/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.xerces.impl;

import java.io.IOException;

import org.apache.xerces.impl.msg.XMLMessageFormatter;
import org.apache.xerces.util.XML11Char;
import org.apache.xerces.util.XMLChar;
import org.apache.xerces.util.XMLStringBuffer;
import org.apache.xerces.xni.XMLString;
import org.apache.xerces.xni.XNIException;

This class is responsible for scanning XML document structure
and content. The scanner acts as the source for the document
information which is communicated to the document handler.

This component requires the following features and properties from the
component manager that uses it:

 
http://xml.org/sax/features/namespaces
 
http://xml.org/sax/features/validation
 
http://apache.org/xml/features/nonvalidating/load-external-dtd
 
http://apache.org/xml/features/scanner/notify-char-refs
 
http://apache.org/xml/features/scanner/notify-builtin-refs
 
http://apache.org/xml/properties/internal/symbol-table
 
http://apache.org/xml/properties/internal/error-reporter
 
http://apache.org/xml/properties/internal/entity-manager
 
http://apache.org/xml/properties/internal/dtd-scanner

Author:
Glenn Marcy, IBM, Andy Clark, IBM, Arnaud  Le Hors, IBM, Eric Ye, IBM
@xerces.internal
Version:
$Id: XML11DocumentScannerImpl.java 572055 2007-09-02 17:55:43Z mrglavas $/**
 * This class is responsible for scanning XML document structure
 * and content. The scanner acts as the source for the document
 * information which is communicated to the document handler.
 * <p>
 * This component requires the following features and properties from the
 * component manager that uses it:
 * <ul>
 *  <li>http://xml.org/sax/features/namespaces</li>
 *  <li>http://xml.org/sax/features/validation</li>
 *  <li>http://apache.org/xml/features/nonvalidating/load-external-dtd</li>
 *  <li>http://apache.org/xml/features/scanner/notify-char-refs</li>
 *  <li>http://apache.org/xml/features/scanner/notify-builtin-refs</li>
 *  <li>http://apache.org/xml/properties/internal/symbol-table</li>
 *  <li>http://apache.org/xml/properties/internal/error-reporter</li>
 *  <li>http://apache.org/xml/properties/internal/entity-manager</li>
 *  <li>http://apache.org/xml/properties/internal/dtd-scanner</li>
 * </ul>
 *
 * @xerces.internal

 *
 * @author Glenn Marcy, IBM
 * @author Andy Clark, IBM
 * @author Arnaud  Le Hors, IBM
 * @author Eric Ye, IBM
 *
 * @version $Id: XML11DocumentScannerImpl.java 572055 2007-09-02 17:55:43Z mrglavas $
 */
public class XML11DocumentScannerImpl
    extends XMLDocumentScannerImpl {

    
String. /** String. */
    private final XMLString fString = new XMLString();

    
String buffer. /** String buffer. */
    private final XMLStringBuffer fStringBuffer = new XMLStringBuffer();
    private final XMLStringBuffer fStringBuffer2 = new XMLStringBuffer();
    private final XMLStringBuffer fStringBuffer3 = new XMLStringBuffer();

    //
    // Constructors
    //

    
Default constructor. /** Default constructor. */
    public XML11DocumentScannerImpl() {super();} // <init>()

    //
    // overridden methods
    //

    // XMLDocumentFragmentImpl methods

    
Scans element content.
Returns:
Returns the next character on the stream./**
     * Scans element content.
     *
     * @return Returns the next character on the stream.
     */
    protected int scanContent() throws IOException, XNIException {

        XMLString content = fString;
        int c = fEntityScanner.scanContent(content);
        if (c == '\r' || c == 0x85 || c == 0x2028) {
            // happens when there is the character reference &#13;
            // but scanContent doesn't do entity expansions...
            // is this *really* necessary???  - NG
            fEntityScanner.scanChar();
            fStringBuffer.clear();
            fStringBuffer.append(fString);
            fStringBuffer.append((char)c);
            content = fStringBuffer;
            c = -1;
        }
        if (fDocumentHandler != null && content.length > 0) {
            fDocumentHandler.characters(content, null);
        }

        if (c == ']' && fString.length == 0) {
            fStringBuffer.clear();
            fStringBuffer.append((char)fEntityScanner.scanChar());
            // remember where we are in case we get an endEntity before we
            // could flush the buffer out - this happens when we're parsing an
            // entity which ends with a ]
            fInScanContent = true;
            //
            // We work on a single character basis to handle cases such as:
            // ']]]>' which we might otherwise miss.
            //
            if (fEntityScanner.skipChar(']')) {
                fStringBuffer.append(']');
                while (fEntityScanner.skipChar(']')) {
                    fStringBuffer.append(']');
                }
                if (fEntityScanner.skipChar('>')) {
                    reportFatalError("CDEndInContent", null);
                }
            }
            if (fDocumentHandler != null && fStringBuffer.length != 0) {
                fDocumentHandler.characters(fStringBuffer, null);
            }
            fInScanContent = false;
            c = -1;
        }
        return c;

    } // scanContent():int

    
Scans an attribute value and normalizes whitespace converting all
whitespace characters to space characters.
[10] AttValue ::= '"' ([^<&"] | Reference)* '"' | "'" ([^<&'] | Reference)* "'"
Params:
value – The XMLString to fill in with the value.
nonNormalizedValue – The XMLString to fill in with the 
                          non-normalized value.
atName – The name of the attribute being parsed (for error msgs).
checkEntities – true if undeclared entities should be reported as VC violation,  
                     false if undeclared entities should be reported as WFC violation.
eleName – The name of element to which this attribute belongs.
Returns:
true if the non-normalized and normalized value are the same
Note: This method uses fStringBuffer2, anything in it
at the time of calling is lost./**
     * Scans an attribute value and normalizes whitespace converting all
     * whitespace characters to space characters.
     * 
     * [10] AttValue ::= '"' ([^<&"] | Reference)* '"' | "'" ([^<&'] | Reference)* "'"
     *
     * @param value The XMLString to fill in with the value.
     * @param nonNormalizedValue The XMLString to fill in with the 
     *                           non-normalized value.
     * @param atName The name of the attribute being parsed (for error msgs).
     * @param checkEntities true if undeclared entities should be reported as VC violation,  
     *                      false if undeclared entities should be reported as WFC violation.
     * @param eleName The name of element to which this attribute belongs.
     *
     * @return true if the non-normalized and normalized value are the same
     * 
     * <strong>Note:</strong> This method uses fStringBuffer2, anything in it
     * at the time of calling is lost.
     **/
    protected boolean scanAttributeValue(XMLString value, 
                                      XMLString nonNormalizedValue,
                                      String atName,
                                      boolean checkEntities,String eleName)
        throws IOException, XNIException
    {
        // quote
        int quote = fEntityScanner.peekChar();
        if (quote != '\'' && quote != '"') {
            reportFatalError("OpenQuoteExpected", new Object[]{eleName,atName});
        }

        fEntityScanner.scanChar();
        int entityDepth = fEntityDepth;

        int c = fEntityScanner.scanLiteral(quote, value);
        if (DEBUG_ATTR_NORMALIZATION) {
            System.out.println("** scanLiteral -> \""
                               + value.toString() + "\"");
        }
        
        int fromIndex = 0;
        if (c == quote && (fromIndex = isUnchangedByNormalization(value)) == -1) {
            /** Both the non-normalized and normalized attribute values are equal. **/
            nonNormalizedValue.setValues(value);
            int cquote = fEntityScanner.scanChar();
            if (cquote != quote) {
                reportFatalError("CloseQuoteExpected", new Object[]{eleName,atName});
            }
            return true;
        }
        fStringBuffer2.clear();
        fStringBuffer2.append(value);
        normalizeWhitespace(value, fromIndex);
        if (DEBUG_ATTR_NORMALIZATION) {
            System.out.println("** normalizeWhitespace -> \""
                               + value.toString() + "\"");
        }
        if (c != quote) {
            fScanningAttribute = true;
            fStringBuffer.clear();
            do {
                fStringBuffer.append(value);
                if (DEBUG_ATTR_NORMALIZATION) {
                    System.out.println("** value2: \""
                                       + fStringBuffer.toString() + "\"");
                }
                if (c == '&') {
                    fEntityScanner.skipChar('&');
                    if (entityDepth == fEntityDepth) {
                        fStringBuffer2.append('&');
                    }
                    if (fEntityScanner.skipChar('#')) {
                        if (entityDepth == fEntityDepth) {
                            fStringBuffer2.append('#');
                        }
                        int ch = scanCharReferenceValue(fStringBuffer, fStringBuffer2);
                        if (ch != -1) {
                            if (DEBUG_ATTR_NORMALIZATION) {
                                System.out.println("** value3: \""
                                                   + fStringBuffer.toString()
                                                   + "\"");
                            }
                        }
                    }
                    else {
                        String entityName = fEntityScanner.scanName();
                        if (entityName == null) {
                            reportFatalError("NameRequiredInReference", null);
                        }
                        else if (entityDepth == fEntityDepth) {
                            fStringBuffer2.append(entityName);
                        }
                        if (!fEntityScanner.skipChar(';')) {
                            reportFatalError("SemicolonRequiredInReference",
                                             new Object []{entityName});
                        }
                        else if (entityDepth == fEntityDepth) {
                            fStringBuffer2.append(';');
                        }
                        if (entityName == fAmpSymbol) {
                            fStringBuffer.append('&');
                            if (DEBUG_ATTR_NORMALIZATION) {
                                System.out.println("** value5: \""
                                                   + fStringBuffer.toString()
                                                   + "\"");
                            }
                        }
                        else if (entityName == fAposSymbol) {
                            fStringBuffer.append('\'');
                            if (DEBUG_ATTR_NORMALIZATION) {
                                System.out.println("** value7: \""
                                                   + fStringBuffer.toString()
                                                   + "\"");
                            }
                        }
                        else if (entityName == fLtSymbol) {
                            fStringBuffer.append('<');
                            if (DEBUG_ATTR_NORMALIZATION) {
                                System.out.println("** value9: \""
                                                   + fStringBuffer.toString()
                                                   + "\"");
                            }
                        }
                        else if (entityName == fGtSymbol) {
                            fStringBuffer.append('>');
                            if (DEBUG_ATTR_NORMALIZATION) {
                                System.out.println("** valueB: \""
                                                   + fStringBuffer.toString()
                                                   + "\"");
                            }
                        }
                        else if (entityName == fQuotSymbol) {
                            fStringBuffer.append('"');
                            if (DEBUG_ATTR_NORMALIZATION) {
                                System.out.println("** valueD: \""
                                                   + fStringBuffer.toString()
                                                   + "\"");
                            }
                        }
                        else {
                            if (fEntityManager.isExternalEntity(entityName)) {
                                reportFatalError("ReferenceToExternalEntity",
                                                 new Object[] { entityName });
                            }
                            else {
                                if (!fEntityManager.isDeclaredEntity(entityName)) {
                                    //WFC & VC: Entity Declared
                                    if (checkEntities) {
                                        if (fValidation) {
                                            fErrorReporter.reportError(XMLMessageFormatter.XML_DOMAIN,
                                                                       "EntityNotDeclared",
                                                                       new Object[]{entityName},
                                                                       XMLErrorReporter.SEVERITY_ERROR);
                                        }
                                    }
                                    else {
                                        reportFatalError("EntityNotDeclared",
                                                         new Object[]{entityName});
                                    }
                                }
                                fEntityManager.startEntity(entityName, true);
                            }
                        }
                    }
                }
                else if (c == '<') {
                    reportFatalError("LessthanInAttValue",
                                     new Object[] { eleName, atName });
                    fEntityScanner.scanChar();
                    if (entityDepth == fEntityDepth) {
                        fStringBuffer2.append((char)c);
                    }
                }
                else if (c == '%' || c == ']') {
                    fEntityScanner.scanChar();
                    fStringBuffer.append((char)c);
                    if (entityDepth == fEntityDepth) {
                        fStringBuffer2.append((char)c);
                    }
                    if (DEBUG_ATTR_NORMALIZATION) {
                        System.out.println("** valueF: \""
                                           + fStringBuffer.toString() + "\"");
                    }
                }
                // note that none of these characters should ever get through
                // XML11EntityScanner.  Not sure why
                // this check was originally necessary.  - NG
                else if (c == '\n' || c == '\r' || c == 0x85 || c == 0x2028) {
                    fEntityScanner.scanChar();
                    fStringBuffer.append(' ');
                    if (entityDepth == fEntityDepth) {
                        fStringBuffer2.append('\n');
                    }
                }
                else if (c != -1 && XMLChar.isHighSurrogate(c)) {
                    fStringBuffer3.clear();
                    if (scanSurrogates(fStringBuffer3)) {
                        fStringBuffer.append(fStringBuffer3);
                        if (entityDepth == fEntityDepth) {
                            fStringBuffer2.append(fStringBuffer3);
                        }
                        if (DEBUG_ATTR_NORMALIZATION) {
                            System.out.println("** valueI: \""
                                               + fStringBuffer.toString()
                                               + "\"");
                        }
                    }
                }
                else if (c != -1 && isInvalidLiteral(c)) {
                    reportFatalError("InvalidCharInAttValue",
                                     new Object[] {eleName, atName, Integer.toString(c, 16)});
                    fEntityScanner.scanChar();
                    if (entityDepth == fEntityDepth) {
                        fStringBuffer2.append((char)c);
                    }
                }
                c = fEntityScanner.scanLiteral(quote, value);
                if (entityDepth == fEntityDepth) {
                    fStringBuffer2.append(value);
                }
                normalizeWhitespace(value);
            } while (c != quote || entityDepth != fEntityDepth);
            fStringBuffer.append(value);
            if (DEBUG_ATTR_NORMALIZATION) {
                System.out.println("** valueN: \""
                                   + fStringBuffer.toString() + "\"");
            }
            value.setValues(fStringBuffer);
            fScanningAttribute = false;
        }
        nonNormalizedValue.setValues(fStringBuffer2);

        // quote
        int cquote = fEntityScanner.scanChar();
        if (cquote != quote) {
            reportFatalError("CloseQuoteExpected", new Object[]{eleName,atName});
        }
        return nonNormalizedValue.equals(value.ch, value.offset, value.length);
    } // scanAttributeValue()

    //
    // XMLScanner methods
    //
    // NOTE:  this is a carbon copy of the code in XML11DTDScannerImpl;
    // we need to override these methods in both places.  
    // this needs to be refactored!!!  - NG
    
Scans public ID literal.
[12] PubidLiteral ::= '"' PubidChar* '"' | "'" (PubidChar - "'")* "'" 
[13] PubidChar::= #x20 | #xD | #xA | [a-zA-Z0-9] | [-'()+,./:=?;!*#@$_%]
The returned string is normalized according to the following rule,
from http://www.w3.org/TR/REC-xml#dt-pubid:
Before a match is attempted, all strings of white space in the public
identifier must be normalized to single space characters (#x20), and
leading and trailing white space must be removed.
Params:
literal – The string to fill in with the public ID literal.
Returns:
True on success.
Note: This method uses fStringBuffer, anything in it at
the time of calling is lost./**
     * Scans public ID literal.
     *
     * [12] PubidLiteral ::= '"' PubidChar* '"' | "'" (PubidChar - "'")* "'" 
     * [13] PubidChar::= #x20 | #xD | #xA | [a-zA-Z0-9] | [-'()+,./:=?;!*#@$_%]
     *
     * The returned string is normalized according to the following rule,
     * from http://www.w3.org/TR/REC-xml#dt-pubid:
     *
     * Before a match is attempted, all strings of white space in the public
     * identifier must be normalized to single space characters (#x20), and
     * leading and trailing white space must be removed.
     *
     * @param literal The string to fill in with the public ID literal.
     * @return True on success.
     *
     * <strong>Note:</strong> This method uses fStringBuffer, anything in it at
     * the time of calling is lost.
     */
    protected boolean scanPubidLiteral(XMLString literal)
        throws IOException, XNIException
    {
        int quote = fEntityScanner.scanChar();
        if (quote != '\'' && quote != '"') {
            reportFatalError("QuoteRequiredInPublicID", null);
            return false;
        }

        fStringBuffer.clear();
        // skip leading whitespace
        boolean skipSpace = true;
        boolean dataok = true;
        while (true) {
            int c = fEntityScanner.scanChar();
            // REVISIT:  none of these except \n and 0x20 should make it past the entity scanner
            if (c == ' ' || c == '\n' || c == '\r' || c == 0x85 || c == 0x2028) {
                if (!skipSpace) {
                    // take the first whitespace as a space and skip the others
                    fStringBuffer.append(' ');
                    skipSpace = true;
                }
            }
            else if (c == quote) {
                if (skipSpace) {
                    // if we finished on a space let's trim it
                    fStringBuffer.length--;
                }
                literal.setValues(fStringBuffer);
                break;
            }
            else if (XMLChar.isPubid(c)) {
                fStringBuffer.append((char)c);
                skipSpace = false;
            }
            else if (c == -1) {
                reportFatalError("PublicIDUnterminated", null);
                return false;
            }
            else {
                dataok = false;
                reportFatalError("InvalidCharInPublicID",
                                 new Object[]{Integer.toHexString(c)});
            }
        }
        return dataok;
   }
   
    
Normalize whitespace in an XMLString converting all whitespace
characters to space characters.
/**
     * Normalize whitespace in an XMLString converting all whitespace
     * characters to space characters.
     */
    protected void normalizeWhitespace(XMLString value) {
        int end = value.offset + value.length;
	    for (int i = value.offset; i < end; ++i) {
           int c = value.ch[i];
           if (XMLChar.isSpace(c)) {
               value.ch[i] = ' ';
           }
       }
    }
    
    
Normalize whitespace in an XMLString converting all whitespace
characters to space characters.
/**
     * Normalize whitespace in an XMLString converting all whitespace
     * characters to space characters.
     */
    protected void normalizeWhitespace(XMLString value, int fromIndex) {
        int end = value.offset + value.length;
        for (int i = value.offset + fromIndex; i < end; ++i) {
            int c = value.ch[i];
            if (XMLChar.isSpace(c)) {
                value.ch[i] = ' ';
            }
        }
    }
    
    
Checks whether this string would be unchanged by normalization.
Returns:
-1 if the value would be unchanged by normalization,
otherwise the index of the first whitespace character which
would be transformed./**
     * Checks whether this string would be unchanged by normalization.
     * 
     * @return -1 if the value would be unchanged by normalization,
     * otherwise the index of the first whitespace character which
     * would be transformed.
     */
    protected int isUnchangedByNormalization(XMLString value) {
        int end = value.offset + value.length;
        for (int i = value.offset; i < end; ++i) {
            int c = value.ch[i];
            if (XMLChar.isSpace(c)) {
                return i - value.offset;
            }
        }
        return -1;
    }

    // returns true if the given character is not
    // valid with respect to the version of
    // XML understood by this scanner.
    protected boolean isInvalid(int value) {
        return (XML11Char.isXML11Invalid(value)); 
    } // isInvalid(int):  boolean 

    // returns true if the given character is not
    // valid or may not be used outside a character reference 
    // with respect to the version of XML understood by this scanner.
    protected boolean isInvalidLiteral(int value) {
        return (!XML11Char.isXML11ValidLiteral(value)); 
    } // isInvalidLiteral(int):  boolean

    // returns true if the given character is 
    // a valid nameChar with respect to the version of
    // XML understood by this scanner.
    protected boolean isValidNameChar(int value) {
        return (XML11Char.isXML11Name(value)); 
    } // isValidNameChar(int):  boolean

    // returns true if the given character is 
    // a valid nameStartChar with respect to the version of
    // XML understood by this scanner.
    protected boolean isValidNameStartChar(int value) {
        return (XML11Char.isXML11NameStart(value)); 
    } // isValidNameStartChar(int):  boolean
    
    // returns true if the given character is
    // a valid NCName character with respect to the version of
    // XML understood by this scanner.
    protected boolean isValidNCName(int value) {
        return (XML11Char.isXML11NCName(value));
    } // isValidNCName(int):  boolean
    
    // returns true if the given character is 
    // a valid high surrogate for a nameStartChar 
    // with respect to the version of XML understood 
    // by this scanner.
    protected boolean isValidNameStartHighSurrogate(int value) {
        return XML11Char.isXML11NameHighSurrogate(value); 
    } // isValidNameStartHighSurrogate(int):  boolean

    protected boolean versionSupported(String version) {
        return (version.equals("1.1") || version.equals("1.0"));
    } // versionSupported(String):  boolean
    
    // returns the error message key for unsupported
    // versions of XML with respect to the version of
    // XML understood by this scanner.
    protected String getVersionNotSupportedKey () {
        return "VersionNotSupported11";
    } // getVersionNotSupportedKey: String

} // class XML11DocumentScannerImpl