
     * @return the performer
     */
    public Artist getPerformer() {
        return performer;
    }

    /**
     * gets the title of this track. if the title is not known (null) "unknown title" is returned (without quotes)
     *
     * @return the title
     */
    public String getTitle() {
        if (title == null || title.isBlank()) {
            return "unknown title";
        }
        return title;
    }

    /**
     * returns the writer of this track
     *
     * @return the writer
     */
    public Artist getWriter() {
        return writer;
    }

    /**
     * gets the production year of this track
     *
     * @return the year
     */
    public int getYear() {
        return year;
    }

    /**
     * sets the duration a negative value is ignored, the object remains unchanged
     *
     * @param duration - the duration to set
     */
    public void setDuration(int duration) {
        if (duration < 0) {
            return;
        }
        this.duration = duration;
    }

    /**
     * sets the performer of this track null arguments are ignored
     *
     * @param performer - the performer to set
     */
    public void setPerformer(Artist performer) {
        if (performer == null) {
            return;
        }
        this.performer = performer;
    }

    /**
     * sets the title of this track.
     *
     * @param title - the title to set
     */
    public void setTitle(String title) {
        this.title = title;
    }

    /**
     * sets the the writer of this track null arguments are ignored
     *
     * @param writer - the writer to set
     */
    public void setWriter(Artist writer) {
        if (writer == null) {
            return;
        }
        this.writer = writer;
    }

    /**
     * sets the production year of this track valid years are between 1900 and 2999 other values are ignored, the object remains unchanged
     *
     * @param year - the year to set
     */
    public void setYear(int year) {
        if (year < 1900 || year > 2999) {
            return;
        }
        this.year = year;
    }

    /**
     * this getter is used to check if the writer of this Track is known.
     *
     * @return true if the writer of this track is known (and has a name), false otherwise.
     */
    public boolean writerIsKnown() {
        return isKnown(writer);
    }

    /**
     * Check whether an artist is known.
     * @param artist the artist to check
     * @return whether the artist is known or not
     */
    protected boolean isKnown(Artist artist) {
        return artist != null && artist.getName() != null && !artist.getName().isBlank();
    }

    /**
     * returns a formatted String containing all information of this track. the String representation is (without quotes):
     * <p>
     * "title by writer performed by performer (min:sec)"
     * <p>
     * where
     * - title stands for the title (exactly 10 chars wide) if not set, return unknown
     * - writer stands for the writer name (exactly 10 chars wide, right justified)
     * - performer stands for the performer name (exactly 10 chars wide, right justified)
     * - min is the duration's amount of full minutes (at least two digits, leading zeros)
     * - sec is the duration's remaining amount of seconds (at least two digits, leading zeros)
     *
     * @return a String representation of this track
     */
    public String getString() {
        String title = Objects.equals(getTitle(), "unknown title") ? "unknown" : this.title;
        String writer = isKnown(getWriter()) ? getWriter().getName() : "unknown";
        String performer = isKnown(getPerformer()) ? getPerformer().getName() : "unknown";

        title = String.format("%10s", title).substring(0, 10);
        writer = String.format("%10s", writer).substring(0, 10);
        performer = String.format("%10s", performer).substring(0, 10);

        String minutes = String.format("%02d", (duration / 60) % 100);
        String seconds = String.format("%02d", duration % 60);

        return title + " by " + writer + " performed by " + performer + " (" + minutes + ":" + seconds + ")";
    }
}