byjp.me
A tool for archiving & converting scans of postcards, and information about them.
feat: :construction: Add web-based postcard maker, including WASM
Postcard web & USDZ generator; Golang server and (golang-built) WASM service worker.
+29
-5
.goreleaser.yaml
+29
-5
.goreleaser.yaml
···
13
13
- go mod tidy
14
14
15
15
builds:
16
-
- main: ./cmd/postcards
16
+
-
17
+
main: ./cmd/postcards
17
18
id: postcards
18
19
binary: postcards
19
20
env:
···
29
30
- wasm
30
31
ldflags:
31
32
- -s -w -X "main.Date={{.CommitDate}}"
32
-
universal_binaries:
33
-
- name_template: postcards
34
-
id: mac-universal
35
-
replace: true
33
+
-
34
+
main: ./cmd/postoffice-serviceworker
35
+
id: postoffice-serviceworker
36
+
binary: postoffice-serviceworker
37
+
env:
38
+
- CGO_ENABLED=0
39
+
goos:
40
+
- js
41
+
goarch:
42
+
- wasm
43
+
# It's important the postoffice native binary is built after the WASM blob
44
+
# As the WASM blob is baked into this server as part of an embed directive
45
+
-
46
+
main: ./cmd/postoffice
47
+
id: postoffice
48
+
binary: postoffice
49
+
env:
50
+
- CGO_ENABLED=0
51
+
goos:
52
+
- linux
53
+
- windows
54
+
- darwin
55
+
- wasip1
56
+
goarch:
57
+
- amd64
58
+
- arm64
59
+
- wasm
36
60
37
61
archives:
38
62
- format: tar.gz
+1
TODO.md
+1
TODO.md
···
17
17
- [ ] Don't re-encode same-same format. (eg. USDZ to Web(no alpha, lossy); Web to Web)
18
18
- [ ] Show warning when using fallback size to generate USDZ
19
19
- [ ] Show warning when losing information on conversion (are there any of these cases now?)
20
+
- [ ] Get HTML format to output the _right_ image extension (perhaps provide argument for what to add into templates?)
20
21
21
22
## Done
22
23
-1
cmd/postbox/main.go
-1
cmd/postbox/main.go
···
1
-
package main
+30
cmd/postoffice-serviceworker/main.go
+30
cmd/postoffice-serviceworker/main.go
···
1
+
//go:build js
2
+
// +build js
3
+
4
+
package main
5
+
6
+
import (
7
+
"fmt"
8
+
"net/http"
9
+
"os"
10
+
11
+
"github.com/jphastings/dotpostcard/pkg/postoffice"
12
+
wasmhttp "github.com/nlepage/go-wasm-http-server/v2"
13
+
)
14
+
15
+
func main() {
16
+
codecChoices, err := postoffice.DefaultCodecChoices()
17
+
check(err, "Unable to load codecs")
18
+
19
+
http.HandleFunc("/", postoffice.HTTPFormHander(codecChoices))
20
+
wasmhttp.Serve(nil)
21
+
22
+
select {}
23
+
}
24
+
25
+
func check(err error, message string) {
26
+
if err != nil {
27
+
fmt.Fprintf(os.Stderr, "%s: %v\n", message, err)
28
+
os.Exit(1)
29
+
}
30
+
}
+35
cmd/postoffice/main.go
+35
cmd/postoffice/main.go
···
1
+
package main
2
+
3
+
import (
4
+
"fmt"
5
+
"net/http"
6
+
"os"
7
+
8
+
"github.com/jphastings/dotpostcard/internal/www"
9
+
"github.com/jphastings/dotpostcard/pkg/postoffice"
10
+
)
11
+
12
+
func main() {
13
+
codecChoices, err := postoffice.DefaultCodecChoices()
14
+
check(err, "Unable to load codecs")
15
+
16
+
fs := http.FileServer(http.FS(www.PostOffice))
17
+
http.Handle("/", fs)
18
+
19
+
http.HandleFunc("/compile", postoffice.HTTPFormHander(codecChoices))
20
+
21
+
port, gavePort := os.LookupEnv("PORT")
22
+
if !gavePort {
23
+
port = "7678"
24
+
}
25
+
26
+
fmt.Printf("Starting server on :%s...\n", port)
27
+
check(http.ListenAndServe(":"+port, nil), "Error starting server")
28
+
}
29
+
30
+
func check(err error, message string) {
31
+
if err != nil {
32
+
fmt.Fprintf(os.Stderr, "%s: %v\n", message, err)
33
+
os.Exit(1)
34
+
}
35
+
}
+24
formats/component/bundle.go
+24
formats/component/bundle.go
···
2
2
3
3
import (
4
4
"errors"
5
+
"io"
5
6
"io/fs"
6
7
"path"
7
8
"regexp"
···
9
10
10
11
"github.com/jphastings/dotpostcard/formats"
11
12
"github.com/jphastings/dotpostcard/formats/metadata"
13
+
"github.com/jphastings/dotpostcard/types"
12
14
)
13
15
14
16
var usableExtensions = []string{".webp", ".png", ".jpg", ".jpeg", ".tif", ".tiff"}
···
92
94
func (b bundle) Name() string {
93
95
return codecName
94
96
}
97
+
98
+
type decodedMeta types.Metadata
99
+
100
+
func (m decodedMeta) Decode(formats.DecodeOptions) (types.Postcard, error) {
101
+
return types.Postcard{Meta: types.Metadata(m)}, nil
102
+
}
103
+
104
+
func BundleFromReaders(meta types.Metadata, front io.ReadCloser, back ...io.ReadCloser) formats.Bundle {
105
+
b := bundle{
106
+
frontFile: front,
107
+
name: meta.Name,
108
+
// TODO: is this right?
109
+
refPath: ".",
110
+
metaBundle: decodedMeta(meta),
111
+
}
112
+
113
+
if len(back) >= 1 {
114
+
b.backFile = back[0]
115
+
}
116
+
117
+
return b
118
+
}
+9
-3
formats/component/codec.go
+9
-3
formats/component/codec.go
···
3
3
import (
4
4
"errors"
5
5
"fmt"
6
+
"io"
6
7
"io/fs"
7
8
8
9
"github.com/jphastings/dotpostcard/formats"
9
10
"github.com/jphastings/dotpostcard/formats/metadata"
11
+
"github.com/jphastings/dotpostcard/types"
10
12
)
11
13
12
14
const codecName = "Component files"
···
18
20
)
19
21
20
22
var _ formats.Bundle = bundle{}
23
+
24
+
type decoder interface {
25
+
Decode(formats.DecodeOptions) (types.Postcard, error)
26
+
}
21
27
22
28
type bundle struct {
23
29
name string
24
30
refPath string
25
-
frontFile fs.File
26
-
backFile fs.File
27
-
metaBundle formats.Bundle
31
+
frontFile io.ReadCloser
32
+
backFile io.ReadCloser
33
+
metaBundle decoder
28
34
}
29
35
30
36
var _ formats.Codec = codec{}
+6
-1
formats/component/decode.go
+6
-1
formats/component/decode.go
···
22
22
)
23
23
24
24
func (b bundle) Decode(opts formats.DecodeOptions) (types.Postcard, error) {
25
+
defer b.frontFile.Close()
26
+
if b.backFile != nil {
27
+
defer b.backFile.Close()
28
+
}
29
+
25
30
pc, err := b.metaBundle.Decode(opts)
26
31
if err != nil {
27
32
return types.Postcard{}, err
···
71
76
pc.Meta.Physical.FrontDimensions.CmHeight = forcedSize.CmHeight
72
77
}
73
78
74
-
if err := validateMetadata(pc); err != nil {
79
+
if err := pc.Validate(); err != nil {
75
80
return types.Postcard{}, err
76
81
}
77
82
+5
-5
formats/component/encode.go
+5
-5
formats/component/encode.go
···
5
5
"image"
6
6
"io"
7
7
8
-
"git.sr.ht/~jackmordaunt/go-libwebp/webp"
9
8
"github.com/jphastings/dotpostcard/formats"
9
+
"github.com/jphastings/dotpostcard/internal/images"
10
10
"github.com/jphastings/dotpostcard/types"
11
11
"golang.org/x/image/draw"
12
12
)
···
18
18
encImg := func(side image.Image) func(io.Writer) error {
19
19
return func(w io.Writer) error {
20
20
if opts != nil && opts.Archival {
21
-
return webp.Encode(w, side, webp.Lossless())
21
+
return images.WriteWebP(w, side, nil, true, pc.Meta.HasTransparency)
22
22
}
23
23
24
24
startSize := side.Bounds()
···
41
41
side = resizedImg
42
42
}
43
43
44
-
return webp.Encode(w, side, webp.Quality(75))
44
+
return images.WriteWebP(w, side, nil, opts.Archival, pc.Meta.HasTransparency)
45
45
}
46
46
}
47
47
48
48
frontName := fmt.Sprintf("%s-front.webp", pc.Name)
49
-
frontW := formats.NewFileWriter(frontName, encImg(pc.Front))
49
+
frontW := formats.NewFileWriter(frontName, "image/webp", encImg(pc.Front))
50
50
51
51
backName := fmt.Sprintf("%s-back.webp", pc.Name)
52
-
backW := formats.NewFileWriter(backName, encImg(pc.Back))
52
+
backW := formats.NewFileWriter(backName, "image/webp", encImg(pc.Back))
53
53
54
54
return []formats.FileWriter{frontW, backW}, nil
55
55
}
-28
formats/component/validate.go
-28
formats/component/validate.go
···
1
-
package component
2
-
3
-
import (
4
-
"fmt"
5
-
6
-
"github.com/jphastings/dotpostcard/types"
7
-
)
8
-
9
-
func validateMetadata(pc types.Postcard) error {
10
-
if pc.Sides() == 2 {
11
-
if pc.Meta.Flip == types.FlipNone || !pc.Meta.Flip.IsValid() {
12
-
var validFlips string
13
-
for _, f := range types.ValidFlips {
14
-
if f != types.FlipNone {
15
-
validFlips += ", " + string(f)
16
-
}
17
-
}
18
-
19
-
return fmt.Errorf(
20
-
"invalid flip type for two-sided postcard '%s' must be one of: %s",
21
-
pc.Meta.Flip,
22
-
validFlips[2:],
23
-
)
24
-
}
25
-
}
26
-
27
-
return nil
28
-
}
+1
-1
formats/css/codec.go
+1
-1
formats/css/codec.go
+3
-1
formats/filewriter.go
+3
-1
formats/filewriter.go
···
48
48
type FileWriter struct {
49
49
fn func(io.Writer) error
50
50
Filename string
51
+
Mimetype string
51
52
}
52
53
53
54
// NewFileWriter is a helper function for creating a read stream for the return values of Encoders
54
-
func NewFileWriter(filename string, fn func(w io.Writer) error) FileWriter {
55
+
func NewFileWriter(filename, mimetype string, fn func(w io.Writer) error) FileWriter {
55
56
return FileWriter{
56
57
Filename: filename,
58
+
Mimetype: mimetype,
57
59
fn: fn,
58
60
}
59
61
}
+1
-1
formats/html/codec.go
+1
-1
formats/html/codec.go
+35
-34
formats/metadata/codec.go
+35
-34
formats/metadata/codec.go
···
7
7
"io"
8
8
"io/fs"
9
9
"path"
10
-
"slices"
11
10
"strings"
12
11
13
12
"github.com/jphastings/dotpostcard/formats"
···
24
23
var _ formats.Bundle = bundle{}
25
24
26
25
type bundle struct {
27
-
ext MetadataType
26
+
mt MetadataType
28
27
file fs.File
29
28
refPath string
30
29
}
31
30
32
31
var _ formats.Codec = codec{}
33
32
34
-
type codec struct{ ext MetadataType }
33
+
type codec MetadataType
35
34
36
-
type MetadataType string
35
+
type MetadataType struct {
36
+
Extension string
37
+
Mimetype string
38
+
HumanName string
39
+
}
37
40
38
-
var AsJSON MetadataType = ".json"
39
-
var AsYAML MetadataType = ".yaml"
40
-
var AsXMP MetadataType = ".xmp"
41
+
var AsJSON = MetadataType{".json", "application/json", "JSON " + codecName}
42
+
var AsYAML = MetadataType{".yaml", "application/yaml", "YAML " + codecName}
43
+
var AsXMP = MetadataType{".xmp", xmp.Mimetype, "XMP " + codecName}
41
44
42
-
var Extensions = []string{".json", ".yaml", ".yml", ".xmp"}
45
+
var Extensions = []string{AsJSON.Extension, AsYAML.Extension, AsXMP.Extension}
43
46
44
-
func Codec(ext MetadataType) formats.Codec { return codec{ext: ext} }
45
-
46
-
func (c codec) Name() string {
47
-
switch c.ext {
48
-
case AsJSON:
49
-
return "JSON " + codecName
50
-
case AsYAML:
51
-
return "YAML " + codecName
52
-
case AsXMP:
53
-
return "XMP " + codecName
47
+
func ExtToMediaType(ext string) (MetadataType, bool) {
48
+
switch ext {
49
+
case AsJSON.Extension:
50
+
return AsJSON, true
51
+
case AsYAML.Extension:
52
+
return AsYAML, true
53
+
case AsXMP.Extension:
54
+
return AsXMP, true
54
55
default:
55
-
return codecName
56
+
return MetadataType{}, false
56
57
}
57
58
}
58
59
60
+
func Codec(mt MetadataType) formats.Codec { return codec(mt) }
61
+
func (c codec) Name() string { return c.HumanName }
62
+
59
63
func BundleFromFile(file fs.File, dirPath string) (formats.Bundle, error) {
60
64
info, err := file.Stat()
61
65
if err != nil {
···
63
67
}
64
68
filename := info.Name()
65
69
ext := path.Ext(filename)
66
-
if !slices.Contains(Extensions, ext) {
70
+
mt, ok := ExtToMediaType(ext)
71
+
if !ok {
67
72
return nil, fmt.Errorf("unknown metadata extension '%s'", ext)
68
73
}
69
74
70
-
return bundle{file: file, ext: MetadataType(ext), refPath: path.Join(dirPath, filename)}, nil
75
+
return bundle{file: file, mt: mt, refPath: path.Join(dirPath, filename)}, nil
71
76
}
72
77
73
78
func (c codec) Bundle(group formats.FileGroup) ([]formats.Bundle, []fs.File, error) {
···
75
80
var remaining []fs.File
76
81
77
82
for _, file := range group.Files {
78
-
if filename, ok := formats.HasFileSuffix(file, string(c.ext)); ok {
79
-
bundles = append(bundles, bundle{file: file, ext: c.ext, refPath: path.Join(group.DirPath, filename)})
83
+
if filename, ok := formats.HasFileSuffix(file, string(c.Extension)); ok {
84
+
bundles = append(bundles, bundle{file: file, mt: MetadataType(c), refPath: path.Join(group.DirPath, filename)})
80
85
} else {
81
86
remaining = append(remaining, file)
82
87
}
···
87
92
88
93
// The structure information is stored in the internal/types/postcard.go file, because Go.
89
94
func (c codec) Encode(pc types.Postcard, _ *formats.EncodeOptions) ([]formats.FileWriter, error) {
90
-
if c.ext != AsJSON && c.ext != AsYAML && c.ext != AsXMP {
91
-
return nil, fmt.Errorf("unknown metadata format '%s'", c.ext)
92
-
}
93
-
94
-
name := fmt.Sprintf("%s-meta%s", pc.Name, c.ext)
95
+
name := fmt.Sprintf("%s-meta%s", pc.Name, c.Extension)
95
96
writer := func(w io.Writer) error {
96
-
switch c.ext {
97
+
switch MetadataType(c) {
97
98
case AsJSON:
98
99
return json.NewEncoder(w).Encode(pc.Meta)
99
100
case AsYAML:
···
106
107
_, err = w.Write(xmp)
107
108
return err
108
109
default:
109
-
return fmt.Errorf("unknown metadata format '%s'", c.ext)
110
+
return fmt.Errorf("cannot encode '%s'", c.HumanName)
110
111
}
111
112
}
112
113
113
-
return []formats.FileWriter{formats.NewFileWriter(name, writer)}, nil
114
+
return []formats.FileWriter{formats.NewFileWriter(name, c.Mimetype, writer)}, nil
114
115
}
115
116
116
117
func (b bundle) Decode(_ formats.DecodeOptions) (types.Postcard, error) {
117
118
var pc types.Postcard
118
119
var err error
119
-
switch b.ext {
120
+
switch b.mt {
120
121
case AsJSON:
121
122
err = json.NewDecoder(b.file).Decode(&pc.Meta)
122
123
case AsYAML:
···
124
125
case AsXMP:
125
126
pc.Meta, err = xmp.MetadataFromXMP(b.file)
126
127
default:
127
-
return types.Postcard{}, fmt.Errorf("unknown metadata format '%s'", b.ext)
128
+
return types.Postcard{}, fmt.Errorf("cannot decode '%s'", b.mt.HumanName)
128
129
}
129
130
130
-
pc.Name = strings.TrimSuffix(path.Base(b.refPath), "-meta"+string(b.ext))
131
+
pc.Name = strings.TrimSuffix(path.Base(b.refPath), "-meta"+string(b.mt.Extension))
131
132
132
133
if err != nil {
133
134
err = fmt.Errorf("error decoding %s: %w", b.refPath, err)
+3
-2
formats/usd/codec.go
+3
-2
formats/usd/codec.go
···
165
165
ext := path.Ext(fw.Filename)
166
166
sideFilename := strings.TrimSuffix(fw.Filename, ext) + "-texture" + ext
167
167
writeImage := func(w io.Writer) error { return fw.WriteTo(w) }
168
+
imageMimetype := fw.Mimetype
168
169
169
170
writeUSD := func(w io.Writer) error {
170
171
maxX, maxY := pc.Meta.Physical.FrontDimensions.MustPhysical()
···
226
227
}
227
228
228
229
return []formats.FileWriter{
229
-
formats.NewFileWriter(usdFilename, writeUSD),
230
-
formats.NewFileWriter(sideFilename, writeImage),
230
+
formats.NewFileWriter(usdFilename, "model/vnd.usda", writeUSD),
231
+
formats.NewFileWriter(sideFilename, imageMimetype, writeImage),
231
232
}, nil
232
233
}
+1
-1
formats/usdz/codec.go
+1
-1
formats/usdz/codec.go
+5
-5
formats/web/encode.go
+5
-5
formats/web/encode.go
···
15
15
"github.com/jphastings/dotpostcard/types"
16
16
)
17
17
18
-
func (c codec) pickFormat(meta types.Metadata, opts *formats.EncodeOptions) (string, error) {
18
+
func (c codec) pickFormat(meta types.Metadata, opts *formats.EncodeOptions) (string, string, error) {
19
19
needs := capabilities{
20
20
transparency: meta.HasTransparency,
21
21
lossless: (opts != nil) && opts.Archival,
···
29
29
}
30
30
}
31
31
if format == "" {
32
-
return "", fmt.Errorf(
32
+
return "", "", fmt.Errorf(
33
33
"none of the configured formats (%s) meet the needs of this postcard & options (%s)",
34
34
strings.Join(c.formats, ", "),
35
35
needs.String(),
36
36
)
37
37
}
38
38
39
-
return format, nil
39
+
return format, "image/" + format, nil
40
40
}
41
41
42
42
func (c codec) Encode(pc types.Postcard, opts *formats.EncodeOptions) ([]formats.FileWriter, error) {
43
-
format, err := c.pickFormat(pc.Meta, opts)
43
+
format, mimetype, err := c.pickFormat(pc.Meta, opts)
44
44
if err != nil {
45
45
return nil, err
46
46
}
···
91
91
return err
92
92
}
93
93
94
-
return []formats.FileWriter{formats.NewFileWriter(name, writer)}, nil
94
+
return []formats.FileWriter{formats.NewFileWriter(name, mimetype, writer)}, nil
95
95
}
96
96
97
97
func rotateForWeb(img image.Image, flip types.Flip) (image.Image, image.Rectangle) {
+3
-1
formats/xmp/encode.go
+3
-1
formats/xmp/encode.go
···
11
11
"github.com/jphastings/dotpostcard/types"
12
12
)
13
13
14
+
const Mimetype = "application/x-xmp"
15
+
14
16
func (c codec) Encode(pc types.Postcard, _ *formats.EncodeOptions) ([]formats.FileWriter, error) {
15
17
filename := fmt.Sprintf("%s-meta.xmp", pc.Name)
16
18
writer := func(w io.Writer) error {
···
22
24
return err
23
25
}
24
26
}
25
-
fw := formats.NewFileWriter(filename, writer)
27
+
fw := formats.NewFileWriter(filename, Mimetype, writer)
26
28
27
29
return []formats.FileWriter{fw}, nil
28
30
}
+3
go.mod
+3
go.mod
···
15
15
github.com/dsoprea/go-tiff-image-structure v0.0.0-20221003165014-8ecc4f52edca
16
16
github.com/ernyoke/imger v1.0.0
17
17
github.com/gen2brain/jpegli v0.3.3
18
+
github.com/nlepage/go-wasm-http-server/v2 v2.0.5
18
19
github.com/spf13/cobra v1.8.1
19
20
github.com/stretchr/testify v1.9.0
20
21
github.com/sunshineplan/tiff v0.0.0-20220128141034-29b9d69bd906
···
46
47
github.com/golang/geo v0.0.0-20230421003525-6adc56603217 // indirect
47
48
github.com/google/uuid v1.6.0 // indirect
48
49
github.com/gorilla/css v1.0.1 // indirect
50
+
github.com/hack-pad/safejs v0.1.1 // indirect
49
51
github.com/hhrutter/lzw v1.0.0 // indirect
50
52
github.com/inconshreveable/mousetrap v1.1.0 // indirect
51
53
github.com/kr/pretty v0.3.1 // indirect
···
56
58
github.com/muesli/reflow v0.3.0 // indirect
57
59
github.com/muesli/termenv v0.15.3-0.20240618155329-98d742f6907a // indirect
58
60
github.com/ncruces/go-strftime v0.1.9 // indirect
61
+
github.com/nlepage/go-js-promise v1.0.0 // indirect
59
62
github.com/pmezard/go-difflib v1.0.0 // indirect
60
63
github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
61
64
github.com/rivo/uniseg v0.4.7 // indirect
+6
-12
go.sum
+6
-12
go.sum
···
4
4
git.sr.ht/~sbinet/cmpimg v0.1.0/go.mod h1:FU12psLbF4TfNXkKH2ZZQ29crIqoiqTZmeQ7dkp/pxE=
5
5
git.sr.ht/~sbinet/gg v0.6.0 h1:RIzgkizAk+9r7uPzf/VfbJHBMKUr0F5hRFxTUGMnt38=
6
6
git.sr.ht/~sbinet/gg v0.6.0/go.mod h1:uucygbfC9wVPQIfrmwM2et0imr8L7KQWywX0xpFMm94=
7
-
github.com/Masterminds/semver v1.5.0/go.mod h1:MB6lktGJrhw8PrUyiEoblNEGEQ+RzHPF078ddwwvV3Y=
8
7
github.com/alecthomas/assert/v2 v2.7.0 h1:QtqSACNS3tF7oasA8CU6A6sXZSBDqnm7RfpLl9bZqbE=
9
8
github.com/alecthomas/assert/v2 v2.7.0/go.mod h1:Bze95FyfUr7x34QZrjL+XP+0qgp/zg8yS+TtBj1WA3k=
10
9
github.com/alecthomas/chroma/v2 v2.14.0 h1:R3+wzpnUArGcQz7fCETQBzO5n9IMNi13iIs46aU4V9E=
···
76
75
github.com/ebitengine/purego v0.7.1/go.mod h1:ah1In8AOtksoNK6yk5z1HTJeUkC1Ez4Wk2idgGslMwQ=
77
76
github.com/ernyoke/imger v1.0.0 h1:v+vnOpZwCfet5AUruwhN54g9v8CnhKOB3ZCsMIa5AZ0=
78
77
github.com/ernyoke/imger v1.0.0/go.mod h1:Ft4UQ3taMpn8EVVLWRlT0ijOvMTKZZqhXXR4VzCsAT4=
79
-
github.com/fogleman/gg v1.3.0/go.mod h1:R/bRT+9gY/C5z7JzPU0zXsXHKM4/ayA+zqcVNZzPa1k=
80
78
github.com/gen2brain/jpegli v0.3.3 h1:ryCOQpmGuVk6FA+QBe9st6cW48jsRdVOPiNrAJ50m+k=
81
79
github.com/gen2brain/jpegli v0.3.3/go.mod h1:6Dbgr+ni1IUBqGVOKHn8lY+6DvwSGfAfC7pPQiSK6uA=
82
80
github.com/go-errors/errors v1.0.1/go.mod h1:f4zRHt4oKfwPJE5k8C9vpYG+aDHdBFUsgrm6/TyX73Q=
···
95
93
github.com/golang/geo v0.0.0-20210211234256-740aa86cb551/go.mod h1:QZ0nwyI2jOfgRAoBvP+ab5aRr7c9x7lhGEJrKvBwjWI=
96
94
github.com/golang/geo v0.0.0-20230421003525-6adc56603217 h1:HKlyj6in2JV6wVkmQ4XmG/EIm+SCYlPZ+V4GWit7Z+I=
97
95
github.com/golang/geo v0.0.0-20230421003525-6adc56603217/go.mod h1:8wI0hitZ3a1IxZfeH3/5I97CI8i5cLGsYe7xNhQGs9U=
98
-
github.com/golang/snappy v0.0.4/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
99
96
github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
100
97
github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
101
98
github.com/gorilla/css v1.0.1 h1:ntNaBIghp6JmvWnxbZKANoLyuXTPZ4cAMlo6RyhlbO8=
102
99
github.com/gorilla/css v1.0.1/go.mod h1:BvnYkspnSzMmwRK+b8/xgNPLiIuNZr6vbZBTPQ2A3b0=
100
+
github.com/hack-pad/safejs v0.1.1 h1:d5qPO0iQ7h2oVtpzGnLExE+Wn9AtytxIfltcS2b9KD8=
101
+
github.com/hack-pad/safejs v0.1.1/go.mod h1:HdS+bKF1NrE72VoXZeWzxFOVQVUSqZJAG0xNCnb+Tio=
103
102
github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
104
103
github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
105
104
github.com/hhrutter/lzw v1.0.0 h1:laL89Llp86W3rRs83LvKbwYRx6INE8gDn0XNb1oXtm0=
···
108
107
github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
109
108
github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
110
109
github.com/jessevdk/go-flags v1.5.0/go.mod h1:Fw0T6WPc1dYxT4mKEZRfG5kJhaTDP9pj1c2EWnYs/m4=
111
-
github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51/go.mod h1:CzGEWj7cYgsdH8dAjBGEr58BoE7ScuLd+fwFZ44+/x8=
112
-
github.com/kolesa-team/go-webp v1.0.1/go.mod h1:oMvdivD6K+Q5qIIkVC2w4k2ZUnI1H+MyP7inwgWq9aA=
113
-
github.com/kolesa-team/goexiv v1.1.0/go.mod h1:njKLWYFnmazfoR/82lj4RBGbKSN6ie0fV180/GlxSFU=
114
110
github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
115
111
github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
116
112
github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
···
127
123
github.com/mattn/go-runewidth v0.0.15/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
128
124
github.com/microcosm-cc/bluemonday v1.0.27 h1:MpEUotklkwCSLeH+Qdx1VJgNqLlpY2KXwXFM08ygZfk=
129
125
github.com/microcosm-cc/bluemonday v1.0.27/go.mod h1:jFi9vgW+H7c3V0lb6nR74Ib/DIB5OBs92Dimizgw2cA=
130
-
github.com/montanaflynn/stats v0.6.6/go.mod h1:etXPPgVO6n31NxCd9KQUMvCM+ve0ruNzt6R8Bnaayow=
131
126
github.com/muesli/reflow v0.3.0 h1:IFsN6K9NfGtjeggFP+68I4chLZV2yIKsXJFNZ+eWh6s=
132
127
github.com/muesli/reflow v0.3.0/go.mod h1:pbwTDkVPibjO2kyvBQRBxTWEEGDGq0FlB1BIKtnHY/8=
133
128
github.com/muesli/termenv v0.15.3-0.20240618155329-98d742f6907a h1:2MaM6YC3mGu54x+RKAA6JiFFHlHDY1UbkxqppT7wYOg=
134
129
github.com/muesli/termenv v0.15.3-0.20240618155329-98d742f6907a/go.mod h1:hxSnBBYLK21Vtq/PHd0S2FYCxBXzBua8ov5s1RobyRQ=
135
130
github.com/ncruces/go-strftime v0.1.9 h1:bY0MQC28UADQmHmaF5dgpLmImcShSi2kHU9XLdhx/f4=
136
131
github.com/ncruces/go-strftime v0.1.9/go.mod h1:Fwc5htZGVVkseilnfgOVb9mKy6w1naJmn9CehxcKcls=
132
+
github.com/nlepage/go-js-promise v1.0.0 h1:K7OmJ3+0BgWJ2LfXchg2sI6RDr7AW/KWR8182epFwGQ=
133
+
github.com/nlepage/go-js-promise v1.0.0/go.mod h1:bdOP0wObXu34euibyK39K1hoBCtlgTKXGc56AGflaRo=
134
+
github.com/nlepage/go-wasm-http-server/v2 v2.0.5 h1:24MooRbGomXxV9dFtP4Z6XCUKlRB39tD8RpL8X1t8hQ=
135
+
github.com/nlepage/go-wasm-http-server/v2 v2.0.5/go.mod h1:r8j7cEOeUqNp+c+C52sNuWaFTvvT/cNqIwBuEtA36HA=
137
136
github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
138
137
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
139
138
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
···
150
149
github.com/spf13/cobra v1.8.1/go.mod h1:wHxEcudfqmLYa8iTfL+OuZPbBZkmvliBWKIezN3kD9Y=
151
150
github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
152
151
github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
153
-
github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
154
152
github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
155
153
github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
156
154
github.com/sunshineplan/tiff v0.0.0-20220128141034-29b9d69bd906 h1:+yYRCj+PGQNnnen4+/Q7eKD2J87RJs+O39bjtHhPauk=
···
165
163
github.com/yuin/goldmark-emoji v1.0.3 h1:aLRkLHOuBR2czCY4R8olwMjID+tENfhyFDMCRhbIQY4=
166
164
github.com/yuin/goldmark-emoji v1.0.3/go.mod h1:tTkZEbwu5wkPmgTcitqddVxY9osFZiavD+r4AzQrh1U=
167
165
golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
168
-
golang.org/x/crypto v0.29.0/go.mod h1:+F4F4N5hv6v38hfeYwTdx20oUvLLc+QfrE9Ax9HtgRg=
169
166
golang.org/x/image v0.22.0 h1:UtK5yLUzilVrkjMAZAZ34DXGpASN8i8pj8g+O+yd10g=
170
167
golang.org/x/image v0.22.0/go.mod h1:9hPFhljd4zZ1GNSIZJ49sqbp45GKK9t6w+iXvGqZUz4=
171
168
golang.org/x/mod v0.17.0 h1:zY54UmvipHiNd+pm+m0x9KhZ9hl1/7QNMyxXbc6ICqA=
···
208
205
gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
209
206
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
210
207
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
211
-
lukechampine.com/uint128 v1.2.0/go.mod h1:c4eWIwlEGaxC/+H1VguhU4PHXNWDCDMUlWdIWl2j1gk=
212
-
modernc.org/cc/v3 v3.41.0/go.mod h1:Ni4zjJYJ04CDOhG7dn640WGfwBzfE0ecX8TyMB0Fv0Y=
213
208
modernc.org/cc/v4 v4.21.4 h1:3Be/Rdo1fpr8GrQ7IVw9OHtplU4gWbb+wNgeoBMmGLQ=
214
209
modernc.org/cc/v4 v4.21.4/go.mod h1:HM7VJTZbUCR3rV8EYBi9wxnJ0ZBRiGE5OeGXNA0IsLQ=
215
-
modernc.org/ccgo/v3 v3.17.0/go.mod h1:Sg3fwVpmLvCUTaqEUjiBDAvshIaKDB0RXaf+zgqFu8I=
216
210
modernc.org/ccgo/v4 v4.19.0 h1:f9K5VdC0nVhHKTFMvhjtZ8TbRgFQbASvE5yO1zs8eC0=
217
211
modernc.org/ccgo/v4 v4.19.0/go.mod h1:CfpAl+673iXNwMG/aqcQn+vDcu4Es/YLya7+9RHjTa4=
218
212
modernc.org/fileutil v1.3.0 h1:gQ5SIzK3H9kdfai/5x41oQiKValumqNTDXMvKo62HvE=
+6
internal/www/embeds.go
+6
internal/www/embeds.go
+42
internal/www/postoffice/index.html
+42
internal/www/postoffice/index.html
···
1
+
<!DOCTYPE html>
2
+
<html>
3
+
<head>
4
+
<title>Postbox</title>
5
+
<script src="postoffice.js"></script>
6
+
</head>
7
+
<body>
8
+
<h1>Postbox</h1>
9
+
<form id="postcard-input" action="/compile/" method="POST" enctype="multipart/form-data">
10
+
<input type="file" name="front" accept=".jpg, .jpeg, .png, .webp" required>
11
+
<input type="file" name="back" accept=".jpg, .jpeg, .png, .webp">
12
+
13
+
<label><input type="checkbox" name="remove-border">Try to remove mono-coloured background</label>
14
+
<label><input type="checkbox" name="ignore-transparency">Force non-transparent</label>
15
+
<label><input type="checkbox" name="archival">Make archival (lossless) version</label>
16
+
17
+
<input type="text" name="name">
18
+
<fieldset>
19
+
<legend>How does the postcard flip?</legend>
20
+
<label><input type="radio" name="flip" value="">One sided</label>
21
+
<label><input type="radio" name="flip" value="book">Like a book</label>
22
+
<label><input type="radio" name="flip" value="calendar">Like a calendar</label>
23
+
<label><input type="radio" name="flip" value="left-hand">Holding in the left hand</label>
24
+
<label><input type="radio" name="flip" value="right-hand">Holding in the right hand</label>
25
+
</fieldset>
26
+
27
+
<fieldset>
28
+
<legend>What format would you like?</legend>
29
+
<label><input type="radio" name="codec-choice" value="web">Web-based image</label>
30
+
<label><input type="radio" name="codec-choice" value="usdz">USDZ</label>
31
+
</fieldset>
32
+
33
+
<button type="submit">Create Postcard</button>
34
+
</form>
35
+
36
+
<div id="output" style="max-width:40vw;margin: auto; display: none;">
37
+
<style></style>
38
+
<div class="postcard-html"></div>
39
+
<a class="postcard-download">Download</a>
40
+
</div>
41
+
</body>
42
+
</html>
+14
internal/www/postoffice/postoffice-serviceworker.js
+14
internal/www/postoffice/postoffice-serviceworker.js
···
1
+
importScripts('https://cdn.jsdelivr.net/gh/golang/go@go1.23.1/misc/wasm/wasm_exec.js')
2
+
importScripts('https://cdn.jsdelivr.net/gh/nlepage/go-wasm-http-server@v2.0.5/sw.js')
3
+
4
+
const wasm = 'postoffice-serviceworker.wasm'
5
+
6
+
// addEventListener('install', (event) => {
7
+
// event.waitUntil(caches.open('postoffice').then((cache) => cache.add(wasm)))
8
+
// })
9
+
10
+
addEventListener('activate', (event) => {
11
+
event.waitUntil(clients.claim())
12
+
})
13
+
14
+
registerWasmHTTPListener(wasm, { base: '/compile' })
+1
internal/www/postoffice/postoffice-serviceworker.wasm
+1
internal/www/postoffice/postoffice-serviceworker.wasm
···
1
+
../../../dist/postoffice-serviceworker_js_wasm/postoffice-serviceworker.wasm
+105
internal/www/postoffice/postoffice.js
+105
internal/www/postoffice/postoffice.js
···
1
+
document.addEventListener("DOMContentLoaded", () => {
2
+
document.getElementById('postcard-input').addEventListener('submit', async (event) => {
3
+
event.preventDefault()
4
+
const {action, method} = event.target
5
+
const body = new FormData(event.target)
6
+
7
+
const res = await fetch(action, { method, body,})
8
+
.then(onlyOk)
9
+
.then(processResult)
10
+
})
11
+
})
12
+
13
+
async function processResult(res) {
14
+
if (res.headers.get('Content-Type') == "multipart/form") {
15
+
const fd = await res.formData()
16
+
displayPostcard(fd.values())
17
+
} else {
18
+
const blob = await res.blob()
19
+
const file = new File([blob], extractFilename(res), { type: blob.type });
20
+
downloadFile(file)
21
+
}
22
+
}
23
+
24
+
function extractFilename(res) {
25
+
const cdh = res.headers.get('Content-Disposition')
26
+
const filenameRegex = /filename=(?:(["'])([^;\n]+?)\1)/i;
27
+
const matches = filenameRegex.exec(cdh);
28
+
if (!matches) {
29
+
return
30
+
}
31
+
32
+
return matches[2]
33
+
}
34
+
35
+
function onlyOk(res) {
36
+
if (!res.ok) {
37
+
throw new Error(`Unusable HTTP response: ${res.res.statusText}`)
38
+
}
39
+
return res
40
+
}
41
+
42
+
async function displayPostcard(files) {
43
+
let image, html
44
+
45
+
for (file of files) {
46
+
switch(file.type) {
47
+
case "model/vnd.usdz+zip":
48
+
// Shortcut and just download the USDZ here, for now
49
+
downloadFile(file)
50
+
return
51
+
case "text/css":
52
+
await file.text().then(insertPostcardCSS)
53
+
break;
54
+
case "text/html":
55
+
html = await file.text()
56
+
break;
57
+
case "image/jpeg":
58
+
case "image/png":
59
+
image = {
60
+
filename: file.name,
61
+
blobURL: URL.createObjectURL(file),
62
+
}
63
+
break;
64
+
}
65
+
}
66
+
67
+
insertPostcardHTML(html, image)
68
+
document.querySelector('#output').style.display = 'block'
69
+
}
70
+
71
+
72
+
function insertPostcardCSS(css) {
73
+
const outCSS = document.querySelector('#output style')
74
+
outCSS.appendChild(document.createTextNode(css));
75
+
}
76
+
77
+
function insertPostcardHTML(html, image) {
78
+
const outHTML = document.querySelector('#output div.postcard-html')
79
+
const outDownload = document.querySelector('#output a.postcard-download')
80
+
81
+
const [_, uniqueHTML] = html.split("\n\n")
82
+
if (!uniqueHTML) {
83
+
throw new Error("Unexpected HTML returned from postcard generator")
84
+
}
85
+
// TODO: fix this hack to replace the filename
86
+
const toReplace = image.filename.replace(/\.[^/.]+$/, '.jpeg')
87
+
outHTML.innerHTML = uniqueHTML.replaceAll(toReplace, image.blobURL)
88
+
outDownload.href = image.blobURL
89
+
outDownload.download = image.filename
90
+
}
91
+
92
+
93
+
function downloadFile(file) {
94
+
const url = URL.createObjectURL(file);
95
+
96
+
const a = document.createElement('a');
97
+
a.href = url;
98
+
a.download = file.name;
99
+
document.body.appendChild(a);
100
+
a.click();
101
+
document.body.removeChild(a);
102
+
URL.revokeObjectURL(url);
103
+
}
104
+
105
+
navigator.serviceWorker.register('postoffice-serviceworker.js').catch(console.error)
+21
pkg/postoffice/choices.go
+21
pkg/postoffice/choices.go
···
1
+
package postoffice
2
+
3
+
import (
4
+
"github.com/jphastings/dotpostcard/formats"
5
+
"github.com/jphastings/dotpostcard/formats/css"
6
+
"github.com/jphastings/dotpostcard/formats/html"
7
+
"github.com/jphastings/dotpostcard/formats/usdz"
8
+
"github.com/jphastings/dotpostcard/formats/web"
9
+
)
10
+
11
+
func DefaultCodecChoices() (CodecChoices, error) {
12
+
webCodec, err := web.Codec("jpeg", "png")
13
+
if err != nil {
14
+
return nil, err
15
+
}
16
+
17
+
return map[string][]formats.Codec{
18
+
"web": {webCodec, html.Codec(), css.Codec()},
19
+
"usdz": {usdz.Codec()},
20
+
}, nil
21
+
}
+143
pkg/postoffice/http.go
+143
pkg/postoffice/http.go
···
1
+
package postoffice
2
+
3
+
import (
4
+
"fmt"
5
+
"io"
6
+
"mime/multipart"
7
+
"net/http"
8
+
"net/textproto"
9
+
"path"
10
+
"strings"
11
+
12
+
"github.com/jphastings/dotpostcard/formats"
13
+
"github.com/jphastings/dotpostcard/formats/component"
14
+
"github.com/jphastings/dotpostcard/types"
15
+
)
16
+
17
+
type CodecChoices map[string][]formats.Codec
18
+
19
+
func HTTPFormHander(codecChoices CodecChoices) func(http.ResponseWriter, *http.Request) {
20
+
return func(w http.ResponseWriter, r *http.Request) {
21
+
pc, codecs, encOpts, err := requestToPostcard(codecChoices, r)
22
+
if err != nil {
23
+
http.Error(w, fmt.Sprintf("Unable to create postcard: %v", err), http.StatusBadRequest)
24
+
}
25
+
26
+
var files []formats.FileWriter
27
+
28
+
for _, c := range codecs {
29
+
fws, err := c.Encode(pc, &encOpts)
30
+
if err != nil {
31
+
http.Error(w, err.Error(), http.StatusBadRequest)
32
+
return
33
+
}
34
+
files = append(files, fws...)
35
+
}
36
+
37
+
if len(files) < 1 {
38
+
http.Error(w, "No postcard image created", http.StatusInternalServerError)
39
+
return
40
+
}
41
+
42
+
if len(files) == 1 {
43
+
w.Header().Add("Content-Type", files[0].Mimetype)
44
+
w.Header().Add("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, files[0].Filename))
45
+
files[0].WriteTo(w)
46
+
return
47
+
}
48
+
49
+
mw := multipart.NewWriter(w)
50
+
w.Header().Add("Content-Type", mw.FormDataContentType())
51
+
52
+
for _, f := range files {
53
+
h := make(textproto.MIMEHeader)
54
+
h.Set("Content-Disposition", fmt.Sprintf(`form-data; name="%s"; filename="%s"`, f.Filename, f.Filename))
55
+
h.Set("Content-Type", f.Mimetype)
56
+
57
+
ww, err := mw.CreatePart(h)
58
+
if err != nil {
59
+
http.Error(w, "Unable to combine files", http.StatusInternalServerError)
60
+
return
61
+
}
62
+
63
+
if err := f.WriteTo(ww); err != nil {
64
+
http.Error(w, "Unable to write files", http.StatusInternalServerError)
65
+
return
66
+
}
67
+
}
68
+
69
+
mw.Close()
70
+
}
71
+
}
72
+
73
+
func checkboxBool(formVal string) bool { return formVal == "on" }
74
+
75
+
func requestToPostcard(codecChoices CodecChoices, r *http.Request) (types.Postcard, []formats.Codec, formats.EncodeOptions, error) {
76
+
codecs, ok := codecChoices[r.FormValue("codec-choice")]
77
+
if !ok {
78
+
return types.Postcard{}, nil, formats.EncodeOptions{}, fmt.Errorf("no acceptable codec choice provided")
79
+
}
80
+
81
+
decOpts := formats.DecodeOptions{
82
+
IgnoreTransparency: checkboxBool(r.FormValue("ignore-transparency")),
83
+
RemoveBorder: checkboxBool(r.FormValue("remove-border")),
84
+
}
85
+
encOpts := formats.EncodeOptions{
86
+
Archival: checkboxBool(r.FormValue("archival")),
87
+
}
88
+
89
+
var meta types.Metadata
90
+
91
+
err := r.ParseMultipartForm(50 << 20) // 50 MB limit
92
+
if err != nil {
93
+
return types.Postcard{}, nil, encOpts, err
94
+
}
95
+
96
+
meta.Name = r.FormValue("name")
97
+
meta.Flip = types.Flip(r.FormValue("flip"))
98
+
99
+
frontR, nameGuess, err := formToFile(r.MultipartForm.File["front"])
100
+
if err != nil {
101
+
return types.Postcard{}, nil, encOpts, err
102
+
}
103
+
backR, _, err := formToFile(r.MultipartForm.File["back"])
104
+
if err != nil {
105
+
return types.Postcard{}, nil, encOpts, err
106
+
}
107
+
108
+
if meta.Name == "" {
109
+
meta.Name = nameGuess
110
+
}
111
+
112
+
pc, err := component.BundleFromReaders(meta, frontR, backR).Decode(decOpts)
113
+
if err != nil {
114
+
return types.Postcard{}, nil, encOpts, err
115
+
}
116
+
117
+
return pc, codecs, encOpts, nil
118
+
}
119
+
120
+
func formToFile(fhs []*multipart.FileHeader) (io.ReadCloser, string, error) {
121
+
if len(fhs) == 0 {
122
+
return nil, "", nil
123
+
}
124
+
125
+
file, err := fhs[0].Open()
126
+
if err != nil {
127
+
return nil, "", err
128
+
}
129
+
130
+
name := fhs[0].Filename
131
+
suffixesToRemove := []string{
132
+
path.Ext(name),
133
+
"-front",
134
+
"-only",
135
+
"-back",
136
+
}
137
+
138
+
for _, suffix := range suffixesToRemove {
139
+
name = strings.TrimSuffix(name, suffix)
140
+
}
141
+
142
+
return file, name, nil
143
+
}
+22
types/validate.go
+22
types/validate.go
···
1
+
package types
2
+
3
+
import (
4
+
"fmt"
5
+
)
6
+
7
+
func (pc Postcard) Validate() error {
8
+
switch pc.Sides() {
9
+
case 0:
10
+
return fmt.Errorf("a postcard must have at least a front side")
11
+
case 1:
12
+
if pc.Meta.Flip != FlipNone {
13
+
return fmt.Errorf("flip of '%s' given, but only 1 side provided", pc.Meta.Flip)
14
+
}
15
+
case 2:
16
+
if pc.Meta.Flip == FlipNone || !pc.Meta.Flip.IsValid() {
17
+
return fmt.Errorf("invalid flip type '%s' for two-sided postcard", pc.Meta.Flip)
18
+
}
19
+
}
20
+
21
+
return nil
22
+
}