package org.eclipse.aether.resolution;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *  http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import static java.util.Objects.requireNonNull;

import org.eclipse.aether.RepositorySystem;
import org.eclipse.aether.artifact.Artifact;
import org.eclipse.aether.repository.ArtifactRepository;
import org.eclipse.aether.transfer.ArtifactNotFoundException;

The result of an artifact resolution request.
See Also:
resolveArtifacts.resolveArtifacts(RepositorySystemSession, Collection)
Artifact.getFile()/**
 * The result of an artifact resolution request.
 * 
 * @see RepositorySystem#resolveArtifacts(org.eclipse.aether.RepositorySystemSession, java.util.Collection)
 * @see Artifact#getFile()
 */
public final class ArtifactResult
{

    private final ArtifactRequest request;

    private List<Exception> exceptions;

    private Artifact artifact;

    private ArtifactRepository repository;

    
Creates a new result for the specified request.
Params:
request – The resolution request, must not be null./**
     * Creates a new result for the specified request.
     *
     * @param request The resolution request, must not be {@code null}.
     */
    public ArtifactResult( ArtifactRequest request )
    {
        this.request = requireNonNull( request, "artifact request cannot be null" );
        exceptions = Collections.emptyList();
    }

    
Gets the resolution request that was made.
Returns:
The resolution request, never null./**
     * Gets the resolution request that was made.
     *
     * @return The resolution request, never {@code null}.
     */
    public ArtifactRequest getRequest()
    {
        return request;
    }

    
Gets the resolved artifact (if any). Use getExceptions() to query the errors that occurred while trying to resolve the artifact. 
Returns:
The resolved artifact or null if the resolution failed./**
     * Gets the resolved artifact (if any). Use {@link #getExceptions()} to query the errors that occurred while trying
     * to resolve the artifact.
     * 
     * @return The resolved artifact or {@code null} if the resolution failed.
     */
    public Artifact getArtifact()
    {
        return artifact;
    }

    
Sets the resolved artifact.
Params:
artifact – The resolved artifact, may be null if the resolution failed.
Returns:
This result for chaining, never null./**
     * Sets the resolved artifact.
     * 
     * @param artifact The resolved artifact, may be {@code null} if the resolution failed.
     * @return This result for chaining, never {@code null}.
     */
    public ArtifactResult setArtifact( Artifact artifact )
    {
        this.artifact = artifact;
        return this;
    }

    
Gets the exceptions that occurred while resolving the artifact. Note that this list can be non-empty even if the
artifact was successfully resolved, e.g. when one of the contacted remote repositories didn't contain the
artifact but a later repository eventually contained it.
See Also:
isResolved()
Returns:
The exceptions that occurred, never null./**
     * Gets the exceptions that occurred while resolving the artifact. Note that this list can be non-empty even if the
     * artifact was successfully resolved, e.g. when one of the contacted remote repositories didn't contain the
     * artifact but a later repository eventually contained it.
     * 
     * @return The exceptions that occurred, never {@code null}.
     * @see #isResolved()
     */
    public List<Exception> getExceptions()
    {
        return exceptions;
    }

    
Records the specified exception while resolving the artifact.
Params:
exception – The exception to record, may be null.
Returns:
This result for chaining, never null./**
     * Records the specified exception while resolving the artifact.
     * 
     * @param exception The exception to record, may be {@code null}.
     * @return This result for chaining, never {@code null}.
     */
    public ArtifactResult addException( Exception exception )
    {
        if ( exception != null )
        {
            if ( exceptions.isEmpty() )
            {
                exceptions = new ArrayList<>();
            }
            exceptions.add( exception );
        }
        return this;
    }

    
Gets the repository from which the artifact was eventually resolved. Note that successive resolutions of the same
artifact might yield different results if the employed local repository does not track the origin of an artifact.
Returns:
The repository from which the artifact was resolved or null if unknown./**
     * Gets the repository from which the artifact was eventually resolved. Note that successive resolutions of the same
     * artifact might yield different results if the employed local repository does not track the origin of an artifact.
     * 
     * @return The repository from which the artifact was resolved or {@code null} if unknown.
     */
    public ArtifactRepository getRepository()
    {
        return repository;
    }

    
Sets the repository from which the artifact was resolved.
Params:
repository – The repository from which the artifact was resolved, may be null.
Returns:
This result for chaining, never null./**
     * Sets the repository from which the artifact was resolved.
     * 
     * @param repository The repository from which the artifact was resolved, may be {@code null}.
     * @return This result for chaining, never {@code null}.
     */
    public ArtifactResult setRepository( ArtifactRepository repository )
    {
        this.repository = repository;
        return this;
    }

    
Indicates whether the requested artifact was resolved. Note that the artifact might have been successfully resolved despite getExceptions() indicating transfer errors while trying to fetch the artifact from some of the specified remote repositories. 
See Also:
Artifact.getFile()
Returns:
true if the artifact was resolved, false otherwise./**
     * Indicates whether the requested artifact was resolved. Note that the artifact might have been successfully
     * resolved despite {@link #getExceptions()} indicating transfer errors while trying to fetch the artifact from some
     * of the specified remote repositories.
     * 
     * @return {@code true} if the artifact was resolved, {@code false} otherwise.
     * @see Artifact#getFile()
     */
    public boolean isResolved()
    {
        return getArtifact() != null && getArtifact().getFile() != null;
    }

    
Indicates whether the requested artifact is not present in any of the specified repositories.
Returns:
true if the artifact is not present in any repository, false otherwise./**
     * Indicates whether the requested artifact is not present in any of the specified repositories.
     * 
     * @return {@code true} if the artifact is not present in any repository, {@code false} otherwise.
     */
    public boolean isMissing()
    {
        for ( Exception e : getExceptions() )
        {
            if ( !( e instanceof ArtifactNotFoundException ) )
            {
                return false;
            }
        }
        return !isResolved();
    }

    @Override
    public String toString()
    {
        return getArtifact() + " < " + getRepository();
    }

}