aboutsummaryrefslogtreecommitdiff
path: root/common/patterns.js
blob: 7381cddcb3232348d4dd4fc45f688698ab8c7a6b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
/**
 * This file is part of Haketilo.
 *
 * Function: Operations on page URL patterns.
 *
 * Copyright (C) 2021 Wojtek Kosior
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * As additional permission under GNU GPL version 3 section 7, you
 * may distribute forms of that code without the copy of the GNU
 * GPL normally required by section 4, provided you include this
 * license notice and, in case of non-source distribution, a URL
 * through which recipients can access the Corresponding Source.
 * If you modify file(s) with this exception, you may extend this
 * exception to your version of the file(s), but you are not
 * obligated to do so. If you do not wish to do so, delete this
 * exception statement from your version.
 *
 * As a special exception to the GPL, any HTML file which merely
 * makes function calls to this code, and for that purpose
 * includes it by reference shall be deemed a separate work for
 * copyright law purposes. If you modify this code, you may extend
 * this exception to your version of the code, but you are not
 * obligated to do so. If you do not wish to do so, delete this
 * exception statement from your version.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * I, Wojtek Kosior, thereby promise not to sue for violation of this file's
 * license. Although I request that you do not make use of this code in a
 * proprietary program, I am not going to enforce this in court.
 */

const MAX = {
    URL_PATH_LEN:   12,
    URL_PATH_CHARS: 255,
    DOMAIN_LEN:     7,
    DOMAIN_CHARS:   100
};

const proto_regex = /^(\w+):\/\/(.*)$/;

const user_re = "[^/?#@]+@"
const domain_re = "[.*a-zA-Z0-9-]+";
const path_re = "[^?#]*";
const query_re = "\\??[^#]*";

const http_regex = new RegExp(`^(${domain_re})(${path_re})(${query_re}).*`);

const file_regex = new RegExp(`^(/${path_re}).*`);

const ftp_regex = new RegExp(`^(${user_re})?(${domain_re})(${path_re}).*`);

function match_or_throw(regex, string, error_msg)
{
    const match = regex.exec(string);
    if (match === null)
	throw error_msg;

    return match;
}

function deconstruct_url(url, use_limits=true)
{
    const max = Object.assign({}, MAX);
    if (!use_limits) {
	for (const key in MAX)
	    max[key] = Infinity;
    }

    const matcher = (re, str) => match_or_throw(re, str, `bad url '${url}'`)

    const proto_match = matcher(proto_regex, url);
    const deco = {proto: proto_match[1]};

    if (deco.proto === "file") {
	deco.path = matcher(file_regex, proto_match[2])[1];
    } else if (deco.proto === "ftp") {
	[deco.domain, deco.path] =
	    matcher(ftp_regex, proto_match[2]).slice(2, 4);
    } else if (deco.proto === "http" || deco.proto === "https") {
	[deco.domain, deco.path, deco.query] =
	    matcher(http_regex, proto_match[2]).slice(1, 4);
	deco.domain = deco.domain.toLowerCase();
    } else {
	throw `unsupported protocol in url '${url}'`;
    }

    deco.trailing_slash = deco.path[deco.path.length - 1] === "/";

    if (deco.domain) {
	if (deco.domain.length > max.DOMAIN_CHARS) {
	    const idx = deco.domain.indexOf(".", deco.domain.length -
					    max.DOMAIN_CHARS);
	    if (idx === -1)
		deco.domain = [];
	    else
		deco.domain = deco.domain.substring(idx + 1);

	    deco.domain_truncated = true;
	}

	if (deco.path.length > max.URL_PATH_CHARS) {
	    deco.path = deco.path.substring(0, deco.path.lastIndexOf("/"));
	    deco.path_truncated = true;
	}
    }

    if (typeof deco.domain === "string") {
	deco.domain = deco.domain.split(".");
	if (deco.domain.splice(0, deco.domain.length - max.DOMAIN_LEN).length
	    > 0)
	    deco.domain_truncated = true;
    }

    deco.path = deco.path.split("/").filter(s => s !== "");
    if (deco.domain && deco.path.splice(max.URL_PATH_LEN).length > 0)
	deco.path_truncated = true;

    return deco;
}
#EXPORT deconstruct_url

function* each_domain_pattern(deco)
{
    for (let slice = 0; slice < deco.domain.length - 1; slice++) {
	const domain_part = deco.domain.slice(slice).join(".");
	const domain_wildcards = [];
	if (slice === 0 && !deco.domain_truncated)
	    yield domain_part;
	if (slice === 1 && !deco.domain_truncated)
	    yield "*." + domain_part;
	if (slice > 1)
	    yield "**." + domain_part;
	yield "***." + domain_part;
    }
}

function* each_path_pattern(deco)
{
    for (let slice = deco.path.length; slice >= 0; slice--) {
	const path_part = ["", ...deco.path.slice(0, slice)].join("/");
	const path_wildcards = [];
	if (slice === deco.path.length && !deco.path_truncated) {
	    if (deco.trailing_slash)
		yield path_part + "/";
	    if (slice > 0 || deco.proto !== "file")
		yield path_part;
	}
	if (slice === deco.path.length - 1 && !deco.path_truncated &&
	    deco.path[slice] !== "*")
	    yield path_part + "/*";
	if (slice < deco.path.length - 1)
	    yield path_part + "/**";
	if (slice !== deco.path.length - 1 || deco.path_truncated ||
	    deco.path[slice] !== "***")
	    yield path_part + "/***";
    }
}

/* Generate every possible pattern that matches url. */
function* each_url_pattern(url)
{
    const deco = deconstruct_url(url);

    if (deco === undefined) {
	console.error("Haketilo: bad url format", url);
	return false;
    }

    const all_domains = deco.domain ? each_domain_pattern(deco) : [""];
    for (const domain of all_domains) {
	for (const path of each_path_pattern(deco))
	    yield `${deco.proto}://${domain}${path}`;
    }
}
#EXPORT each_url_pattern

const patterns_doc_url =
      "https://hydrillabugs.koszko.org/projects/haketilo/wiki/URL_patterns";
#EXPORT patterns_doc_url

function reconstruct_url(deco)
{
    const domain = (deco.domain || []).join(".");
    const path = ["", ...deco.path].join("/");
    const trail = deco.trailing_slash ? "/" : "";
    return `${deco.proto}://${domain}${path}${trail}`;
}
#EXPORT reconstruct_url

function validate_normalize_url_pattern(url_pattern)
{
    try {
	return reconstruct_url(deconstruct_url(url_pattern));
    } catch(e) {
	const patterns_doc_link = document.createElement("a");
	patterns_doc_link.href = patterns_doc_url;
	patterns_doc_link.innerText = "here";
	const msg = document.createElement("span");
	msg.prepend(`'${url_pattern}' is not a valid URL pattern. See `,
		    patterns_doc_link, " for more details.");
	throw msg;
    }
}
#EXPORT validate_normalize_url_pattern