/*
    * SPDX-FileCopyrightText: none
    * SPDX-License-Identifier: CC0-1.0
    */
   
   package dev.metaschema.cli.commands;
   
   import org.apache.commons.cli.CommandLine;
   import org.apache.commons.cli.Option;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  
  import java.io.File;
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.net.URI;
  import java.net.UnknownHostException;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.util.Collection;
  import java.util.List;
  import java.util.Locale;
  import java.util.Set;
  
  import dev.metaschema.cli.processor.CLIProcessor;
  import dev.metaschema.cli.processor.CallingContext;
  import dev.metaschema.cli.processor.ExitCode;
  import dev.metaschema.cli.processor.command.AbstractCommandExecutor;
  import dev.metaschema.cli.processor.command.AbstractTerminalCommand;
  import dev.metaschema.cli.processor.command.CommandExecutionException;
  import dev.metaschema.cli.processor.command.ExtraArgument;
  import dev.metaschema.cli.util.LoggingValidationHandler;
  import dev.metaschema.core.configuration.DefaultConfiguration;
  import dev.metaschema.core.configuration.IMutableConfiguration;
  import dev.metaschema.core.metapath.MetapathException;
  import dev.metaschema.core.metapath.format.IPathFormatter;
  import dev.metaschema.core.metapath.format.PathFormatSelection;
  import dev.metaschema.core.model.IModule;
  import dev.metaschema.core.model.MetaschemaException;
  import dev.metaschema.core.model.constraint.ConstraintValidationException;
  import dev.metaschema.core.model.constraint.IConstraintSet;
  import dev.metaschema.core.model.constraint.ValidationFeature;
  import dev.metaschema.core.model.validation.AggregateValidationResult;
  import dev.metaschema.core.model.validation.IValidationResult;
  import dev.metaschema.core.util.IVersionInfo;
  import dev.metaschema.core.util.ObjectUtils;
  import dev.metaschema.databind.IBindingContext;
  import dev.metaschema.databind.IBindingContext.ISchemaValidationProvider;
  import dev.metaschema.databind.io.Format;
  import dev.metaschema.databind.io.IBoundLoader;
  import dev.metaschema.modules.sarif.SarifValidationHandler;
  import edu.umd.cs.findbugs.annotations.NonNull;
  import edu.umd.cs.findbugs.annotations.Nullable;
  
  /**
   * Used by implementing classes to provide a content validation command.
   */
  public abstract class AbstractValidateContentCommand
      extends AbstractTerminalCommand {
    private static final Logger LOGGER = LogManager.getLogger(AbstractValidateContentCommand.class);
    @NonNull
    private static final String COMMAND = "validate";
    @NonNull
    private static final List<ExtraArgument> EXTRA_ARGUMENTS = ObjectUtils.notNull(List.of(
        ExtraArgument.newInstance("file-or-URI-to-validate", true, URI.class)));
  
    @NonNull
    private static final Option CONSTRAINTS_OPTION = ObjectUtils.notNull(
        Option.builder("c")
            .hasArgs()
            .argName("URL")
            .type(URI.class)
            .desc("additional constraint definitions")
            .get());
    @NonNull
    private static final Option SARIF_OUTPUT_FILE_OPTION = ObjectUtils.notNull(
        Option.builder("o")
            .hasArg()
            .argName("FILE")
            .type(File.class)
            .desc("write SARIF results to the provided FILE")
            .numberOfArgs(1)
            .get());
    @NonNull
    private static final Option SARIF_INCLUDE_PASS_OPTION = ObjectUtils.notNull(
        Option.builder()
            .longOpt("sarif-include-pass")
            .desc("include pass results in SARIF")
            .get());
    @NonNull
    private static final Option NO_SCHEMA_VALIDATION_OPTION = ObjectUtils.notNull(
        Option.builder()
            .longOpt("disable-schema-validation")
            .desc("do not perform schema validation")
            .get());
    @NonNull
    private static final Option NO_CONSTRAINT_VALIDATION_OPTION = ObjectUtils.notNull(
        Option.builder()
            .longOpt("disable-constraint-validation")
           .desc("do not perform constraint validation")
           .get());
   @NonNull
   private static final Option PATH_FORMAT_OPTION = ObjectUtils.notNull(
       Option.builder()
           .longOpt("path-format")
           .hasArg()
           .argName("FORMAT")
           .type(PathFormatSelection.class)
           .desc("path format in validation output: auto (default, selects based on document format), "
               + "metapath, xpath, jsonpointer")
           .get());
   @NonNull
   private static final Option PARALLEL_THREADS_OPTION = ObjectUtils.notNull(
       Option.builder()
           .longOpt("threads")
           .hasArg()
           .argName("count")
           .type(Number.class)
           .desc("number of threads for parallel constraint validation (default: 1, experimental)")
           .get());
 
   @Override
   public String getName() {
     return COMMAND;
   }
 
   @SuppressWarnings("null")
   @Override
   public Collection<? extends Option> gatherOptions() {
     return List.of(
         MetaschemaCommands.AS_FORMAT_OPTION,
         CONSTRAINTS_OPTION,
         SARIF_OUTPUT_FILE_OPTION,
         SARIF_INCLUDE_PASS_OPTION,
         NO_SCHEMA_VALIDATION_OPTION,
         NO_CONSTRAINT_VALIDATION_OPTION,
         PATH_FORMAT_OPTION,
         PARALLEL_THREADS_OPTION);
   }
 
   @Override
   public List<ExtraArgument> getExtraArguments() {
     return EXTRA_ARGUMENTS;
   }
 
   /**
    * Drives the validation execution.
    */
   protected abstract class AbstractValidationCommandExecutor
       extends AbstractCommandExecutor {
 
     /**
      * Construct a new command executor.
      *
      * @param callingContext
      *          the context of the command execution
      * @param commandLine
      *          the parsed command line details
      */
     public AbstractValidationCommandExecutor(
         @NonNull CallingContext callingContext,
         @NonNull CommandLine commandLine) {
       super(callingContext, commandLine);
     }
 
     /**
      * Get the binding context to use for data processing.
      *
      * @param constraintSets
      *          the constraints to configure in the resulting binding context
      * @return the context
      * @throws CommandExecutionException
      *           if a error occurred while getting the binding context
      */
     @NonNull
     protected abstract IBindingContext getBindingContext(@NonNull Set<IConstraintSet> constraintSets)
         throws CommandExecutionException;
 
     /**
      * Get the module to use for validation.
      * <p>
      * This module is used to generate schemas and as a source of built-in
      * constraints.
      *
      * @param commandLine
      *          the provided command line argument information
      * @param bindingContext
      *          the context used to access Metaschema module information based on
      *          Java class bindings
      * @return the loaded Metaschema module
      * @throws CommandExecutionException
      *           if an error occurred while loading the module
      */
     @NonNull
     protected abstract IModule getModule(
         @NonNull CommandLine commandLine,
         @NonNull IBindingContext bindingContext)
         throws CommandExecutionException;
 
     /**
      * Get the schema validation implementation requested based on the provided
      * command line arguments.
      * <p>
      * It is typical for this call to result in the dynamic generation of a schema
      * to use for validation.
      *
      * @param module
      *          the Metaschema module to generate the schema from
      * @param commandLine
      *          the provided command line argument information
      * @param bindingContext
      *          the context used to access Metaschema module information based on
      *          Java class bindings
      * @return the provider
      */
     @NonNull
     protected abstract ISchemaValidationProvider getSchemaValidationProvider(
         @NonNull IModule module,
         @NonNull CommandLine commandLine,
         @NonNull IBindingContext bindingContext);
 
     /**
      * Execute the validation operation.
      */
     @Override
     public void execute() throws CommandExecutionException {
       CommandLine cmdLine = getCommandLine();
       @SuppressWarnings("synthetic-access")
       URI currentWorkingDirectory = ObjectUtils.notNull(getCurrentWorkingDirectory().toUri());
 
       Set<IConstraintSet> constraintSets = MetaschemaCommands.loadConstraintSets(
           cmdLine,
           CONSTRAINTS_OPTION,
           currentWorkingDirectory);
 
       List<String> extraArgs = cmdLine.getArgList();
 
       URI source = MetaschemaCommands.handleSource(
           ObjectUtils.requireNonNull(extraArgs.get(0)),
           currentWorkingDirectory);
 
       IBindingContext bindingContext = getBindingContext(constraintSets);
       IBoundLoader loader = bindingContext.newBoundLoader();
       Format asFormat = MetaschemaCommands.determineSourceFormat(
           cmdLine,
           MetaschemaCommands.AS_FORMAT_OPTION,
           loader,
           source);
 
       IValidationResult validationResult = validate(source, asFormat, cmdLine, bindingContext);
       handleOutput(source, validationResult, asFormat, cmdLine, bindingContext);
 
       if (validationResult == null || validationResult.isPassing()) {
         if (LOGGER.isInfoEnabled()) {
           LOGGER.info("The file '{}' is valid.", source);
         }
       } else if (LOGGER.isErrorEnabled()) {
         LOGGER.error("The file '{}' is invalid.", source);
       }
 
       if (validationResult != null && !validationResult.isPassing()) {
         throw new CommandExecutionException(ExitCode.FAIL);
       }
     }
 
     @SuppressWarnings("PMD.CyclomaticComplexity")
     @Nullable
     private IValidationResult validate(
         @NonNull URI source,
         @NonNull Format asFormat,
         @NonNull CommandLine commandLine,
         @NonNull IBindingContext bindingContext) throws CommandExecutionException {
 
       if (LOGGER.isInfoEnabled()) {
         LOGGER.info("Validating '{}' as {}.", source, asFormat.name());
       }
 
       IValidationResult validationResult = null;
       try {
         // get the module, but don't register it
         IModule module = getModule(commandLine, bindingContext);
         if (!commandLine.hasOption(NO_SCHEMA_VALIDATION_OPTION)) {
           // perform schema validation
           validationResult = getSchemaValidationProvider(module, commandLine, bindingContext)
               .validateWithSchema(source, asFormat, bindingContext);
         }
 
         if (!commandLine.hasOption(NO_CONSTRAINT_VALIDATION_OPTION)) {
           IMutableConfiguration<ValidationFeature<?>> configuration = new DefaultConfiguration<>();
           if (commandLine.hasOption(SARIF_OUTPUT_FILE_OPTION) && commandLine.hasOption(SARIF_INCLUDE_PASS_OPTION)) {
             configuration.enableFeature(ValidationFeature.VALIDATE_GENERATE_PASS_FINDINGS);
           }
 
           // Configure parallel validation if requested
           if (commandLine.hasOption(PARALLEL_THREADS_OPTION)) {
             String threadValue = commandLine.getOptionValue(PARALLEL_THREADS_OPTION);
             int threadCount;
             try {
               threadCount = Integer.parseInt(threadValue);
             } catch (NumberFormatException ex) {
               throw new CommandExecutionException(
                   ExitCode.INVALID_ARGUMENTS,
                   String.format("Invalid thread count '%s': must be a positive integer", threadValue),
                   ex);
             }
             if (threadCount < 1) {
               throw new CommandExecutionException(
                   ExitCode.INVALID_ARGUMENTS,
                   String.format("Thread count must be at least 1, got: %d", threadCount));
             }
             if (threadCount > 1) {
               if (LOGGER.isWarnEnabled()) {
                 LOGGER.warn("Parallel constraint validation is an experimental feature. "
                     + "Using {} threads.", threadCount);
               }
               configuration.set(ValidationFeature.PARALLEL_THREADS, threadCount);
             }
           }
 
           // perform constraint validation
           bindingContext.registerModule(module); // ensure the module is registered
           IValidationResult constraintValidationResult = bindingContext.validateWithConstraints(source, configuration);
           validationResult = validationResult == null
               ? constraintValidationResult
               : AggregateValidationResult.aggregate(validationResult, constraintValidationResult);
         }
       } catch (FileNotFoundException ex) {
         throw new CommandExecutionException(
             ExitCode.IO_ERROR,
             String.format("Resource not found at '%s'", source),
             ex);
       } catch (UnknownHostException ex) {
         throw new CommandExecutionException(
             ExitCode.IO_ERROR,
             String.format("Unknown host for '%s'.", source),
             ex);
       } catch (IOException ex) {
         throw new CommandExecutionException(ExitCode.IO_ERROR, ex.getLocalizedMessage(), ex);
       } catch (MetapathException | MetaschemaException | ConstraintValidationException ex) {
         throw new CommandExecutionException(ExitCode.PROCESSING_ERROR, ex.getLocalizedMessage(), ex);
       }
       return validationResult;
     }
 
     private void handleOutput(
         @NonNull URI source,
         @Nullable IValidationResult validationResult,
         @NonNull Format asFormat,
         @NonNull CommandLine commandLine,
         @NonNull IBindingContext bindingContext) throws CommandExecutionException {
       if (commandLine.hasOption(SARIF_OUTPUT_FILE_OPTION)) {
         Path sarifFile = ObjectUtils.notNull(Paths.get(commandLine.getOptionValue(SARIF_OUTPUT_FILE_OPTION)));
 
         IVersionInfo version
             = getCallingContext().getCLIProcessor().getVersionInfos().get(CLIProcessor.COMMAND_VERSION);
 
         try {
           SarifValidationHandler sarifHandler = new SarifValidationHandler(source, version);
           if (validationResult != null) {
             sarifHandler.addFindings(validationResult.getFindings());
           }
           sarifHandler.write(sarifFile, bindingContext);
         } catch (IOException ex) {
           throw new CommandExecutionException(ExitCode.IO_ERROR, ex.getLocalizedMessage(), ex);
         }
       } else if (validationResult != null && !validationResult.getFindings().isEmpty()) {
         LOGGER.info("Validation identified the following issues:");
         IPathFormatter pathFormatter = resolvePathFormatter(commandLine, asFormat);
         LoggingValidationHandler.withPathFormatter(pathFormatter).handleResults(validationResult);
       }
 
     }
 
     /**
      * Resolve the path formatter based on command line option and document format.
      *
      * @param commandLine
      *          the parsed command line
      * @param asFormat
      *          the document format
      * @return the resolved path formatter
      */
     @NonNull
     private IPathFormatter resolvePathFormatter(
         @NonNull CommandLine commandLine,
         @NonNull Format asFormat) {
       PathFormatSelection selection = PathFormatSelection.AUTO;
 
       if (commandLine.hasOption(PATH_FORMAT_OPTION)) {
         String value = commandLine.getOptionValue(PATH_FORMAT_OPTION);
         if (value != null) {
           selection = parsePathFormatSelection(value);
         }
       }
 
       return Format.resolvePathFormatter(selection, asFormat);
     }
 
     /**
      * Parse the path format selection from a string value.
      *
      * @param value
      *          the string value from the command line
      * @return the parsed selection, defaults to AUTO if unrecognized
      */
     @NonNull
     private PathFormatSelection parsePathFormatSelection(@NonNull String value) {
       switch (value.toLowerCase(Locale.ROOT)) {
       case "auto":
         return PathFormatSelection.AUTO;
       case "metapath":
         return PathFormatSelection.METAPATH;
       case "xpath":
         return PathFormatSelection.XPATH;
       case "jsonpointer":
       case "json-pointer":
         return PathFormatSelection.JSON_POINTER;
       default:
         LOGGER.warn("Unrecognized path format '{}', using auto", value);
         return PathFormatSelection.AUTO;
       }
     }
   }
 }