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
|
package completer
import (
"bufio"
"fmt"
"io"
"log"
"mime"
"net/mail"
"os/exec"
"strings"
"github.com/google/shlex"
)
// A Completer is used to autocomplete text inputs based on the configured
// completion commands.
type Completer struct {
// AddressBookCmd is the command to run for completing email addresses. This
// command must output one completion on each line with fields separated by a
// tab character. The first field must be the address, and the second field,
// if present, the contact name. Only the email address field is required.
// The name field is optional. Additional fields are ignored.
AddressBookCmd string
errHandler func(error)
logger *log.Logger
}
// A CompleteFunc accepts a string to be completed and returns a slice of
// possible completions.
type CompleteFunc func(string) []string
// New creates a new Completer with the specified address book command.
func New(addressBookCmd string, errHandler func(error), logger *log.Logger) *Completer {
return &Completer{
AddressBookCmd: addressBookCmd,
errHandler: errHandler,
logger: logger,
}
}
// ForHeader returns a CompleteFunc appropriate for the specified mail header. In
// the case of To, From, etc., the completer will get completions from the
// configured address book command. For other headers, a noop completer will be
// returned. If errors arise during completion, the errHandler will be called.
func (c *Completer) ForHeader(h string) CompleteFunc {
if isAddressHeader(h) {
if c.AddressBookCmd == "" {
return nil
}
// wrap completeAddress in an error handler
return func(s string) []string {
completions, err := c.completeAddress(s)
if err != nil {
c.handleErr(err)
return []string{}
}
return completions
}
}
return nil
}
// isAddressHeader determines whether the address completer should be used for
// header h.
func isAddressHeader(h string) bool {
switch strings.ToLower(h) {
case "to", "from", "cc", "bcc":
return true
}
return false
}
// completeAddress uses the configured address book completion command to fetch
// completions for the specified string, returning a slice of completions or an
// error.
func (c *Completer) completeAddress(s string) ([]string, error) {
cmd, err := c.getAddressCmd(s)
if err != nil {
return nil, err
}
stdout, err := cmd.StdoutPipe()
if err != nil {
return nil, fmt.Errorf("stdout: %v", err)
}
if err := cmd.Start(); err != nil {
return nil, fmt.Errorf("cmd start: %v", err)
}
completions, err := readCompletions(stdout)
if err != nil {
return nil, fmt.Errorf("read completions: %v", err)
}
// Wait returns an error if the exit status != 0, which some completion
// programs will do to signal no matches. We don't want to spam the user with
// spurious error messages, so we'll ignore any errors that arise at this
// point.
if err := cmd.Wait(); err != nil {
c.logger.Printf("completion error: %v", err)
}
return completions, nil
}
// getAddressCmd constructs an exec.Cmd based on the configured command and
// specified query.
func (c *Completer) getAddressCmd(s string) (*exec.Cmd, error) {
if strings.TrimSpace(c.AddressBookCmd) == "" {
return nil, fmt.Errorf("no command configured")
}
queryCmd := strings.Replace(c.AddressBookCmd, "%s", s, -1)
parts, err := shlex.Split(queryCmd)
if err != nil {
return nil, fmt.Errorf("could not lex command")
}
if len(parts) < 1 {
return nil, fmt.Errorf("empty command")
}
if len(parts) > 1 {
return exec.Command(parts[0], parts[1:]...), nil
}
return exec.Command(parts[0]), nil
}
// readCompletions reads a slice of completions from r line by line. Each line
// must consist of tab-delimited fields. Only the first field (the email
// address field) is required, the second field (the contact name) is optional,
// and subsequent fields are ignored.
func readCompletions(r io.Reader) ([]string, error) {
buf := bufio.NewReader(r)
completions := []string{}
for {
line, err := buf.ReadString('\n')
if err == io.EOF {
return completions, nil
} else if err != nil {
return nil, err
}
parts := strings.SplitN(line, "\t", 3)
if addr, err := mail.ParseAddress(parts[0]); err == nil {
if len(parts) > 1 {
addr.Name = strings.TrimSpace(parts[1])
}
decoded, err := decodeMIME(addr.String())
if err != nil {
return nil, fmt.Errorf("could not decode MIME string: %w", err)
}
completions = append(completions, decoded)
}
}
}
func decodeMIME(s string) (string, error) {
var d mime.WordDecoder
return d.DecodeHeader(s)
}
func (c *Completer) handleErr(err error) {
if c.errHandler != nil {
c.errHandler(err)
}
}
|
