DMDirc-Client/src/com/dmdirc/logger/ErrorManager.java

/*
 * Copyright (c) 2006-2013 DMDirc Developers
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package com.dmdirc.logger;

import com.dmdirc.config.ConfigManager;
import com.dmdirc.config.IdentityManager;
import com.dmdirc.interfaces.ConfigChangeListener;
import com.dmdirc.interfaces.IdentityController;
import com.dmdirc.ui.FatalErrorDialog;
import com.dmdirc.util.collections.ListenerList;

import java.awt.GraphicsEnvironment;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.atomic.AtomicLong;

/**
 * Error manager.
 */
public class ErrorManager implements ConfigChangeListener {

    /** Previously instantiated instance of ErrorManager. */
    private static ErrorManager me;

    /** A list of exceptions which we don't consider bugs and thus don't report. */
    private static final Class<?>[] BANNED_EXCEPTIONS = new Class<?>[]{
        NoSuchMethodError.class, NoClassDefFoundError.class,
        UnsatisfiedLinkError.class, AbstractMethodError.class,
        IllegalAccessError.class, OutOfMemoryError.class,
        NoSuchFieldError.class,
    };

    /** Whether or not to send error reports. */
    private boolean sendReports;

    /** Whether or not to log error reports. */
    private boolean logReports;

    /** Queue of errors to be reported. */
    private final BlockingQueue<ProgramError> reportQueue = new LinkedBlockingQueue<>();

    /** Thread used for sending errors. */
    private volatile Thread reportThread;

    /** Error list. */
    private final List<ProgramError> errors;

    /** Listener list. */
    private final ListenerList errorListeners = new ListenerList();

    /** Next error ID. */
    private final AtomicLong nextErrorID;

    /** Creates a new instance of ErrorListDialog. */
    public ErrorManager() {
        errors = new LinkedList<>();
        nextErrorID = new AtomicLong();
    }

    /**
     * Initialiases the error manager.
     *
     * @param controller The controller to use to read/write settings.
     */
    public void initialise(final IdentityController controller) {
        final ConfigManager config = controller.getGlobalConfiguration();

        config.addChangeListener("general", "logerrors", this);
        config.addChangeListener("general", "submitErrors", this);
        config.addChangeListener("temp", "noerrorreporting", this);

        updateSettings();
    }

    /**
     * Returns the instance of ErrorManager.
     *
     * @return Instance of ErrorManager
     */
    public static synchronized ErrorManager getErrorManager() {
        if (me == null) {
            me = new ErrorManager();
            me.initialise(IdentityManager.getIdentityManager());
        }
        return me;
    }

    /**
     * Sets the singleton instance of the error manager.
     *
     * @param errorManager The error manager to use.
     */
    public static void setErrorManager(final ErrorManager errorManager) {
        me = errorManager;
    }

    /**
     * Adds a new error to the manager with the specified details. It is
     * assumed that errors without exceptions or details are not application
     * errors.
     *
     * @param level The severity of the error
     * @param message The error message
     * @since 0.6.3m1
     */
    protected void addError(final ErrorLevel level, final String message) {
        addError(level, message, new String[0], false);
    }

    /**
     * Adds a new error to the manager with the specified details.
     *
     * @param level The severity of the error
     * @param message The error message
     * @param exception The exception that caused this error
     * @param appError Whether or not this is an application error
     * @since 0.6.3m1
     */
    protected void addError(final ErrorLevel level, final String message,
            final Throwable exception, final boolean appError) {
        addError(level, message, getTrace(exception), appError, isValidError(exception));
    }

    /**
     * Adds a new error to the manager with the specified details.
     *
     * @param level The severity of the error
     * @param message The error message
     * @param details The details of the exception
     * @param appError Whether or not this is an application error
     * @since 0.6.3m1
     */
    protected void addError(final ErrorLevel level, final String message,
            final String[] details, final boolean appError) {
        addError(level, message, details, appError, true);
    }

    /**
     * Adds a new error to the manager with the specified details.
     *
     * @param level The severity of the error
     * @param message The error message
     * @param details The details of the exception
     * @param appError Whether or not this is an application error
     * @param canReport Whether or not this error can be reported
     * @since 0.6.3m1
     */
    protected void addError(final ErrorLevel level, final String message,
            final String[] details, final boolean appError, final boolean canReport) {
        final ProgramError error = getError(level, message, details, appError);

        final boolean dupe = addError(error);
        if (level.equals(ErrorLevel.FATAL)) {
            if (dupe) {
                error.setReportStatus(ErrorReportStatus.NOT_APPLICABLE);
                error.setFixedStatus(ErrorFixedStatus.DUPLICATE);
            }
        } else if (!canReport || (appError && !error.isValidSource())) {
            error.setReportStatus(ErrorReportStatus.NOT_APPLICABLE);
            error.setFixedStatus(ErrorFixedStatus.INVALID);
        } else if (!appError) {
            error.setReportStatus(ErrorReportStatus.NOT_APPLICABLE);
            error.setFixedStatus(ErrorFixedStatus.UNREPORTED);
        } else if (dupe) {
            error.setReportStatus(ErrorReportStatus.NOT_APPLICABLE);
            error.setFixedStatus(ErrorFixedStatus.DUPLICATE);
        } else if (sendReports) {
            sendError(error);
        }

        if (logReports) {
            error.save();
        }

        if (!dupe) {
            if (level == ErrorLevel.FATAL) {
                fireFatalError(error);
            } else {
                fireErrorAdded(error);
            }
        }
    }

    /**
     * Adds the specified error to the list of known errors and determines if
     * it was previously added.
     *
     * @param error The error to be added
     * @return True if a duplicate error has already been registered, false
     * otherwise
     */
    protected boolean addError(final ProgramError error) {
        int index;

        synchronized (errors) {
            index = errors.indexOf(error);
            if (index == -1) {
                errors.add(error);
            } else {
                errors.get(index).updateLastDate();
            }
        }

        return index > -1;
    }

    /**
     * Retrieves a {@link ProgramError} that represents the specified details.
     *
     * @param level The severity of the error
     * @param message The error message
     * @param details The details of the exception
     * @param appError Whether or not this is an application error
     * @since 0.6.3m1
     * @return A corresponding ProgramError
     */
    protected ProgramError getError(final ErrorLevel level, final String message,
            final String[] details, final boolean appError) {
        return new ProgramError(nextErrorID.getAndIncrement(), level, message,
                details, new Date());
    }

    /**
     * Determines whether or not the specified exception is one that we are
     * willing to report.
     *
     * @param exception The exception to test
     * @since 0.6.3m1
     * @return True if the exception may be reported, false otherwise
     */
    protected boolean isValidError(final Throwable exception) {
        Throwable target = exception;

        while (target != null) {
            for (Class<?> bad : BANNED_EXCEPTIONS) {
                if (bad.equals(target.getClass())) {
                    return false;
                }
            }

            target = target.getCause();
        }

        return true;
    }

    /**
     * Converts an exception into a string array.
     *
     * @param throwable Exception to convert
     * @since 0.6.3m1
     * @return Exception string array
     */
    public static String[] getTrace(final Throwable throwable) {
        String[] trace;

        if (throwable == null) {
            trace = new String[0];
        } else {
            final StackTraceElement[] traceElements = throwable.getStackTrace();
            trace = new String[traceElements.length + 1];

            trace[0] = throwable.toString();

            for (int i = 0; i < traceElements.length; i++) {
                trace[i + 1] = traceElements[i].toString();
            }

            if (throwable.getCause() != null) {
                final String[] causeTrace = getTrace(throwable.getCause());
                final String[] newTrace = new String[trace.length + causeTrace.length];
                trace[0] = "\nWhich caused: " + trace[0];

                System.arraycopy(causeTrace, 0, newTrace, 0, causeTrace.length);
                System.arraycopy(trace, 0, newTrace, causeTrace.length, trace.length);

                trace = newTrace;
            }
        }

        return trace;
    }

    /**
     * Sends an error to the developers.
     *
     * @param error error to be sent
     */
    public void sendError(final ProgramError error) {
        if (error.getReportStatus() != ErrorReportStatus.ERROR
                && error.getReportStatus() != ErrorReportStatus.WAITING) {
            return;
        }

        error.setReportStatus(ErrorReportStatus.QUEUED);

        reportQueue.add(error);

        if (reportThread == null || !reportThread.isAlive()) {
            reportThread = new ErrorReportingThread(reportQueue);
            reportThread.start();
        }
    }

    /**
     * Called when an error needs to be deleted from the list.
     *
     * @param error ProgramError that changed
     */
    public void deleteError(final ProgramError error) {
        synchronized (errors) {
            errors.remove(error);
        }

        fireErrorDeleted(error);
    }

    /**
     * Deletes all errors from the manager.
     *
     * @since 0.6.3m1
     */
    public void deleteAll() {
        synchronized (errors) {
            for (ProgramError error : errors) {
                fireErrorDeleted(error);
            }

            errors.clear();
        }
    }

    /**
     * Returns the number of errors.
     *
     * @return Number of ProgramErrors
     */
    public int getErrorCount() {
        return errors.size();
    }

    /**
     * Returns the list of program errors.
     *
     * @return Program error list
     */
    public List<ProgramError> getErrors() {
        synchronized (errors) {
            return new LinkedList<>(errors);
        }
    }

    /**
     * Adds an ErrorListener to the listener list.
     *
     * @param listener Listener to add
     */
    public void addErrorListener(final ErrorListener listener) {
        if (listener == null) {
            return;
        }

        errorListeners.add(ErrorListener.class, listener);
    }

    /**
     * Removes an ErrorListener from the listener list.
     *
     * @param listener Listener to remove
     */
    public void removeErrorListener(final ErrorListener listener) {
       errorListeners.remove(ErrorListener.class, listener);
    }

    /**
     * Fired when the program encounters an error.
     *
     * @param error Error that occurred
     */
    protected void fireErrorAdded(final ProgramError error) {
        int firedListeners = 0;

        for (ErrorListener listener : errorListeners.get(ErrorListener.class)) {
            if (listener.isReady()) {
                listener.errorAdded(error);
                firedListeners++;
            }
        }

        if (firedListeners == 0) {
            System.err.println("An error has occurred: " + error.getLevel()
                    + ": " + error.getMessage());

            for (String line : error.getTrace()) {
                System.err.println("\t" + line);
            }
        }
    }

    /**
     * Fired when the program encounters a fatal error.
     *
     * @param error Error that occurred
     */
    protected void fireFatalError(final ProgramError error) {
        final boolean restart;
        if (GraphicsEnvironment.isHeadless()) {
            System.err.println("A fatal error has occurred: " + error.getMessage());
            for (String line : error.getTrace()) {
                System.err.println("\t" + line);
            }
            restart = false;
        } else {
            final FatalErrorDialog fed = new FatalErrorDialog(error);
            fed.setVisible(true);
            try {
                synchronized (fed) {
                    while (fed.isWaiting()) {
                        fed.wait();
                    }
                }
            } catch (InterruptedException ex) {
                //Oh well, carry on
            }
            restart = fed.getRestart();
        }

        try {
            synchronized (error) {
                while (!error.getReportStatus().isTerminal()) {
                    error.wait();
                }
            }
        } catch (InterruptedException ex) {
            // Do nothing
        }

        if (restart) {
            System.exit(42);
        } else {
            System.exit(1);
        }
    }

    /**
     * Fired when an error is deleted.
     *
     * @param error Error that has been deleted
     */
    protected void fireErrorDeleted(final ProgramError error) {
        for (ErrorListener listener : errorListeners.get(ErrorListener.class)) {
            listener.errorDeleted(error);
        }
    }

    /**
     * Fired when an error's status is changed.
     *
     * @param error Error that has been altered
     */
    protected void fireErrorStatusChanged(final ProgramError error) {
        for (ErrorListener listener : errorListeners.get(ErrorListener.class)) {
            listener.errorStatusChanged(error);
        }
    }

    /** {@inheritDoc} */
    @Override
    public void configChanged(final String domain, final String key) {
        updateSettings();
    }

    /** Updates the settings used by this error manager. */
    protected void updateSettings() {
        final ConfigManager config = IdentityManager.getIdentityManager().getGlobalConfiguration();

        try {
            sendReports = config.getOptionBool("general", "submitErrors")
                    && !config.getOptionBool("temp", "noerrorreporting");
            logReports = config.getOptionBool("general", "logerrors");
        } catch (IllegalArgumentException ex) {
            sendReports = false;
            logReports = true;
        }
    }

}