summaryrefslogtreecommitdiffstats
path: root/modules/base/markdown.go
blob: 4a7adc8a4864a38a6eff4e1b86b817eace73e646 (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
217
218
219
220
221
222
223
224
225
226
227
228
// Copyright 2014 The Gogs Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package base

import (
	"bytes"
	"fmt"
	"net/http"
	"path"
	"path/filepath"
	"regexp"
	"strings"

	"github.com/russross/blackfriday"

	"github.com/gogits/gogs/modules/setting"
)

func isletter(c byte) bool {
	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')
}

func isalnum(c byte) bool {
	return (c >= '0' && c <= '9') || isletter(c)
}

var validLinks = [][]byte{[]byte("http://"), []byte("https://"), []byte("ftp://"), []byte("mailto://")}

func isLink(link []byte) bool {
	for _, prefix := range validLinks {
		if len(link) > len(prefix) && bytes.Equal(bytes.ToLower(link[:len(prefix)]), prefix) && isalnum(link[len(prefix)]) {
			return true
		}
	}

	return false
}

func IsMarkdownFile(name string) bool {
	name = strings.ToLower(name)
	switch filepath.Ext(name) {
	case ".md", ".markdown", ".mdown", ".mkd":
		return true
	}
	return false
}

func IsTextFile(data []byte) (string, bool) {
	contentType := http.DetectContentType(data)
	if strings.Index(contentType, "text/") != -1 {
		return contentType, true
	}
	return contentType, false
}

func IsImageFile(data []byte) (string, bool) {
	contentType := http.DetectContentType(data)
	if strings.Index(contentType, "image/") != -1 {
		return contentType, true
	}
	return contentType, false
}

// IsReadmeFile returns true if given file name suppose to be a README file.
func IsReadmeFile(name string) bool {
	name = strings.ToLower(name)
	if len(name) < 6 {
		return false
	} else if len(name) == 6 {
		if name == "readme" {
			return true
		}
		return false
	}
	if name[:7] == "readme." {
		return true
	}
	return false
}

type CustomRender struct {
	blackfriday.Renderer
	urlPrefix string
}

func (options *CustomRender) Link(out *bytes.Buffer, link []byte, title []byte, content []byte) {
	if len(link) > 0 && !isLink(link) {
		if link[0] == '#' {
			// link = append([]byte(options.urlPrefix), link...)
		} else {
			link = []byte(path.Join(options.urlPrefix, string(link)))
		}
	}

	options.Renderer.Link(out, link, title, content)
}

func (options *CustomRender) Image(out *bytes.Buffer, link []byte, title []byte, alt []byte) {
	if len(link) > 0 && !isLink(link) {
		link = []byte(path.Join(strings.Replace(options.urlPrefix, "/src/", "/raw/", 1), string(link)))
	}

	options.Renderer.Image(out, link, title, alt)
}

var (
	MentionPattern     = regexp.MustCompile(`(\s|^)@[0-9a-zA-Z_]+`)
	commitPattern      = regexp.MustCompile(`(\s|^)https?.*commit/[0-9a-zA-Z]+(#+[0-9a-zA-Z-]*)?`)
	issueFullPattern   = regexp.MustCompile(`(\s|^)https?.*issues/[0-9]+(#+[0-9a-zA-Z-]*)?`)
	issueIndexPattern  = regexp.MustCompile(`( |^)#[0-9]+`)
	sha1CurrentPattern = regexp.MustCompile(`\b[0-9a-f]{40}\b`)
)

func RenderSpecialLink(rawBytes []byte, urlPrefix string) []byte {
	buf := bytes.NewBufferString("")
	inCodeBlock := false
	codeBlockPrefix := []byte("```")
	lineBreak := []byte("\n")
	tab := []byte("\t")
	lines := bytes.Split(rawBytes, lineBreak)
	for _, line := range lines {
		if bytes.HasPrefix(line, codeBlockPrefix) {
			inCodeBlock = !inCodeBlock
		}

		if !inCodeBlock && !bytes.HasPrefix(line, tab) {
			ms := MentionPattern.FindAll(line, -1)
			for _, m := range ms {
				m = bytes.TrimSpace(m)
				line = bytes.Replace(line, m,
					[]byte(fmt.Sprintf(`<a href="%s/%s">%s</a>`, setting.AppSubUrl, m[1:], m)), -1)
			}
		}

		buf.Write(line)
		buf.Write(lineBreak)
	}

	rawBytes = buf.Bytes()
	ms := commitPattern.FindAll(rawBytes, -1)
	for _, m := range ms {
		m = bytes.TrimSpace(m)
		i := strings.Index(string(m), "commit/")
		j := strings.Index(string(m), "#")
		if j == -1 {
			j = len(m)
		}
		rawBytes = bytes.Replace(rawBytes, m, []byte(fmt.Sprintf(
			` <code><a href="%s">%s</a></code>`, m, ShortSha(string(m[i+7:j])))), -1)
	}
	ms = issueFullPattern.FindAll(rawBytes, -1)
	for _, m := range ms {
		m = bytes.TrimSpace(m)
		i := strings.Index(string(m), "issues/")
		j := strings.Index(string(m), "#")
		if j == -1 {
			j = len(m)
		}
		rawBytes = bytes.Replace(rawBytes, m, []byte(fmt.Sprintf(
			` <a href="%s">#%s</a>`, m, ShortSha(string(m[i+7:j])))), -1)
	}
	rawBytes = RenderIssueIndexPattern(rawBytes, urlPrefix)
	rawBytes = RenderSha1CurrentPattern(rawBytes, urlPrefix)
	return rawBytes
}

func RenderSha1CurrentPattern(rawBytes []byte, urlPrefix string) []byte {
	ms := sha1CurrentPattern.FindAll(rawBytes, -1)
	for _, m := range ms {
		rawBytes = bytes.Replace(rawBytes, m, []byte(fmt.Sprintf(
			`<a href="%s/commit/%s"><code>%s</code></a>`, urlPrefix, m, ShortSha(string(m)))), -1)
	}
	return rawBytes
}

func RenderIssueIndexPattern(rawBytes []byte, urlPrefix string) []byte {
	ms := issueIndexPattern.FindAll(rawBytes, -1)
	for _, m := range ms {
		rawBytes = bytes.Replace(rawBytes, m, []byte(fmt.Sprintf(`<a href="%s/issues/%s">%s</a>`,
			urlPrefix, strings.TrimPrefix(string(m[1:]), "#"), m)), -1)
	}
	return rawBytes
}

func RenderRawMarkdown(body []byte, urlPrefix string) []byte {
	htmlFlags := 0
	// htmlFlags |= blackfriday.HTML_USE_XHTML
	// htmlFlags |= blackfriday.HTML_USE_SMARTYPANTS
	// htmlFlags |= blackfriday.HTML_SMARTYPANTS_FRACTIONS
	// htmlFlags |= blackfriday.HTML_SMARTYPANTS_LATEX_DASHES
	// htmlFlags |= blackfriday.HTML_SKIP_HTML
	htmlFlags |= blackfriday.HTML_SKIP_STYLE
	// htmlFlags |= blackfriday.HTML_SKIP_SCRIPT
	// htmlFlags |= blackfriday.HTML_GITHUB_BLOCKCODE
	htmlFlags |= blackfriday.HTML_OMIT_CONTENTS
	// htmlFlags |= blackfriday.HTML_COMPLETE_PAGE
	renderer := &CustomRender{
		Renderer:  blackfriday.HtmlRenderer(htmlFlags, "", ""),
		urlPrefix: urlPrefix,
	}

	// set up the parser
	extensions := 0
	extensions |= blackfriday.EXTENSION_NO_INTRA_EMPHASIS
	extensions |= blackfriday.EXTENSION_TABLES
	extensions |= blackfriday.EXTENSION_FENCED_CODE
	extensions |= blackfriday.EXTENSION_AUTOLINK
	extensions |= blackfriday.EXTENSION_STRIKETHROUGH
	extensions |= blackfriday.EXTENSION_HARD_LINE_BREAK
	extensions |= blackfriday.EXTENSION_SPACE_HEADERS
	extensions |= blackfriday.EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK

	body = blackfriday.Markdown(body, renderer, extensions)
	return body
}

func RenderMarkdown(rawBytes []byte, urlPrefix string) []byte {
	body := RenderSpecialLink(rawBytes, urlPrefix)
	body = RenderRawMarkdown(body, urlPrefix)
	body = Sanitizer.SanitizeBytes(body)
	return body
}

func RenderMarkdownString(raw, urlPrefix string) string {
	return string(RenderMarkdown([]byte(raw), urlPrefix))
}