1 /*
2  * Copyright (c) 2022 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "compat.h"
18 
19 #include <stdlib.h>
20 #include <stdint.h>
21 #include <string.h>
22 
23 #include "telescope.h"
24 #include "mcache.h"
25 #include "parser.h"
26 #include "utils.h"
27 
28 const char *gemtext_prefixes[] = {
29 	[LINE_TEXT] = "",
30 	[LINE_TITLE_1] = "# ",
31 	[LINE_TITLE_2] = "## ",
32 	[LINE_TITLE_3] = "### ",
33 	[LINE_ITEM] = "* ",
34 	[LINE_QUOTE] = "> ",
35 	[LINE_PRE_START] = "``` ",
36 	[LINE_PRE_CONTENT] = "",
37 	[LINE_PRE_END] = "```",
38 };
39 
40 struct mcache {
41 	struct ohash	h;
42 	size_t		tot;
43 } mcache;
44 
45 struct mcache_entry {
46 	const char	*parser_name;
47 	int		 trust;
48 	struct evbuffer	*evb;
49 	char		 url[];
50 };
51 
52 static void
53 mcache_free_entry(const char *url)
54 {
55 	struct mcache_entry	*e;
56 	unsigned int		 slot;
57 
58 	slot = ohash_qlookup(&mcache.h, url);
59 	if ((e = ohash_remove(&mcache.h, slot)) == NULL)
60 		return;
61 
62 	evbuffer_free(e->evb);
63 	free(e);
64 }
65 
66 void
67 mcache_init(void)
68 {
69 	struct ohash_info info = {
70 		.key_offset = offsetof(struct mcache_entry, url),
71 		.calloc = hash_calloc,
72 		.free = hash_free,
73 		.alloc = hash_alloc,
74 	};
75 
76 	ohash_init(&mcache.h, 5, &info);
77 }
78 
79 int
80 mcache_tab(struct tab *tab)
81 {
82 	struct mcache_entry	*e;
83 	struct line		*line;
84 	unsigned int		 slot;
85 	size_t			 l, len;
86 	const char		*url;
87 
88 	url = tab->hist_cur->h;
89 	l = strlen(url);
90 	len = sizeof(*e) + l + 1;
91 
92 	if ((e = calloc(1, len)) == NULL)
93 		return -1;
94 	e->parser_name = tab->buffer.page.name;
95 	e->trust = tab->trust;
96 	memcpy(e->url, url, l);
97 
98 	if ((e->evb = evbuffer_new()) == NULL)
99 		goto err;
100 
101 	TAILQ_FOREACH(line, &tab->buffer.page.head, lines) {
102 		const char	*text, *alt;
103 		int		 r;
104 
105 		if ((text = line->line) == NULL)
106 			text = "";
107 
108 		if ((alt = line->alt) == NULL)
109 			alt = "";
110 
111 		switch (line->type) {
112 		case LINE_TEXT:
113 		case LINE_TITLE_1:
114 		case LINE_TITLE_2:
115 		case LINE_TITLE_3:
116 		case LINE_ITEM:
117 		case LINE_QUOTE:
118 		case LINE_PRE_START:
119 		case LINE_PRE_CONTENT:
120 		case LINE_PRE_END:
121 			r = evbuffer_add_printf(e->evb, "%s%s\n",
122 			    gemtext_prefixes[line->type], text);
123 			break;
124 
125 		case LINE_LINK:
126 			r = evbuffer_add_printf(e->evb, "=> %s %s\n",
127 			    alt, text);
128 			break;
129 
130 		case LINE_PATCH:
131 		case LINE_PATCH_HDR:
132 		case LINE_PATCH_HUNK_HDR:
133 		case LINE_PATCH_ADD:
134 		case LINE_PATCH_DEL:
135 			/* TODO */
136 			r = -1;
137 			break;
138 
139 		case LINE_COMPL:
140 		case LINE_COMPL_CURRENT:
141 		case LINE_HELP:
142 		case LINE_DOWNLOAD:
143 		case LINE_DOWNLOAD_DONE:
144 		case LINE_DOWNLOAD_INFO:
145 		case LINE_FRINGE:
146 			/* not reached */
147 			abort();
148 		}
149 
150 		if (r == -1)
151 			goto err;
152 	}
153 
154 	/* free any previously cached copies of this page */
155 	mcache_free_entry(url);
156 
157 	slot = ohash_qlookup(&mcache.h, url);
158 	ohash_insert(&mcache.h, slot, e);
159 	return 0;
160 
161 err:
162 	if (e->evb != NULL)
163 		evbuffer_free(e->evb);
164 	free(e);
165 	return -1;
166 }
167 
168 int
169 mcache_lookup(const char *url, struct tab *tab)
170 {
171 	struct mcache_entry	*e;
172 	unsigned int		 slot;
173 
174 	slot = ohash_qlookup(&mcache.h, url);
175 	if ((e = ohash_find(&mcache.h, slot)) == NULL)
176 		return 0;
177 
178 	parser_init(tab, gemtext_initparser);
179 	if (!parser_parse(tab, EVBUFFER_DATA(e->evb), EVBUFFER_LENGTH(e->evb)))
180 		goto err;
181 	if (!parser_free(tab))
182 		goto err;
183 
184 	tab->buffer.page.name = e->parser_name;
185 	tab->trust = e->trust;
186 	return 1;
187 
188 err:
189 	parser_free(tab);
190 	erase_buffer(&tab->buffer);
191 	return 0;
192 }