/*
    * 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.basepom.inline.mojo;
  
  import static java.lang.String.format;
  
  import java.io.IOException;
  import java.io.OutputStreamWriter;
  import java.io.StringReader;
  import java.util.List;
  import javax.xml.stream.XMLInputFactory;
  import javax.xml.stream.XMLStreamException;
  import javax.xml.stream.XMLStreamReader;
  
  import com.google.common.base.Strings;
  import com.google.common.collect.Iterables;
  import org.eclipse.aether.graph.Dependency;
  import org.eclipse.aether.util.artifact.JavaScopes;
  import org.jdom2.Content;
  import org.jdom2.Content.CType;
  import org.jdom2.Document;
  import org.jdom2.Element;
  import org.jdom2.JDOMException;
  import org.jdom2.Namespace;
  import org.jdom2.Text;
  import org.jdom2.filter.Filters;
  import org.jdom2.input.StAXStreamBuilder;
  import org.jdom2.output.Format;
  import org.jdom2.output.LineSeparator;
  import org.jdom2.output.XMLOutputter;
  import org.jdom2.xpath.XPathExpression;
  import org.jdom2.xpath.XPathFactory;
  
  final class PomUtil {
  
      private final String pomText;
      private final Document pomDocument;
  
      PomUtil(String pomText) throws XMLStreamException, JDOMException {
          this.pomText = pomText;
  
          final XMLInputFactory xmlInputFactory = XMLInputFactory.newFactory();
          final XMLStreamReader reader = xmlInputFactory.createXMLStreamReader(new StringReader(pomText));
          final StAXStreamBuilder builder = new StAXStreamBuilder();
          this.pomDocument = builder.build(reader);
      }
  
      void writePom(OutputStreamWriter writer) throws IOException {
          // this is a hack because jdom2 has the annoying habit of removing a newline between
          // a leading comment and the root element.
          if (pomDocument.getContentSize() > 1
                  && pomDocument.getContent(0).getCType() == CType.Comment
                  && pomDocument.getContent(1).getCType() == CType.Element) {
              this.pomDocument.addContent(1, new Text("\n"));
          }
  
          XMLOutputter xml = new XMLOutputter();
          xml.setFormat(Format.getPrettyFormat()
                  .setLineSeparator(LineSeparator.SYSTEM));
          xml.output(pomDocument, writer);
      }
  
      void removeDependency(Dependency dependency) {
          Namespace pomNs = Namespace.getNamespace("pom", pomDocument.getRootElement().getNamespaceURI());
          XPathFactory xpathFactory = XPathFactory.instance();
          final var artifact = dependency.getArtifact();
          String xpathExpression;
  
          if (Strings.emptyToNull(artifact.getClassifier()) == null) {
              xpathExpression =
                      format("//pom:dependencies/pom:dependency[pom:artifactId[text() = '%s'] and pom:groupId[text() = '%s'] and not(pom:classifier) ]",
                              artifact.getArtifactId(), artifact.getGroupId());
          } else {
              xpathExpression =
                      format("//pom:dependencies/pom:dependency[pom:artifactId[text() = '%s'] and pom:groupId[text() = '%s'] and pom:classifier[text() = '%s']]",
                              artifact.getArtifactId(), artifact.getGroupId(), artifact.getClassifier());
          }
  
          XPathExpression<Content> dependencies = xpathFactory.compile(xpathExpression, Filters.content(), null, pomNs);
          List<Content> contents = dependencies.evaluate(pomDocument.getRootElement());
          for (Content content : contents) {
              content.getParentElement().removeContent(content);
          }
      }
  
      void addDependency(Dependency dependency) {
          Namespace pomNs = Namespace.getNamespace("pom", pomDocument.getRootElement().getNamespaceURI());
          XPathFactory xpathFactory = XPathFactory.instance();
 
         XPathExpression<Content> dependencies = xpathFactory.compile("/pom:project/pom:dependencies", Filters.content(), null, pomNs);
         Content content = Iterables.getOnlyElement(dependencies.evaluate(pomDocument.getRootElement()));
 
         Namespace newNs = pomDocument.getRootElement().getNamespace();
 
         Element dependencyElement = new Element("dependency", newNs);
         dependencyElement.addContent(new Element("groupId", newNs).addContent(dependency.getArtifact().getGroupId()));
         dependencyElement.addContent(new Element("artifactId", newNs).addContent(dependency.getArtifact().getArtifactId()));
         dependencyElement.addContent(new Element("version", newNs).addContent(dependency.getArtifact().getVersion()));
 
         String scope = dependency.getScope();
         if (Strings.emptyToNull(scope) != null && !JavaScopes.COMPILE.equals(scope)) {
             dependencyElement.addContent(new Element("scope", newNs).addContent(scope));
         }
 
         if (dependency.isOptional()) {
             dependencyElement.addContent(new Element("optional", newNs).addContent("true"));
         }
 
         ((Element) content).addContent(dependencyElement);
     }
 }