/*
 * Copyright 2009 Ludovic Claude.
 * Copyright 2011 Damien Raude-Morvan.
 *
 * Licensed 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.debian.maven.packager;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.xml.stream.XMLStreamException;

import org.debian.maven.packager.interaction.ChoiceQuestion;
import org.debian.maven.packager.interaction.SimpleQuestion;
import org.debian.maven.packager.interaction.YesNoQuestion;
import org.debian.maven.packager.util.*;
import org.debian.maven.repo.Dependency;
import org.debian.maven.repo.DependencyNotFoundException;
import org.debian.maven.repo.DependencyRule;
import org.debian.maven.repo.DependencyRuleSet;
import org.debian.maven.repo.DependencyRuleSetFiles;
import org.debian.maven.repo.ListOfPOMs;
import org.debian.maven.repo.POMHandler;
import org.debian.maven.repo.POMInfo;
import org.debian.maven.repo.POMOptions;
import org.debian.maven.repo.Substvars;
import org.debian.maven.repo.DependencyRuleSetFiles.RulesType;
import org.debian.maven.repo.POMInfo.DependencyType;
import org.debian.maven.repo.POMTransformer;
import org.debian.maven.repo.Repository;
import org.debian.maven.repo.Rule;

import static org.debian.maven.packager.DebianDependencies.Type.*;
import static org.debian.maven.repo.DependencyRuleSetFiles.RulesType.*;

/**
 * Analyze the Maven dependencies and extract the Maven rules to use
 * as well as the list of dependent packages.
 *
 * @author Ludovic Claude
 */
public class DependenciesSolver {

    private static final Logger log = Logger.getLogger(DependenciesSolver.class.getName());
    private final IgnoreDependencyQuestions ignoreDependencyQuestion;

    private File baseDir;
    final POMTransformer pomTransformer = new POMTransformer();
    private final File outputDirectory;
    String packageName;
    String packageType;
    private String packageVersion;
    File mavenRepo = new File("/usr/share/maven-repo");
    // explore (search) for additional pom files or look only for those defined in debian/*.poms?
    boolean exploreProjects;
    private Repository repository;
    List<String> issues = new ArrayList<String>();
    private List<Dependency> projectPoms = new ArrayList<Dependency>();
    private List<ToResolve> toResolve = new ArrayList<ToResolve>();
    private Set<Dependency> knownProjectDependencies = new TreeSet<Dependency>();
    private Set<Dependency> ignoredDependencies = new TreeSet<Dependency>();

    private DebianDependencies debianDeps = new DebianDependencies();
    boolean runTests;
    boolean generateJavadoc;
    final boolean interactive;
    private boolean askedToFilterModules = false;
    private boolean filterModules = false;
    boolean verbose = false;
    private Map<String, POMInfo> pomInfoCache = new HashMap<String, POMInfo>();

    /** The original POMs for reference */
    private Map<String, POMInfo> originalPomInfoCache = new HashMap<String, POMInfo>();

    /** Map of the previously selected rule for a given version */
    private Map<String, Rule> versionToRules = new HashMap<String, Rule>();

    /** List of packages and dependencies */
    private Map<DebianDependency, Dependency> versionedPackagesAndDependencies = new HashMap<DebianDependency, Dependency>();

    private List<Rule> defaultRules = new ArrayList<Rule>();
    private PackageScanner scanner;

    public DependenciesSolver(File outputDirectory, PackageScanner scanner, boolean interactive) {
        this.outputDirectory = outputDirectory;
        this.scanner = scanner;
        this.interactive = interactive;
        this.ignoreDependencyQuestion = new IgnoreDependencyQuestions(interactive);
        pomTransformer.setVerbose(true);
        pomTransformer.setFixVersions(false);
        pomTransformer.setRulesFiles(initDependencyRuleSetFiles(outputDirectory, verbose));

        defaultRules.add(new Rule("s/.*/debian/", "Change the version to the symbolic 'debian' version"));
        defaultRules.add(new Rule("*", "Keep the version"));
        defaultRules.add(new Rule("CUSTOM", "Custom rule"));
    }

    public static DependencyRuleSetFiles initDependencyRuleSetFiles(File outputDirectory, boolean verbose) {
        DependencyRuleSetFiles depFiles = new DependencyRuleSetFiles();
        for (RulesType type : RulesType.values()) {
            if (type.filename != null) {
                File rulesFile = new File(outputDirectory, type.filename);
                String description = readResource(type.descriptionResource);
                DependencyRuleSet ruleSet = DependencyRuleSet.readRules(rulesFile, description, verbose, false);
                depFiles.get(type).addAll(ruleSet);
            }
        }

        return depFiles;
    }

    // TODO move to another class for reuse
    private static String readResource(String resource) {
        StringBuilder sb = new StringBuilder();
        try {
            InputStream is = DependenciesSolver.class.getResourceAsStream("/" + resource);
            BufferedReader r = new BufferedReader(new InputStreamReader(is));
            String line;
            while ((line = r.readLine()) != null) {
                sb.append(line);
                sb.append("\n");
            }
            r.close();
        } catch (IOException e) {
            log.log(Level.SEVERE, "Cannot read resource " + resource, e);
        }
        return sb.toString();
    }

    private boolean isDefaultMavenPlugin(Dependency dependency) {
        if (getRepository() != null && getRepository().getSuperPOM() != null) {
            for (Dependency defaultPlugin : getRepository().getSuperPOM().getDependencies().get(DependencyType.PLUGIN_MANAGEMENT)) {
                if (defaultPlugin.equalsIgnoreVersion(dependency)) {
                    return true;
                }
            }
        }
        return false;
    }

    private class ToResolve {

        private final File sourcePom;
        private final DependencyType listType;
        private final boolean buildTime;
        private final boolean mavenExtension;
        private final boolean management;

        private ToResolve(File sourcePom, DependencyType listType, boolean buildTime, boolean mavenExtension, boolean management) {
            this.sourcePom = sourcePom;
            this.listType = listType;
            this.buildTime = buildTime;
            this.mavenExtension = mavenExtension;
            this.management = management;
        }

        public void resolve() {
            try {
                POMInfo pom = getPOM(sourcePom);
                List<Dependency> dependenciesByType = pom.getDependencies().get(listType);

                for (Dependency dependency : dependenciesByType) {
                    resolveDependency(dependency, sourcePom, buildTime, mavenExtension, management, false);
                }
            } catch (DependencyNotFoundException e) {
                log.log(Level.SEVERE, "Cannot resolve dependencies in " + sourcePom + ": " + e.getMessage());
            } catch (Exception e) {
                log.log(Level.SEVERE, "Cannot resolve dependencies in " + sourcePom + ": " + e.getMessage(), e);
            }
        }
    }

    public void saveSubstvars() {
        Properties depVars = Substvars.loadSubstvars(outputDirectory, packageName);

        if (generateJavadoc) {
            System.out.println("Checking dependencies for documentation packages...");

            debianDeps.add(DOC_RUNTIME, new DebianDependency("default-jdk-doc"));
            debianDeps.add(DOC_RUNTIME, scanner.addDocDependencies(debianDeps.get(RUNTIME), versionedPackagesAndDependencies));
            debianDeps.add(DOC_OPTIONAL, scanner.addDocDependencies(debianDeps.get(OPTIONAL), versionedPackagesAndDependencies));
        }

        debianDeps.putInProperties(depVars);

        if (packageVersion != null) {
            depVars.put("maven.UpstreamPackageVersion", packageVersion);
        }
        // Write everything to debian/substvars
        Substvars.write(outputDirectory, packageName, depVars);
    }

    public void setBaseDir(File baseDir) {
        this.baseDir = baseDir;
        if (pomTransformer.getListOfPOMs() != null) {
            pomTransformer.getListOfPOMs().setBaseDir(baseDir);
        }
    }

    public void setListOfPoms(File listOfPoms) {
        if (pomTransformer.getListOfPOMs() == null) {
            pomTransformer.setListOfPOMs(new ListOfPOMs(listOfPoms));
        } else {
            pomTransformer.getListOfPOMs().setListOfPOMsFile(listOfPoms);
        }
        pomTransformer.getListOfPOMs().setBaseDir(baseDir);
    }

    private Repository getRepository() {
        if (repository == null && mavenRepo != null) {
            repository = new Repository(mavenRepo);
            repository.scan();
        }
        return repository;
    }

    public void solveDependencies() {
        pomTransformer.setRepository(getRepository());
        pomTransformer.usePluginVersionsFromRepository();

        IOUtil.mkDirIfNotExists(outputDirectory);

        if (exploreProjects) {
            File pom;
            if (pomTransformer.getListOfPOMs().getPomOptions().isEmpty()) {
                pom = new File(baseDir, "pom.xml");
                if (pom.exists()) {
                    pomTransformer.getListOfPOMs().addPOM("pom.xml");
                } else {
                    pom = new File(baseDir, "debian/pom.xml");
                    if (pom.exists()) {
                        pomTransformer.getListOfPOMs().addPOM("debian/pom.xml");
                    } else {
                        System.err.println("Cannot find the POM file");
                        return;
                    }
                }
            } else {
                pom = new File(baseDir, pomTransformer.getListOfPOMs().getFirstPOM());
            }
            resolveDependencies(pom);
        } else {
            pomTransformer.getListOfPOMs().foreachPoms(new POMHandler() {

                public void handlePOM(File pomFile, boolean noParent, boolean hasPackageVersion) throws Exception {
                    resolveDependencies(pomFile);
                }

                public void ignorePOM(File pomFile) throws Exception {
                }
            });
        }

        for (ToResolve tr : toResolve) {
            tr.resolve();
        }

        if (!issues.isEmpty()) {
            System.err.println("ERROR:");
            for (String issue : issues) {
                System.err.println(issue);
            }
            System.err.println("--------");
        }
    }

    private void resolveDependencies(File projectPom) {

        if (pomTransformer.getListOfPOMs().getOrCreatePOMOptions(projectPom) != null && pomTransformer.getListOfPOMs().getOrCreatePOMOptions(projectPom).isIgnore()) {
            return;
        }

        System.out.println("Analysing " + IOUtil.relativePath(baseDir, projectPom) + "...");

        try {
            POMInfo pom = getPOM(projectPom);
            pom.setProperties(new HashMap<String, String>());
            pom.getProperties().put("debian.package", packageName);

            if (pomTransformer.getListOfPOMs().getOrCreatePOMOptions(projectPom).isNoParent()) {
                pom.setParent(null);
            } else if (pom.getParent() != null && !pom.getParent().isSuperPom()) {
                boolean oldNoParent = pomTransformer.getListOfPOMs().getOrCreatePOMOptions(projectPom).isNoParent();
                // Don't mark the parent dependency as 'build time' dependency because once installed,
                // the POM for this project will always need the parent POM to be available
                Dependency parent = resolveDependency(pom.getParent(), projectPom, false, false, false, true);
                // The user may have set or unset the --no-parent option, if so we update the POM to include or not the
                // parent according to the user's choice
                if (pomTransformer.getListOfPOMs().getOrCreatePOMOptions(projectPom).isNoParent() != oldNoParent) {
                    pomInfoCache.remove(projectPom.getAbsolutePath());
                    pom = getPOM(projectPom);
                }
                pom.setParent(parent);
                // If the parent is found, search the parent POM and update current POM 
                if (parent != null) {
                    POMInfo parentPOM = getRepository().searchMatchingPOM(parent);
                    pom.setParentPOM(parentPOM);
                }
            }

            getRepository().registerPom(projectPom, pom);
            // Also register automatically the test jar which may accompany the current jar and be
            // used in another module of the same project
            if (pom.getThisPom().isJar()) {
                POMInfo testPom = (POMInfo) pom.clone();
                testPom.getThisPom().setType("test-jar");
                getRepository().registerPom(projectPom, testPom);
            }

            knownProjectDependencies.add(pom.getThisPom());

            if (interactive && packageVersion == null) {
                String question = "Enter the upstream version for the package.";
                String v = new SimpleQuestion(question, pom.getOriginalVersion()).ask();
                if (v.isEmpty()) {
                    v = pom.getOriginalVersion();
                }
                packageVersion = v;
            }

            if (pom.getOriginalVersion().equals(packageVersion)) {
                pom.getProperties().put("debian.hasPackageVersion", "true");
                pomTransformer.getListOfPOMs().getOrCreatePOMOptions(projectPom).setHasPackageVersion(true);
            }

            if (filterModules) {
                boolean includeModule = new YesNoQuestion("Include the module " + IOUtil.relativePath(baseDir, projectPom) + " ?", true).ask();
                if (!includeModule) {
                    pomTransformer.getListOfPOMs().getOrCreatePOMOptions(projectPom).setIgnore(true);
                    pomTransformer.getRulesFiles().get(IGNORE).add(DependencyRule.newToMatch(pom.getThisPom()));
                    return;
                }
            }

            projectPoms.add(pom.getThisPom());

            // Previous rule from another run
            boolean explicitlyMentionedInRules = false;
            for (DependencyRule previousRule : pomTransformer.getRulesFiles().get(RULES).findMatchingRules(pom.getThisPom())) {
                if (!previousRule.explicitlyMentions(pom.getThisPom())) {
                    explicitlyMentionedInRules = true;
                    break;
                }
            }

            if (interactive && !explicitlyMentionedInRules && !pom.getThisPom().isPlugin()) {
                Rule selectedRule = askForVersionRule(pom.getThisPom());
                versionToRules.put(pom.getThisPom().getVersion(), selectedRule);
                if (selectedRule.getPattern().equals("CUSTOM")) {
                    String rule = new SimpleQuestion("Enter the pattern for your custom rule (in the form s/regex/replace/)").ask().toLowerCase();
                    selectedRule = new Rule(rule, "My custom rule " + rule);
                    defaultRules.add(selectedRule);
                }

                pomTransformer.getRulesFiles().get(RULES).add(new DependencyRule(pom.getThisPom().getGroupId(), 
                    pom.getThisPom().getArtifactId(), pom.getThisPom().getType(), selectedRule.toString()));
                POMInfo transformedPom = pom.newPOMFromRules(pomTransformer.getRulesFiles().get(RULES).getRules(), getRepository());
                getRepository().registerPom(projectPom, transformedPom);
                projectPoms.add(transformedPom.getThisPom());

                if (pom.getThisPom().isBundle()) {
                    String question2 = pom.getThisPom().getGroupId() + ":" + pom.getThisPom().getArtifactId() +
                            " is a bundle.\n"
                            + "Inform mh_make that dependencies of type jar which may match this library should be transformed into bundles automatically?";

                    boolean transformJarsIntoBundle = new YesNoQuestion(question2, true).ask();

                    if (transformJarsIntoBundle) {
                        String transformBundleRule = pom.getThisPom().getGroupId() + " " + pom.getThisPom().getArtifactId()
                                + " s/jar/bundle/ " + selectedRule.toString();
                        pomTransformer.getRulesFiles().get(PUBLISHED).add(new DependencyRule(transformBundleRule));
                    }
                }
            }

            if (pom.getParent() != null && !pom.getParent().isSuperPom()) {
                POMInfo parentPom = getRepository().searchMatchingPOM(pom.getParent());
                if (parentPom == null || parentPom.equals(getRepository().getSuperPOM())) {
                    pomTransformer.getListOfPOMs().getOrCreatePOMOptions(projectPom).setNoParent(true);
                }
                if (!baseDir.equals(projectPom.getParentFile())) {
                    System.out.println("Checking the parent dependency in the sub project " + IOUtil.relativePath(baseDir, projectPom));
                    resolveDependency(pom.getParent(), projectPom, false, false, false, true);
                }
            }

            toResolve.add(new ToResolve(projectPom, DependencyType.DEPENDENCIES, false, false, false));
            toResolve.add(new ToResolve(projectPom, DependencyType.DEPENDENCY_MANAGEMENT_LIST, false, false, true));
            toResolve.add(new ToResolve(projectPom, DependencyType.PLUGINS, true, true, false));
            toResolve.add(new ToResolve(projectPom, DependencyType.PLUGIN_DEPENDENCIES, true, true, false));
            toResolve.add(new ToResolve(projectPom, DependencyType.PLUGIN_MANAGEMENT, true, true, true));
            toResolve.add(new ToResolve(projectPom, DependencyType.REPORTING_PLUGINS, true, true, false));
            toResolve.add(new ToResolve(projectPom, DependencyType.EXTENSIONS, true, true, false));

            if (exploreProjects && !pom.getModules().isEmpty()) {
                if (interactive && !askedToFilterModules) {
                    filterModules = !new YesNoQuestion("This project contains modules. Include all modules?", true).ask();
                    askedToFilterModules = true;
                }
                for (String module : pom.getModules()) {
                    resolveDependencies(new File(projectPom.getParent(), module + "/pom.xml"));
                }
            }
        } catch (Exception ex) {
            log.log(Level.SEVERE, "Error while resolving " + projectPom + ": " + ex.getMessage());
            log.log(Level.SEVERE, "", ex);
            System.exit(1);
        }
    }

    /**
     * Asks the user to specify the substitution rule for the version.
     * 
     * @param dependency
     * @return the version rule selected
     */
    public Rule askForVersionRule(Dependency dependency) {
        String question = "\n"
                + "Version of " + dependency.getGroupId() + ":"
                + dependency.getArtifactId() + " is " + dependency.getVersion()
                + "\nChoose how the version will be transformed:";

        List<Rule> choices = getVersionRules(dependency.getVersion());       
        
        // select the default choice (either the previously selected rule or the 'debian' version rule)
        int defaultChoice = 1; // the 'debian' version rule is the first one of the default rules
        if (versionToRules.containsKey(dependency.getVersion())) {
            Rule previouslySelectedRule = versionToRules.get(dependency.getVersion());
            if (choices.contains(previouslySelectedRule)) {
                defaultChoice = choices.indexOf(previouslySelectedRule);
            }
        }

        List<String> choicesDescriptions = new ArrayList<String>();
        for (Rule choice : choices) {
            choicesDescriptions.add(choice.getDescription());
        }

        int choice = new ChoiceQuestion(question, defaultChoice, choicesDescriptions).ask();
        return choices.get(choice);
    }

    /**
     * Returns the substitution rules for the specified version.
     */
    private List<Rule> getVersionRules(String version) {
        List<Rule> rules = new ArrayList<Rule>();

        // add the 1.0 -> 1.x rule
        Pattern p = Pattern.compile("(\\d+)(\\..*)");
        Matcher matcher = p.matcher(version);
        if (matcher.matches()) {
            String mainVersion = matcher.group(1);
            Rule mainVersionRule = new Rule("s/" + mainVersion + "\\..*/" + mainVersion + ".x/",
                    "Replace all versions starting by " + mainVersion + ". with " + mainVersion + ".x");
            rules.add(mainVersionRule);
        }
        
        // add the default rules
        rules.addAll(defaultRules);
        
        return rules;
    }

    private POMInfo getPOM(File projectPom) throws XMLStreamException, IOException {
        POMInfo info = pomInfoCache.get(projectPom.getAbsolutePath());
        if (info != null) {
            return info;
        }
        File tmpDest = File.createTempFile("pom", ".tmp", baseDir);
        tmpDest.deleteOnExit();
        POMOptions options = pomTransformer.getListOfPOMs().getOrCreatePOMOptions(projectPom);
        boolean noParent = false;
        boolean hasPackageVersion = false;
        if (options != null) {
            noParent = options.isNoParent();
            hasPackageVersion = options.getHasPackageVersion();
        }

        info = pomTransformer.transformPom(projectPom, tmpDest, noParent, hasPackageVersion, false, false, null, null, true);
        pomInfoCache.put(projectPom.getAbsolutePath(), info);
        return info;
    }

    private POMInfo getOriginalPOM(File projectPom) throws XMLStreamException, IOException {
        POMInfo info = originalPomInfoCache.get(projectPom.getAbsolutePath());
        if (info != null) {
            return info;
        }

        info = pomTransformer.readPom(projectPom);
        originalPomInfoCache.put(projectPom.getAbsolutePath(), info);
        return info;
    }

    private static boolean canBeSkippedBecauseAntIsUsedForPackaging(Dependency thisPom, String packageType, Dependency dependency, boolean runTests, boolean verbose) {
        if (!packageType.equals("ant")) return false;

        if (dependency.isPlugin() && !thisPom.isPom()) {
            if(verbose) System.out.println("[skipped - Maven plugins are not used during a build with Ant]");
            return true;
        }

        if (!runTests && "test".equals(dependency.getScope())) {
            if(verbose) System.out.println("[skipped - Tests are not executed during the build]");
            return true;
        }

        return false;
    }

    private Dependency resolveDependency(Dependency dependency, File sourcePom, boolean buildTime, boolean mavenExtension, boolean management, boolean resolvingParent) throws DependencyNotFoundException {

        if (containsDependencyIgnoreVersion(knownProjectDependencies, dependency)) {
            return dependency;
        }

        if (containsDependencyIgnoreVersion(ignoredDependencies, dependency) ||
                (management && isDefaultMavenPlugin(dependency))) {
            return null;
        }

        if (resolvingParent && dependency.isSuperPom()) {
            return dependency;
        }

        String sourcePomLoc = sourcePom.getAbsolutePath();
        String baseDirPath = baseDir.getAbsolutePath();
        sourcePomLoc = sourcePomLoc.substring(baseDirPath.length() + 1, sourcePomLoc.length());
        if (verbose) {
             System.out.println("Resolving " + dependency + (dependency.getScope() == null ? "" : " of scope " + dependency.getScope()) + "...");
        }

        // First let the packager mark as ignored those dependencies which should be ignored
        if (ignoreDependencyQuestion.askIgnoreUnnecessaryDependency(dependency, sourcePomLoc, runTests, generateJavadoc)) {
            ignoredDependencies.add(dependency);
            pomTransformer.getRulesFiles().get(IGNORE).add(new DependencyRule(dependency.getGroupId(), dependency.getArtifactId(), "*", "*"));
            if (verbose) {
                System.out.println("[ignored]");
            }
            return null;
        }

        // Automatically skip some dependencies when ant packaging is used

        try {
            if (canBeSkippedBecauseAntIsUsedForPackaging(getPOM(sourcePom).getThisPom(), packageType, dependency, runTests, verbose)) {
                // Even if we skip the dependency, try to locate its associated maven rules,
                // as this may be useful later - but never fail if the dependency is not found.
                POMInfo pom = getRepository().searchMatchingPOM(dependency);
                if (pom != null) {
                    pomTransformer.getRulesFiles().get(RULES).addAll(pom.getPublishedRules());
                }

                return null;
            }
        } catch (XMLStreamException e) { e.printStackTrace(); // TODO Auto-generated catch block
        } catch (IOException e) { e.printStackTrace(); }

        POMInfo pom = getRepository().searchMatchingPOM(dependency);
        try {
            if (pom == null && dependency.getVersion() == null) {
                POMInfo containerPom = getPOM(sourcePom);
                String version = containerPom.getVersionFromManagementDependency(dependency);
                dependency.setVersion(version);
                if (version != null) {
                    pom = getRepository().searchMatchingPOM(dependency);
                } else {
                    System.out.println("In " + sourcePomLoc + ", cannot find the version for dependency " + dependency + " from this POM or its parent POMs");
                    if (pomTransformer.getListOfPOMs().getOrCreatePOMOptions(sourcePom).isNoParent()) {
                        Dependency originalParent = getOriginalPOM(sourcePom).getParent();
                        System.out.println("[warning] Option --no-parent has been set for POM file " + sourcePomLoc + ", maybe it was not a good idea and you should first package the parent POM " + originalParent);
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        if (pom == null && dependency.getVersion() != null) {
            List<POMInfo> poms = getRepository().searchMatchingPOMsIgnoreVersion(dependency);
            for (POMInfo potentialPom : poms) {
                for(DependencyRule rule : potentialPom.getPublishedRules()) {
                    if (rule.matches(dependency) && rule.apply(dependency).equals(potentialPom.getThisPom())) {
                        pom = potentialPom;
                        pomTransformer.getRulesFiles().get(RULES).add(rule);
                    }
                }
            }
        }
        if (pom == null && dependency.getVersion() == null) {
            // Set a dummy version and try again
            for (int version = 0; version < 10; version++) {
                dependency.setVersion(version + ".0");
                pom = getRepository().searchMatchingPOM(dependency);
                if (pom != null) {
                    System.out.println("Use best guess version: " + dependency.getVersion() + " for "
                      + dependency.getGroupId() + ":" + dependency.getArtifactId());
                    break;
                }
                dependency.setVersion(null);
            }
        }

        if (pom == null && dependency.isPlugin()) {
            List<POMInfo> matchingPoms = getRepository().searchMatchingPOMsIgnoreVersion(dependency);
            if (matchingPoms.size() > 1) {
                issues.add(sourcePomLoc + ": More than one version matches the plugin " + dependency.getGroupId() + ":"
                        + dependency.getArtifactId() + ":" + dependency.getVersion());
            }
            if (!matchingPoms.isEmpty()) {
                pom = matchingPoms.get(0);
                // Don't add a rule to force the version of a Maven plugin, it's now done
                // automatically at build time
            }
        }

        // Ignore fast cases
        if (pom == null) {
            if (management) {
                if (verbose) System.out.println("[skipped dependency or plugin management]");
                return null;
            } else if (dependency.isPlugin() && packageType.equals("ant")) {
                if (verbose) System.out.println("[skipped - not used in Ant build]");
                return null;
            }
        }

        // In case we didn't find anything for "jar" packaging type, just check for a "bundle" type inside repository.
        // Some jars have been upgraded to OSGi bundles as OSGi metadata has been added to them.
        //
        // drazzib: I'm not sure this is really the right way to fix that (ie. maybe we should install "bundle" artifacts
        // directly with "jar" type inside Debian ?).
        //
        // ludovicc: a complex issue, I believe that libraries which evolve from a jar type to a bundle type should
        // inform packagers with a rule of the form
        // '<groupId> <artifactId> s/jar/bundle/ <versionRule>'
        // in other words, the packager of the library should add a published rule which will transform matching
        // libraries from jar type into bundle types, and apply as well the version substitution (for example to 2.x)
        // for Debian.
        //
        if (pom == null && dependency.isJar()) {
            if (verbose) System.out.println("[check dependency with bundle type]");

            Dependency bundleDependency = dependency.builder().setType("bundle").build();
            pom = getRepository().searchMatchingPOM(bundleDependency);
            if (pom != null) {
                dependency = bundleDependency;
                for (DependencyRule rule: pom.getPublishedRules()) {
                    if (rule.matchesAndPreservesGroupArtifactAndType(dependency)) {
                        pomTransformer.getRulesFiles().get(RULES).add(new DependencyRule(
                            pom.getThisPom().getGroupId(),
                            pom.getThisPom().getArtifactId(),
                            "s/jar/bundle/",
                            rule.getVersionRule().toString()));
                    }
                }
            }
        }

        if (pom == null) {
            if (resolvingParent && ignoreDependencyQuestion.askIgnoreDependency(sourcePomLoc, dependency,
                    "The parent POM cannot be found in the Maven repository for Debian. Ignore it?")) {
                pomTransformer.getListOfPOMs().getOrCreatePOMOptions(sourcePom).setNoParent(true);
                if (verbose) System.out.println("[no-parent]");
                return null;
            }
            boolean ignoreDependency = ignoreDependencyQuestion.askIgnoreDocOrReportPlugin(sourcePomLoc, dependency);
            if(!ignoreDependency) {
                String issue = ignoreDependencyQuestion.askIgnoreNeededDependency(sourcePomLoc, dependency);
                if(issue.isEmpty()) {
                    ignoreDependency = true;
                } else {
                    issues.add(issue);
                }
            }
            if (ignoreDependency) {
                ignoredDependencies.add(dependency);
                pomTransformer.getRulesFiles().get(IGNORE).add(new DependencyRule(dependency.getGroupId(), dependency.getArtifactId(), "*", "*"));
                if (verbose) System.out.println("[ignored]");
                return null;
            }

            // We're not ignoring the dependency
            DebianDependency pkg = scanner.searchPkgContainingPom(dependency);
            if (pkg != null) {
                String installedVersion = scanner.getPackageVersion(pkg, true);
                if (installedVersion != null) {
                    System.out.println("[error] Package " + pkg + " (" + installedVersion + ") is already installed and contains a possible match," );
                    System.out.println("but I cannot resolve library " + dependency + " in it.");
                    System.out.println("[error] Please check manually that the library is up to date, otherwise it may be necessary to package version "
                            + dependency.getVersion() + " in Debian.");
                } else {
                    System.out.println("[warning] Please install the missing dependency. Run the following command in another terminal:");
                    System.out.println("  sudo apt-get install " + pkg);
                }
            }

            if (interactive && pkg == null) {
                pkg = scanner.searchPkgContainingJar(dependency);
                if (pkg != null) {
                    String question = "[error] Package " + pkg + " does not contain Maven dependency " + dependency + " but there seem to be a match\n"
                     + "If the package contains already Maven artifacts but the names don't match, try to enter a substitution rule\n"
                     + "of the form s/groupId/newGroupId/ s/artifactId/newArtifactId/ jar s/version/newVersion/ here:";
                    String newRule = new SimpleQuestion(question).ask();
                    if (!newRule.isEmpty()) {
                        DependencyRule userRule = new DependencyRule(newRule);
                        pomTransformer.getRulesFiles().get(RULES).add(userRule);
                        System.out.println("Please suggest the maintainer of package " + pkg + " to add this rule to debian/maven.publishedRules");
                        return resolveDependency(dependency.applyRules(Arrays.asList(userRule)), sourcePom, buildTime, mavenExtension, management, false);
                    }
                } else {
                    String newRule = new SimpleQuestion(
                            "[error] Cannot resolve Maven dependency " + dependency + ". If you know a package that contains a compatible dependency,\n"
                          + "try to enter a substitution rule of the form s/groupId/newGroupId/ s/artifactId/newArtifactId/ jar s/version/newVersion/ here:\n").ask();
                    while (!newRule.isEmpty()) {
                        DependencyRule userRule = new DependencyRule(newRule);
                        Dependency newDependency = dependency.applyRules(Arrays.asList(userRule));
                        if (newDependency.equals(dependency)) {
                            newRule = new SimpleQuestion("Your rule doesn't seem to apply on " + dependency
                             + "Please enter a substitution rule of the form s/groupId/newGroupId/ s/artifactId/newArtifactId/ jar s/version/newVersion/ here,"
                             + "or press <Enter> to give up").ask();
                        } else {
                            pomTransformer.getRulesFiles().get(RULES).add(userRule);
                            System.out.println("Rescanning /usr/share/maven-repo...");
                            pomTransformer.getRepository().scan();
                            return resolveDependency(dependency.applyRules(Arrays.asList(userRule)), sourcePom, buildTime, mavenExtension, management, false);
                        }
                    }
                }
            }

            if (interactive && new YesNoQuestion("Try again to resolve the dependency?", true).ask()) {
                System.out.println("Rescanning /usr/share/maven-repo...");
                pomTransformer.getRepository().scan();
                // Clear caches
                scanner = scanner.newInstanceWithFreshCaches();
                return resolveDependency(dependency, sourcePom, buildTime, mavenExtension, management, false);
            }

            if (verbose) System.out.println("[error]");

            throw new DependencyNotFoundException(dependency);
        }

        // Handle the case of Maven plugins built and used in a multi-module build:
        // they need to be added to maven.cleanIgnoreRules to avoid errors during
        // a mvn clean
        if (dependency.isPlugin() && containsDependencyIgnoreVersion(projectPoms, dependency)) {
            String ruleDef = dependency.getGroupId() + " " + dependency.getArtifactId() + " maven-plugin *";
            pomTransformer.getRulesFiles().get(CLEAN).add(new DependencyRule(ruleDef));
        }

        // Discover the library to import for the dependency
        DebianDependency pkg = getPackage(pom, sourcePomLoc);

        if (pkg != null && !pkg.equals(packageName)) {
            DebianDependency libraryWithVersionConstraint;
            if (pom.getOriginalVersion() != null && (pom.getProperties().containsKey("debian.hasPackageVersion"))) {
                String version = dependency.getVersion();
                if (version == null || (pom.getOriginalVersion() != null && version.compareTo(pom.getOriginalVersion()) > 0)) {
                    version = pom.getOriginalVersion();
                }
                libraryWithVersionConstraint = new DebianDependency(pkg.getPackageName(), version);
            } else {
                libraryWithVersionConstraint = pkg;
            }
            if (!management) {
                if (buildTime) {
                    if ("test".equals(dependency.getScope())) {
                        debianDeps.add(TEST, libraryWithVersionConstraint);
                    } else if (dependency.isPlugin()) {
                        if (!packageType.equals("ant")) {
                            debianDeps.add(COMPILE, libraryWithVersionConstraint);
                        }
                    } else if (mavenExtension) {
                        if (!packageType.equals("ant")) {
                            debianDeps.add(COMPILE, libraryWithVersionConstraint);
                        }
                    } else {
                        debianDeps.add(COMPILE, libraryWithVersionConstraint);
                    }
                } else {
                    if ("test".equals(dependency.getScope())) {
                        debianDeps.add(TEST, libraryWithVersionConstraint);
                    } else if (dependency.isOptional()) {
                        debianDeps.add(OPTIONAL, libraryWithVersionConstraint);
                    } else if (!"provided".equals(dependency.getScope())) {
                        debianDeps.add(RUNTIME, libraryWithVersionConstraint);
                    }
                }
            }
            versionedPackagesAndDependencies.put(libraryWithVersionConstraint, dependency);
        }

        pomTransformer.getRulesFiles().get(RULES).addAll(pom.getPublishedRules());

        if (verbose) {
            System.out.println("Dependency " + dependency + " found in package " + pkg);
            System.out.println("[ok]");
            System.out.println();
        }

        if (resolvingParent) {
            try {
                POMInfo containerPom = getPOM(sourcePom);
                containerPom.setParentPOM(pom);

            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return pom.getThisPom();
    }

    private DebianDependency getPackage(POMInfo pom, String sourcePomLoc) {
        DebianDependency pkg = null;
        if (pom.getProperties() != null) {
            pkg = new DebianDependency(pom.getProperties().get("debian.package"));
        }
        if (pkg == null) {
            Dependency dependency = pom.getThisPom();
            issues.add(sourcePomLoc + ": Dependency is missing the Debian properties in its POM: " + dependency.getGroupId() + ":"
                    + dependency.getArtifactId() + ":" + dependency.getVersion());
            File pomFile = new File(mavenRepo, dependency.getGroupId().replace(".", "/") + "/" + dependency.getArtifactId() + "/" + dependency.getVersion() + "/" + dependency.getArtifactId() + "-" + dependency.getVersion() + ".pom");
            pkg = scanner.searchPkg(pomFile);
        }
        return pkg;
    }

    private boolean containsDependencyIgnoreVersion(Collection<Dependency> dependencies, Dependency dependency) {
        for (Dependency ignoredDependency : dependencies) {
            if (ignoredDependency.equalsIgnoreVersion(dependency)) {
                return true;
            }
        }
        return false;
    }

    public static void main(String[] args) {
        if (args.length == 0 || "-h".equals(args[0]) || "--help".equals(args[0])) {
            System.out.println("Purpose: Solve the dependencies in the POM(s).");
            System.out.println("Usage: [option]");
            System.out.println("");
            System.out.println("Options:");
            System.out.println("  -v, --verbose: be extra verbose");
            System.out.println("  -p<package>, --package=<package>: name of the Debian package containing");
            System.out.println("    this library");
//            System.out.println("  -r<rules>, --rules=<rules>: path to the file containing the");
//            System.out.println("    extra rules to apply when cleaning the POM");
//            System.out.println("  -i<rules>, --published-rules=<rules>: path to the file containing the");
//            System.out.println("    extra rules to publish in the property debian.mavenRules in the cleaned POM");
            System.out.println("  --ant: use ant for the packaging");
            System.out.println("  --run-tests: run the unit tests");
            System.out.println("  --generate-javadoc: generate Javadoc");
            System.out.println("  --non-interactive: non interactive session");
            System.out.println("  --offline: offline mode for Debian build compatibility");
            System.out.println("  -m<repo root>--maven-repo=<repo root>: location of the Maven repository,");
            System.out.println("    used to force the versions of the Maven plugins used in the current");
            System.out.println("    POM file with the versions found in the repository");
            System.out.println("  --base-directory: path to root directory of package");
            System.out.println("  --non-explore: doesn't explore directories for pom.xml");
            return;
        }

        // Default values
        boolean verbose = false;
        String debianPackage = "";
        String packageType = "maven";
        File mavenRepo = null;
        File baseDirectory = new File(".");
        boolean exploreProjects = true;
        boolean runTests = false;
        boolean generateJavadoc = false;
        boolean interactive = true;
        boolean offline = false;

        // Parse parameters
        int i = inc(-1, args);
        while (i < args.length && (args[i].trim().startsWith("-") || args[i].trim().isEmpty())) {
            String arg = args[i].trim();
            if ("--verbose".equals(arg) || "-v".equals(arg)) {
                verbose = true;
            } else if ("--debug".equals(arg)) {
                log.setLevel(Level.FINEST);
            } else if (arg.startsWith("-p")) {
                debianPackage = arg.substring(2);
            } else if (arg.startsWith("--package=")) {
                debianPackage = arg.substring("--package=".length());
            } else if (arg.equals("--ant")) {
                packageType = "ant";
            } else if (arg.equals("--run-tests")) {
                runTests = true;
            } else if (arg.equals("--generate-javadoc")) {
                generateJavadoc = true;
            } else if (arg.equals("--non-interactive")) {
                interactive = false;
            } else if (arg.equals("--offline")) {
                offline = true;
            } else if (arg.startsWith("-m")) {
                mavenRepo = new File(arg.substring(2));
            } else if (arg.startsWith("--maven-repo=")) {
                mavenRepo = new File(arg.substring("--maven-repo=".length()));
            } else if (arg.startsWith("-b")) {
                baseDirectory = new File(arg.substring(2));
            } else if (arg.startsWith("--base-directory=")) {
                baseDirectory = new File(arg.substring("--base-directory=".length()));
            } else if (arg.equals("--non-explore")) {
                exploreProjects = false;
            }
            i = inc(i, args);
        }

        File outputDirectory = new File(baseDirectory, "debian");
        DependenciesSolver solver = new DependenciesSolver(outputDirectory, new PackageScanner(offline), interactive);
        solver.generateJavadoc = generateJavadoc;
        solver.runTests = runTests;
        solver.exploreProjects = exploreProjects;
        solver.setBaseDir(baseDirectory);
        solver.packageName = debianPackage;
        solver.packageType = packageType;
        File poms = new File(solver.outputDirectory, debianPackage + ".poms");
        solver.setListOfPoms(poms);

        if (mavenRepo != null) {
            Repository repository = new Repository(mavenRepo);
            solver.pomTransformer.setRepository(repository);
            solver.pomTransformer.usePluginVersionsFromRepository();
        }

        if (verbose) {
            String msg = "Solving dependencies for package " + debianPackage;
            if (solver.runTests) {
                msg += " (tests are included)";
            }
            if (solver.generateJavadoc) {
                msg += " (documentation is included)";
            }
            System.out.println(msg);
            solver.verbose = true;
        }

        solver.solveDependencies();

        solver.pomTransformer.getListOfPOMs().save();
        solver.pomTransformer.getRulesFiles().save(outputDirectory);
        solver.saveSubstvars();

        if (!solver.issues.isEmpty()) {
            System.err.println("Some problems were found in this project, exiting...");
            System.exit(1);
        }
    }

    private static int inc(int i, String[] args) {
        do {
            i++;
        } while (i < args.length && args[i].isEmpty());
        return i;
    }
}
