/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.classic.spi;

import ch.qos.logback.core.CoreConstants;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class ThrowableProxy implements IThrowableProxy {

    private Throwable throwable;
    private String className;
    private String message;
    // package-private because of ThrowableProxyUtil
    StackTraceElementProxy[] stackTraceElementProxyArray;
    // package-private because of ThrowableProxyUtil
    int commonFrames;
    private ThrowableProxy cause;
    private ThrowableProxy[] suppressed = NO_SUPPRESSED;

    private transient PackagingDataCalculator packagingDataCalculator;
    private boolean calculatedPackageData = false;

    private static final Method GET_SUPPRESSED_METHOD;

    static {
        Method method = null;
        try {
            method = Throwable.class.getMethod("getSuppressed");
        } catch (NoSuchMethodException e) {
            // ignore, will get thrown in Java < 7
        }
        GET_SUPPRESSED_METHOD = method;
    }

    private static final ThrowableProxy[] NO_SUPPRESSED = new ThrowableProxy[0];

    public ThrowableProxy(Throwable throwable) {

        this.throwable = throwable;
        this.className = throwable.getClass().getName();
        this.message = throwable.getMessage();
        this.stackTraceElementProxyArray = ThrowableProxyUtil.steArrayToStepArray(throwable.getStackTrace());

        Throwable nested = throwable.getCause();

        if (nested != null) {
            this.cause = new ThrowableProxy(nested);
            this.cause.commonFrames = ThrowableProxyUtil.findNumberOfCommonFrames(nested.getStackTrace(), stackTraceElementProxyArray);
        }
        if (GET_SUPPRESSED_METHOD != null) {
            // this will only execute on Java 7
            try {
                Object obj = GET_SUPPRESSED_METHOD.invoke(throwable);
                if (obj instanceof Throwable[]) {
                    Throwable[] throwableSuppressed = (Throwable[]) obj;
                    if (throwableSuppressed.length > 0) {
                        suppressed = new ThrowableProxy[throwableSuppressed.length];
                        for (int i = 0; i < throwableSuppressed.length; i++) {
                            this.suppressed[i] = new ThrowableProxy(throwableSuppressed[i]);
                            this.suppressed[i].commonFrames = ThrowableProxyUtil.findNumberOfCommonFrames(throwableSuppressed[i].getStackTrace(),
                                            stackTraceElementProxyArray);
                        }
                    }
                }
            } catch (IllegalAccessException e) {
                // ignore
            } catch (InvocationTargetException e) {
                // ignore
            }
        }

    }

    public Throwable getThrowable() {
        return throwable;
    }

    public String getMessage() {
        return message;
    }

    /*
     * (non-Javadoc)
     * 
     * @see ch.qos.logback.classic.spi.IThrowableProxy#getClassName()
     */
    public String getClassName() {
        return className;
    }

    public StackTraceElementProxy[] getStackTraceElementProxyArray() {
        return stackTraceElementProxyArray;
    }

    public int getCommonFrames() {
        return commonFrames;
    }

    /*
     * (non-Javadoc)
     * 
     * @see ch.qos.logback.classic.spi.IThrowableProxy#getCause()
     */
    public IThrowableProxy getCause() {
        return cause;
    }

    public IThrowableProxy[] getSuppressed() {
        return suppressed;
    }

    public PackagingDataCalculator getPackagingDataCalculator() {
        // if original instance (non-deserialized), and packagingDataCalculator
        // is not already initialized, then create an instance.
        // here we assume that (throwable == null) for deserialized instances
        if (throwable != null && packagingDataCalculator == null) {
            packagingDataCalculator = new PackagingDataCalculator();
        }
        return packagingDataCalculator;
    }

    public void calculatePackagingData() {
        if (calculatedPackageData) {
            return;
        }
        PackagingDataCalculator pdc = this.getPackagingDataCalculator();
        if (pdc != null) {
            calculatedPackageData = true;
            pdc.calculate(this);
        }
    }

    public void fullDump() {
        StringBuilder builder = new StringBuilder();
        for (StackTraceElementProxy step : stackTraceElementProxyArray) {
            String string = step.toString();
            builder.append(CoreConstants.TAB).append(string);
            ThrowableProxyUtil.subjoinPackagingData(builder, step);
            builder.append(CoreConstants.LINE_SEPARATOR);
        }
        System.out.println(builder.toString());
    }

}
