package info.glogalcode.parameterLister;

 import info.glogalcode.parameterLister.modules.TerminalModuleFactory;

 import java.util.Arrays;

 import java.util.HashMap;

 import java.util.Map;

 import java.util.ServiceLoader;

 import java.util.logging.Level;

 import java.util.logging.Logger;

 /**

  *

  * @author Ing. František Kučera (frantovo.cz)

  */

 public class CLI {

 	public static final String ENV_BASE = "PARAMETER_LISTER";

 	public static final String ENV_OUTPUT_MODULE_NAME = ENV_BASE + "_OUTPUT";

 	public static final String DEFAULT_MODULE = TerminalModuleFactory.MODULE_NAME;

 	public static final int EXIT_SUCCESS = 0;

 	public static final int EXIT_UNEXPECTED_ERROR = 1;

 	// 2 is reserved: http://www.tldp.org/LDP/abs/html/exitcodes.html#EXITCODESREF

 	public static final int EXIT_MODULE_ERROR = 3;

 	private static final Logger log = Logger.getLogger(CLI.class.getName());

 	public static void main(String[] args) {

 		try {

 			ServiceLoader<OutputModuleFactory> modulesLoader = ServiceLoader.load(OutputModuleFactory.class);

 			final Map<String, OutputModuleFactory> modules = new HashMap<>();

 			modulesLoader.forEach(f -> modules.put(f.getName(), f));

 			String moduleName = System.getenv(ENV_OUTPUT_MODULE_NAME);

 			OutputModuleFactory moduleFactory = modules.getOrDefault(moduleName, modules.get(DEFAULT_MODULE));

 			OutputModule module = moduleFactory.createModule();

 			try {

 				module.process(System.out, Arrays.asList(args));

 			} catch (OutputModuleException e) {

 				log.log(Level.SEVERE, "Error while processing output with module " + module.getClass().getName(), e);

 				System.exit(EXIT_MODULE_ERROR);

 			}

 		} catch (Exception e) {

 			log.log(Level.SEVERE, "Unexpected exception, probably bug.", e);

 			System.exit(EXIT_UNEXPECTED_ERROR);

 		}

 		System.exit(EXIT_SUCCESS);

 	}

 }