/*
    * 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.model.building;
  
  import javax.inject.Inject;
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.Reader;
  import java.nio.file.Path;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.List;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Optional;
  
  import org.apache.maven.api.model.Model;
  import org.apache.maven.api.spi.ModelParser;
  import org.apache.maven.api.spi.ModelParserException;
  import org.apache.maven.building.Source;
  import org.apache.maven.model.io.ModelParseException;
  import org.apache.maven.model.io.ModelReader;
  import org.apache.maven.model.locator.ModelLocator;
  import org.eclipse.sisu.Typed;
  
  /**
   *
   * Note: uses @Typed to limit the types it is available for injection to just ModelProcessor.
   *
   * This is because the ModelProcessor interface extends ModelLocator and ModelReader. If we
   * made this component available under all its interfaces then it could end up being injected
   * into itself leading to a stack overflow.
   *
   * A side effect of using @Typed is that it translates to explicit bindings in the container.
   * So instead of binding the component under a 'wildcard' key it is now bound with an explicit
   * key. Since this is a default component this will be a plain binding of ModelProcessor to
   * this implementation type, ie. no hint/name.
   *
   * This leads to a second side effect in that any @Inject request for just ModelProcessor in
   * the same injector is immediately matched to this explicit binding, which means extensions
   * cannot override this binding. This is because the lookup is always short-circuited in this
   * specific situation (plain @Inject request, and plain explicit binding for the same type.)
   *
   * The simplest solution is to use a custom @Named here so it isn't bound under the plain key.
   * This is only necessary for default components using @Typed that want to support overriding.
   *
   * As a non-default component this now gets a negative priority relative to other implementations
   * of the same interface. Since we want to allow overriding this doesn't matter in this case.
   * (if it did we could add @Priority of 0 to match the priority given to default components.)
   */
  @Named("core-default")
  @Singleton
  @Typed(ModelProcessor.class)
  public class DefaultModelProcessor implements ModelProcessor {
  
      private final Collection<ModelParser> modelParsers;
      private final ModelLocator modelLocator;
      private final ModelReader modelReader;
  
      @Inject
      public DefaultModelProcessor(
              Collection<ModelParser> modelParsers, ModelLocator modelLocator, ModelReader modelReader) {
          this.modelParsers = modelParsers;
          this.modelLocator = modelLocator;
          this.modelReader = modelReader;
      }
  
      @Override
      public File locatePom(File projectDirectory) {
          return locatePom(projectDirectory.toPath()).toFile();
      }
  
      public Path locatePom(Path projectDirectory) {
          // Note that the ModelProcessor#locatePom never returns null
          // while the ModelParser#locatePom needs to return an existing path!
          Path pom = modelParsers.stream()
                  .map(m -> m.locate(projectDirectory)
                          .map(org.apache.maven.api.services.Source::getPath)
                          .orElse(null))
                 .filter(Objects::nonNull)
                 .findFirst()
                 .orElseGet(
                         () -> modelLocator.locatePom(projectDirectory.toFile()).toPath());
         if (!pom.equals(projectDirectory) && !pom.getParent().equals(projectDirectory)) {
             throw new IllegalArgumentException("The POM found does not belong to the given directory: " + pom);
         }
         return pom;
     }
 
     public File locateExistingPom(File projectDirectory) {
         Path path = locateExistingPom(projectDirectory.toPath());
         return path != null ? path.toFile() : null;
     }
 
     public Path locateExistingPom(Path projectDirectory) {
         // Note that the ModelProcessor#locatePom never returns null
         // while the ModelParser#locatePom needs to return an existing path!
         Path pom = modelParsers.stream()
                 .map(m -> m.locate(projectDirectory).map(s -> s.getPath()).orElse(null))
                 .filter(Objects::nonNull)
                 .findFirst()
                 .orElseGet(() -> {
                     File f = modelLocator.locateExistingPom(projectDirectory.toFile());
                     return f != null ? f.toPath() : null;
                 });
         if (pom != null && !pom.equals(projectDirectory) && !pom.getParent().equals(projectDirectory)) {
             throw new IllegalArgumentException("The POM found does not belong to the given directory: " + pom);
         }
         return pom;
     }
 
     protected org.apache.maven.api.model.Model read(
             Path pomFile, InputStream input, Reader reader, Map<String, ?> options) throws IOException {
         Source source = (Source) options.get(ModelProcessor.SOURCE);
         if (pomFile == null && source instanceof org.apache.maven.building.FileSource) {
             pomFile = ((org.apache.maven.building.FileSource) source).getFile().toPath();
         }
         if (pomFile != null) {
             Path projectDirectory = pomFile.getParent();
             List<ModelParserException> exceptions = new ArrayList<>();
             for (ModelParser parser : modelParsers) {
                 try {
                     Optional<Model> model = parser.locateAndParse(projectDirectory, options);
                     if (model.isPresent()) {
                         return model.get().withPomFile(pomFile);
                     }
                 } catch (ModelParserException e) {
                     exceptions.add(e);
                 }
             }
             try {
                 return readXmlModel(pomFile, null, null, options);
             } catch (IOException e) {
                 exceptions.forEach(e::addSuppressed);
                 throw e;
             }
         } else {
             return readXmlModel(pomFile, input, reader, options);
         }
     }
 
     private org.apache.maven.api.model.Model readXmlModel(
             Path pomFile, InputStream input, Reader reader, Map<String, ?> options) throws IOException {
         if (pomFile != null) {
             return modelReader.read(pomFile.toFile(), options).getDelegate();
         } else if (input != null) {
             return modelReader.read(input, options).getDelegate();
         } else {
             return modelReader.read(reader, options).getDelegate();
         }
     }
 
     @Override
     public org.apache.maven.model.Model read(File file, Map<String, ?> options) throws IOException {
         Objects.requireNonNull(file, "file cannot be null");
         Path path = file.toPath();
         org.apache.maven.api.model.Model model = read(path, null, null, options);
         return new org.apache.maven.model.Model(model);
     }
 
     @Override
     public org.apache.maven.model.Model read(InputStream input, Map<String, ?> options) throws IOException {
         Objects.requireNonNull(input, "input cannot be null");
         try (InputStream in = input) {
             org.apache.maven.api.model.Model model = read(null, in, null, options);
             return new org.apache.maven.model.Model(model);
         } catch (ModelParserException e) {
             throw new ModelParseException("Unable to read model: " + e, e.getLineNumber(), e.getColumnNumber(), e);
         }
     }
 
     @Override
     public org.apache.maven.model.Model read(Reader reader, Map<String, ?> options) throws IOException {
         Objects.requireNonNull(reader, "reader cannot be null");
         try (Reader r = reader) {
             org.apache.maven.api.model.Model model = read(null, null, r, options);
             return new org.apache.maven.model.Model(model);
         }
     }
 }