1 /*
2  * Copyright (c) 2021 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 <errno.h>
18 #include <stdlib.h>
19 #include <string.h>
20 
21 #include "gmid.h"
22 
23 struct etm {			/* extension to mime */
24 	const char	*mime;
25 	const char	*ext;
26 };
27 
28 struct mimes {
29 	struct etm	*t;
30 	size_t		len;
31 	size_t		cap;
32 };
33 
34 struct mimes mimes;
35 
36 void
37 init_mime(void)
38 {
39 	mimes.len = 0;
40 	mimes.cap = 2;
41 
42 	if ((mimes.t = calloc(mimes.cap, sizeof(struct etm))) == NULL)
43 		fatal("calloc: %s", strerror(errno));
44 }
45 
46 /* register mime for the given extension */
47 void
48 add_mime(const char *mime, const char *ext)
49 {
50 	if (mimes.len == mimes.cap) {
51 		mimes.cap *= 1.5;
52 		mimes.t = realloc(mimes.t, mimes.cap * sizeof(struct etm));
53 		if (mimes.t == NULL)
54 			fatal("realloc: %s", strerror(errno));
55 	}
56 
57 	mimes.t[mimes.len].mime = mime;
58 	mimes.t[mimes.len].ext  = ext;
59 	mimes.len++;
60 }
61 
62 /* load a default set of common mime-extension associations */
63 void
64 load_default_mime()
65 {
66 	struct etm *i, m[] = {
67 		{"application/pdf",	"pdf"},
68 		{"image/gif",		"gif"},
69 		{"image/jpeg",		"jpg"},
70 		{"image/jpeg",		"jpeg"},
71 		{"image/png",		"png"},
72 		{"image/svg+xml",	"svg"},
73 		{"text/gemini",		"gemini"},
74 		{"text/gemini",		"gmi"},
75 		{"text/markdown",	"markdown"},
76 		{"text/markdown",	"md"},
77 		{"text/plain",		"txt"},
78 		{"text/xml",		"xml"},
79 		{NULL, NULL}
80 	};
81 
82 	for (i = m; i->mime != NULL; ++i)
83 		add_mime(i->mime, i->ext);
84 }
85 
86 static const char *
87 path_ext(const char *path)
88 {
89 	const char *end;
90 
91 	end = path + strlen(path)-1;
92 	for (; end != path; --end) {
93 		if (*end == '.')
94 			return end+1;
95 		if (*end == '/')
96 			break;
97 	}
98 
99 	return NULL;
100 }
101 
102 const char *
103 mime(const char *path)
104 {
105 	const char *ext, *def = "application/octet-stream";
106 	struct etm *t;
107 
108 	if ((ext = path_ext(path)) == NULL)
109 		return def;
110 
111 	for (t = mimes.t; t->mime != NULL; ++t)
112 		if (!strcmp(ext, t->ext))
113 			return t->mime;
114 
115 	return def;
116 }