/*

 * 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.

 */

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 {@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

     */

    public static void guarantee(boolean condition, String msg) {

        if (!condition) {

            throw new GraalError("failed guarantee: " + msg);

        }

    }

    /**

     * 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 arg argument to the format string in {@code msg}

     */

    public static void guarantee(boolean condition, String msg, Object arg) {

        if (!condition) {

            throw new GraalError("failed guarantee: " + msg, arg);

        }

    }

    /**

     * 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 arg1 argument to the format string in {@code msg}

     * @param arg2 argument to the format string in {@code msg}

     */

    public static void guarantee(boolean condition, String msg, Object arg1, Object arg2) {

        if (!condition) {

            throw new GraalError("failed guarantee: " + msg, arg1, arg2);

        }

    }

    /**

     * 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 arg1 argument to the format string in {@code msg}

     * @param arg2 argument to the format string in {@code msg}

     * @param arg3 argument to the format string in {@code msg}

     */

    public static void guarantee(boolean condition, String msg, Object arg1, Object arg2, Object arg3) {

        if (!condition) {

            throw new GraalError("failed guarantee: " + msg, arg1, arg2, arg3);

        }

    }

    /**

     * This override exists to catch cases when {@link #guarantee(boolean, String, Object)} is

     * called with one argument bound to a varargs method parameter. It will bind to this method

     * instead of the single arg variant and produce a deprecation warning instead of silently

     * wrapping the Object[] inside of another Object[].

     */

    @Deprecated

    public static void guarantee(boolean condition, String msg, Object... args) {

        if (!condition) {

            throw new GraalError("failed guarantee: " + msg, args);

        }

    }

    /**

     * 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 {@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 {@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 {@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());

        str.append(context());

        return str.toString();

    }

    public String context() {

        StringBuilder str = new StringBuilder();

        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));

    }

}