Added the pending image data file

cmd/fetch-header-image/models.go

@@ -0,0 +1,72 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+	"os"
+	"sort"
+	"time"
+)
+
+const CropBottom = "bottom"
+
+var ErrNon200Error = errors.New("non 200 status code")
+
+type PendingImage struct {
+	Date time.Time `json:"date"`
+	URL  string    `json:"url"`
+	Crop string    `json:"crop"`
+}
+
+func LoadPendingImageFromURL(url string) (pi PendingImage, err error) {
+	resp, err := http.Get(url)
+	if err != nil {
+		return PendingImage{}, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return PendingImage{}, ErrNon200Error
+	}
+
+	if err := json.NewDecoder(resp.Body).Decode(&pi); err != nil {
+		return PendingImage{}, err
+	}
+	return pi, nil
+}
+
+type PendingImages struct {
+	Images []PendingImage `json:"images"`
+}
+
+func (pi PendingImages) FindPendingImage() (bestImg PendingImage, ok bool) {
+	timeNow := time.Now().UTC()
+
+	if len(pi.Images) == 0 {
+		return PendingImage{}, false
+	}
+
+	for _, img := range pi.Images {
+		if timeNow.Before(img.Date) {
+			continue
+		}
+		bestImg = img
+	}
+	return bestImg, bestImg.URL != ""
+}
+
+func LoadPendingImages(jsonFile string) (pi PendingImages, _ error) {
+	f, err := os.Open(jsonFile)
+	if err != nil {
+		return PendingImages{}, err
+	}
+	defer f.Close()
+
+	if err := json.NewDecoder(f).Decode(&pi); err != nil {
+		return PendingImages{}, err
+	}
+
+	sort.Slice(pi.Images, func(i, j int) bool { return pi.Images[i].Date.Before(pi.Images[j].Date) })
+	return pi, nil
+}