1/**
2 * Copyright 2007 Google Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.tonicsystems.jarjar;
18
19import java.io.*;
20import java.util.*;
21
22class RulesFileParser
23{
24    private RulesFileParser() {
25    }
26
27    public static List<PatternElement> parse(File file) throws IOException {
28        return parse(new FileReader(file));
29    }
30
31    public static List<PatternElement> parse(String value) throws IOException {
32        return parse(new java.io.StringReader(value));
33    }
34
35    private static String stripComment(String in) {
36      int p = in.indexOf("#");
37      return p < 0 ? in : in.substring(0, p);
38    }
39
40    private static List<PatternElement> parse(Reader r) throws IOException {
41      try {
42        List<PatternElement> patterns = new ArrayList<PatternElement>();
43        BufferedReader br = new BufferedReader(r);
44        int c = 1;
45        String line;
46        while ((line = br.readLine()) != null) {
47            line = stripComment(line);
48            if (line.isEmpty())
49                continue;
50            String[] parts = line.split("\\s+");
51            if (parts.length < 2)
52                error(c, parts);
53            String type = parts[0];
54            PatternElement element = null;
55            if (type.equals("rule")) {
56                if (parts.length < 3)
57                    error(c, parts);
58                Rule rule = new Rule();
59                rule.setResult(parts[2]);
60                element = rule;
61            } else if (type.equals("zap")) {
62                element = new Zap();
63            } else if (type.equals("keep")) {
64                element = new Keep();
65            } else {
66                error(c, parts);
67            }
68            element.setPattern(parts[1]);
69            patterns.add(element);
70            c++;
71        }
72        return patterns;
73      } finally {
74        r.close();
75      }
76    }
77
78    private static void error(int line, String[] parts) {
79      throw new IllegalArgumentException("Error on line " + line + ": " + Arrays.asList(parts));
80    }
81}
82