/*

 * Copyright (c) 2000, 2017, 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.

 */

package javax.xml.transform;

import java.lang.reflect.Method;

import java.lang.reflect.InvocationTargetException;

import java.security.AccessControlContext;

import java.security.AccessController;

import java.security.CodeSigner;

import java.security.CodeSource;

import java.security.PermissionCollection;

import java.security.Permissions;

import java.security.PrivilegedAction;

import java.security.ProtectionDomain;

import java.util.Objects;

/**

 * This class specifies an exceptional condition that occurred

 * during the transformation process.

 *

 * @since 1.4

 */

public class TransformerException extends Exception {

    /** Field locator specifies where the error occurred */

    SourceLocator locator;

    /**

     * Method getLocator retrieves an instance of a SourceLocator

     * object that specifies where an error occurred.

     *

     * @return A SourceLocator object, or null if none was specified.

     */

    public SourceLocator getLocator() {

        return this.locator;

    }

    /**

     * Method setLocator sets an instance of a SourceLocator

     * object that specifies where an error occurred.

     *

     * @param location A SourceLocator object, or null to clear the location.

     */

    public void setLocator(SourceLocator location) {

        this.locator = location;

    }

    /** Field containedException specifies a wrapped exception.  May be null. */

    Throwable containedException;

    /**

     * This method retrieves an exception that this exception wraps.

     *

     * @return An Throwable object, or null.

     * @see #getCause

     */

    public Throwable getException() {

        return containedException;

    }

    /**

     * Returns the cause of this throwable or <code>null</code> if the

     * cause is nonexistent or unknown.  (The cause is the throwable that

     * caused this throwable to get thrown.)

     * @return the cause, or null if unknown

     */

    @Override

    public Throwable getCause() {

        return ((containedException == this)

                ? null

                : containedException);

    }

    /**

     * Initializes the <i>cause</i> of this throwable to the specified value.

     * (The cause is the throwable that caused this throwable to get thrown.)

     *

     * <p>This method can be called at most once.  It is generally called from

     * within the constructor, or immediately after creating the

     * throwable.  If this throwable was created

     * with {@link #TransformerException(Throwable)} or

     * {@link #TransformerException(String,Throwable)}, this method cannot be called

     * even once.

     *

     * @param  cause the cause (which is saved for later retrieval by the

     *         {@link #getCause()} method).  (A <code>null</code> value is

     *         permitted, and indicates that the cause is nonexistent or

     *         unknown.)

     * @return  a reference to this <code>Throwable</code> instance.

     * @throws IllegalArgumentException if <code>cause</code> is this

     *         throwable.  (A throwable cannot

     *         be its own cause.)

     * @throws IllegalStateException if this throwable was

     *         created with {@link #TransformerException(Throwable)} or

     *         {@link #TransformerException(String,Throwable)}, or this method has already

     *         been called on this throwable.

     */

    @Override

    public synchronized Throwable initCause(Throwable cause) {

        // TransformerException doesn't set its cause (probably

        // because it predates initCause()) - and we may not want

        // to change this since Exceptions are serializable...

        // But this also leads to the broken code in printStackTrace

        // below...

        if (this.containedException != null) {

            throw new IllegalStateException("Can't overwrite cause");

        }

        if (cause == this) {

            throw new IllegalArgumentException(

                "Self-causation not permitted");

        }

        this.containedException = cause;

        return this;

    }

    /**

     * Create a new TransformerException.

     *

     * @param message The error or warning message.

     */

    public TransformerException(String message) {

        this(message, null, null);

    }

    /**

     * Create a new TransformerException wrapping an existing exception.

     *

     * @param e The exception to be wrapped.

     */

    public TransformerException(Throwable e) {

        this(null, null, e);

    }

    /**

     * Wrap an existing exception in a TransformerException.

     *

     * <p>This is used for throwing processor exceptions before

     * the processing has started.</p>

     *

     * @param message The error or warning message, or null to

     *                use the message from the embedded exception.

     * @param e Any exception

     */

    public TransformerException(String message, Throwable e) {

        this(message, null, e);

    }

    /**

     * Create a new TransformerException from a message and a Locator.

     *

     * <p>This constructor is especially useful when an application is

     * creating its own exception from within a DocumentHandler

     * callback.</p>

     *

     * @param message The error or warning message.

     * @param locator The locator object for the error or warning.

     */

    public TransformerException(String message, SourceLocator locator) {

        this(message, locator, null);

    }

    /**

     * Wrap an existing exception in a TransformerException.

     *

     * @param message The error or warning message, or null to

     *                use the message from the embedded exception.

     * @param locator The locator object for the error or warning.

     * @param e Any exception

     */

    public TransformerException(String message, SourceLocator locator,

                                Throwable e) {

        super(((message == null) || (message.length() == 0))

              ? ((e == null) ? "" : e.toString())

              : message);

        this.containedException = e;

        this.locator            = locator;

    }

    /**

     * Get the error message with location information

     * appended.

     *

     * @return A <code>String</code> representing the error message with

     *         location information appended.

     */

    public String getMessageAndLocation() {

        StringBuilder sbuffer = new StringBuilder();

        sbuffer.append(Objects.toString(super.getMessage(), ""));

        sbuffer.append(Objects.toString(getLocationAsString(), ""));

        return sbuffer.toString();

    }

    /**

     * Get the location information as a string.

     *

     * @return A string with location info, or null

     * if there is no location information.

     */

    public String getLocationAsString() {

        if (locator == null) {

            return null;

        }

        if (System.getSecurityManager() == null) {

            return getLocationString();

        } else {

            return AccessController.doPrivileged((PrivilegedAction<String>) () ->

                getLocationString(),

                new AccessControlContext(new ProtectionDomain[] {getNonPrivDomain()}));

        }

    }

    /**

     * Constructs the location string.

     * @return the location string

     */

    private String getLocationString() {

        if (locator == null) {

            return null;

        }

        StringBuilder sbuffer  = new StringBuilder();

            String       systemID = locator.getSystemId();

            int          line     = locator.getLineNumber();

            int          column   = locator.getColumnNumber();

            if (null != systemID) {

                sbuffer.append("; SystemID: ");

                sbuffer.append(systemID);

            }

            if (0 != line) {

                sbuffer.append("; Line#: ");

                sbuffer.append(line);

            }

            if (0 != column) {

                sbuffer.append("; Column#: ");

                sbuffer.append(column);

            }

            return sbuffer.toString();

    }

    /**

     * Print the the trace of methods from where the error

     * originated.  This will trace all nested exception

     * objects, as well as this object.

     */

    @Override

    public void printStackTrace() {

        printStackTrace(new java.io.PrintWriter(System.err, true));

    }

    /**

     * Print the the trace of methods from where the error

     * originated.  This will trace all nested exception

     * objects, as well as this object.

     * @param s The stream where the dump will be sent to.

     */

    @Override

    public void printStackTrace(java.io.PrintStream s) {

        printStackTrace(new java.io.PrintWriter(s));

    }

    /**

     * Print the the trace of methods from where the error

     * originated.  This will trace all nested exception

     * objects, as well as this object.

     * @param s The writer where the dump will be sent to.

     */

    @Override

    public void printStackTrace(java.io.PrintWriter s) {

        if (s == null) {

            s = new java.io.PrintWriter(System.err, true);

        }

        try {

            try {

                String locInfo = getLocationAsString();

                if (null != locInfo) {

                    s.println(locInfo);

                }

                super.printStackTrace(s);

            } catch (Throwable e) {}

            Throwable exception = getException();

            for (int i = 0; (i < 10) && (null != exception); i++) {

                s.println("---------");

                try {

                    exception.printStackTrace(s);

                    // if exception is a TransformerException it will print

                    // its contained exception, so we don't need to redo it here,

                    // and we can exit the loop now.

                    if (exception instanceof TransformerException) break;

                } catch (Throwable e) {

                    s.println("Could not print stack trace...");

                }

                try {

                    // Is this still needed?

                    Method meth = exception.getClass().getMethod("getException");

                    if (null != meth) {

                        Throwable prev = exception;

                        exception = (Throwable) meth.invoke(exception, (Object[]) null);

                        if (prev == exception) {

                            break;

                        }

                    } else {

                        exception = null;

                    }

                } catch (InvocationTargetException | IllegalAccessException

                        | NoSuchMethodException e) {

                    exception = null;

                }

            }

        } finally {

            // ensure output is written

            s.flush();

        }

    }

    /**

     * Creates a ProtectionDomain that has no permission.

     * @return a ProtectionDomain

     */

    private ProtectionDomain getNonPrivDomain() {

        CodeSource nullSource = new CodeSource(null, (CodeSigner[]) null);

        PermissionCollection noPermission = new Permissions();

        return new ProtectionDomain(nullSource, noPermission);

}

}