/*
    * 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.cling.invoker;
  
  import javax.xml.stream.XMLStreamException;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  import java.util.function.Function;
  import java.util.stream.Collectors;
  
  import org.apache.maven.api.Constants;
  import org.apache.maven.api.annotations.Nullable;
  import org.apache.maven.api.cli.InvokerRequest;
  import org.apache.maven.api.cli.Options;
  import org.apache.maven.api.cli.Parser;
  import org.apache.maven.api.cli.ParserException;
  import org.apache.maven.api.cli.ParserRequest;
  import org.apache.maven.api.cli.extensions.CoreExtension;
  import org.apache.maven.cling.internal.extension.io.CoreExtensionsStaxReader;
  import org.apache.maven.cling.props.MavenPropertiesLoader;
  import org.apache.maven.cling.utils.CLIReportingUtils;
  import org.apache.maven.properties.internal.EnvironmentUtils;
  import org.apache.maven.properties.internal.SystemProperties;
  
  import static java.util.Objects.requireNonNull;
  import static org.apache.maven.api.Constants.MAVEN_HOME;
  import static org.apache.maven.api.Constants.MAVEN_INSTALLATION_CONF;
  import static org.apache.maven.cling.invoker.Utils.getCanonicalPath;
  import static org.apache.maven.cling.invoker.Utils.or;
  import static org.apache.maven.cling.invoker.Utils.prefix;
  import static org.apache.maven.cling.invoker.Utils.stripLeadingAndTrailingQuotes;
  import static org.apache.maven.cling.invoker.Utils.toMap;
  
  public abstract class BaseParser implements Parser {
  
      @SuppressWarnings("VisibilityModifier")
      public static class LocalContext {
          public final ParserRequest parserRequest;
          public final Map<String, String> systemPropertiesOverrides;
  
          public LocalContext(ParserRequest parserRequest) {
              this.parserRequest = parserRequest;
              this.systemPropertiesOverrides = new HashMap<>();
          }
  
          public Path cwd;
          public Path installationDirectory;
          public Path userHomeDirectory;
          public Map<String, String> systemProperties;
          public Map<String, String> userProperties;
          public Path topDirectory;
  
          @Nullable
          public Path rootDirectory;
  
          public List<CoreExtension> extensions;
          public Options options;
  
          public Map<String, String> extraInterpolationSource() {
              Map<String, String> extra = new HashMap<>();
              extra.put("session.topDirectory", topDirectory.toString());
              if (rootDirectory != null) {
                  extra.put("session.rootDirectory", rootDirectory.toString());
              }
              return extra;
          }
      }
  
      @Override
      public InvokerRequest parseInvocation(ParserRequest parserRequest) throws ParserException, IOException {
          requireNonNull(parserRequest);
  
         LocalContext context = new LocalContext(parserRequest);
 
         // the basics
         context.cwd = requireNonNull(getCwd(context));
         context.installationDirectory = requireNonNull(getInstallationDirectory(context));
         context.userHomeDirectory = requireNonNull(getUserHomeDirectory(context));
 
         // top/root
         context.topDirectory = requireNonNull(getTopDirectory(context));
         context.rootDirectory = getRootDirectory(context);
 
         // options
         List<Options> parsedOptions = parseCliOptions(context);
 
         // warn about deprecated options
         PrintWriter printWriter = new PrintWriter(parserRequest.out() != null ? parserRequest.out() : System.out, true);
         parsedOptions.forEach(o -> o.warnAboutDeprecatedOptions(parserRequest, printWriter::println));
 
         // assemble options if needed
         context.options = assembleOptions(parsedOptions);
 
         // system and user properties
         context.systemProperties = populateSystemProperties(context);
         context.userProperties = populateUserProperties(context);
 
         // options: interpolate
         context.options = context.options.interpolate(
                 Arrays.asList(context.extraInterpolationSource(), context.userProperties, context.systemProperties));
 
         // core extensions
         context.extensions = readCoreExtensionsDescriptor(context);
 
         return getInvokerRequest(context);
     }
 
     protected abstract InvokerRequest getInvokerRequest(LocalContext context);
 
     protected Path getCwd(LocalContext context) throws ParserException {
         if (context.parserRequest.cwd() != null) {
             Path result = getCanonicalPath(context.parserRequest.cwd());
             context.systemPropertiesOverrides.put("user.dir", result.toString());
             return result;
         } else {
             return getCanonicalPath(Paths.get(System.getProperty("user.dir")));
         }
     }
 
     protected Path getInstallationDirectory(LocalContext context) throws ParserException {
         Path result;
         if (context.parserRequest.mavenHome() != null) {
             result = getCanonicalPath(context.parserRequest.mavenHome());
             context.systemPropertiesOverrides.put(MAVEN_HOME, result.toString());
         } else {
             String mavenHome = System.getProperty(Constants.MAVEN_HOME);
             if (mavenHome == null) {
                 throw new ParserException("local mode requires " + Constants.MAVEN_HOME + " Java System Property set");
             }
             result = getCanonicalPath(Paths.get(mavenHome));
         }
         return result;
     }
 
     protected Path getUserHomeDirectory(LocalContext context) throws ParserException {
         if (context.parserRequest.userHome() != null) {
             Path result = getCanonicalPath(context.parserRequest.userHome());
             context.systemPropertiesOverrides.put("user.home", result.toString());
             return result;
         } else {
             return getCanonicalPath(Paths.get(System.getProperty("user.home")));
         }
     }
 
     protected Path getTopDirectory(LocalContext context) throws ParserException {
         // We need to locate the top level project which may be pointed at using
         // the -f/--file option.
         Path topDirectory = requireNonNull(context.cwd);
         boolean isAltFile = false;
         for (String arg : context.parserRequest.args()) {
             if (isAltFile) {
                 // this is the argument following -f/--file
                 Path path = topDirectory.resolve(stripLeadingAndTrailingQuotes(arg));
                 if (Files.isDirectory(path)) {
                     topDirectory = path;
                 } else if (Files.isRegularFile(path)) {
                     topDirectory = path.getParent();
                     if (!Files.isDirectory(topDirectory)) {
                         throw new ParserException("Directory " + topDirectory
                                 + " extracted from the -f/--file command-line argument " + arg + " does not exist");
                     }
                 } else {
                     throw new ParserException(
                             "POM file " + arg + " specified with the -f/--file command line argument does not exist");
                 }
                 break;
             } else {
                 // Check if this is the -f/--file option
                 isAltFile = arg.equals("-f") || arg.equals("--file");
             }
         }
         return getCanonicalPath(topDirectory);
     }
 
     @Nullable
     protected Path getRootDirectory(LocalContext context) throws ParserException {
         return Utils.findRoot(context.topDirectory);
     }
 
     protected Map<String, String> populateSystemProperties(LocalContext context) throws ParserException {
         Properties systemProperties = new Properties();
 
         // ----------------------------------------------------------------------
         // Load environment and system properties
         // ----------------------------------------------------------------------
 
         EnvironmentUtils.addEnvVars(systemProperties);
         SystemProperties.addSystemProperties(systemProperties);
 
         // ----------------------------------------------------------------------
         // Properties containing info about the currently running version of Maven
         // These override any corresponding properties set on the command line
         // ----------------------------------------------------------------------
 
         Properties buildProperties = CLIReportingUtils.getBuildProperties();
 
         String mavenVersion = buildProperties.getProperty(CLIReportingUtils.BUILD_VERSION_PROPERTY);
         systemProperties.setProperty("maven.version", mavenVersion);
 
         String mavenBuildVersion = CLIReportingUtils.createMavenVersionString(buildProperties);
         systemProperties.setProperty("maven.build.version", mavenBuildVersion);
 
         Map<String, String> result = toMap(systemProperties);
         result.putAll(context.systemPropertiesOverrides);
         return result;
     }
 
     protected Map<String, String> populateUserProperties(LocalContext context) throws ParserException, IOException {
         Properties userProperties = new Properties();
 
         // ----------------------------------------------------------------------
         // Options that are set on the command line become system properties
         // and therefore are set in the session properties. System properties
         // are most dominant.
         // ----------------------------------------------------------------------
 
         Map<String, String> userSpecifiedProperties =
                 context.options.userProperties().orElse(new HashMap<>());
 
         // ----------------------------------------------------------------------
         // Load config files
         // ----------------------------------------------------------------------
         Map<String, String> paths = context.extraInterpolationSource();
         Function<String, String> callback =
                 or(paths::get, prefix("cli.", userSpecifiedProperties::get), context.systemProperties::get);
 
         Path mavenConf;
         if (context.systemProperties.get(MAVEN_INSTALLATION_CONF) != null) {
             mavenConf = context.installationDirectory.resolve(context.systemProperties.get(MAVEN_INSTALLATION_CONF));
         } else if (context.systemProperties.get("maven.conf") != null) {
             mavenConf = context.installationDirectory.resolve(context.systemProperties.get("maven.conf"));
         } else if (context.systemProperties.get(MAVEN_HOME) != null) {
             mavenConf = context.installationDirectory
                     .resolve(context.systemProperties.get(MAVEN_HOME))
                     .resolve("conf");
         } else {
             mavenConf = context.installationDirectory.resolve("");
         }
         Path propertiesFile = mavenConf.resolve("maven.properties");
         MavenPropertiesLoader.loadProperties(userProperties, propertiesFile, callback, false);
 
         // CLI specified properties are most dominant
         userProperties.putAll(userSpecifiedProperties);
 
         return toMap(userProperties);
     }
 
     protected abstract List<Options> parseCliOptions(LocalContext context) throws ParserException, IOException;
 
     protected abstract Options assembleOptions(List<Options> parsedOptions);
 
     protected List<CoreExtension> readCoreExtensionsDescriptor(LocalContext context)
             throws ParserException, IOException {
         ArrayList<CoreExtension> extensions = new ArrayList<>();
         String installationExtensionsFile = context.userProperties.get(Constants.MAVEN_INSTALLATION_EXTENSIONS);
         extensions.addAll(readCoreExtensionsDescriptorFromFile(
                 context.installationDirectory.resolve(installationExtensionsFile)));
 
         String projectExtensionsFile = context.userProperties.get(Constants.MAVEN_PROJECT_EXTENSIONS);
         extensions.addAll(readCoreExtensionsDescriptorFromFile(context.cwd.resolve(projectExtensionsFile)));
 
         String userExtensionsFile = context.userProperties.get(Constants.MAVEN_USER_EXTENSIONS);
         extensions.addAll(readCoreExtensionsDescriptorFromFile(context.userHomeDirectory.resolve(userExtensionsFile)));
 
         return extensions;
     }
 
     protected List<CoreExtension> readCoreExtensionsDescriptorFromFile(Path extensionsFile)
             throws ParserException, IOException {
         try {
             if (extensionsFile != null && Files.exists(extensionsFile)) {
                 try (InputStream is = Files.newInputStream(extensionsFile)) {
                     return new CoreExtensionsStaxReader().read(is, true).getExtensions();
                 }
             }
             return List.of();
         } catch (XMLStreamException e) {
             throw new ParserException("Failed to parse extensions file: " + extensionsFile, e);
         }
     }
 
     protected List<String> getJvmArguments(Path rootDirectory) throws ParserException {
         if (rootDirectory != null) {
             Path jvmConfig = rootDirectory.resolve(".mvn/jvm.config");
             if (Files.exists(jvmConfig)) {
                 try {
                     return Files.readAllLines(jvmConfig).stream()
                             .filter(l -> !l.isBlank() && !l.startsWith("#"))
                             .flatMap(l -> Arrays.stream(l.split(" ")))
                             .collect(Collectors.toList());
                 } catch (IOException e) {
                     throw new ParserException("Failed to read JVM configuration file: " + jvmConfig, e);
                 }
             }
         }
         return null;
     }
 }