/*
    * SPDX-FileCopyrightText: none
    * SPDX-License-Identifier: CC0-1.0
    */
   
   package gov.nist.secauto.metaschema.cli.processor.command;
   
   import gov.nist.secauto.metaschema.cli.processor.CLIProcessor.CallingContext;
   import gov.nist.secauto.metaschema.cli.processor.ExitCode;
  import gov.nist.secauto.metaschema.cli.processor.ExitStatus;
  import gov.nist.secauto.metaschema.core.util.ObjectUtils;
  
  import org.apache.commons.cli.CommandLine;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.LinkedHashMap;
  import java.util.Map;
  import java.util.stream.Collectors;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  
  /**
   * A base class for a command that supports hierarchical command structure with
   * child commands. This class provides the foundation for implementing complex
   * CLI commands that can have multiple levels of sub-commands.
   * <p>
   * This class is thread-safe and supports concurrent access to command handlers.
   */
  public abstract class AbstractParentCommand implements ICommand {
    @NonNull
    private final Map<String, ICommand> commandToSubcommandHandlerMap;
  
    /**
     * Construct a new parent command.
     */
    protected AbstractParentCommand() {
      this.commandToSubcommandHandlerMap = ObjectUtils.notNull(Collections.synchronizedMap(new LinkedHashMap<>()));
    }
  
    /**
     * Add a child command.
     *
     * @param handler
     *          the command handler for the child command
     */
    protected final void addCommandHandler(ICommand handler) {
      String commandName = handler.getName();
      this.commandToSubcommandHandlerMap.put(commandName, handler);
    }
  
    @Override
    public ICommand getSubCommandByName(String name) {
      return commandToSubcommandHandlerMap.get(name);
    }
  
    @Override
    public Collection<ICommand> getSubCommands() {
      return ObjectUtils.notNull(Collections.unmodifiableCollection(commandToSubcommandHandlerMap.values()));
    }
  
    @Override
    public boolean isSubCommandRequired() {
      return true;
    }
  
    @Override
    public ICommandExecutor newExecutor(CallingContext callingContext, CommandLine cmdLine) {
      return ICommandExecutor.using(callingContext, cmdLine, this::executeCommand);
    }
  
    @NonNull
    private ExitStatus executeCommand(
        @NonNull CallingContext callingContext,
        @SuppressWarnings("unused") @NonNull CommandLine commandLine) {
      callingContext.showHelp();
      ExitStatus status;
      if (isSubCommandRequired()) {
        status = ExitCode.INVALID_COMMAND
            .exitMessage("Please use one of the following sub-commands: " +
                getSubCommands().stream()
                    .map(ICommand::getName)
                    .collect(Collectors.joining(", ")));
      } else {
        status = ExitCode.OK.exit();
      }
      return status;
    }
  
  }