/*
 * Copyright (C) 2010, Google Inc.
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.eclipse.jgit.iplog;

import java.io.BufferedReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

/** A crude CSV file parser. */
class CSV {
	private final BufferedReader in;

	private List<String> columns;

	CSV(BufferedReader br) throws IOException {
		in = br;
		columns = readLine();
	}

	Map<String, String> next() throws IOException {
		List<String> row = readLine();
		if (columns == null || row == null)
			return null;

		Map<String, String> r = new LinkedHashMap<String, String>();
		for (int col = 0; col < columns.size(); col++)
			r.put(columns.get(col), row.get(col));
		return r;
	}

	private List<String> readLine() throws IOException {
		String line = in.readLine();
		if (line == null || line.length() == 0)
			return null;

		ArrayList<String> row;
		if (columns != null)
			row = new ArrayList<String>(columns.size());
		else
			row = new ArrayList<String>();

		int p = 0;
		while (p < line.length()) {
			if (line.charAt(p) == '"') {
				p++; // skip the opening quote.

				StringBuilder b = new StringBuilder();
				SCAN: while (p < line.length()) {
					char c = line.charAt(p);
					switch (c) {
					case '"':
						p++;
						break SCAN;

					case '\\':
						b.append(line.charAt(p + 1));
						p += 2;
						break;

					default:
						b.append(c);
						p++;
						break;
					}
				}
				if (p < line.length() && line.charAt(p) != ',')
					throw new IOException("CSV parsing error: " + line);
				row.add(b.toString());
				p++; // skip the trailing comma (if present)

			} else if (line.charAt(p) == ',') {
				row.add("");
				p++;

			} else {
				int comma = line.indexOf(',', p);
				row.add(line.substring(p, comma));
				p = comma + 1;
			}
		}
		return row;
	}
}