BEGIN LICENSE BLOCK *****
Version: EPL 2.0/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Eclipse Public
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.eclipse.org/legal/epl-v20.html
Software distributed under the License is distributed on an "AS
IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
implied. See the License for the specific language governing
rights and limitations under the License.
Copyright (C) 2005 David Corbin 
Alternatively, the contents of this file may be used under the terms of
either of the GNU General Public License Version 2 or later (the "GPL"),
or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of either the GPL or the LGPL, and not to allow others to
use your version of this file under the terms of the EPL, indicate your
decision by deleting the provisions above and replace them with the notice
and other provisions required by the GPL or the LGPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the EPL, the GPL or the LGPL.
END LICENSE BLOCK /***** BEGIN LICENSE BLOCK *****
 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * 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.eclipse.org/legal/epl-v20.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2005 David Corbin <dcorbin@users.sourceforge.net>
 * 
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the EPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/

package org.jruby;

import java.lang.reflect.Member;
import java.util.Arrays;

import com.headius.backport9.stack.StackWalker;
import org.jruby.anno.JRubyClass;
import org.jruby.anno.JRubyMethod;
import org.jruby.exceptions.RaiseException;
import org.jruby.javasupport.Java;
import org.jruby.runtime.Block;
import org.jruby.runtime.ObjectAllocator;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.backtrace.RubyStackTraceElement;
import org.jruby.runtime.backtrace.TraceType;
import org.jruby.runtime.builtin.IRubyObject;

@Deprecated
@JRubyClass(name = "NativeException", parent = "RuntimeError")
public class NativeException extends RubyException {

    private final Throwable cause;
    private final String messageAsJavaString;
    public static final String CLASS_NAME = "NativeException";

    public NativeException(Ruby runtime, RubyClass rubyClass, Throwable cause) {
        this(runtime, rubyClass, cause, buildMessage(cause));
    }

    private NativeException(Ruby runtime, RubyClass rubyClass, Throwable cause, String message) {
        super(runtime, rubyClass, message);
        this.cause = cause;
        String s = buildMessage(cause);
        this.messageAsJavaString = message;
    }

    private static String buildMessage(Throwable cause) {
        return cause.getClass().getName() + ": " + searchStackMessage(cause);
    }

    private NativeException(Ruby runtime, RubyClass rubyClass) {
        super(runtime, rubyClass, null);
        this.cause = new Throwable();
        this.messageAsJavaString = null;
    }
    
    private static ObjectAllocator NATIVE_EXCEPTION_ALLOCATOR = (runtime, klazz) -> new NativeException(runtime, klazz);

    public static RubyClass createClass(Ruby runtime, RubyClass baseClass) {
        RubyClass exceptionClass = runtime.defineClass(CLASS_NAME, baseClass, NATIVE_EXCEPTION_ALLOCATOR);
        runtime.getObject().deprecateConstant(runtime, CLASS_NAME);

        exceptionClass.defineAnnotatedMethods(NativeException.class);

        return exceptionClass;
    }

    @JRubyMethod
    public final IRubyObject cause() {
        return Java.getInstance(getRuntime(), getCause());
    }

    @Deprecated
    public final IRubyObject cause(Block unusedBlock) {
        return cause();
    }

    @Override
    public final IRubyObject backtrace() {
        IRubyObject rubyTrace = super.backtrace();
        if ( rubyTrace.isNil() ) return rubyTrace;
        final Ruby runtime = getRuntime();
        final RubyArray rTrace = (RubyArray) rubyTrace;
        StackTraceElement[] jTrace = cause.getStackTrace();

        // NOTE: with the new filtering ruby trace will already include the source (Java) part
        if ( rTrace.size() > 0 && jTrace.length > 0 ) {
            final String r0 = rTrace.eltInternal(0).toString();
            // final StackTraceElement j0 = jTrace[0];
            final String method = jTrace[0].getMethodName();
            final String file = jTrace[0].getFileName();
            if ( method != null && file != null &&
                r0.indexOf(method) != -1 && r0.indexOf(file) != -1 ) {
                return rTrace; // as is
            }
        }
        // so join-ing is mostly unnecessary, but just in case (due compatibility) make sure :

        return joinedBacktrace(runtime, rTrace, jTrace);
    }

    private static RubyArray joinedBacktrace(final Ruby runtime, final RubyArray rTrace, final StackTraceElement[] jTrace) {
        final IRubyObject[] trace = new IRubyObject[jTrace.length + rTrace.size()];
        final StringBuilder line = new StringBuilder(32);
        for ( int i = 0; i < jTrace.length; i++ ) {
            StackTraceElement element = jTrace[i];
            final String className = element.getClassName();
            line.setLength(0);
            if (element.getFileName() == null) {
                line.append(className).append(':').append(element.getLineNumber()).append(":in `").append(element.getMethodName()).append('\'');
            } else {
                final int index = className.lastIndexOf('.');
                if ( index > - 1 ) {
                    line.append(className.substring(0, index).replace('.', '/'));
                    line.append('/');
                }
                line.append(element.getFileName()).append(':').append(element.getLineNumber()).append(":in `").append(element.getMethodName()).append('\'');
            }
            trace[i] = RubyString.newString(runtime, line.toString());
        }
        System.arraycopy(rTrace.toJavaArrayMaybeUnsafe(), 0, trace, jTrace.length, rTrace.size());
        return RubyArray.newArrayMayCopy(runtime, trace);
    }

    @Deprecated // not used
    public void trimStackTrace(Member target) {
        Throwable t = new Throwable();
        StackTraceElement[] origStackTrace = cause.getStackTrace();
        StackTraceElement[] currentStackTrace = t.getStackTrace();
        int skip = 0;
        for (int i = 1;
                i <= origStackTrace.length && i <= currentStackTrace.length;
                ++i) {
            StackTraceElement a = origStackTrace[origStackTrace.length - i];
            StackTraceElement b = currentStackTrace[currentStackTrace.length - i];
            if (a.equals(b)) {
                skip += 1;
            } else {
                break;
            }
        }
        // If we know what method was being called, strip everything
        // before the call. This hides the JRuby and reflection internals.
        if (target != null) {
            String className = target.getDeclaringClass().getName();
            String methodName = target.getName();
            for (int i = origStackTrace.length - skip - 1; i >= 0; --i) {
                StackTraceElement frame = origStackTrace[i];
                if (frame.getClassName().equals(className) &&
                    frame.getMethodName().equals(methodName)) {
                    skip = origStackTrace.length - i - 1;
                    break;
                }
            }
        }
        if (skip > 0) {
            final int len = origStackTrace.length - skip;
            StackTraceElement[] newStackTrace = new StackTraceElement[len];
            System.arraycopy(origStackTrace, 0, newStackTrace, 0, len);
            cause.setStackTrace(newStackTrace);
        }
    }

    @Override
    public final IRubyObject getMessage() {
        if (message == null) {
            if (messageAsJavaString == null) {
                return message = getRuntime().getNil();
            }
            return message = getRuntime().newString(messageAsJavaString);
        }
        return message;
    }

    @Override
    public final String getMessageAsJavaString() {
        return messageAsJavaString;
    }

    public final Throwable getCause() {
        return cause;
    }

    private static String searchStackMessage(Throwable cause) {
        String message;
        do {
            message = cause.getMessage();
            if ( message != null ) return message;
            cause = cause.getCause();
        } while ( cause != null );
        return null;
    }
}