package info.globalcode.sql.dk;

import java.sql.Types;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 *
 * @author Ing. František Kučera (frantovo.cz)
 */
public class CLIParser {

	public static final String TYPE_NAME_SEPARATOR = ":";
	private final Map<String, Integer> types;

	public CLIParser() {
		Map<String, Integer> m = new HashMap<>();
		m.put("int", Types.INTEGER);
		m.put("string", Types.VARCHAR);
		m.put("boolean", Types.BOOLEAN);
		/**
		 * TODO: more types
		 */
		types = Collections.unmodifiableMap(m);
	}

	public CLIOptions parseOptions(String[] args) throws CLIParserException {
		CLIOptions options = new CLIOptions();

		List<Integer> numberedTypes = new ArrayList<>();
		Map<String, Integer> namedTypes = new HashMap<>();

		for (int i = 0; i < args.length; i++) {
			String arg = args[i];
			switch (arg) {
				case Tokens.TYPES:
					String typesString = fetchNext(args, ++i);

					for (String oneType : typesString.split("\\s*,\\s*")) {
						int sepatratorIndex = oneType.indexOf(TYPE_NAME_SEPARATOR);
						if (sepatratorIndex == -1) {
							numberedTypes.add(getType(oneType));
						} else {
							String namePart = oneType.substring(0, sepatratorIndex);
							String typePart = oneType.substring(sepatratorIndex + TYPE_NAME_SEPARATOR.length(), oneType.length());
							namedTypes.put(namePart, getType(typePart));
						}
					}
					break;
				case Tokens.NAME_PREFIX:
					options.setNamePrefix(fetchNext(args, ++i));
					break;
				case Tokens.DB:
					options.setDatabaseName(fetchNext(args, ++i));
					break;
				case Tokens.SQL:
					options.setSql(fetchNext(args, ++i));
					options.setCommandType(CLIOptions.COMMAND_TYPE.QUERY);
					break;
				case Tokens.SQL_UPDATE:
				case Tokens.SQL_INSERT:
					options.setSql(fetchNext(args, ++i));
					options.setCommandType(CLIOptions.COMMAND_TYPE.UPDATE);
					break;
				case Tokens.BATCH:
					options.setBatch(true);
					break;
				case Tokens.DATA: // --data is the last option
					for (i++; i < args.length; i++) {
						arg = args[i];

						if (arg.startsWith(options.getNamePrefix())) { // Named parameters:
							String paramName = arg.substring(options.getNamePrefix().length());
							String paramValue = fetchNext(args, ++i);
							options.addNamedParameter(new NamedParameter(paramName, paramValue, namedTypes.get(paramName)));
						} else { // Numbered parameters:
							Parameter parameter;
							if (numberedTypes.isEmpty()) {
								parameter = new Parameter(arg, null);
							} else {
								int paramIndex = options.getNumberedParameters().size();
								int paramType;
								try {
									paramType = numberedTypes.get(paramIndex);
								} catch (IndexOutOfBoundsException e) {
									throw new CLIParserException("Missing type for parameter #" + paramIndex, e);
								} catch (NullPointerException e) {
									throw new CLIParserException("Invalid type definition for parameter #" + paramIndex, e);
								}
								parameter = new Parameter(arg, paramType);
							}
							options.addNumberedParameter(parameter);
						}
					}
					break;
				default:
					throw new CLIParserException("Unknown option: " + arg);
			}
		}
		return options;
	}

	private String fetchNext(String[] args, int index) throws CLIParserException {
		if (index < args.length) {
			return args[index];
		} else {
			throw new CLIParserException("Expecting value for option: " + args[index - 1]);
		}
	}

	public static class Tokens {

		public static final String DB = "--db";
		public static final String SQL = "--sql";
		public static final String SQL_UPDATE = "--sql-update";
		public static final String SQL_INSERT = "--sql-insert";
		public static final String BATCH = "--batch";
		public static final String DATA = "--data";
		public static final String NAME_PREFIX = "--name-prefix";
		public static final String TYPES = "--types";

		private Tokens() {
		}
	}

	private int getType(String typeString) throws CLIParserException {
		Integer type = types.get(typeString);
		if (type == null) {
			throw new CLIParserException("Unsupported type: " + typeString);
		} else {
			return type;
		}
	}
}