navidrome/server/backgrounds/handler.go

93 lines
2.0 KiB
Go

package backgrounds
import (
"context"
"encoding/base64"
"errors"
"net/http"
"net/url"
"path"
"sync"
"time"
"github.com/navidrome/navidrome/consts"
"github.com/navidrome/navidrome/log"
"github.com/navidrome/navidrome/utils/number"
"gopkg.in/yaml.v3"
)
type Handler struct {
list []string
lock sync.RWMutex
}
func NewHandler() *Handler {
h := &Handler{}
go func() {
_, _ = h.getImageList(context.Background())
}()
return h
}
const ndImageServiceURL = "https://www.navidrome.org/images"
func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
image, err := h.getRandomImage(r.Context())
if err != nil {
defaultImage, _ := base64.StdEncoding.DecodeString(consts.DefaultUILoginBackgroundOffline)
w.Header().Set("content-type", "image/png")
_, _ = w.Write(defaultImage)
return
}
http.Redirect(w, r, buildPath(ndImageServiceURL, image), http.StatusFound)
}
func (h *Handler) getRandomImage(ctx context.Context) (string, error) {
list, err := h.getImageList(ctx)
if err != nil {
return "", err
}
if len(list) == 0 {
return "", errors.New("no images available")
}
rnd := number.RandomInt64(int64(len(list)))
return list[rnd], nil
}
func (h *Handler) getImageList(ctx context.Context) ([]string, error) {
h.lock.RLock()
if len(h.list) > 0 {
defer h.lock.RUnlock()
return h.list, nil
}
h.lock.RUnlock()
h.lock.Lock()
defer h.lock.Unlock()
start := time.Now()
c := http.Client{
Timeout: 5 * time.Second,
}
req, _ := http.NewRequestWithContext(ctx, http.MethodGet, buildPath(ndImageServiceURL, "index.yml"), nil)
resp, err := c.Do(req)
if err != nil {
log.Warn(ctx, "Could not get list from image service", err)
return nil, err
}
defer resp.Body.Close()
dec := yaml.NewDecoder(resp.Body)
err = dec.Decode(&h.list)
log.Debug(ctx, "Loaded images from image service", "total", len(h.list), "elapsed", time.Since(start))
return h.list, err
}
func buildPath(baseURL string, endpoint ...string) string {
u, _ := url.Parse(baseURL)
p := path.Join(endpoint...)
u.Path = path.Join(u.Path, p)
return u.String()
}