// $Id$
/*
 * WorldEdit
 * Copyright (C) 2010, 2011 sk89q <http://www.sk89q.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

package com.sk89q.worldedit.util;

import java.util.EnumSet;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import com.sk89q.worldedit.EditSession;
import com.sk89q.worldedit.LocalWorld;
import com.sk89q.worldedit.MaxChangedBlocksException;
import com.sk89q.worldedit.Vector;
import com.sk89q.worldedit.blocks.BaseBlock;
import com.sk89q.worldedit.blocks.BlockID;

/**
 * Tree generator.
 *
 * @author sk89q
 */
public class TreeGenerator {
    public enum TreeType {
        TREE("Regular tree", new String[] {"tree", "regular"}),
        BIG_TREE("Big tree", new String[] {"big", "bigtree"}),
        REDWOOD("Redwood", new String[] {"redwood", "sequoia", "sequoioideae"}),
        TALL_REDWOOD("Tall redwood", new String[] {"tallredwood", "tallsequoia", "tallsequoioideae"}),
        BIRCH("Birch", new String[] {"birch", "white", "whitebark"}),
        PINE("Pine", new String[] {"pine"}),
        RANDOM_REDWOOD("Random redwood", new String[] {"randredwood", "randomredwood", "anyredwood"}),
        RANDOM("Random", new String[] {"rand", "random"});

        /**
         * Stores a map of the names for fast access.
         */
        private static final Map<String,TreeType> lookup = new HashMap<String,TreeType>();

        private final String name;
        private final String[] lookupKeys;

        static {
            for (TreeType type : EnumSet.allOf(TreeType.class)) {
                for (String key : type.lookupKeys) {
                    lookup.put(key, type);
                }
            }
        }
        
        TreeType(String name, String lookupKey) {
            this.name = name;
            this.lookupKeys = new String[]{ lookupKey };
        }
        
        TreeType(String name, String[] lookupKeys) {
            this.name = name;
            this.lookupKeys = lookupKeys;
        }
        
        /**
         * Get user-friendly tree type name.
         *
         * @return
         */
        public String getName() {
            return name;
        }
        
        /**
         * Return type from name. May return null.
         *
         * @param name
         * @return
         */
        public static TreeType lookup(String name) {
            return lookup.get(name.toLowerCase());
        }
    };
    
    private static Random rand = new Random();
    
    private TreeType type;
    
    /**
     * Construct the tree generator with a tree type.
     * 
     * @param type
     */
    public TreeGenerator(TreeType type) {
        this.type = type;
    }
    
    /**
     * Generate a tree.
     * 
     * @param editSession
     * @param pos
     * @return
     * @throws MaxChangedBlocksException
     */
    public boolean generate(EditSession editSession, Vector pos)
            throws MaxChangedBlocksException {
        return generate(type, editSession, pos);
    }
    
    /**
     * Generate a tree.
     * 
     * @param world
     * @param editSession
     * @param pos
     * @return
     * @throws MaxChangedBlocksException
     */
    private boolean generate(TreeType type, EditSession editSession, Vector pos)
            throws MaxChangedBlocksException {
        LocalWorld world = editSession.getWorld();
        
        TreeType[] choices;
        TreeType realType;
        
        switch (type) {
            case TREE:
                return world.generateTree(editSession, pos);
            case BIG_TREE:
                return world.generateBigTree(editSession, pos);
            case BIRCH:
                return world.generateBirchTree(editSession, pos);
            case REDWOOD:
                return world.generateRedwoodTree(editSession, pos);
            case TALL_REDWOOD:
                return world.generateTallRedwoodTree(editSession, pos);
            case PINE:
                makePineTree(editSession, pos);
                return true;
            case RANDOM_REDWOOD:
                choices = 
                    new TreeType[] {
                        TreeType.REDWOOD, TreeType.TALL_REDWOOD
                        };
                realType = choices[rand.nextInt(choices.length)];
                return generate(realType, editSession, pos);
            case RANDOM:
                choices = 
                    new TreeType[] {
                        TreeType.TREE, TreeType.BIG_TREE, TreeType.BIRCH,
                        TreeType.REDWOOD, TreeType.TALL_REDWOOD, TreeType.PINE
                        };
                realType = choices[rand.nextInt(choices.length)];
                return generate(realType, editSession, pos);
        }
        
        return false;
    }

    /**
     * Makes a terrible looking pine tree.
     * 
     * @param basePos
     */
    private static void makePineTree(EditSession editSession, Vector basePos)
            throws MaxChangedBlocksException {
        int trunkHeight = (int) Math.floor(Math.random() * 2) + 3;
        int height = (int) Math.floor(Math.random() * 5) + 8;

        BaseBlock logBlock = new BaseBlock(BlockID.LOG);
        BaseBlock leavesBlock = new BaseBlock(BlockID.LEAVES);

        // Create trunk
        for (int i = 0; i < trunkHeight; ++i) {
            if (!editSession.setBlockIfAir(basePos.add(0, i, 0), logBlock)) {
                return;
            }
        }

        // Move up
        basePos = basePos.add(0, trunkHeight, 0);

        // Create tree + leaves
        for (int i = 0; i < height; ++i) {
            editSession.setBlockIfAir(basePos.add(0, i, 0), logBlock);

            // Less leaves at these levels
            double chance = ((i == 0 || i == height - 1) ? 0.6 : 1);

            // Inner leaves
            editSession.setChanceBlockIfAir(basePos.add(-1, i, 0), leavesBlock, chance);
            editSession.setChanceBlockIfAir(basePos.add(1, i, 0), leavesBlock, chance);
            editSession.setChanceBlockIfAir(basePos.add(0, i, -1), leavesBlock, chance);
            editSession.setChanceBlockIfAir(basePos.add(0, i, 1), leavesBlock, chance);
            editSession.setChanceBlockIfAir(basePos.add(1, i, 1), leavesBlock, chance);
            editSession.setChanceBlockIfAir(basePos.add(-1, i, 1), leavesBlock, chance);
            editSession.setChanceBlockIfAir(basePos.add(1, i, -1), leavesBlock, chance);
            editSession.setChanceBlockIfAir(basePos.add(-1, i, -1), leavesBlock, chance);

            if (!(i == 0 || i == height - 1)) {
                for (int j = -2; j <= 2; ++j) {
                    editSession.setChanceBlockIfAir(basePos.add(-2, i, j), leavesBlock, 0.6);
                }
                for (int j = -2; j <= 2; ++j) {
                    editSession.setChanceBlockIfAir(basePos.add(2, i, j), leavesBlock, 0.6);
                }
                for (int j = -2; j <= 2; ++j) {
                    editSession.setChanceBlockIfAir(basePos.add(j, i, -2), leavesBlock, 0.6);
                }
                for (int j = -2; j <= 2; ++j) {
                    editSession.setChanceBlockIfAir(basePos.add(j, i, 2), leavesBlock, 0.6);
                }
            }
        }

        editSession.setBlockIfAir(basePos.add(0, height, 0), leavesBlock);
    }
    
    /**
     * Looks up a tree type. May return null if a tree type by that
     * name is not found.
     * 
     * @param type
     * @return
     */
    public static TreeType lookup(String type) {
        return TreeType.lookup(type);
    }
}