/*

 * Copyright (C) 2007-2010 Júlio Vilmar Gesser.

 * Copyright (C) 2011, 2013-2021 The JavaParser Team.

 *

 * This file is part of JavaParser.

 *

 * JavaParser can be used either under the terms of

 * a) the GNU Lesser General Public License as published by

 *     the Free Software Foundation, either version 3 of the License, or

 *     (at your option) any later version.

 * b) the terms of the Apache License

 *

 * You should have received a copy of both licenses in LICENCE.LGPL and

 * LICENCE.APACHE. Please refer to those files for details.

 *

 * JavaParser 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 Lesser General Public License for more details.

 */

package com.github.javaparser;

import java.util.Comparator;

import java.util.Optional;

import static com.github.javaparser.utils.Utils.SYSTEM_EOL;

import static com.github.javaparser.utils.Utils.assertNotNull;

/**

 * A problem that was encountered during parsing.

 */

public class Problem {

    private final String message;

    private final TokenRange location;

    private final Throwable cause;

    public Problem(String message, TokenRange location, Throwable cause) {

        assertNotNull(message);

        this.message = message;

        this.location = location;

        this.cause = cause;

    }

    @Override

    public String toString() {

        final StringBuilder str = new StringBuilder(getVerboseMessage());

        if (cause != null) {

            str.append(SYSTEM_EOL).append("Problem stacktrace : ").append(SYSTEM_EOL);

            for (int i = 0; i < cause.getStackTrace().length; i++) {

                StackTraceElement ste = cause.getStackTrace()[i];

                str.append("  ").append(ste.toString());

                if (i + 1 != cause.getStackTrace().length)

                    str.append(SYSTEM_EOL);

            }

        }

        return str.toString();

    }

    /**

     * @return the message that was passed into the constructor.

     */

    public String getMessage() {

        return message;

    }

    /**

     * @return the message plus location information.

     */

    public String getVerboseMessage() {

        return getLocation().map(l -> l.getBegin().getRange().map(r -> r.begin.toString()).orElse("(line ?,col ?)") + " " + message).orElse(message);

    }

    /**

     * @return the location that was passed into the constructor.

     */

    public Optional<TokenRange> getLocation() {

        return Optional.ofNullable(location);

    }

    /**

     * @return the cause that was passed into the constructor.

     */

    public Optional<Throwable> getCause() {

        return Optional.ofNullable(cause);

    }

    /**

     * Sorts problems on position.

     */

    public static Comparator<Problem> PROBLEM_BY_BEGIN_POSITION = (a, b) -> {

        final Optional<Position> aBegin= a.getLocation().flatMap(l -> l.getBegin().getRange().map(r -> r.begin));

        final Optional<Position> bBegin = b.getLocation().flatMap(l -> l.getBegin().getRange().map(r -> r.begin));

        if (aBegin.isPresent() && bBegin.isPresent()) {

            return aBegin.get().compareTo(bBegin.get());

        }

        if (a.getLocation().isPresent() || b.getLocation().isPresent()) {

            if (a.getLocation().isPresent()) {

                return 1;

            }

            return -1;

        }

        return 0;

    };

}