/*
 * 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.
 */
package org.apache.maven.shared.release.phase;

import java.io.File;
import java.net.URI;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.TimeZone;

import org.apache.maven.artifact.Artifact;
import org.apache.maven.artifact.ArtifactUtils;
import org.apache.maven.model.Build;
import org.apache.maven.model.BuildBase;
import org.apache.maven.model.Model;
import org.apache.maven.model.ModelBase;
import org.apache.maven.model.Plugin;
import org.apache.maven.model.Profile;
import org.apache.maven.project.MavenProject;
import org.apache.maven.scm.ScmException;
import org.apache.maven.scm.ScmFileSet;
import org.apache.maven.scm.command.edit.EditScmResult;
import org.apache.maven.scm.manager.NoSuchScmProviderException;
import org.apache.maven.scm.provider.ScmProvider;
import org.apache.maven.scm.repository.ScmRepository;
import org.apache.maven.scm.repository.ScmRepositoryException;
import org.apache.maven.shared.release.ReleaseExecutionException;
import org.apache.maven.shared.release.ReleaseFailureException;
import org.apache.maven.shared.release.ReleaseResult;
import org.apache.maven.shared.release.config.ReleaseDescriptor;
import org.apache.maven.shared.release.env.ReleaseEnvironment;
import org.apache.maven.shared.release.scm.ReleaseScmCommandException;
import org.apache.maven.shared.release.scm.ReleaseScmRepositoryException;
import org.apache.maven.shared.release.scm.ScmRepositoryConfigurator;
import org.apache.maven.shared.release.scm.ScmTranslator;
import org.apache.maven.shared.release.transform.MavenCoordinate;
import org.apache.maven.shared.release.transform.ModelETL;
import org.apache.maven.shared.release.transform.ModelETLFactory;
import org.apache.maven.shared.release.transform.ModelETLRequest;
import org.apache.maven.shared.release.transform.jdom2.JDomModelETLFactory;
import org.apache.maven.shared.release.util.ReleaseUtil;
import org.codehaus.plexus.util.StringUtils;

import static java.util.Objects.requireNonNull;
import static org.apache.maven.shared.utils.logging.MessageUtils.buffer;

/**
 * Base class for rewriting phases.
 *
 * @author <a href="mailto:brett@apache.org">Brett Porter</a>
 */
public abstract class AbstractRewritePomsPhase extends AbstractReleasePhase implements ResourceGenerator {
    /**
     * Tool that gets a configured SCM repository from release configuration.
     */
    private final ScmRepositoryConfigurator scmRepositoryConfigurator;

    private final Map<String, ModelETLFactory> modelETLFactories;

    /**
     * SCM URL translators mapped by provider name.
     */
    private Map<String, ScmTranslator> scmTranslators;

    /**
     * Use jdom2-sax as default
     */
    private String modelETL = JDomModelETLFactory.NAME;

    private long startTime = -1 * 1000;

    protected AbstractRewritePomsPhase(
            ScmRepositoryConfigurator scmRepositoryConfigurator,
            Map<String, ModelETLFactory> modelETLFactories,
            Map<String, ScmTranslator> scmTranslators) {
        this.scmRepositoryConfigurator = requireNonNull(scmRepositoryConfigurator);
        this.modelETLFactories = requireNonNull(modelETLFactories);
        this.scmTranslators = requireNonNull(scmTranslators);
    }

    /**
     * <p>Getter for the field <code>scmTranslators</code>.</p>
     *
     * @return a {@link java.util.Map} object
     */
    protected final Map<String, ScmTranslator> getScmTranslators() {
        return scmTranslators;
    }

    /**
     * <p>Setter for the field <code>modelETL</code>.</p>
     *
     * @param modelETL a {@link java.lang.String} object
     */
    public void setModelETL(String modelETL) {
        this.modelETL = modelETL;
    }

    /**
     * <p>Setter for the field <code>startTime</code>.</p>
     *
     * @param startTime a long
     */
    public void setStartTime(long startTime) {
        this.startTime = startTime;
    }

    /**
     * <p>getPomSuffix.</p>
     *
     * @return a {@link java.lang.String} object
     */
    protected abstract String getPomSuffix();

    @Override
    public ReleaseResult execute(
            ReleaseDescriptor releaseDescriptor,
            ReleaseEnvironment releaseEnvironment,
            List<MavenProject> reactorProjects)
            throws ReleaseExecutionException, ReleaseFailureException {
        ReleaseResult result = new ReleaseResult();

        transform(releaseDescriptor, releaseEnvironment, reactorProjects, false, result);

        result.setResultCode(ReleaseResult.SUCCESS);

        return result;
    }

    @Override
    public ReleaseResult simulate(
            ReleaseDescriptor releaseDescriptor,
            ReleaseEnvironment releaseEnvironment,
            List<MavenProject> reactorProjects)
            throws ReleaseExecutionException, ReleaseFailureException {
        ReleaseResult result = new ReleaseResult();

        transform(releaseDescriptor, releaseEnvironment, reactorProjects, true, result);

        result.setResultCode(ReleaseResult.SUCCESS);

        return result;
    }

    @Override
    public ReleaseResult clean(List<MavenProject> reactorProjects) {
        ReleaseResult result = new ReleaseResult();

        if (reactorProjects != null) {
            for (MavenProject project : reactorProjects) {
                File pomFile = ReleaseUtil.getStandardPom(project);
                // MRELEASE-273 : if no pom
                if (pomFile != null) {
                    File file = new File(pomFile.getParentFile(), pomFile.getName() + "." + getPomSuffix());
                    if (file.exists()) {
                        file.delete();
                    }
                }
            }
        }

        result.setResultCode(ReleaseResult.SUCCESS);

        return result;
    }

    private void transform(
            ReleaseDescriptor releaseDescriptor,
            ReleaseEnvironment releaseEnvironment,
            List<MavenProject> reactorProjects,
            boolean simulate,
            ReleaseResult result)
            throws ReleaseExecutionException, ReleaseFailureException {
        result.setStartTime((startTime >= 0) ? startTime : System.currentTimeMillis());

        URI root = ReleaseUtil.getRootProject(reactorProjects).getBasedir().toURI();

        for (MavenProject project : reactorProjects) {
            URI pom = project.getFile().toURI();
            logInfo(
                    result,
                    "Transforming " + root.relativize(pom).getPath() + ' '
                            + buffer().project(project.getArtifactId()) + " '" + project.getName() + "'"
                            + (simulate ? " with ." + getPomSuffix() + " suffix" : "") + "...");

            transformProject(project, releaseDescriptor, releaseEnvironment, simulate, result);
        }
    }

    private void transformProject(
            MavenProject project,
            ReleaseDescriptor releaseDescriptor,
            ReleaseEnvironment releaseEnvironment,
            boolean simulate,
            ReleaseResult result)
            throws ReleaseExecutionException, ReleaseFailureException {
        File pomFile = ReleaseUtil.getStandardPom(project);

        ModelETLRequest request = new ModelETLRequest();
        request.setProject(project);
        request.setReleaseDescriptor(releaseDescriptor);

        ModelETL etl = modelETLFactories.get(modelETL).newInstance(request);

        etl.extract(pomFile);

        ScmRepository scmRepository = null;
        ScmProvider provider = null;

        if (isUpdateScm()) {
            try {
                scmRepository = scmRepositoryConfigurator.getConfiguredRepository(
                        releaseDescriptor, releaseEnvironment.getSettings());

                provider = scmRepositoryConfigurator.getRepositoryProvider(scmRepository);
            } catch (ScmRepositoryException e) {
                throw new ReleaseScmRepositoryException(e.getMessage(), e.getValidationMessages());
            } catch (NoSuchScmProviderException e) {
                throw new ReleaseExecutionException("Unable to configure SCM repository: " + e.getMessage(), e);
            }
        }

        transformDocument(project, etl.getModel(), releaseDescriptor, scmRepository, result, simulate);

        File outputFile;
        if (simulate) {
            outputFile = new File(pomFile.getParentFile(), pomFile.getName() + "." + getPomSuffix());
        } else {
            outputFile = pomFile;
            prepareScm(pomFile, releaseDescriptor, scmRepository, provider);
        }
        etl.load(outputFile);
    }

    private void transformDocument(
            MavenProject project,
            Model modelTarget,
            ReleaseDescriptor releaseDescriptor,
            ScmRepository scmRepository,
            ReleaseResult result,
            boolean simulate)
            throws ReleaseExecutionException, ReleaseFailureException {
        Model model = project.getModel();

        Properties properties = modelTarget.getProperties();

        String parentVersion = rewriteParent(project, modelTarget, releaseDescriptor, simulate);

        String projectId = ArtifactUtils.versionlessKey(project.getGroupId(), project.getArtifactId());

        rewriteVersion(modelTarget, releaseDescriptor, projectId, project);

        Build buildTarget = modelTarget.getBuild();
        if (buildTarget != null) {
            // profile.build.extensions doesn't exist, so only rewrite project.build.extensions
            rewriteArtifactVersions(
                    toMavenCoordinates(buildTarget.getExtensions()),
                    model,
                    properties,
                    result,
                    releaseDescriptor,
                    simulate);

            rewriteArtifactVersions(
                    toMavenCoordinates(buildTarget.getPlugins()),
                    model,
                    properties,
                    result,
                    releaseDescriptor,
                    simulate);

            for (Plugin plugin : buildTarget.getPlugins()) {
                rewriteArtifactVersions(
                        toMavenCoordinates(plugin.getDependencies()),
                        model,
                        properties,
                        result,
                        releaseDescriptor,
                        simulate);
            }

            if (buildTarget.getPluginManagement() != null) {
                rewriteArtifactVersions(
                        toMavenCoordinates(buildTarget.getPluginManagement().getPlugins()),
                        model,
                        properties,
                        result,
                        releaseDescriptor,
                        simulate);

                for (Plugin plugin : buildTarget.getPluginManagement().getPlugins()) {
                    rewriteArtifactVersions(
                            toMavenCoordinates(plugin.getDependencies()),
                            model,
                            properties,
                            result,
                            releaseDescriptor,
                            simulate);
                }
            }
        }

        for (Profile profile : modelTarget.getProfiles()) {
            BuildBase profileBuild = profile.getBuild();
            if (profileBuild != null) {
                rewriteArtifactVersions(
                        toMavenCoordinates(profileBuild.getPlugins()),
                        model,
                        properties,
                        result,
                        releaseDescriptor,
                        simulate);

                for (Plugin plugin : profileBuild.getPlugins()) {
                    rewriteArtifactVersions(
                            toMavenCoordinates(plugin.getDependencies()),
                            model,
                            properties,
                            result,
                            releaseDescriptor,
                            simulate);
                }

                if (profileBuild.getPluginManagement() != null) {
                    rewriteArtifactVersions(
                            toMavenCoordinates(
                                    profileBuild.getPluginManagement().getPlugins()),
                            model,
                            properties,
                            result,
                            releaseDescriptor,
                            simulate);

                    for (Plugin plugin : profileBuild.getPluginManagement().getPlugins()) {
                        rewriteArtifactVersions(
                                toMavenCoordinates(plugin.getDependencies()),
                                model,
                                properties,
                                result,
                                releaseDescriptor,
                                simulate);
                    }
                }
            }
        }

        List<ModelBase> modelBases = new ArrayList<>();
        modelBases.add(modelTarget);
        modelBases.addAll(modelTarget.getProfiles());

        for (ModelBase modelBase : modelBases) {
            rewriteArtifactVersions(
                    toMavenCoordinates(modelBase.getDependencies()),
                    model,
                    properties,
                    result,
                    releaseDescriptor,
                    simulate);

            if (modelBase.getDependencyManagement() != null) {
                rewriteArtifactVersions(
                        toMavenCoordinates(modelBase.getDependencyManagement().getDependencies()),
                        model,
                        properties,
                        result,
                        releaseDescriptor,
                        simulate);
            }

            if (modelBase.getReporting() != null) {
                rewriteArtifactVersions(
                        toMavenCoordinates(modelBase.getReporting().getPlugins()),
                        model,
                        properties,
                        result,
                        releaseDescriptor,
                        simulate);
            }
        }

        transformScm(project, modelTarget, releaseDescriptor, projectId, scmRepository, result);

        if (properties != null) {
            rewriteBuildOutputTimestampProperty(properties, result);
        }
    }

    private void rewriteBuildOutputTimestampProperty(Properties properties, ReleaseResult result) {
        String buildOutputTimestamp = properties.getProperty("project.build.outputTimestamp");
        if (buildOutputTimestamp == null || StringUtils.isEmpty(buildOutputTimestamp)) {
            // no Reproducible Builds output timestamp defined
            return;
        }

        if (StringUtils.isNumeric(buildOutputTimestamp)) {
            // int representing seconds since the epoch, like SOURCE_DATE_EPOCH
            buildOutputTimestamp = String.valueOf(result.getStartTime() / 1000);
        } else if (buildOutputTimestamp.length() <= 1) {
            // value length == 1 means disable Reproducible Builds
            return;
        } else {
            // ISO-8601
            DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
            df.setTimeZone(TimeZone.getTimeZone("UTC"));
            buildOutputTimestamp = df.format(new Date(result.getStartTime()));
        }
        properties.setProperty("project.build.outputTimestamp", buildOutputTimestamp);
    }

    private void rewriteVersion(
            Model modelTarget, ReleaseDescriptor releaseDescriptor, String projectId, MavenProject project)
            throws ReleaseFailureException {
        String version = getNextVersion(releaseDescriptor, projectId);
        if (version == null) {
            throw new ReleaseFailureException("Version for '" + project.getName() + "' was not mapped");
        }

        modelTarget.setVersion(version);
    }

    private String rewriteParent(
            MavenProject project, Model targetModel, ReleaseDescriptor releaseDescriptor, boolean simulate)
            throws ReleaseFailureException {
        String parentVersion = null;
        if (project.hasParent()) {
            MavenProject parent = project.getParent();
            String key = ArtifactUtils.versionlessKey(parent.getGroupId(), parent.getArtifactId());
            parentVersion = getNextVersion(releaseDescriptor, key);
            if (parentVersion == null) {
                // MRELEASE-317
                parentVersion = getResolvedSnapshotVersion(key, releaseDescriptor);
            }
            if (parentVersion == null) {
                String original = getOriginalVersion(releaseDescriptor, key, simulate);
                if (parent.getVersion().equals(original)) {
                    throw new ReleaseFailureException("Version for parent '" + parent.getName() + "' was not mapped");
                }
            } else {
                targetModel.getParent().setVersion(parentVersion);
            }
        }
        return parentVersion;
    }

    private void rewriteArtifactVersions(
            Collection<MavenCoordinate> elements,
            Model projectModel,
            Properties properties,
            ReleaseResult result,
            ReleaseDescriptor releaseDescriptor,
            boolean simulate)
            throws ReleaseExecutionException, ReleaseFailureException {
        if (elements == null) {
            return;
        }
        String projectId = ArtifactUtils.versionlessKey(projectModel.getGroupId(), projectModel.getArtifactId());
        for (MavenCoordinate coordinate : elements) {
            String rawVersion = coordinate.getVersion();
            if (rawVersion == null) {
                // managed dependency or unversioned plugin
                continue;
            }

            String rawGroupId = coordinate.getGroupId();
            if (rawGroupId == null) {
                if ("plugin".equals(coordinate.getName())) {
                    rawGroupId = "org.apache.maven.plugins";
                } else {
                    // incomplete dependency
                    continue;
                }
            }
            String groupId = ReleaseUtil.interpolate(rawGroupId, projectModel);

            String rawArtifactId = coordinate.getArtifactId();
            if (rawArtifactId == null) {
                // incomplete element
                continue;
            }
            String artifactId = ReleaseUtil.interpolate(rawArtifactId, projectModel);

            String key = ArtifactUtils.versionlessKey(groupId, artifactId);
            String resolvedSnapshotVersion = getResolvedSnapshotVersion(key, releaseDescriptor);
            String mappedVersion = getNextVersion(releaseDescriptor, key);
            String originalVersion = getOriginalVersion(releaseDescriptor, key, simulate);
            if (originalVersion == null) {
                originalVersion = getOriginalResolvedSnapshotVersion(key, releaseDescriptor);
            }

            // MRELEASE-220
            if (mappedVersion != null
                    && mappedVersion.endsWith(Artifact.SNAPSHOT_VERSION)
                    && !rawVersion.endsWith(Artifact.SNAPSHOT_VERSION)
                    && !releaseDescriptor.isUpdateDependencies()) {
                continue;
            }

            if (mappedVersion != null) {
                if (rawVersion.equals(originalVersion)) {
                    logInfo(result, "  Updating " + artifactId + " to " + mappedVersion);
                    coordinate.setVersion(mappedVersion);
                } else if (rawVersion.matches("\\$\\{.+\\}")) {
                    String expression = rawVersion.substring(2, rawVersion.length() - 1);

                    if (expression.startsWith("project.")
                            || expression.startsWith("pom.")
                            || "version".equals(expression)) {
                        if (!mappedVersion.equals(getNextVersion(releaseDescriptor, projectId))) {
                            logInfo(result, "  Updating " + artifactId + " to " + mappedVersion);
                            coordinate.setVersion(mappedVersion);
                        } else {
                            logInfo(result, "  Ignoring artifact version update for expression " + rawVersion);
                        }
                    } else if (properties != null) {
                        // version is an expression, check for properties to update instead

                        String propertyValue = properties.getProperty(expression);

                        if (propertyValue != null) {
                            if (propertyValue.equals(originalVersion)) {
                                logInfo(result, "  Updating " + rawVersion + " to " + mappedVersion);
                                // change the property only if the property is the same as what's in the reactor
                                properties.setProperty(expression, mappedVersion);
                            } else if (mappedVersion.equals(propertyValue)) {
                                // this property may have been updated during processing a sibling.
                                logInfo(
                                        result,
                                        "  Ignoring artifact version update for expression " + rawVersion
                                                + " because it is already updated");
                            } else if (!mappedVersion.equals(rawVersion)) {
                                // WARNING: ${pom.*} prefix support and ${version} is about to be dropped in mvn4!
                                // https://issues.apache.org/jira/browse/MNG-7404
                                // https://issues.apache.org/jira/browse/MNG-7244
                                if (mappedVersion.matches("\\$\\{project.+\\}")
                                        || mappedVersion.matches("\\$\\{pom.+\\}")
                                        || "${version}".equals(mappedVersion)) {
                                    logInfo(
                                            result,
                                            "  Ignoring artifact version update for expression " + mappedVersion);
                                    // ignore... we cannot update this expression
                                } else {
                                    // the value of the expression conflicts with what the user wanted to release
                                    throw new ReleaseFailureException("The artifact (" + key + ") requires a "
                                            + "different version (" + mappedVersion + ") than what is found ("
                                            + propertyValue + ") for the expression (" + expression + ") in the "
                                            + "project (" + projectId + ").");
                                }
                            }
                        } else {
                            // the expression used to define the version of this artifact may be inherited
                            // TODO needs a better error message, what pom? what dependency?
                            throw new ReleaseFailureException("The version could not be updated: " + rawVersion);
                        }
                    }
                } else {
                    // different/previous version not related to current release
                }
            } else if (resolvedSnapshotVersion != null) {
                logInfo(result, "  Updating " + artifactId + " to " + resolvedSnapshotVersion);

                coordinate.setVersion(resolvedSnapshotVersion);
            } else {
                // artifact not related to current release
            }
        }
    }

    private void prepareScm(
            File pomFile, ReleaseDescriptor releaseDescriptor, ScmRepository repository, ScmProvider provider)
            throws ReleaseExecutionException, ReleaseScmCommandException {
        try {
            if (isUpdateScm() && (releaseDescriptor.isScmUseEditMode() || provider.requiresEditMode())) {
                EditScmResult result = provider.edit(
                        repository, new ScmFileSet(new File(releaseDescriptor.getWorkingDirectory()), pomFile));

                if (!result.isSuccess()) {
                    throw new ReleaseScmCommandException("Unable to enable editing on the POM", result);
                }
            }
        } catch (ScmException e) {
            throw new ReleaseExecutionException("An error occurred enabling edit mode: " + e.getMessage(), e);
        }
    }

    /**
     * <p>getResolvedSnapshotVersion.</p>
     *
     * @param artifactVersionlessKey a {@link java.lang.String} object
     * @param releaseDscriptor       a {@link org.apache.maven.shared.release.config.ReleaseDescriptor} object
     * @return a {@link java.lang.String} object
     */
    protected abstract String getResolvedSnapshotVersion(
            String artifactVersionlessKey, ReleaseDescriptor releaseDscriptor);

    /**
     * <p>getOriginalVersion.</p>
     *
     * @param releaseDescriptor a {@link org.apache.maven.shared.release.config.ReleaseDescriptor} object
     * @param projectKey        a {@link java.lang.String} object
     * @param simulate          a boolean
     * @return a {@link java.lang.String} object
     */
    protected abstract String getOriginalVersion(
            ReleaseDescriptor releaseDescriptor, String projectKey, boolean simulate);

    /**
     * <p>getNextVersion.</p>
     *
     * @param releaseDescriptor a {@link org.apache.maven.shared.release.config.ReleaseDescriptor} object
     * @param key               a {@link java.lang.String} object
     * @return a {@link java.lang.String} object
     */
    protected abstract String getNextVersion(ReleaseDescriptor releaseDescriptor, String key);

    /**
     * <p>transformScm.</p>
     *
     * @param project           a {@link org.apache.maven.project.MavenProject} object
     * @param modelTarget       a {@link org.apache.maven.model.Model} object
     * @param releaseDescriptor a {@link org.apache.maven.shared.release.config.ReleaseDescriptor} object
     * @param projectId         a {@link java.lang.String} object
     * @param scmRepository     a {@link org.apache.maven.scm.repository.ScmRepository} object
     * @param result            a {@link org.apache.maven.shared.release.ReleaseResult} object
     * @throws org.apache.maven.shared.release.ReleaseExecutionException if any.
     */
    protected abstract void transformScm(
            MavenProject project,
            Model modelTarget,
            ReleaseDescriptor releaseDescriptor,
            String projectId,
            ScmRepository scmRepository,
            ReleaseResult result)
            throws ReleaseExecutionException;

    /**
     * <p>isUpdateScm.</p>
     *
     * @return {@code true} if the SCM-section should be updated, otherwise {@code false}
     * @since 2.4
     */
    protected boolean isUpdateScm() {
        return true;
    }

    /**
     * <p>getOriginalResolvedSnapshotVersion.</p>
     *
     * @param artifactVersionlessKey a {@link java.lang.String} object
     * @param releaseDescriptor      a {@link org.apache.maven.shared.release.config.ReleaseDescriptor} object
     * @return a {@link java.lang.String} object
     */
    protected String getOriginalResolvedSnapshotVersion(
            String artifactVersionlessKey, ReleaseDescriptor releaseDescriptor) {
        return releaseDescriptor.getDependencyOriginalVersion(artifactVersionlessKey);
    }

    /**
     * Determines the relative path from trunk to tag, and adds this relative path
     * to the url.
     *
     * @param trunkPath - The trunk url
     * @param tagPath   - The tag base
     * @param urlPath   - scm.url or scm.connection
     * @return The url path for the tag.
     */
    protected static String translateUrlPath(String trunkPath, String tagPath, String urlPath) {
        trunkPath = trunkPath.trim();
        tagPath = tagPath.trim();
        // Strip the slash at the end if one is present
        if (trunkPath.endsWith("/")) {
            trunkPath = trunkPath.substring(0, trunkPath.length() - 1);
        }
        if (tagPath.endsWith("/")) {
            tagPath = tagPath.substring(0, tagPath.length() - 1);
        }
        char[] tagPathChars = trunkPath.toCharArray();
        char[] trunkPathChars = tagPath.toCharArray();
        // Find the common path between trunk and tags
        int i = 0;
        while ((i < tagPathChars.length) && (i < trunkPathChars.length) && tagPathChars[i] == trunkPathChars[i]) {
            ++i;
        }
        // If there is nothing common between trunk and tags, or the relative
        // path does not exist in the url, then just return the tag.
        if (i == 0 || urlPath.indexOf(trunkPath.substring(i)) < 0) {
            return tagPath;
        } else {
            return StringUtils.replace(urlPath, trunkPath.substring(i), tagPath.substring(i));
        }
    }

    private Collection<MavenCoordinate> toMavenCoordinates(List<?> objects) {
        Collection<MavenCoordinate> coordinates = new ArrayList<>(objects.size());
        for (Object object : objects) {
            if (object instanceof MavenCoordinate) {
                coordinates.add((MavenCoordinate) object);
            } else {
                throw new UnsupportedOperationException();
            }
        }
        return coordinates;
    }
}
