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);

	}

}