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.Map;



import net.roarsoftware.xml.DomElement;



/**

 * Provides nothing more than a namespace for the API methods starting with geo.

 *

 * @author Janni Kovacs

 */

public class Geo {



	private Geo() {

	}



	/**

	 * Get all events in a specific location by country or city name.<br/>

	 * This method returns <em>all</em> events by subsequently calling {@link #getEvents(String, String, int, String)}

	 * and concatenating the single results into one list.<br/>

	 * Pay attention if you use this method as it may produce a lot of network traffic and therefore

	 * may consume a long time.

	 *

	 * @param location Specifies a location to retrieve events for

	 * @param distance Find events within a specified distance

	 * @param apiKey A Last.fm API key.

	 * @return a list containing all events

	 */

	public static Collection<Event> getAllEvents(String location, String distance, String apiKey) {

		Collection<Event> events = null;

		int page = 1, total;

		do {

			PaginatedResult<Event> result = getEvents(location, distance, page, apiKey);

			total = result.getTotalPages();

			Collection<Event> pageResults = result.getPageResults();

			if (events == null) {

				// events is initialized here to initialize it with the right size and avoid array copying later on

				events = new ArrayList<Event>(total * pageResults.size());

			}

			for (Event artist : pageResults) {

				events.add(artist);

			}

			page++;

		} while (page <= total);

		return events;

	}



	/**

	 * Get all events in a specific location by country or city name.<br/>

	 * This method only returns the first page of a possibly paginated result. To retrieve all pages

	 * get the total number of pages via {@link net.roarsoftware.lastfm.PaginatedResult#getTotalPages()} and

	 * subsequently call {@link #getEvents(String, String, int, String)} with the successive page numbers.

	 *

	 * @param location Specifies a location to retrieve events for

	 * @param distance Find events within a specified distance

	 * @param apiKey A Last.fm API key.

	 * @return a {@link PaginatedResult} containing a list of events

	 */

	public static PaginatedResult<Event> getEvents(String location, String distance, String apiKey) {

		return getEvents(location, distance, 1, apiKey);

	}



	/**

	 * Get all events in a specific location by country or city name.<br/>

	 * This method only returns the specified page of a paginated result.

	 *

	 * @param location Specifies a location to retrieve events for

	 * @param distance Find events within a specified distance

	 * @param page A page number for pagination

	 * @param apiKey A Last.fm API key.

	 * @return a {@link PaginatedResult} containing a list of events

	 */

	public static PaginatedResult<Event> getEvents(String location, String distance, int page, String apiKey) {

		Map<String, String> params = new HashMap<String, String>();

		params.put("page", String.valueOf(page));

		if (location != null)

			params.put("location", location);

		if (distance != null)

			params.put("distance", distance);

		Result result = Caller.getInstance().call("geo.getEvents", apiKey, params);

		if (!result.isSuccessful())

			return new PaginatedResult<Event>(0, 0, Collections.<Event>emptyList());

		DomElement element = result.getContentElement();

		List<Event> events = new ArrayList<Event>();

		for (DomElement domElement : element.getChildren("event")) {

			events.add(Event.eventFromElement(domElement));

		}

		int currentPage = Integer.valueOf(element.getAttribute("page"));

		int totalPages = Integer.valueOf(element.getAttribute("totalpages"));

		return new PaginatedResult<Event>(page, totalPages, events);

	}



	/**

	 * Get all events in a specific location by country or city name.<br/>

	 * This method only returns the specified page of a paginated result.

	 *

	 * @param latitude Latitude

	 * @param longitude Longitude

	 * @param page A page number for pagination

	 * @param apiKey A Last.fm API key.

	 * @return a {@link PaginatedResult} containing a list of events

	 */

	public static PaginatedResult<Event> getEvents(double latitude, double longitude, int page, String apiKey) {

		Map<String, String> params = new HashMap<String, String>();

		params.put("page", String.valueOf(page));

		params.put("lat", String.valueOf(latitude));

		params.put("long", String.valueOf(longitude));

		Result result = Caller.getInstance().call("geo.getEvents", apiKey, params);

		if (!result.isSuccessful())

			return new PaginatedResult<Event>(0, 0, Collections.<Event>emptyList());

		DomElement element = result.getContentElement();

		List<Event> events = new ArrayList<Event>();

		for (DomElement domElement : element.getChildren("event")) {

			events.add(Event.eventFromElement(domElement));

		}

		int currentPage = Integer.valueOf(element.getAttribute("page"));

		int totalPages = Integer.valueOf(element.getAttribute("totalpages"));

		return new PaginatedResult<Event>(page, totalPages, events);

	}



	/**

	 * Get the most popular artists on Last.fm by country

	 *

	 * @param country A country name, as defined by the ISO 3166-1 country names standard

	 * @param apiKey A Last.fm API key.

	 * @return list of Artists

	 */

	public static Collection<Artist> getTopArtists(String country, String apiKey) {

		Result result = Caller.getInstance().call("geo.getTopArtists", apiKey, "country", country);

		if (!result.isSuccessful())

			return Collections.emptyList();

		List<Artist> artists = new ArrayList<Artist>();

		for (DomElement domElement : result.getContentElement().getChildren("artist")) {

			artists.add(Artist.artistFromElement(domElement));

		}

		return artists;

	}



	/**

	 * Get the most popular tracks on Last.fm by country

	 *

	 * @param country A country name, as defined by the ISO 3166-1 country names standard

	 * @param apiKey A Last.fm API key.

	 * @return a list of Tracks

	 */

	public static Collection<Track> getTopTracks(String country, String apiKey) {

		Result result = Caller.getInstance().call("geo.getTopTracks", apiKey, "country", country);

		if (!result.isSuccessful())

			return Collections.emptyList();

		List<Track> tracks = new ArrayList<Track>();

		for (DomElement domElement : result.getContentElement().getChildren("track")) {

			tracks.add(Track.trackFromElement(domElement));

		}

		return tracks;

	}



}