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) {

		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 IllegalArgumentException("Missing type for parameter #" + paramIndex, e);

								} catch (NullPointerException e) {

									throw new IllegalArgumentException("Invalid type definition for parameter #" + paramIndex, e);

								}

								parameter = new Parameter(arg, paramType);

							}

							options.addNumberedParameter(parameter);

						}

					}

					break;

				default:

					throw new IllegalArgumentException("Unknown option: " + arg);

			}

		}

		return options;

	}

	private String fetchNext(String[] args, int index) {

		if (index < args.length) {

			return args[index];

		} else {

			throw new IllegalArgumentException("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) {

		Integer type = types.get(typeString);

		if (type == null) {

			throw new IllegalArgumentException("Unsupported type: " + typeString);

		} else {

			return type;

		}

	}

}