package net.roarsoftware.lastfm;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;

import net.roarsoftware.util.StringUtilities;
import net.roarsoftware.xml.DomElement;

/**
 * Bean that contains artist information.<br/>
 * This class contains static methods that executes API methods relating to artists.<br/>
 * Method names are equivalent to the last.fm API method names.
 *
 * @author Janni Kovacs
 */
public class Artist extends MusicEntry {

	private Collection<Artist> similar = new ArrayList<Artist>();

	private float similarityMatch;

	protected Artist(String name, String url) {
		super(name, url);
	}

	protected Artist(String name, String url, String mbid, int playcount, int listeners, boolean streamable) {
		super(name, url, mbid, playcount, listeners, streamable);
	}

	public float getSimilarityMatch() {
		return similarityMatch;
	}

	/**
	 * Returns a list of similar <code>Artist</code>s. Note that this method does not retrieve this list
	 * from the server but instead returns the result of an <code>artist.getInfo</code> call.<br/>
	 * If you need to retrieve similar artists to a specified artist use the {@link #getSimilar(String, String)} method.
	 *
	 * @return list of similar artists
	 * @see #getSimilar(String, String)
	 * @see #getSimilar(String, int, String)
	 */
	public Collection<Artist> getSimilar() {
		return similar;
	}

	/**
	 * Retrieves detailed artist info for the given artist or mbid entry.
	 *
	 * @param artistOrMbid Name of the artist or an mbid
	 * @param apiKey The API key
	 * @return detailed artist info
	 */
	public static Artist getInfo(String artistOrMbid, String apiKey) {
		return getInfo(artistOrMbid, Locale.getDefault(), apiKey);
	}

	/**
	 * Retrieves detailed artist info for the given artist or mbid entry.
	 *
	 * @param artistOrMbid Name of the artist or an mbid
	 * @param locale The language to fetch info in
	 * @param apiKey The API key
	 * @return detailed artist info
	 */
	public static Artist getInfo(String artistOrMbid, Locale locale, String apiKey) {
		Map<String, String> params = new HashMap<String, String>();
		if (StringUtilities.isMbid(artistOrMbid)) {
			params.put("mbid", artistOrMbid);
		} else {
			params.put("artist", artistOrMbid);
		}
		if (locale != null && locale.getLanguage().length() != 0) {
			params.put("lang", locale.getLanguage());
		}
		Result result = Caller.getInstance().call("artist.getInfo", apiKey, params);
		if (!result.isSuccessful())
			return null;
		DomElement artistElement = result.getContentElement();
		return artistFromElement(artistElement);
	}

	/**
	 * Calls {@link #getSimilar(String, int, String)} with the default limit of 100.
	 *
	 * @param artist Artist's name
	 * @param apiKey The API key
	 * @return similar artists
	 * @see #getSimilar(String, int, String)
	 */
	public static Collection<Artist> getSimilar(String artist, String apiKey) {
		return getSimilar(artist, 100, apiKey);
	}

	/**
	 * Returns <code>limit</code> similar artists to the given one.
	 *
	 * @param artist Artist's name
	 * @param limit Number of maximum results
	 * @param apiKey The API key
	 * @return similar artists
	 */
	public static Collection<Artist> getSimilar(String artist, int limit, String apiKey) {
		Result result = Caller.getInstance()
				.call("artist.getSimilar", apiKey, "artist", artist, "limit", String.valueOf(limit));
		if (!result.isSuccessful())
			return Collections.emptyList();
		DomElement element = result.getContentElement();
		List<Artist> artists = new ArrayList<Artist>();
		for (DomElement e : element.getChildren("artist")) {
			artists.add(artistFromElement(e));
		}
		return artists;
	}

	/**
	 * Searches for an artist and returns a <code>Collection</code> of possible matches.
	 *
	 * @param name The artist name to look up
	 * @param apiKey The API key
	 * @return a list of possible matches
	 */
	public static Collection<Artist> search(String name, String apiKey) {
		Result result = Caller.getInstance().call("artist.search", apiKey, "artist", name);
		Collection<DomElement> children = result.getContentElement().getChild("artistmatches")
				.getChildren("artist");
		List<Artist> list = new ArrayList<Artist>(children.size());
		for (DomElement c : children) {
			list.add(artistFromElement(c));
		}
		return list;
	}

	/**
	 * Returns a list of the given artist's top albums.
	 *
	 * @param artist Artist's name
	 * @param apiKey The API key
	 * @return list of top albums
	 */
	public static Collection<Album> getTopAlbums(String artist, String apiKey) {
		Result result = Caller.getInstance().call("artist.getTopAlbums", apiKey, "artist", artist);
		if (!result.isSuccessful())
			return Collections.emptyList();
		DomElement element = result.getContentElement();
		String artistName = element.getAttribute("artist"); // may be different from user input
		List<Album> albums = new ArrayList<Album>();
		for (DomElement e : element.getChildren("album")) {
			albums.add(Album.albumFromElement(e, artistName));
		}
		return albums;
	}

	/**
	 * Retrieves a list of the top fans of the given artist.
	 *
	 * @param artist Artist's name
	 * @param apiKey The API key
	 * @return list of top fans
	 */
	public static Collection<User> getTopFans(String artist, String apiKey) {
		Result result = Caller.getInstance().call("artist.getTopFans", apiKey, "artist", artist);
		if (!result.isSuccessful())
			return Collections.emptyList();
		DomElement element = result.getContentElement();
		List<User> users = new ArrayList<User>();
		for (DomElement domElement : element.getChildren("user")) {
			users.add(User.userFromElement(domElement));
		}
		return users;
	}

	/**
	 * Retrieves the top tags for the given artist.
	 *
	 * @param artist Artist's name
	 * @param apiKey The API key
	 * @return list of top tags
	 */
	public static Collection<String> getTopTags(String artist, String apiKey) {
		Result result = Caller.getInstance().call("artist.getTopTags", apiKey, "artist", artist);
		if (!result.isSuccessful())
			return Collections.emptyList();
		DomElement element = result.getContentElement();
		List<String> tags = new ArrayList<String>();
		for (DomElement domElement : element.getChildren("tag")) {
			tags.add(domElement.getChildText("name"));
		}
		return tags;
	}

	/**
	 * Get the top tracks by an artist on Last.fm, ordered by popularity
	 *
	 * @param artist The artist name in question
	 * @param apiKey A Last.fm API key.
	 * @return list of top tracks
	 */
	public static Collection<Track> getTopTracks(String artist, String apiKey) {
		Result result = Caller.getInstance().call("artist.getTopTracks", apiKey, "artist", artist);
		if (!result.isSuccessful())
			return Collections.emptyList();
		DomElement element = result.getContentElement();
		String artistName = element.getAttribute("artist"); // may be different from user input
		List<Track> tracks = new ArrayList<Track>();
		for (DomElement e : element.getChildren("track")) {
			tracks.add(Track.trackFromElement(e, artistName));
		}
		return tracks;
	}

	/**
	 * Tag an artist with one or more user supplied tags.
	 *
	 * @param artist The artist name in question.
	 * @param tags A comma delimited list of user supplied tags to apply to this artist. Accepts a maximum of 10 tags.
	 * @param session A Session instance
	 * @return the result of the operation
	 */
	public static Result addTags(String artist, String tags, Session session) {
		return Caller.getInstance().call("artist.addTags", session, "artist", artist, "tags", tags);
	}

	/**
	 * Remove a user's tag from an artist.
	 *
	 * @param artist The artist name in question.
	 * @param tag A single user tag to remove from this artist.
	 * @param session A Session instance
	 * @return the result of the operation
	 */
	public static Result removeTag(String artist, String tag, Session session) {
		return Caller.getInstance().call("artist.removeTag", session, "artist", artist, "tag", tag);
	}

	/**
	 * Share an artist with one or more Last.fm users or other friends.
	 *
	 * @param artist The artist to share.
	 * @param recipients A comma delimited list of email addresses or Last.fm usernames. Maximum is 10.
	 * @param message An optional message to send with the recommendation.
	 * @param session A Session instance
	 * @return the Result of the operation
	 */
	public static Result share(String artist, String recipients, String message, Session session) {
		return Caller.getInstance()
				.call("artist.share", session, "artist", artist, "recipient", recipients, "message", message);
	}

	/**
	 * Get the tags applied by an individual user to an artist on Last.fm.
	 *
	 * @param artist The artist name in question
	 * @param session A Session instance
	 * @return a list of tags
	 */
	public static Collection<String> getTags(String artist, Session session) {
		Result result = Caller.getInstance().call("artist.getTags", session, "artist", artist);
		if (!result.isSuccessful())
			return Collections.emptyList();
		DomElement element = result.getContentElement();
		Collection<String> tags = new ArrayList<String>();
		for (DomElement domElement : element.getChildren("tag")) {
			tags.add(domElement.getChildText("name"));
		}
		return tags;
	}

	/**
	 * Returns a list of upcoming events for an artist.
	 *
	 * @param artist The artist name in question
	 * @param apiKey A Last.fm API key.
	 * @return a list of events
	 */
	public static Collection<Event> getEvents(String artist, String apiKey) {
		Result result = Caller.getInstance().call("artist.getEvents", apiKey, "artist", artist);
		if (!result.isSuccessful())
			return Collections.emptyList();
		DomElement element = result.getContentElement();
		Collection<Event> events = new ArrayList<Event>();
		for (DomElement domElement : element.getChildren("event")) {
			events.add(Event.eventFromElement(domElement));
		}
		return events;
	}

	/**
	 * Get {@link Image}s for this artist in a variety of sizes.
	 *
	 * @param artist The artist name in question
	 * @param apiKey A Last.fm API key
	 * @return a list of {@link Image}s
	 */
	public static PaginatedResult<Image> getImages(String artist, String apiKey) {
		return getImages(artist, 1, 50, apiKey);
	}

	/**
	 * Get {@link Image}s for this artist in a variety of sizes.
	 *
	 * @param artist The artist name in question
	 * @param page Which page of limit amount to display
	 * @param limit How many to return. Defaults and maxes out at 50
	 * @param apiKey A Last.fm API key
	 * @return a list of {@link Image}s
	 */
	public static PaginatedResult<Image> getImages(String artist, int page, int limit, String apiKey) {
		Result result = Caller.getInstance()
				.call("artist.getImages", apiKey, "artist", artist, "page", String.valueOf(page), "limit",
						String.valueOf(limit));
		DomElement root = result.getContentElement();
		List<Image> images = new ArrayList<Image>(limit);
		for (DomElement element : root.getChildren("image")) {
			images.add(Image.imageFromElement(element));
		}
		return new PaginatedResult<Image>(Integer.parseInt(root.getAttribute("page")),
				Integer.parseInt(root.getAttribute("totalpages")), images);
	}

	/**
	 * Shout on this artist's shoutbox
	 *
	 * @param artist The name of the artist to shout on
	 * @param message The message to post to the shoutbox
	 * @param session A Session instance
	 * @return the result of the operation
	 */
	public static Result shout(String artist, String message, Session session) {
		return Caller.getInstance().call("artist.shout", session, "artist", artist, "message", message);
	}

	/**
	 * Creates artist info out of a DomElement.
	 *
	 * @param element An XML DomElement
	 * @return artist info
	 */
	static Artist artistFromElement(DomElement element) {
		Artist artist = new Artist(null, null);
		MusicEntry.loadStandardInfo(artist, element);
		// match for similar artists response
		if (element.hasChild("match")) {
			artist.similarityMatch = Float.parseFloat(element.getChildText("match"));
		}
		// similar artists
		DomElement similar = element.getChild("similar");
		if (similar != null) {
			Collection<DomElement> children = similar.getChildren("artist");
			for (DomElement child : children) {
				artist.similar.add(artistFromElement(child));
			}
		}
		return artist;
	}

}