/*
 * Copyright 2010, 2011, 2012 mapsforge.org
 *
 * This program is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.mapsforge.map.rendertheme.rule;

import java.util.ArrayList;
import java.util.List;

import org.mapsforge.core.model.Tag;
import org.mapsforge.core.util.LRUCache;
import org.mapsforge.map.rendertheme.RenderCallback;
import org.mapsforge.map.rendertheme.renderinstruction.RenderInstruction;

/**
 * A RenderTheme defines how ways and nodes are drawn.
 */
public class RenderTheme {
	private static final int MATCHING_CACHE_SIZE = 512;

	private final float baseStrokeWidth;
	private final float baseTextSize;
	private int levels;
	private final int mapBackground;
	private final LRUCache<MatchingCacheKey, List<RenderInstruction>> matchingCache;
	private final ArrayList<Rule> rulesList;

	RenderTheme(RenderThemeBuilder renderThemeBuilder) {
		this.baseStrokeWidth = renderThemeBuilder.baseStrokeWidth;
		this.baseTextSize = renderThemeBuilder.baseTextSize;
		this.mapBackground = renderThemeBuilder.mapBackground;
		this.rulesList = new ArrayList<Rule>();
		this.matchingCache = new LRUCache<MatchingCacheKey, List<RenderInstruction>>(MATCHING_CACHE_SIZE);
	}

	/**
	 * Must be called when this RenderTheme gets destroyed to clean up and free resources.
	 */
	public void destroy() {
		this.matchingCache.clear();
		for (int i = 0, n = this.rulesList.size(); i < n; ++i) {
			this.rulesList.get(i).onDestroy();
		}
	}

	/**
	 * @return the number of distinct drawing levels required by this RenderTheme.
	 */
	public int getLevels() {
		return this.levels;
	}

	/**
	 * @return the map background color of this RenderTheme.
	 */
	public int getMapBackground() {
		return this.mapBackground;
	}

	/**
	 * Matches a closed way with the given parameters against this RenderTheme.
	 * 
	 * @param renderCallback
	 *            the callback implementation which will be executed on each match.
	 * @param tags
	 *            the tags of the way.
	 * @param zoomLevel
	 *            the zoom level at which the way should be matched.
	 */
	public void matchClosedWay(RenderCallback renderCallback, List<Tag> tags, byte zoomLevel) {
		matchWay(renderCallback, tags, zoomLevel, Closed.YES);
	}

	/**
	 * Matches a linear way with the given parameters against this RenderTheme.
	 * 
	 * @param renderCallback
	 *            the callback implementation which will be executed on each match.
	 * @param tags
	 *            the tags of the way.
	 * @param zoomLevel
	 *            the zoom level at which the way should be matched.
	 */
	public void matchLinearWay(RenderCallback renderCallback, List<Tag> tags, byte zoomLevel) {
		matchWay(renderCallback, tags, zoomLevel, Closed.NO);
	}

	/**
	 * Matches a node with the given parameters against this RenderTheme.
	 * 
	 * @param renderCallback
	 *            the callback implementation which will be executed on each match.
	 * @param tags
	 *            the tags of the node.
	 * @param zoomLevel
	 *            the zoom level at which the node should be matched.
	 */
	public void matchNode(RenderCallback renderCallback, List<Tag> tags, byte zoomLevel) {
		for (int i = 0, n = this.rulesList.size(); i < n; ++i) {
			this.rulesList.get(i).matchNode(renderCallback, tags, zoomLevel);
		}
	}

	/**
	 * Scales the stroke width of this RenderTheme by the given factor.
	 * 
	 * @param scaleFactor
	 *            the factor by which the stroke width should be scaled.
	 */
	public void scaleStrokeWidth(float scaleFactor) {
		for (int i = 0, n = this.rulesList.size(); i < n; ++i) {
			this.rulesList.get(i).scaleStrokeWidth(scaleFactor * this.baseStrokeWidth);
		}
	}

	/**
	 * Scales the text size of this RenderTheme by the given factor.
	 * 
	 * @param scaleFactor
	 *            the factor by which the text size should be scaled.
	 */
	public void scaleTextSize(float scaleFactor) {
		for (int i = 0, n = this.rulesList.size(); i < n; ++i) {
			this.rulesList.get(i).scaleTextSize(scaleFactor * this.baseTextSize);
		}
	}

	private void matchWay(RenderCallback renderCallback, List<Tag> tags, byte zoomLevel, Closed closed) {
		MatchingCacheKey matchingCacheKey = new MatchingCacheKey(tags, zoomLevel, closed);

		List<RenderInstruction> matchingList = this.matchingCache.get(matchingCacheKey);
		if (matchingList != null) {
			// cache hit
			for (int i = 0, n = matchingList.size(); i < n; ++i) {
				matchingList.get(i).renderWay(renderCallback, tags);
			}
			return;
		}

		// cache miss
		matchingList = new ArrayList<RenderInstruction>();
		for (int i = 0, n = this.rulesList.size(); i < n; ++i) {
			this.rulesList.get(i).matchWay(renderCallback, tags, zoomLevel, closed, matchingList);
		}

		this.matchingCache.put(matchingCacheKey, matchingList);
	}

	void addRule(Rule rule) {
		this.rulesList.add(rule);
	}

	void complete() {
		this.rulesList.trimToSize();
		for (int i = 0, n = this.rulesList.size(); i < n; ++i) {
			this.rulesList.get(i).onComplete();
		}
	}

	void setLevels(int levels) {
		this.levels = levels;
	}
}