/
style.go
130 lines (102 loc) · 2.88 KB
/
style.go
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package style
import (
"context"
"crypto/md5"
"fmt"
"net"
"strings"
"github.com/lucasb-eyer/go-colorful"
"github.com/rs/zerolog/log"
)
var pixl = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII="
type Key string
func (s Key) Key() interface{} {
return s
}
type Style struct {
Avatar,
Cover,
Background string
Palette []string
}
func GetStyle(ctx context.Context, email string) (*Style, error) {
log := log.Ctx(ctx)
avatarHost, styleHost, err := GetSRV(ctx, email)
if err != nil {
return nil, err
}
log.Info().Str("avatar", avatarHost).Str("style", styleHost).Msg("getStyle")
hash := md5.New()
email = strings.TrimSpace(strings.ToLower(email))
_, _ = hash.Write([]byte(email))
id := hash.Sum(nil)
style := &Style{}
style.Palette = GetPalette(fmt.Sprintf("#%x", id[:3]))
style.Avatar = fmt.Sprintf("https://%s/avatar/%x", avatarHost, id)
style.Cover = pixl
style.Background = pixl
if styleHost != "" {
style.Cover = fmt.Sprintf("https://%s/cover/%x", styleHost, id)
style.Background = fmt.Sprintf("https://%s/bg/%x", styleHost, id)
}
return style, err
}
func GetSRV(ctx context.Context, email string) (avatar string, style string, err error) {
// Defaults
style = ""
avatar = "www.libravatar.org"
parts := strings.SplitN(email, "@", 2)
if _, srv, err := net.DefaultResolver.LookupSRV(ctx, "style-sec", "tcp", parts[1]); err == nil {
if len(srv) > 0 {
style = strings.TrimSuffix(srv[0].Target, ".")
avatar = strings.TrimSuffix(srv[0].Target, ".")
return avatar, style, err
}
}
if _, srv, err := net.DefaultResolver.LookupSRV(ctx, "avatars-sec", "tcp", parts[1]); err == nil {
if len(srv) > 0 {
avatar = strings.TrimSuffix(srv[0].Target, ".")
return avatar, style, err
}
}
return
}
// getPalette maes a complementary color palette. https://play.golang.org/p/nBXLUocGsU5
func GetPalette(hex string) []string {
reference, _ := colorful.Hex(hex)
reference = sat(lum(reference, 0, .5), 0, .5)
white := colorful.Color{R: 1, G: 1, B: 1}
black := colorful.Color{R: 0, G: 0, B: 0}
accentA := hue(reference, 60)
accentB := hue(reference, -60)
accentC := hue(reference, -180)
return append(
[]string{},
white.Hex(),
lum(reference, .4, .6).Hex(),
reference.Hex(),
lum(reference, .4, 0).Hex(),
black.Hex(),
lum(accentA, .4, .6).Hex(),
accentA.Hex(),
lum(accentA, .4, 0).Hex(),
lum(accentB, .4, .6).Hex(),
accentB.Hex(),
lum(accentB, .4, 0).Hex(),
lum(accentC, .4, .6).Hex(),
accentC.Hex(),
lum(accentC, .4, 0).Hex(),
)
}
func hue(in colorful.Color, H float64) colorful.Color {
h, s, l := in.Hsl()
return colorful.Hsl(h+H, s, l)
}
func sat(in colorful.Color, S, V float64) colorful.Color {
h, s, l := in.Hsl()
return colorful.Hsl(h, V+s*S, l)
}
func lum(in colorful.Color, L, V float64) colorful.Color {
h, s, l := in.Hsl()
return colorful.Hsl(h, s, V+l*L)
}