/*******************************************************************************
 * Copyright (c) 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.parser;

import java.io.DataInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

public class ScannerHelper {
	public final static int Bit1 = 0x1;
	public final static int Bit2 = 0x2;
	public final static int Bit3 = 0x4;
	public final static int Bit4 = 0x8;
	public final static int Bit5 = 0x10;
	public final static int Bit6 = 0x20;
	public final static int Bit7 = 0x40;
	public final static int Bit8 = 0x80;
	public final static int Bit9 = 0x100;
	public final static int Bit10= 0x200;
	public final static int Bit11 = 0x400;
	public final static int Bit12 = 0x800;
	public final static int Bit13 = 0x1000;
	public final static int Bit14 = 0x2000;
	public final static int Bit15 = 0x4000;
	public final static int Bit16 = 0x8000;
	public final static int Bit17 = 0x10000;
	public final static int Bit18 = 0x20000; 
	public final static int Bit19 = 0x40000; 
	public final static int Bit20 = 0x80000; 
	public final static int Bit21 = 0x100000; 		
	public final static int Bit22 = 0x200000;
	public final static int Bit23 = 0x400000;
	public final static int Bit24 = 0x800000;
	public final static int Bit25 = 0x1000000;
	public final static int Bit26 = 0x2000000;
	public final static int Bit27 = 0x4000000;
	public final static int Bit28 = 0x8000000;
	public final static int Bit29 = 0x10000000;
	public final static int Bit30 = 0x20000000;
	public final static int Bit31 = 0x40000000;
	public final static int Bit32 = 0x80000000;
	public final static long Bit33 = 0x100000000L;
	public final static long Bit34 = 0x200000000L;
	public final static long Bit35 = 0x400000000L;
	public final static long Bit36 = 0x800000000L;
	public final static long Bit37 = 0x1000000000L;
	public final static long Bit38 = 0x2000000000L;
	public final static long Bit39 = 0x4000000000L;
	public final static long Bit40 = 0x8000000000L;
	public final static long Bit41 = 0x10000000000L;
	public final static long Bit42 = 0x20000000000L;
	public final static long Bit43 = 0x40000000000L;
	public final static long Bit44 = 0x80000000000L;
	public final static long Bit45 = 0x100000000000L;
	public final static long Bit46 = 0x200000000000L;
	public final static long Bit47 = 0x400000000000L;
	public final static long Bit48 = 0x800000000000L;
	public final static long Bit49 = 0x1000000000000L;
	public final static long Bit50 = 0x2000000000000L;
	public final static long Bit51 = 0x4000000000000L;
	public final static long Bit52 = 0x8000000000000L;
	public final static long Bit53 = 0x10000000000000L;
	public final static long Bit54 = 0x20000000000000L;
	public final static long Bit55 = 0x40000000000000L;
	public final static long Bit56 = 0x80000000000000L;
	public final static long Bit57 = 0x100000000000000L;
	public final static long Bit58 = 0x200000000000000L;
	public final static long Bit59 = 0x400000000000000L;
	public final static long Bit60 = 0x800000000000000L;
	public final static long Bit61 = 0x1000000000000000L;
	public final static long Bit62 = 0x2000000000000000L;
	public final static long Bit63 = 0x4000000000000000L;
	public final static long Bit64 = 0x8000000000000000L;
	public final static long[] Bits = { Bit1, Bit2, Bit3, Bit4, Bit5, Bit6,
			Bit7, Bit8, Bit9, Bit10, Bit11, Bit12, Bit13, Bit14, Bit15, Bit16,
			Bit17, Bit18, Bit19, Bit20, Bit21, Bit22, Bit23, Bit24, Bit25,
			Bit26, Bit27, Bit28, Bit29, Bit30, Bit31, Bit32, Bit33, Bit34,
			Bit35, Bit36, Bit37, Bit38, Bit39, Bit40, Bit41, Bit42, Bit43,
			Bit44, Bit45, Bit46, Bit47, Bit48, Bit49, Bit50, Bit51, Bit52,
			Bit53, Bit54, Bit55, Bit56, Bit57, Bit58, Bit59, Bit60, Bit61,
			Bit62, Bit63, Bit64,
	};

	private static final int START_INDEX = 0;
	private static final int PART_INDEX = 1;

	private static long[][][] Tables;

	static {
		Tables = new long[2][][];
		Tables[START_INDEX] = new long[2][];
		Tables[PART_INDEX] = new long[3][];
		try {
			DataInputStream inputStream = new DataInputStream(ScannerHelper.class.getResourceAsStream("start1.rsc")); //$NON-NLS-1$
			long[] readValues = new long[1024];
			for (int i = 0; i < 1024; i++) {
				readValues[i] = inputStream.readLong();
			}
			inputStream.close();
			Tables[START_INDEX][0] = readValues;
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		try {
			DataInputStream inputStream = new DataInputStream(ScannerHelper.class.getResourceAsStream("start2.rsc")); //$NON-NLS-1$
			long[] readValues = new long[1024];
			for (int i = 0; i < 1024; i++) {
				readValues[i] = inputStream.readLong();
			}
			inputStream.close();
			Tables[START_INDEX][1] = readValues;
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		try {
			DataInputStream inputStream = new DataInputStream(ScannerHelper.class.getResourceAsStream("part1.rsc")); //$NON-NLS-1$
			long[] readValues = new long[1024];
			for (int i = 0; i < 1024; i++) {
				readValues[i] = inputStream.readLong();
			}
			inputStream.close();
			Tables[PART_INDEX][0] = readValues;
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		try {
			DataInputStream inputStream = new DataInputStream(ScannerHelper.class.getResourceAsStream("part2.rsc")); //$NON-NLS-1$
			long[] readValues = new long[1024];
			for (int i = 0; i < 1024; i++) {
				readValues[i] = inputStream.readLong();
			}
			inputStream.close();
			Tables[PART_INDEX][1] = readValues;
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		try {
			DataInputStream inputStream = new DataInputStream(ScannerHelper.class.getResourceAsStream("part14.rsc")); //$NON-NLS-1$
			long[] readValues = new long[1024];
			for (int i = 0; i < 1024; i++) {
				readValues[i] = inputStream.readLong();
			}
			inputStream.close();
			Tables[PART_INDEX][2] = readValues;
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	private final static boolean isBitSet(long[] values, int i) {
		try {
			return (values[i / 64] & Bits[i % 64]) != 0;
		} catch (NullPointerException e) {
			return false;
		}
	}

	public static boolean isJavaIdentifierPart(char high, char low) {
		int codePoint = toCodePoint(high, low);
		switch((codePoint & 0x1F0000) >> 16) {
			case 0 :
				return Character.isJavaIdentifierPart((char) codePoint);
			case 1 :
				return isBitSet(Tables[PART_INDEX][0], codePoint & 0xFFFF);
			case 2 :
				return isBitSet(Tables[PART_INDEX][1], codePoint & 0xFFFF);
			case 14 :
				return isBitSet(Tables[PART_INDEX][2], codePoint & 0xFFFF);
		}
		return false;
	}
	
	public static boolean isJavaIdentifierStart(char high, char low) {
		int codePoint = toCodePoint(high, low);
		switch((codePoint & 0x1F0000) >> 16) {
			case 0 :
				return Character.isJavaIdentifierStart((char) codePoint);
			case 1 :
				return isBitSet(Tables[START_INDEX][0], codePoint & 0xFFFF);
			case 2 :
				return isBitSet(Tables[START_INDEX][1], codePoint & 0xFFFF);
		}
		return false;
	}
	
	private static int toCodePoint(char high, char low) {	
		return (high - Scanner.HIGH_SURROGATE_MIN_VALUE) * 0x400 + (low - Scanner.LOW_SURROGATE_MIN_VALUE) + 0x10000;
	}
}