/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code 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
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
/* Generated By:JavaCC: Do not edit this line. UCode_UCodeESC_CharStream.java Version 0.7pre6 */
/* The previous line keeps JavaCC quiet. In fact, the JavaCC generated file
   has been edited to fix some bugs. */
package com.sun.xml.internal.rngom.parse.compact;

import com.sun.xml.internal.rngom.util.Utf16;
import com.sun.xml.internal.rngom.ast.builder.BuildException;

import java.io.IOException;

/**
 * An implementation of interface CharStream, where the stream is assumed to
 * contain 16-bit unicode characters.
 */
public final class UCode_UCodeESC_CharStream {
  public static final boolean staticFlag = false;

  static final int hexval(char c) {
    switch (c) {
    case '0':
      return 0;
    case '1':
      return 1;
    case '2':
      return 2;
    case '3':
      return 3;
    case '4':
      return 4;
    case '5':
      return 5;
    case '6':
      return 6;
    case '7':
      return 7;
    case '8':
      return 8;
    case '9':
      return 9;

    case 'a':
    case 'A':
      return 10;
    case 'b':
    case 'B':
      return 11;
    case 'c':
    case 'C':
      return 12;
    case 'd':
    case 'D':
      return 13;
    case 'e':
    case 'E':
      return 14;
    case 'f':
    case 'F':
      return 15;
    }
    return -1;
  }

  public int bufpos = -1;
  int bufsize;
  int available;
  int tokenBegin;
  private int bufline[];
  private int bufcolumn[];

  private int column = 0;
  private int line = 1;

  private java.io.Reader inputStream;
  private boolean closed = false;

  private boolean prevCharIsLF = false;

  private char[] nextCharBuf;
  private char[] buffer;
  private int maxNextCharInd = 0;
  private int nextCharInd = -1;
  private int inBuf = 0;

  private final void ExpandBuff(boolean wrapAround) {
    char[] newbuffer = new char[bufsize + 2048];
    int newbufline[] = new int[bufsize + 2048];
    int newbufcolumn[] = new int[bufsize + 2048];

    if (wrapAround) {
      System.arraycopy(buffer, tokenBegin, newbuffer, 0, bufsize - tokenBegin);
      System.arraycopy(buffer, 0, newbuffer,
                       bufsize - tokenBegin, bufpos);
      buffer = newbuffer;

      System.arraycopy(bufline, tokenBegin, newbufline, 0, bufsize - tokenBegin);
      System.arraycopy(bufline, 0, newbufline, bufsize - tokenBegin, bufpos);
      bufline = newbufline;

      System.arraycopy(bufcolumn, tokenBegin, newbufcolumn, 0, bufsize - tokenBegin);
      System.arraycopy(bufcolumn, 0, newbufcolumn, bufsize - tokenBegin, bufpos);
      bufcolumn = newbufcolumn;

      bufpos += (bufsize - tokenBegin);
    }
    else {
      System.arraycopy(buffer, tokenBegin, newbuffer, 0, bufsize - tokenBegin);
      buffer = newbuffer;

      System.arraycopy(bufline, tokenBegin, newbufline, 0, bufsize - tokenBegin);
      bufline = newbufline;

      System.arraycopy(bufcolumn, tokenBegin, newbufcolumn, 0, bufsize - tokenBegin);
      bufcolumn = newbufcolumn;

      bufpos -= tokenBegin;
    }

    available = (bufsize += 2048);
    tokenBegin = 0;
  }

  private final void FillBuff() throws EOFException {
    int i;
    if (maxNextCharInd == 4096)
      maxNextCharInd = nextCharInd = 0;

    if (closed)
      throw new EOFException();
    try {
      if ((i = inputStream.read(nextCharBuf, maxNextCharInd, 4096 - maxNextCharInd)) == -1) {
        closed = true;
        inputStream.close();
        throw new EOFException();
      }
      else
        maxNextCharInd += i;
    }
    catch (IOException e) {
      throw new BuildException(e);
    }
  }

  private final char ReadChar() throws EOFException {
    if (++nextCharInd >= maxNextCharInd)
      FillBuff();

    return nextCharBuf[nextCharInd];
  }

  private final char PeekChar() throws EOFException {
    char c = ReadChar();
    --nextCharInd;
    return c;
  }

  public final char BeginToken() throws EOFException {
    if (inBuf > 0) {
      --inBuf;
      return buffer[tokenBegin = (bufpos == bufsize - 1) ? (bufpos = 0)
              : ++bufpos];
    }

    tokenBegin = 0;
    bufpos = -1;

    return readChar();
  }

  private final void AdjustBuffSize() {
    if (available == bufsize) {
      if (tokenBegin > 2048) {
        bufpos = 0;
        available = tokenBegin;
      }
      else
        ExpandBuff(false);
    }
    else if (available > tokenBegin)
      available = bufsize;
    else if ((tokenBegin - available) < 2048)
      ExpandBuff(true);
    else
      available = tokenBegin;
  }

  private final void UpdateLineColumn(char c) {
    column++;

    if (prevCharIsLF) {
      prevCharIsLF = false;
      line += (column = 1);
    }

    switch (c) {
    case NEWLINE_MARKER:
      prevCharIsLF = true;
      break;
    case '\t':
      column--;
      column += (8 - (column & 07));
      break;
    default :
      break;
    }

    bufline[bufpos] = line;
    bufcolumn[bufpos] = column;
  }

  private final char NEWLINE_MARKER = '\u0000';

  public final char readChar() throws EOFException {
    if (inBuf > 0) {
      --inBuf;
      return buffer[(bufpos == bufsize - 1) ? (bufpos = 0) : ++bufpos];
    }

    char c;
    try {
      c = ReadChar();
      switch (c) {
      case '\r':
        c = NEWLINE_MARKER;
        try {
          if (PeekChar() == '\n')
            ReadChar();
        }
        catch (EOFException e) {
        }
        break;
      case '\n':
        c = NEWLINE_MARKER;
        break;
      case '\t':
        break;
      default:
        if (c >= 0x20) {
          if (Utf16.isSurrogate(c)) {
            if (Utf16.isSurrogate2(c))
              throw new EscapeSyntaxException("illegal_surrogate_pair", line, column + 1);
            if (++bufpos == available)
              AdjustBuffSize();
            buffer[bufpos] = c;
            // UpdateLineColumn(c);
            try {
              c = ReadChar();
            }
            catch (EOFException e) {
              throw new EscapeSyntaxException("illegal_surrogate_pair", line, column + 1);
            }
            if (!Utf16.isSurrogate2(c))
              throw new EscapeSyntaxException("illegal_surrogate_pair", line, column + 2);
          }
          break;
        }
        // fall through
      case '\uFFFE':
      case '\uFFFF':
        throw new EscapeSyntaxException("illegal_char_code", line, column + 1);
      }
    }
    catch (EOFException e) {
      if (bufpos == -1) {
        if (++bufpos == available)
          AdjustBuffSize();
        bufline[bufpos] = line;
        bufcolumn[bufpos] = column;
      }
      throw e;
    }
    if (++bufpos == available)
      AdjustBuffSize();
    buffer[bufpos] = c;
    UpdateLineColumn(c);
    try {
      if (c != '\\' || PeekChar() != 'x')
        return c;
    }
    catch (EOFException e) {
      return c;
    }

    int xCnt = 1;
    for (;;) {
      ReadChar();
      if (++bufpos == available)
        AdjustBuffSize();
      buffer[bufpos] = 'x';
      UpdateLineColumn('x');
      try {
        c = PeekChar();
      }
      catch (EOFException e) {
        backup(xCnt);
        return '\\';
      }
      if (c == '{') {
        ReadChar();
        column++;
        // backup past the 'x's
        bufpos -= xCnt;
        if (bufpos < 0)
          bufpos += bufsize;
        break;
      }
      if (c != 'x') {
        backup(xCnt);
        return '\\';
      }
      xCnt++;
    }
    try {
      int scalarValue = hexval(ReadChar());
      column++;
      if (scalarValue < 0)
        throw new EscapeSyntaxException("illegal_hex_digit", line, column);
      while ((c = ReadChar()) != '}') {
        column++;
        int n = hexval(c);
        if (n < 0)
          throw new EscapeSyntaxException("illegal_hex_digit", line, column);
        scalarValue <<= 4;
        scalarValue |= n;
        if (scalarValue >= 0x110000)
          throw new EscapeSyntaxException("char_code_too_big", line, column);
      }
      column++; // for the '}'
      if (scalarValue <= 0xFFFF) {
        c = (char)scalarValue;
        switch (c) {
        case '\n':
        case '\r':
        case '\t':
          break;
        default:
          if (c >= 0x20 && !Utf16.isSurrogate(c))
            break;
          // fall through
        case '\uFFFE':
        case '\uFFFF':
          throw new EscapeSyntaxException("illegal_char_code_ref", line, column);
        }
        buffer[bufpos] = c;
        return c;
      }
      c = Utf16.surrogate1(scalarValue);
      buffer[bufpos] = c;
      int bufpos1 = bufpos;
      if (++bufpos == bufsize)
        bufpos = 0;
      buffer[bufpos] = Utf16.surrogate2(scalarValue);
      bufline[bufpos] = bufline[bufpos1];
      bufcolumn[bufpos] = bufcolumn[bufpos1];
      backup(1);
      return c;
    }
    catch (EOFException e) {
      throw new EscapeSyntaxException("incomplete_escape", line, column);
    }
  }

  /**
   * @deprecated
   * @see #getEndColumn
   */

  public final int getColumn() {
    return bufcolumn[bufpos];
  }

  /**
   * @deprecated
   * @see #getEndLine
   */

  public final int getLine() {
    return bufline[bufpos];
  }

  public final int getEndColumn() {
    return bufcolumn[bufpos];
  }

  public final int getEndLine() {
    return bufline[bufpos];
  }

  public final int getBeginColumn() {
    return bufcolumn[tokenBegin];
  }

  public final int getBeginLine() {
    return bufline[tokenBegin];
  }

  public final void backup(int amount) {

    inBuf += amount;
    if ((bufpos -= amount) < 0)
      bufpos += bufsize;
  }

  public UCode_UCodeESC_CharStream(java.io.Reader dstream,
                                   int startline, int startcolumn, int buffersize) {
    inputStream = dstream;
    line = startline;
    column = startcolumn - 1;

    available = bufsize = buffersize;
    buffer = new char[buffersize];
    bufline = new int[buffersize];
    bufcolumn = new int[buffersize];
    nextCharBuf = new char[4096];
    skipBOM();
  }

  public UCode_UCodeESC_CharStream(java.io.Reader dstream,
                                   int startline, int startcolumn) {
    this(dstream, startline, startcolumn, 4096);
  }

  public void ReInit(java.io.Reader dstream,
                     int startline, int startcolumn, int buffersize) {
    inputStream = dstream;
    closed = false;
    line = startline;
    column = startcolumn - 1;

    if (buffer == null || buffersize != buffer.length) {
      available = bufsize = buffersize;
      buffer = new char[buffersize];
      bufline = new int[buffersize];
      bufcolumn = new int[buffersize];
      nextCharBuf = new char[4096];
    }
    prevCharIsLF = false;
    tokenBegin = inBuf = maxNextCharInd = 0;
    nextCharInd = bufpos = -1;
    skipBOM();
  }

  public void ReInit(java.io.Reader dstream,
                     int startline, int startcolumn) {
    ReInit(dstream, startline, startcolumn, 4096);
  }

  public UCode_UCodeESC_CharStream(java.io.InputStream dstream, int startline,
                                   int startcolumn, int buffersize) {
    this(new java.io.InputStreamReader(dstream), startline, startcolumn, 4096);
  }

  public UCode_UCodeESC_CharStream(java.io.InputStream dstream, int startline,
                                   int startcolumn) {
    this(dstream, startline, startcolumn, 4096);
  }

  public void ReInit(java.io.InputStream dstream, int startline,
                     int startcolumn, int buffersize) {
    ReInit(new java.io.InputStreamReader(dstream), startline, startcolumn, 4096);
  }

  public void ReInit(java.io.InputStream dstream, int startline,
                     int startcolumn) {
    ReInit(dstream, startline, startcolumn, 4096);
  }

  static private final char BOM = '\ufeff';

  private void skipBOM() {
    try {
      if (PeekChar() == BOM)
        ReadChar();
    }
    catch (EOFException e) {
    }
  }

  public final String GetImage() {
    if (bufpos >= tokenBegin)
      return new String(buffer, tokenBegin, bufpos - tokenBegin + 1);
    else
      return new String(buffer, tokenBegin, bufsize - tokenBegin) +
              new String(buffer, 0, bufpos + 1);
  }

  public final char[] GetSuffix(int len) {
    char[] ret = new char[len];

    if ((bufpos + 1) >= len)
      System.arraycopy(buffer, bufpos - len + 1, ret, 0, len);
    else {
      System.arraycopy(buffer, bufsize - (len - bufpos - 1), ret, 0,
                       len - bufpos - 1);
      System.arraycopy(buffer, 0, ret, len - bufpos - 1, bufpos + 1);
    }

    return ret;
  }

  public void Done() {
    nextCharBuf = null;
    buffer = null;
    bufline = null;
    bufcolumn = null;
  }

  /**
   * Method to adjust line and column numbers for the start of a token.<BR>
   */
  public void adjustBeginLineColumn(int newLine, int newCol) {
    int start = tokenBegin;
    int len;

    if (bufpos >= tokenBegin) {
      len = bufpos - tokenBegin + inBuf + 1;
    }
    else {
      len = bufsize - tokenBegin + bufpos + 1 + inBuf;
    }

    int i = 0, j = 0, k = 0;
    int nextColDiff = 0, columnDiff = 0;

    while (i < len &&
            bufline[j = start % bufsize] == bufline[k = ++start % bufsize]) {
      bufline[j] = newLine;
      nextColDiff = columnDiff + bufcolumn[k] - bufcolumn[j];
      bufcolumn[j] = newCol + columnDiff;
      columnDiff = nextColDiff;
      i++;
    }

    if (i < len) {
      bufline[j] = newLine++;
      bufcolumn[j] = newCol + columnDiff;

      while (i++ < len) {
        if (bufline[j = start % bufsize] != bufline[++start % bufsize])
          bufline[j] = newLine++;
        else
          bufline[j] = newLine;
      }
    }

    line = bufline[j];
    column = bufcolumn[j];
  }

}