package org.apache.maven.building;

/**
 * Describes a problem that was encountered during settings building. A problem can either be an exception that was
 * thrown or a simple string message. In addition, a problem carries a hint about its source, e.g. the settings file
 * that exhibits the problem.
 *
 */
public interface Problem {

    /**
     * The different severity levels for a problem, in decreasing order.
     */
    enum Severity {

     */
    public ToolchainsBuildingException(List<Problem> problems) {
        super(toMessage(problems));

        this.problems = new ArrayList<>();
        if (problems != null) {
            this.problems.addAll(problems);
        }
    }

    /**
     * Gets the problems that caused this exception.
     *
     * @return The problems that caused this exception, never {@code null}.
     */

     * @param column The one-based index of the column containing the problem or {@code -1} if unknown.
     * @param cause The cause of the problem, may be {@code null}.
     */
    void add(Problem.Severity severity, String message, int line, int column, Exception cause);

    /**
     * The next messages will be bound to this source. When calling this method again, previous messages keep

    }

    public void add(ModelProblem problem) {
        problems.add(problem);

        severities.add(problem.getSeverity());
    }

    public void addAll(List<ModelProblem> problems) {
        this.problems.addAll(problems);

        for (ModelProblem problem : problems) {
            severities.add(problem.getSeverity());
        }
    }

    @Override

import java.util.ArrayList;
import java.util.List;

/**
 * Collects problems that are encountered during settings building.
 *
 */
class DefaultProblemCollector implements ProblemCollector {

    private final List<Problem> problems;

    private String source;

    DefaultProblemCollector(List<Problem> problems) {
        this.problems = (problems != null) ? problems : new ArrayList<>();
    }

    @Override

        problem = new DefaultProblem(null, null, "", -1, -1, null);
        assertEquals("", problem.getSource());

        problem = new DefaultProblem(null, null, "SOURCE", -1, -1, null);
        assertEquals("SOURCE", problem.getSource());
    }

    @Test
    void testGetLocation() {
        DefaultProblem problem = new DefaultProblem(null, null, null, -1, -1, null);
        assertEquals("", problem.getLocation());

- component not found

Plugins:
- plugin metadata missing
- plugin metadata retrieval problem
- plugin artifact missing
- plugin artifact retrieval problem
- plugin dependency metadata missing
- plugin dependency metadata retrieval problem
- plugin configuration problem
- plugin execution failure due to something that is know to possibly go wrong (like compilation failure)

     */
    Exception getException();

    /**
     * Gets the message that describes this problem.
     *
     * @return The message describing this problem, never {@code null}.
     */
    String getMessage();

    /**
     * Gets the severity level of this problem.
     *
     * @return The severity level of this problem, never {@code null}.
     */

/**
 * Describes a problem that was encountered during project building. A problem can either be an exception that was
 * thrown or a simple string message. In addition, a problem carries a hint about its source.
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
public interface BuilderProblem {

    /**

 * under the License.
 */
package org.apache.maven.settings.building;

/**
 * Describes a problem that was encountered during settings building. A problem can either be an exception that was
 * thrown or a simple string message. In addition, a problem carries a hint about its source, e.g. the settings file
 * that exhibits the problem.
 *
 * @deprecated since 4.0.0, use {@link org.apache.maven.api.services.SettingsBuilder} instead
 */