/*
 *    Fernflower - The Analytical Java Decompiler
 *    http://www.reversed-java.com
 *
 *    (C) 2008 - 2010, Stiver
 *
 *    This software is NEITHER public domain NOR free software 
 *    as per GNU License. See license.txt for more details.
 *
 *    This software is distributed WITHOUT ANY WARRANTY; without 
 *    even the implied warranty of MERCHANTABILITY or FITNESS FOR 
 *    A PARTICULAR PURPOSE. 
 */

package org.jetbrains.java.decompiler.util;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.Map.Entry;

import org.jetbrains.java.decompiler.modules.decompiler.exps.VarExprent;
import org.jetbrains.java.decompiler.util.FastSparseSetFactory.FastSparseSet;

public class SFormsFastMapDirect {

	private int size;
	
	private FastSparseSet<Integer>[][] elements = new FastSparseSet[3][];

	private int[][] next = new int[3][];
	
	public SFormsFastMapDirect() {
		this(true);
	}

	private SFormsFastMapDirect(boolean initialize) {
		if(initialize) {
			for(int i=2; i>=0; i--) {
				elements[i] = new FastSparseSet[0];
				next[i] = new int[0];
			}
		}
	}
	
	public SFormsFastMapDirect(SFormsFastMapDirect map) {
		for(int i=2;i>=0;i--) {
			FastSparseSet<Integer>[] arr = map.elements[i];
			int[] arrnext = map.next[i];

			int length = arr.length;
			FastSparseSet<Integer>[] arrnew = new FastSparseSet[length];
			int[] arrnextnew = new int[length];
			
			System.arraycopy(arr, 0, arrnew, 0, length);
			System.arraycopy(arrnext, 0, arrnextnew, 0, length);
			
			elements[i] = arrnew;
			next[i] = arrnextnew;
			
			size = map.size;
		}
	}
	
	public SFormsFastMapDirect getCopy() {

		SFormsFastMapDirect map = new SFormsFastMapDirect(false);
		map.size = size;
		
		FastSparseSet[][] mapelements = map.elements;
		int[][] mapnext = map.next;
		
		for(int i=2;i>=0;i--) {
			FastSparseSet<Integer>[] arr = elements[i];
			int length = arr.length;
			
			if(length > 0) {
				int[] arrnext = next[i];

				FastSparseSet<Integer>[] arrnew = new FastSparseSet[length];
				int[] arrnextnew = new int[length];

				System.arraycopy(arrnext, 0, arrnextnew, 0, length);

				mapelements[i] = arrnew;
				mapnext[i] = arrnextnew;
				
				int pointer = 0;
				do {
					FastSparseSet<Integer> set = arr[pointer];
					if(set != null) {
						arrnew[pointer] = set.getCopy();
					}

					pointer = arrnext[pointer];
				} while(pointer != 0);

			} else {
				mapelements[i] = new FastSparseSet[0];
				mapnext[i] = new int[0];
			}
		}
		
		return map;
	}
	
	public int size() {
		return size;
	}
	
	public boolean isEmpty() {
		return size == 0;
	}
	
	public void put(int key, FastSparseSet<Integer> value) {
		putInternal(key, value, false);
	}
	
	public void remove(int key) {
		putInternal(key, null, true);
	}
	
	public void removeAllFields() {
		FastSparseSet<Integer>[] arr = elements[2];
		int[] arrnext = next[2];
		
		for(int i=arr.length-1;i>=0;i--) {
			FastSparseSet<Integer> val = arr[i];
			if(val != null) {
				arr[i] = null;
				size--;
			}
			arrnext[i] = 0;
		}
	}
	
	public void putInternal(final int key, final FastSparseSet<Integer> value, boolean remove) {
		
		int index = 0;
		int ikey = key; 
		if(ikey < 0) {
			index = 2;
			ikey = -ikey;
		} else if(ikey >= VarExprent.STACK_BASE) {
			index = 1;
			ikey -= VarExprent.STACK_BASE;
		}
		
		FastSparseSet<Integer>[] arr = elements[index];
		if(ikey >= arr.length) {
			if(remove) {
				return;
			} else {
				arr = ensureCapacity(index, ikey+1, false);
			}
		}
		
		FastSparseSet<Integer> oldval = arr[ikey];
		arr[ikey] = value;
		
		int[] arrnext = next[index];
		
		if(oldval == null && value != null) {
			size++;
			changeNext(arrnext, ikey, arrnext[ikey], ikey);
		} else if(oldval != null && value == null) {
			size--;
			changeNext(arrnext, ikey, ikey, arrnext[ikey]);
		}
	}
	
	private void changeNext(int[] arrnext, int key, int oldnext, int newnext) {
		for(int i=key-1;i>=0;i--) {
			if(arrnext[i] == oldnext) {
				arrnext[i] = newnext;
			} else {
				break;
			}
		}
	}
	
	public boolean containsKey(int key) {
		return get(key) != null;
	}
	
	public FastSparseSet<Integer> get(int key) {
		
		int index = 0;
		if(key < 0) {
			index = 2;
			key = -key;
		} else if(key >= VarExprent.STACK_BASE) {
			index = 1;
			key -= VarExprent.STACK_BASE;
		}
		
		FastSparseSet<Integer>[] arr = elements[index];
		
		if(key < arr.length) {
			return arr[key];
		}
		return null;
	}
	
	public void complement(SFormsFastMapDirect map) {
	
		for(int i=2;i>=0;i--) {
			FastSparseSet<Integer>[] lstOwn = elements[i];
			
			if(lstOwn.length == 0) {
				continue;
			}
			
			FastSparseSet<Integer>[] lstExtern = map.elements[i];
			int[] arrnext = next[i];
			
			int pointer = 0;
			do {
				FastSparseSet<Integer> first = lstOwn[pointer];

				if(first != null) {
					if(pointer >= lstExtern.length) {
						break;
					}
					FastSparseSet<Integer> second = lstExtern[pointer];

					if(second != null) {
						first.complement(second);
						if(first.isEmpty()) {
							lstOwn[pointer] = null;
							size--;
							changeNext(arrnext, pointer, pointer, arrnext[pointer]);
						}
					}
				}

				pointer = arrnext[pointer];
				
			} while(pointer != 0);
			
		}
		
	}

	public void intersection(SFormsFastMapDirect map) {
		
		for(int i=2;i>=0;i--) {
			FastSparseSet<Integer>[] lstOwn = elements[i];
			
			if(lstOwn.length == 0) {
				continue;
			}
			
			FastSparseSet<Integer>[] lstExtern = map.elements[i];
			int[] arrnext = next[i];
			
			int pointer = 0;
			do {
				FastSparseSet<Integer> first = lstOwn[pointer];

				if(first != null) {
					FastSparseSet<Integer> second = null;
					if(pointer < lstExtern.length) {
						second = lstExtern[pointer];
					}
					
					if(second != null) {
						first.intersection(second);
					}
					
					if(second == null || first.isEmpty()) {
						lstOwn[pointer] = null;
						size--;
						changeNext(arrnext, pointer, pointer, arrnext[pointer]);
					}
				}

				pointer = arrnext[pointer];
				
			} while(pointer != 0);
			
		}
		
	}
	
	public void union(SFormsFastMapDirect map) {
		
		for(int i=2;i>=0;i--) {
			FastSparseSet<Integer>[] lstExtern = map.elements[i];
			
			if(lstExtern.length == 0) {
				continue;
			}
			
			FastSparseSet<Integer>[] lstOwn = elements[i];
			int[] arrnext = next[i];
			int[] arrnextExtern = map.next[i];
			
			int pointer = 0;
			do {
				if(pointer >= lstOwn.length) {
					lstOwn = ensureCapacity(i, lstExtern.length, true);
					arrnext = next[i];
				}
				
				FastSparseSet<Integer> second = lstExtern[pointer];

				if(second != null) {
					FastSparseSet<Integer> first = lstOwn[pointer];

					if(first == null) {
						lstOwn[pointer] = second.getCopy();
						size++;
						changeNext(arrnext, pointer, arrnext[pointer], pointer);
					} else {
						first.union(second);
					}
				}

				pointer = arrnextExtern[pointer];
				
			} while(pointer != 0);
			
		}
		
	}
	
	public String toString() {
		
		StringBuilder buffer = new StringBuilder("{");
		
		List<Entry<Integer, FastSparseSet<Integer>>> lst = entryList();
		if(lst != null) {
			boolean first = true;
			for(Entry<Integer, FastSparseSet<Integer>> entry : lst) {
				if(!first) {
					buffer.append(", ");
				} else {
					first = false;
				}
				
				Set<Integer> set = entry.getValue().toPlainSet();
				buffer.append(entry.getKey()+"={"+set.toString()+"}");
			}
		}
		
		buffer.append("}");
		return buffer.toString();
	}
	
	public List<Entry<Integer, FastSparseSet<Integer>>> entryList() {
		List<Entry<Integer, FastSparseSet<Integer>>> list = new ArrayList<Entry<Integer, FastSparseSet<Integer>>>();
		
		for(int i=2;i>=0;i--) {
			int ikey = 0;
			for(final FastSparseSet<Integer> ent : elements[i]) {
				if(ent != null) {
					final int key = i==0?ikey:(i==1?ikey+VarExprent.STACK_BASE:-ikey);
					
					list.add(new Entry<Integer, FastSparseSet<Integer>>() {
						
						private Integer var = key;
						private FastSparseSet<Integer> val = ent;
						
						public Integer getKey() {
							return var;
						}
			
						public FastSparseSet<Integer> getValue() {
							return val;
						}
			
						public FastSparseSet<Integer> setValue(FastSparseSet<Integer> newvalue) {
							return null;
						}
					});
				}
				
				ikey++;
			}
		}
		
		return list;
	}
	
	private FastSparseSet<Integer>[] ensureCapacity(int index, int size, boolean exact) {
		
		FastSparseSet<Integer>[] arr = elements[index];
		int[] arrnext = next[index];
		
		int minsize = size;
		if(!exact) {
			minsize = 2*arr.length/3 +1;
			if(size > minsize) {
				minsize = size;
			}
		}
		
		FastSparseSet<Integer>[] arrnew = new FastSparseSet[minsize];
		System.arraycopy(arr, 0, arrnew, 0, arr.length);

		int[] arrnextnew = new int[minsize];
		System.arraycopy(arrnext, 0, arrnextnew, 0, arrnext.length);
		
		elements[index] = arrnew;
		next[index] = arrnextnew;
		
		return arrnew;
	}
	
}