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 * Wisconsin-Madison, Broad Institute of MIT and Harvard, Max Planck
 * Institute of Molecular Cell Biology and Genetics, University of
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package org.scijava.command;

import java.util.List;
import java.util.Map;
import java.util.concurrent.Future;

import org.scijava.event.EventService;
import org.scijava.module.Module;
import org.scijava.module.ModuleService;
import org.scijava.module.process.PostprocessorPlugin;
import org.scijava.module.process.PreprocessorPlugin;
import org.scijava.plugin.PTService;
import org.scijava.plugin.PluginInfo;
import org.scijava.plugin.PluginService;
import org.scijava.plugin.SciJavaPlugin;
import org.scijava.service.SciJavaService;

/**
 * Interface for service that keeps track of available commands.
 * <p>
 * A <em>command</em> is a particular type of plugin that is also a
 * {@link Module}; i.e., it is {@link Runnable}, with typed inputs and outputs.
 * <p>
 * The command service keeps a master index of all commands known to the system.
 * It asks the {@link PluginService} for available commands, then takes care of
 * registering them with the {@link ModuleService}.
 * </p>
 * 
 * @author Curtis Rueden
 * @see SciJavaPlugin
 * @see ModuleService
 * @see PluginService
 */
public interface CommandService extends PTService<Command>, SciJavaService {

	default EventService eventService() {
		return context().getService(EventService.class);
	}

	default ModuleService moduleService() {
		return context().getService(ModuleService.class);
	}

	/** Gets the list of all available {@link Command}s). */
	List<CommandInfo> getCommands();

	/** Gets the list of {@link Command}s corresponding to the given plugins. */
	<CT extends Command> List<CommandInfo> getCommands(
		final List<PluginInfo<CT>> plugins);

	/** Gets the first available command of the given class, or null if none. */
	<C extends Command> CommandInfo getCommand(Class<C> commandClass);

	/**
	 * Gets the first available command of the given class name, or null if none.
	 */
	CommandInfo getCommand(String className);

	/** Gets the list of {@link Command}s of the given type. */
	<CT extends Command> List<CommandInfo> getCommandsOfType(Class<CT> type);

	/**
	 * Gets the list of commands of the given class.
	 * <p>
	 * Most classes will have only a single match, but some special classes (such
	 * as ImageJ's {@code LegacyCommand}) may match many entries.
	 * </p>
	 * <p>
	 * NB: Classes are matched by strict equality, not assignability; subtypes of
	 * the specified class will not match. For this behavior, use
	 * {@link #getCommandsOfType(Class)} on a common parent interface.
	 * </p>
	 */
	<C extends Command> List<CommandInfo> getCommandsOfClass(
		Class<C> commandClass);

	/**
	 * Gets the list of commands with the given class name.
	 * <p>
	 * Most classes will have only a single match, but some special classes (such
	 * as ImageJ's {@code LegacyCommand}) may match many entries.
	 * </p>
	 * <p>
	 * NB: Classes are matched by strict equality, not assignability; subtypes of
	 * the specified class will not match. For this behavior, use
	 * {@link #getCommandsOfType(Class)} on a common parent interface.
	 * </p>
	 */
	List<CommandInfo> getCommandsOfClass(String className);

	/**
	 * Executes the first command of the given class name.
	 * <p>
	 * If no command with the given class name is registered with the service,
	 * then a default one is created and then executed. This default command is
	 * <em>not</em> registered with the service for subsequent usage.
	 * </p>
	 * 
	 * @param className Class name of the command to execute.
	 * @param process If true, executes the command with pre- and postprocessing
	 *          steps from all available {@link PreprocessorPlugin}s and
	 *          {@link PostprocessorPlugin}s in the plugin index; if false,
	 *          executes the command with no pre- or postprocessing. For more
	 *          fine-grained control, see the {@link ModuleService#run} methods.
	 * @param inputs List of input parameter names and values. The expected order
	 *          is in pairs: an input name followed by its value, for each desired
	 *          input to populate. Leaving some inputs unpopulated is allowed.
	 *          Passing the name of an input that is not valid for the plugin, or
	 *          passing a value of a type incompatible with the associated input
	 *          parameter, will issue an error and ignore that name/value pair.
	 * @return {@link Future} of the module instance being executed. Calling
	 *         {@link Future#get()} will block until execution is complete.
	 */
	Future<CommandModule>
		run(String className, boolean process, Object... inputs);

	/**
	 * Executes the first command of the given class name.
	 * <p>
	 * If no command with the given class name is registered with the service,
	 * then a default one is created and then executed. This default command is
	 * <em>not</em> registered with the service for subsequent usage.
	 * </p>
	 * 
	 * @param className Class name of the command to execute.
	 * @param process If true, executes the command with pre- and postprocessing
	 *          steps from all available {@link PreprocessorPlugin}s and
	 *          {@link PostprocessorPlugin}s in the plugin index; if false,
	 *          executes the command with no pre- or postprocessing. For more
	 *          fine-grained control, see the {@link ModuleService#run} methods.
	 * @param inputMap Table of input parameter values, with keys matching the
	 *          plugin's input parameter names. Passing a value of a type
	 *          incompatible with the associated input parameter will issue an
	 *          error and ignore that value.
	 * @return {@link Future} of the module instance being executed. Calling
	 *         {@link Future#get()} will block until execution is complete.
	 */
	Future<CommandModule> run(String className, boolean process,
		Map<String, Object> inputMap);

	/**
	 * Executes the first command of the given class.
	 * <p>
	 * If no command of the given class is registered with the service, then a
	 * default one is created and then executed. This default command is
	 * <em>not</em> registered with the service for subsequent usage.
	 * </p>
	 * 
	 * @param <C> Class of the command to execute.
	 * @param commandClass Class object of the command to execute.
	 * @param process If true, executes the command with pre- and postprocessing
	 *          steps from all available {@link PreprocessorPlugin}s and
	 *          {@link PostprocessorPlugin}s in the plugin index; if false,
	 *          executes the command with no pre- or postprocessing. For more
	 *          fine-grained control, see the {@link ModuleService#run} methods.
	 * @param inputs List of input parameter names and values. The expected order
	 *          is in pairs: an input name followed by its value, for each desired
	 *          input to populate. Leaving some inputs unpopulated is allowed.
	 *          Passing the name of an input that is not valid for the plugin, or
	 *          passing a value of a type incompatible with the associated input
	 *          parameter, will issue an error and ignore that name/value pair.
	 * @return {@link Future} of the module instance being executed. Calling
	 *         {@link Future#get()} will block until execution is complete.
	 */
	<C extends Command> Future<CommandModule> run(Class<C> commandClass,
		boolean process, Object... inputs);

	/**
	 * Executes the first command of the given class.
	 * <p>
	 * If no command of the given class is registered with the service, then a
	 * default one is created and then executed. This default command is
	 * <em>not</em> registered with the service for subsequent usage.
	 * </p>
	 * 
	 * @param <C> Class of the command to execute.
	 * @param commandClass Class object of the command to execute.
	 * @param process If true, executes the command with pre- and postprocessing
	 *          steps from all available {@link PreprocessorPlugin}s and
	 *          {@link PostprocessorPlugin}s in the plugin index; if false,
	 *          executes the command with no pre- or postprocessing. For more
	 *          fine-grained control, see the {@link ModuleService#run} methods.
	 * @param inputMap Table of input parameter values, with keys matching the
	 *          plugin's input parameter names. Passing a value of a type
	 *          incompatible with the associated input parameter will issue an
	 *          error and ignore that value.
	 * @return {@link Future} of the module instance being executed. Calling
	 *         {@link Future#get()} will block until execution is complete.
	 */
	<C extends Command> Future<CommandModule> run(Class<C> commandClass,
		boolean process, Map<String, Object> inputMap);

	/**
	 * Executes the given command.
	 * 
	 * @param info The command to instantiate and run.
	 * @param process If true, executes the command with pre- and postprocessing
	 *          steps from all available {@link PreprocessorPlugin}s and
	 *          {@link PostprocessorPlugin}s in the plugin index; if false,
	 *          executes the command with no pre- or postprocessing. For more
	 *          fine-grained control, see the {@link ModuleService#run} methods.
	 * @param inputs List of input parameter names and values. The expected order
	 *          is in pairs: an input name followed by its value, for each desired
	 *          input to populate. Leaving some inputs unpopulated is allowed.
	 *          Passing the name of an input that is not valid for the plugin, or
	 *          passing a value of a type incompatible with the associated input
	 *          parameter, will issue an error and ignore that name/value pair.
	 * @return {@link Future} of the module instance being executed. Calling
	 *         {@link Future#get()} will block until execution is complete.
	 */
	Future<CommandModule>
		run(CommandInfo info, boolean process, Object... inputs);

	/**
	 * Executes the given command.
	 * 
	 * @param info The command to instantiate and run.
	 * @param process If true, executes the command with pre- and postprocessing
	 *          steps from all available {@link PreprocessorPlugin}s and
	 *          {@link PostprocessorPlugin}s in the plugin index; if false,
	 *          executes the command with no pre- or postprocessing. For more
	 *          fine-grained control, see the {@link ModuleService#run} methods.
	 * @param inputMap Table of input parameter values, with keys matching the
	 *          plugin's input parameter names. Passing a value of a type
	 *          incompatible with the associated input parameter will issue an
	 *          error and ignore that value.
	 * @return {@link Future} of the module instance being executed. Calling
	 *         {@link Future#get()} will block until execution is complete.
	 */
	Future<CommandModule> run(CommandInfo info, boolean process,
		Map<String, Object> inputMap);

	// -- Deprecated methods --

	/** @deprecated Use {@link #eventService()} instead. */
	@Deprecated
	default EventService getEventService() {
		return eventService();
	}

	/** @deprecated Use {@link #moduleService()} instead. */
	@Deprecated
	default ModuleService getModuleService() {
		return moduleService();
	}
}
