1package md2man
2
3import (
4	"bytes"
5	"fmt"
6	"html"
7	"strings"
8
9	"github.com/russross/blackfriday"
10)
11
12type roffRenderer struct {
13	ListCounters []int
14}
15
16// RoffRenderer creates a new blackfriday Renderer for generating roff documents
17// from markdown
18func RoffRenderer(flags int) blackfriday.Renderer {
19	return &roffRenderer{}
20}
21
22func (r *roffRenderer) GetFlags() int {
23	return 0
24}
25
26func (r *roffRenderer) TitleBlock(out *bytes.Buffer, text []byte) {
27	out.WriteString(".TH ")
28
29	splitText := bytes.Split(text, []byte("\n"))
30	for i, line := range splitText {
31		line = bytes.TrimPrefix(line, []byte("% "))
32		if i == 0 {
33			line = bytes.Replace(line, []byte("("), []byte("\" \""), 1)
34			line = bytes.Replace(line, []byte(")"), []byte("\" \""), 1)
35		}
36		line = append([]byte("\""), line...)
37		line = append(line, []byte("\" ")...)
38		out.Write(line)
39	}
40	out.WriteString("\n")
41
42	// disable hyphenation
43	out.WriteString(".nh\n")
44	// disable justification (adjust text to left margin only)
45	out.WriteString(".ad l\n")
46}
47
48func (r *roffRenderer) BlockCode(out *bytes.Buffer, text []byte, lang string) {
49	out.WriteString("\n.PP\n.RS\n\n.nf\n")
50	escapeSpecialChars(out, text)
51	out.WriteString("\n.fi\n.RE\n")
52}
53
54func (r *roffRenderer) BlockQuote(out *bytes.Buffer, text []byte) {
55	out.WriteString("\n.PP\n.RS\n")
56	out.Write(text)
57	out.WriteString("\n.RE\n")
58}
59
60func (r *roffRenderer) BlockHtml(out *bytes.Buffer, text []byte) { // nolint: golint
61	out.Write(text)
62}
63
64func (r *roffRenderer) Header(out *bytes.Buffer, text func() bool, level int, id string) {
65	marker := out.Len()
66
67	switch {
68	case marker == 0:
69		// This is the doc header
70		out.WriteString(".TH ")
71	case level == 1:
72		out.WriteString("\n\n.SH ")
73	case level == 2:
74		out.WriteString("\n.SH ")
75	default:
76		out.WriteString("\n.SS ")
77	}
78
79	if !text() {
80		out.Truncate(marker)
81		return
82	}
83}
84
85func (r *roffRenderer) HRule(out *bytes.Buffer) {
86	out.WriteString("\n.ti 0\n\\l'\\n(.lu'\n")
87}
88
89func (r *roffRenderer) List(out *bytes.Buffer, text func() bool, flags int) {
90	marker := out.Len()
91	r.ListCounters = append(r.ListCounters, 1)
92	out.WriteString("\n.RS\n")
93	if !text() {
94		out.Truncate(marker)
95		return
96	}
97	r.ListCounters = r.ListCounters[:len(r.ListCounters)-1]
98	out.WriteString("\n.RE\n")
99}
100
101func (r *roffRenderer) ListItem(out *bytes.Buffer, text []byte, flags int) {
102	if flags&blackfriday.LIST_TYPE_ORDERED != 0 {
103		out.WriteString(fmt.Sprintf(".IP \"%3d.\" 5\n", r.ListCounters[len(r.ListCounters)-1]))
104		r.ListCounters[len(r.ListCounters)-1]++
105	} else {
106		out.WriteString(".IP \\(bu 2\n")
107	}
108	out.Write(text)
109	out.WriteString("\n")
110}
111
112func (r *roffRenderer) Paragraph(out *bytes.Buffer, text func() bool) {
113	marker := out.Len()
114	out.WriteString("\n.PP\n")
115	if !text() {
116		out.Truncate(marker)
117		return
118	}
119	if marker != 0 {
120		out.WriteString("\n")
121	}
122}
123
124func (r *roffRenderer) Table(out *bytes.Buffer, header []byte, body []byte, columnData []int) {
125	out.WriteString("\n.TS\nallbox;\n")
126
127	maxDelims := 0
128	lines := strings.Split(strings.TrimRight(string(header), "\n")+"\n"+strings.TrimRight(string(body), "\n"), "\n")
129	for _, w := range lines {
130		curDelims := strings.Count(w, "\t")
131		if curDelims > maxDelims {
132			maxDelims = curDelims
133		}
134	}
135	out.Write([]byte(strings.Repeat("l ", maxDelims+1) + "\n"))
136	out.Write([]byte(strings.Repeat("l ", maxDelims+1) + ".\n"))
137	out.Write(header)
138	if len(header) > 0 {
139		out.Write([]byte("\n"))
140	}
141
142	out.Write(body)
143	out.WriteString("\n.TE\n")
144}
145
146func (r *roffRenderer) TableRow(out *bytes.Buffer, text []byte) {
147	if out.Len() > 0 {
148		out.WriteString("\n")
149	}
150	out.Write(text)
151}
152
153func (r *roffRenderer) TableHeaderCell(out *bytes.Buffer, text []byte, align int) {
154	if out.Len() > 0 {
155		out.WriteString("\t")
156	}
157	if len(text) == 0 {
158		text = []byte{' '}
159	}
160	out.Write([]byte("\\fB\\fC" + string(text) + "\\fR"))
161}
162
163func (r *roffRenderer) TableCell(out *bytes.Buffer, text []byte, align int) {
164	if out.Len() > 0 {
165		out.WriteString("\t")
166	}
167	if len(text) > 30 {
168		text = append([]byte("T{\n"), text...)
169		text = append(text, []byte("\nT}")...)
170	}
171	if len(text) == 0 {
172		text = []byte{' '}
173	}
174	out.Write(text)
175}
176
177func (r *roffRenderer) Footnotes(out *bytes.Buffer, text func() bool) {
178
179}
180
181func (r *roffRenderer) FootnoteItem(out *bytes.Buffer, name, text []byte, flags int) {
182
183}
184
185func (r *roffRenderer) AutoLink(out *bytes.Buffer, link []byte, kind int) {
186	out.WriteString("\n\\[la]")
187	out.Write(link)
188	out.WriteString("\\[ra]")
189}
190
191func (r *roffRenderer) CodeSpan(out *bytes.Buffer, text []byte) {
192	out.WriteString("\\fB\\fC")
193	escapeSpecialChars(out, text)
194	out.WriteString("\\fR")
195}
196
197func (r *roffRenderer) DoubleEmphasis(out *bytes.Buffer, text []byte) {
198	out.WriteString("\\fB")
199	out.Write(text)
200	out.WriteString("\\fP")
201}
202
203func (r *roffRenderer) Emphasis(out *bytes.Buffer, text []byte) {
204	out.WriteString("\\fI")
205	out.Write(text)
206	out.WriteString("\\fP")
207}
208
209func (r *roffRenderer) Image(out *bytes.Buffer, link []byte, title []byte, alt []byte) {
210}
211
212func (r *roffRenderer) LineBreak(out *bytes.Buffer) {
213	out.WriteString("\n.br\n")
214}
215
216func (r *roffRenderer) Link(out *bytes.Buffer, link []byte, title []byte, content []byte) {
217	out.Write(content)
218	r.AutoLink(out, link, 0)
219}
220
221func (r *roffRenderer) RawHtmlTag(out *bytes.Buffer, tag []byte) { // nolint: golint
222	out.Write(tag)
223}
224
225func (r *roffRenderer) TripleEmphasis(out *bytes.Buffer, text []byte) {
226	out.WriteString("\\s+2")
227	out.Write(text)
228	out.WriteString("\\s-2")
229}
230
231func (r *roffRenderer) StrikeThrough(out *bytes.Buffer, text []byte) {
232}
233
234func (r *roffRenderer) FootnoteRef(out *bytes.Buffer, ref []byte, id int) {
235
236}
237
238func (r *roffRenderer) Entity(out *bytes.Buffer, entity []byte) {
239	out.WriteString(html.UnescapeString(string(entity)))
240}
241
242func (r *roffRenderer) NormalText(out *bytes.Buffer, text []byte) {
243	escapeSpecialChars(out, text)
244}
245
246func (r *roffRenderer) DocumentHeader(out *bytes.Buffer) {
247}
248
249func (r *roffRenderer) DocumentFooter(out *bytes.Buffer) {
250}
251
252func needsBackslash(c byte) bool {
253	for _, r := range []byte("-_&\\~") {
254		if c == r {
255			return true
256		}
257	}
258	return false
259}
260
261func escapeSpecialChars(out *bytes.Buffer, text []byte) {
262	for i := 0; i < len(text); i++ {
263		// escape initial apostrophe or period
264		if len(text) >= 1 && (text[0] == '\'' || text[0] == '.') {
265			out.WriteString("\\&")
266		}
267
268		// directly copy normal characters
269		org := i
270
271		for i < len(text) && !needsBackslash(text[i]) {
272			i++
273		}
274		if i > org {
275			out.Write(text[org:i])
276		}
277
278		// escape a character
279		if i >= len(text) {
280			break
281		}
282		out.WriteByte('\\')
283		out.WriteByte(text[i])
284	}
285}
286