/*
 * Copyright 2010 NCHOVY
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.araqne.log.api;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class DelimiterParser extends V1LogParser {
	private final char delimiter;
	private final String[] columnHeaders;
	private final String targetField;
	private final boolean includeTargetField;
	private final List<FieldDefinition> fieldDefs;

	public DelimiterParser(String delimiter, String[] columnHeaders) {
		this(delimiter, columnHeaders, "line", false);
	}

	public DelimiterParser(String delimiter, String[] columnHeaders, String targetField, boolean includeTargetField) {
		if (delimiter.startsWith("\\u")) {
			this.delimiter = (char) Integer.parseInt(delimiter.substring(2, 6), 16);
		} else {
			this.delimiter = delimiter.charAt(0);
		}
		this.columnHeaders = columnHeaders;
		this.targetField = targetField;
		this.includeTargetField = includeTargetField;

		this.fieldDefs = new ArrayList<FieldDefinition>();
		if (columnHeaders != null)
			for (String c : columnHeaders) {
				fieldDefs.add(new FieldDefinition(c, "string"));
			}
	}

	@Override
	public Map<String, Object> parse(Map<String, Object> params) {
		String line = (String) params.get(targetField);
		if (line == null)
			return params;

		HashMap<String, Object> m = new HashMap<String, Object>(40);
		if (includeTargetField)
			m.put(targetField, line);

		int i = 0;
		int last = 0;
		while (true) {
			int p = line.indexOf(delimiter, last);

			String token = null;
			if (p >= 0)
				token = line.substring(last, p);
			else
				token = line.substring(last);

			if (token.isEmpty())
				token = null;

			if (columnHeaders != null && i < columnHeaders.length)
				m.put(columnHeaders[i], token);
			else
				m.put("column" + Integer.toString(i), token);

			if (p < 0)
				break;

			last = p + 1;
			i++;
		}

		return m;
	}

	/**
	 * @since 2.9.1
	 */
	@Override
	public List<FieldDefinition> getFieldDefinitions() {
		return fieldDefs;
	}
}