/*
 * Copyright (c) 2011, 2014, 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.
 *
 * 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 org.graalvm.compiler.debug;

import java.util.ArrayList;
import java.util.Locale;

Indicates a condition that should never occur during normal operation.
/**
 * Indicates a condition that should never occur during normal operation.
 */
public class GraalError extends Error {

    private static final long serialVersionUID = 531632331813456233L;
    private final ArrayList<String> context = new ArrayList<>();

    public static RuntimeException unimplemented() {
        throw new GraalError("unimplemented");
    }

    public static RuntimeException unimplemented(String msg) {
        throw new GraalError("unimplemented: %s", msg);
    }

    public static RuntimeException shouldNotReachHere() {
        throw new GraalError("should not reach here");
    }

    public static RuntimeException shouldNotReachHere(String msg) {
        throw new GraalError("should not reach here: %s", msg);
    }

    public static RuntimeException shouldNotReachHere(Throwable cause) {
        throw new GraalError(cause);
    }

    
Checks a given condition and throws a GraalError if it is false. Guarantees are stronger than assertions in that they are always checked. Error messages for guarantee violations should clearly indicate the nature of the problem as well as a suggested solution if possible. 
Params:
condition – the condition to check
msg – the message that will be associated with the error, in String.format(String, Object...) syntax
args – arguments to the format string/**
     * Checks a given condition and throws a {@link GraalError} if it is false. Guarantees are
     * stronger than assertions in that they are always checked. Error messages for guarantee
     * violations should clearly indicate the nature of the problem as well as a suggested solution
     * if possible.
     *
     * @param condition the condition to check
     * @param msg the message that will be associated with the error, in
     *            {@link String#format(String, Object...)} syntax
     * @param args arguments to the format string
     */
    public static void guarantee(boolean condition, String msg, Object... args) {
        if (!condition) {
            throw new GraalError("failed guarantee: " + msg, args);
        }
    }

    
This constructor creates a GraalError with a given message. 
Params:
msg – the message that will be associated with the error/**
     * This constructor creates a {@link GraalError} with a given message.
     *
     * @param msg the message that will be associated with the error
     */
    public GraalError(String msg) {
        super(msg);
    }

    
This constructor creates a GraalError with a message assembled via String.format(String, Object...). It always uses the ENGLISH locale in order to always generate the same output. 
Params:
msg – the message that will be associated with the error, in String.format syntax
args – parameters to String.format - parameters that implement Iterable will be expanded into a [x, x, ...] representation./**
     * This constructor creates a {@link GraalError} with a message assembled via
     * {@link String#format(String, Object...)}. It always uses the ENGLISH locale in order to
     * always generate the same output.
     *
     * @param msg the message that will be associated with the error, in String.format syntax
     * @param args parameters to String.format - parameters that implement {@link Iterable} will be
     *            expanded into a [x, x, ...] representation.
     */
    public GraalError(String msg, Object... args) {
        super(format(msg, args));
    }

    
This constructor creates a GraalError for a given causing Throwable instance. 
Params:
cause – the original exception that contains additional information on this error/**
     * This constructor creates a {@link GraalError} for a given causing Throwable instance.
     *
     * @param cause the original exception that contains additional information on this error
     */
    public GraalError(Throwable cause) {
        super(cause);
    }

    
This constructor creates a GraalError and adds all the context of another GraalError. 
Params:
e – the original GraalError/**
     * This constructor creates a {@link GraalError} and adds all the
     * {@linkplain #addContext(String) context} of another {@link GraalError}.
     *
     * @param e the original {@link GraalError}
     */
    public GraalError(GraalError e) {
        super(e);
        context.addAll(e.context);
    }

    @Override
    public String toString() {
        StringBuilder str = new StringBuilder();
        str.append(super.toString());
        for (String s : context) {
            str.append("\n\tat ").append(s);
        }
        return str.toString();
    }

    private static String format(String msg, Object... args) {
        if (args != null) {
            // expand Iterable parameters into a list representation
            for (int i = 0; i < args.length; i++) {
                if (args[i] instanceof Iterable<?>) {
                    ArrayList<Object> list = new ArrayList<>();
                    for (Object o : (Iterable<?>) args[i]) {
                        list.add(o);
                    }
                    args[i] = list.toString();
                }
            }
        }
        return String.format(Locale.ENGLISH, msg, args);
    }

    public GraalError addContext(String newContext) {
        this.context.add(newContext);
        return this;
    }

    public GraalError addContext(String name, Object obj) {
        return addContext(format("%s: %s", name, obj));
    }
}