package tim.prune.gui.map;

import java.net.MalformedURLException;
import java.net.URL;

/**
 * Class to represent any map source, whether an OsmMapSource
 * or one of the more complicated ones.
 * Map sources may contain just one or several layers, and may
 * build their URLs in different ways depending on the source
 */
public abstract class MapSource
{
	/**
	 * @return the number of layers used in this source
	 */
	public abstract int getNumLayers();

	/**
	 * @return the name of the source
	 */
	public abstract String getName();

	/**
	 * @return the base url for the specified layer
	 */
	public abstract String getBaseUrl(int inLayerNum);

	/**
	 * @return the site name for the specified layer
	 */
	public abstract String getSiteName(int inLayerNum);

	/**
	 * @return the file extension for the specified layer
	 */
	public abstract String getFileExtension(int inLayerNum);

	/**
	 * Make the URL to get the specified tile
	 * @param inLayerNum number of layer, from 0 (base) to getNumLayers-1 (top)
	 * @param inZoom zoom level
	 * @param inX x coordinate of tile
	 * @param inY y coordinate of tile
	 * @return URL as string
	 */
	public abstract String makeURL(int inLayerNum, int inZoom, int inX, int inY);

	/**
	 * @return the maximum zoom level for this source
	 */
	public abstract int getMaxZoomLevel();

	/**
	 * Make a relative file path from the base directory including site name
	 * @param inLayerNum layer number
	 * @param inZoom zoom level
	 * @param inX x coordinate
	 * @param inY y coordinate
	 * @return relative file path as String
	 */
	public String makeFilePath(int inLayerNum, int inZoom, int inX, int inY)
	{
		return getSiteName(inLayerNum) + inZoom + "/" + inX + "/" + inY + getFileExtension(inLayerNum);
	}

	/**
	 * Checks the given url for having the right prefix and trailing slash
	 * @param inUrl url to check
	 * @return validated url with correct prefix and trailing slash, or null
	 */
	protected static String fixBaseUrl(String inUrl)
	{
		if (inUrl == null || inUrl.equals("")) {return null;}
		String url = inUrl;
		// check prefix
		try {
			new URL(url);
		}
		catch (MalformedURLException e) {
			// add the http protocol
			url = "http://" + url;
		}
		// check trailing /
		if (!url.endsWith("/")) {
			url = url + "/";
		}
		return url;
	}

	/**
	 * Fix the site name by stripping off protocol and www.
	 * This is used to create the file path for disk caching
	 * @param inUrl url to strip
	 * @return stripped url
	 */
	protected static String fixSiteName(String inUrl)
	{
		if (inUrl == null || inUrl.equals("")) {return null;}
		String url = inUrl.toLowerCase();
		int idx = url.indexOf("://");
		if (idx >= 0) {url = url.substring(idx + 3);}
		if (url.startsWith("www.")) {url = url.substring(4);}
		return url;
	}

	/**
	 * @return string which can be written to the Config
	 */
	public abstract String getConfigString();

	/**
	 * @return semicolon-separated list of base urls in order
	 */
	public String getSiteStrings()
	{
		String s = "";
		for (int i=0; i<getNumLayers(); i++) {
			String url = getBaseUrl(i);
			if (url != null) {s = s + url + ";";}
		}
		return s;
	}
}