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
|
package lib
import (
"bufio"
"io"
"mime"
"net/http"
"os"
"path/filepath"
"github.com/emersion/go-message/mail"
"github.com/pkg/errors"
)
type Part struct {
MimeType string
Params map[string]string
Body io.Reader
}
func NewPart(mimetype string, params map[string]string, body io.Reader) *Part {
return &Part{
MimeType: mimetype,
Params: params,
Body: body,
}
}
type Attachment interface {
Name() string
WriteTo(w *mail.Writer) error
}
type FileAttachment struct {
path string
}
func NewFileAttachment(path string) *FileAttachment {
return &FileAttachment{
path,
}
}
func (fa *FileAttachment) Name() string {
return fa.path
}
func (fa *FileAttachment) WriteTo(w *mail.Writer) error {
f, err := os.Open(fa.path)
if err != nil {
return errors.Wrap(err, "os.Open")
}
defer f.Close()
reader := bufio.NewReader(f)
// if we have an extension, prefer that instead of trying to sniff the header.
// That's generally more accurate than sniffing as lots of things are zip files
// under the hood, e.g. most office file types
ext := filepath.Ext(fa.path)
var mimeString string
if mimeString = mime.TypeByExtension(ext); mimeString != "" {
// found it in the DB
} else {
// Sniff the mime type instead
// http.DetectContentType only cares about the first 512 bytes
head, err := reader.Peek(512)
if err != nil && err != io.EOF {
return errors.Wrap(err, "Peek")
}
mimeString = http.DetectContentType(head)
}
// mimeString can contain type and params (like text encoding),
// so we need to break them apart before passing them to the headers
mimeType, params, err := mime.ParseMediaType(mimeString)
if err != nil {
return errors.Wrap(err, "ParseMediaType")
}
filename := filepath.Base(fa.path)
params["name"] = filename
// set header fields
ah := mail.AttachmentHeader{}
ah.SetContentType(mimeType, params)
// setting the filename auto sets the content disposition
ah.SetFilename(filename)
aw, err := w.CreateAttachment(ah)
if err != nil {
return errors.Wrap(err, "CreateAttachment")
}
defer aw.Close()
if _, err := reader.WriteTo(aw); err != nil {
return errors.Wrap(err, "reader.WriteTo")
}
return nil
}
type PartAttachment struct {
part *Part
name string
}
func NewPartAttachment(part *Part, name string) *PartAttachment {
return &PartAttachment{
part,
name,
}
}
func (pa *PartAttachment) Name() string {
return pa.name
}
func (pa *PartAttachment) WriteTo(w *mail.Writer) error {
// set header fields
ah := mail.AttachmentHeader{}
ah.SetContentType(pa.part.MimeType, pa.part.Params)
// setting the filename auto sets the content disposition
ah.SetFilename(pa.Name())
aw, err := w.CreateAttachment(ah)
if err != nil {
return errors.Wrap(err, "CreateAttachment")
}
defer aw.Close()
if _, err := io.Copy(aw, pa.part.Body); err != nil {
return errors.Wrap(err, "io.Copy")
}
return nil
}
|
