1
package readline
2

3
import (
4
	"bufio"
5
	"bytes"
6
	"fmt"
7
	"io"
8
)
9

10
type AutoCompleter interface {
11
	// Readline will pass the whole line and current offset to it
12
	// Completer need to pass all the candidates, and how long they shared the same characters in line
13
	// Example:
14
	//   [go, git, git-shell, grep]
15
	//   Do("g", 1) => ["o", "it", "it-shell", "rep"], 1
16
	//   Do("gi", 2) => ["t", "t-shell"], 2
17
	//   Do("git", 3) => ["", "-shell"], 3
18
	Do(line []rune, pos int) (newLine [][]rune, length int)
19
}
20

21
type TabCompleter struct{}
22

23
func (t *TabCompleter) Do([]rune, int) ([][]rune, int) {
24
	return [][]rune{[]rune("\t")}, 0
25
}
26

27
type opCompleter struct {
28
	w     io.Writer
29
	op    *Operation
30
	width int
31

32
	inCompleteMode  bool
33
	inSelectMode    bool
34
	candidate       [][]rune
35
	candidateSource []rune
36
	candidateOff    int
37
	candidateChoise int
38
	candidateColNum int
39
}
40

41
func newOpCompleter(w io.Writer, op *Operation, width int) *opCompleter {
42
	return &opCompleter{
43
		w:     w,
44
		op:    op,
45
		width: width,
46
	}
47
}
48

49
func (o *opCompleter) doSelect() {
50
	if len(o.candidate) == 1 {
51
		o.op.buf.WriteRunes(o.candidate[0])
52
		o.ExitCompleteMode(false)
53
		return
54
	}
55
	o.nextCandidate(1)
56
	o.CompleteRefresh()
57
}
58

59
func (o *opCompleter) nextCandidate(i int) {
60
	o.candidateChoise += i
61
	o.candidateChoise = o.candidateChoise % len(o.candidate)
62
	if o.candidateChoise < 0 {
63
		o.candidateChoise = len(o.candidate) + o.candidateChoise
64
	}
65
}
66

67
func (o *opCompleter) OnComplete() bool {
68
	if o.width == 0 {
69
		return false
70
	}
71
	if o.IsInCompleteSelectMode() {
72
		o.doSelect()
73
		return true
74
	}
75

76
	buf := o.op.buf
77
	rs := buf.Runes()
78

79
	if o.IsInCompleteMode() && o.candidateSource != nil && runes.Equal(rs, o.candidateSource) {
80
		o.EnterCompleteSelectMode()
81
		o.doSelect()
82
		return true
83
	}
84

85
	o.ExitCompleteSelectMode()
86
	o.candidateSource = rs
87
	newLines, offset := o.op.cfg.AutoComplete.Do(rs, buf.idx)
88
	if len(newLines) == 0 {
89
		o.ExitCompleteMode(false)
90
		return true
91
	}
92

93
	// only Aggregate candidates in non-complete mode
94
	if !o.IsInCompleteMode() {
95
		if len(newLines) == 1 {
96
			buf.WriteRunes(newLines[0])
97
			o.ExitCompleteMode(false)
98
			return true
99
		}
100

101
		same, size := runes.Aggregate(newLines)
102
		if size > 0 {
103
			buf.WriteRunes(same)
104
			o.ExitCompleteMode(false)
105
			return true
106
		}
107
	}
108

109
	o.EnterCompleteMode(offset, newLines)
110
	return true
111
}
112

113
func (o *opCompleter) IsInCompleteSelectMode() bool {
114
	return o.inSelectMode
115
}
116

117
func (o *opCompleter) IsInCompleteMode() bool {
118
	return o.inCompleteMode
119
}
120

121
func (o *opCompleter) HandleCompleteSelect(r rune) bool {
122
	next := true
123
	switch r {
124
	case CharEnter, CharCtrlJ:
125
		next = false
126
		o.op.buf.WriteRunes(o.op.candidate[o.op.candidateChoise])
127
		o.ExitCompleteMode(false)
128
	case CharLineStart:
129
		num := o.candidateChoise % o.candidateColNum
130
		o.nextCandidate(-num)
131
	case CharLineEnd:
132
		num := o.candidateColNum - o.candidateChoise%o.candidateColNum - 1
133
		o.candidateChoise += num
134
		if o.candidateChoise >= len(o.candidate) {
135
			o.candidateChoise = len(o.candidate) - 1
136
		}
137
	case CharBackspace:
138
		o.ExitCompleteSelectMode()
139
		next = false
140
	case CharTab, CharForward:
141
		o.doSelect()
142
	case CharBell, CharInterrupt:
143
		o.ExitCompleteMode(true)
144
		next = false
145
	case CharNext:
146
		tmpChoise := o.candidateChoise + o.candidateColNum
147
		if tmpChoise >= o.getMatrixSize() {
148
			tmpChoise -= o.getMatrixSize()
149
		} else if tmpChoise >= len(o.candidate) {
150
			tmpChoise += o.candidateColNum
151
			tmpChoise -= o.getMatrixSize()
152
		}
153
		o.candidateChoise = tmpChoise
154
	case CharBackward:
155
		o.nextCandidate(-1)
156
	case CharPrev:
157
		tmpChoise := o.candidateChoise - o.candidateColNum
158
		if tmpChoise < 0 {
159
			tmpChoise += o.getMatrixSize()
160
			if tmpChoise >= len(o.candidate) {
161
				tmpChoise -= o.candidateColNum
162
			}
163
		}
164
		o.candidateChoise = tmpChoise
165
	default:
166
		next = false
167
		o.ExitCompleteSelectMode()
168
	}
169
	if next {
170
		o.CompleteRefresh()
171
		return true
172
	}
173
	return false
174
}
175

176
func (o *opCompleter) getMatrixSize() int {
177
	line := len(o.candidate) / o.candidateColNum
178
	if len(o.candidate)%o.candidateColNum != 0 {
179
		line++
180
	}
181
	return line * o.candidateColNum
182
}
183

184
func (o *opCompleter) OnWidthChange(newWidth int) {
185
	o.width = newWidth
186
}
187

188
func (o *opCompleter) CompleteRefresh() {
189
	if !o.inCompleteMode {
190
		return
191
	}
192
	lineCnt := o.op.buf.CursorLineCount()
193
	colWidth := 0
194
	for _, c := range o.candidate {
195
		w := runes.WidthAll(c)
196
		if w > colWidth {
197
			colWidth = w
198
		}
199
	}
200
	colWidth += o.candidateOff + 1
201
	same := o.op.buf.RuneSlice(-o.candidateOff)
202

203
	// -1 to avoid reach the end of line
204
	width := o.width - 1
205
	colNum := width / colWidth
206
	if colNum != 0 {
207
		colWidth += (width - (colWidth * colNum)) / colNum
208
	}
209

210
	o.candidateColNum = colNum
211
	buf := bufio.NewWriter(o.w)
212
	buf.Write(bytes.Repeat([]byte("\n"), lineCnt))
213

214
	colIdx := 0
215
	lines := 1
216
	buf.WriteString("\033[J")
217
	for idx, c := range o.candidate {
218
		inSelect := idx == o.candidateChoise && o.IsInCompleteSelectMode()
219
		if inSelect {
220
			buf.WriteString("\033[30;47m")
221
		}
222
		buf.WriteString(string(same))
223
		buf.WriteString(string(c))
224
		buf.Write(bytes.Repeat([]byte(" "), colWidth-runes.WidthAll(c)-runes.WidthAll(same)))
225

226
		if inSelect {
227
			buf.WriteString("\033[0m")
228
		}
229

230
		colIdx++
231
		if colIdx == colNum {
232
			buf.WriteString("\n")
233
			lines++
234
			colIdx = 0
235
		}
236
	}
237

238
	// move back
239
	fmt.Fprintf(buf, "\033[%dA\r", lineCnt-1+lines)
240
	fmt.Fprintf(buf, "\033[%dC", o.op.buf.idx+o.op.buf.PromptLen())
241
	buf.Flush()
242
}
243

244
func (o *opCompleter) aggCandidate(candidate [][]rune) int {
245
	offset := 0
246
	for i := 0; i < len(candidate[0]); i++ {
247
		for j := 0; j < len(candidate)-1; j++ {
248
			if i > len(candidate[j]) {
249
				goto aggregate
250
			}
251
			if candidate[j][i] != candidate[j+1][i] {
252
				goto aggregate
253
			}
254
		}
255
		offset = i
256
	}
257
aggregate:
258
	return offset
259
}
260

261
func (o *opCompleter) EnterCompleteSelectMode() {
262
	o.inSelectMode = true
263
	o.candidateChoise = -1
264
	o.CompleteRefresh()
265
}
266

267
func (o *opCompleter) EnterCompleteMode(offset int, candidate [][]rune) {
268
	o.inCompleteMode = true
269
	o.candidate = candidate
270
	o.candidateOff = offset
271
	o.CompleteRefresh()
272
}
273

274
func (o *opCompleter) ExitCompleteSelectMode() {
275
	o.inSelectMode = false
276
	o.candidate = nil
277
	o.candidateChoise = -1
278
	o.candidateOff = -1
279
	o.candidateSource = nil
280
}
281

282
func (o *opCompleter) ExitCompleteMode(revent bool) {
283
	o.inCompleteMode = false
284
	o.ExitCompleteSelectMode()
285
}
286

287