Added the pending image data file

cmd/fetch-header-image/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"encoding/json"
 	"flag"
 	"io"
 	"log"
@@ -13,12 +14,53 @@ import (
 )
 
 func main() {
+	headerImages := flag.String("i", "data/pending-header-images.json", "header images json file")
+	currentPendingImage := flag.String("ip", "", "current pending image")
 	targetFile := flag.String("o", "out.jpg", "target file")
+	odFile := flag.String("od", "out-data.json", "target file data")
 	flag.Parse()
 
-	var bfr bytes.Buffer
+	pis, err := LoadPendingImages(*headerImages)
+	if err != nil {
+		log.Fatal(err)
+	}
 
-	if err := fetchHeaderImage(&bfr, "https://lmika.org/uploads/2025/pxl-20251120-083552448.jpg"); err != nil {
+	pi, ok := pis.FindPendingImage()
+	if !ok {
+		log.Println("no pending image found")
+		return
+	}
+	log.Printf("found pending image: %s\n", pi.URL)
+
+	if *currentPendingImage != "" {
+		if cpi, err := LoadPendingImageFromURL(*currentPendingImage); err == nil {
+			if pi.URL == cpi.URL {
+				log.Println("current pending image is already the latest")
+				return
+			}
+		} else {
+			log.Printf("warn: failed to load current pending image: %s\n", err)
+		}
+	}
+
+	if err := fetchHeaderImageFromURL(*targetFile, pi); err != nil {
+		log.Fatal(err)
+	}
+
+	// Write out the current pending image to the data file
+	var dBfr bytes.Buffer
+	if err := json.NewEncoder(&dBfr).Encode(pi); err != nil {
+		log.Fatal(err)
+	}
+
+	if err := os.WriteFile(*odFile, dBfr.Bytes(), 0644); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func fetchHeaderImageFromURL(outFile string, pi PendingImage) error {
+	var bfr bytes.Buffer
+	if err := fetchHeaderImage(&bfr, pi.URL); err != nil {
 		log.Fatal(err)
 	}
 
@@ -29,16 +71,19 @@ func main() {
 
 	rImg := imaging.Resize(img, 1280, 0, imaging.Lanczos)
 
-	// TEMP: crop bottom half
+	if pi.Crop == CropBottom {
 		rImg = imaging.CropAnchor(rImg, rImg.Bounds().Dx(), rImg.Bounds().Dy()/2, imaging.Bottom)
+	}
 
-	if err := os.MkdirAll(filepath.Dir(*targetFile), 0755); err != nil {
+	if err := os.MkdirAll(filepath.Dir(outFile), 0755); err != nil {
 		log.Fatal(err)
 	}
 
-	if err := imaging.Save(rImg, *targetFile, imaging.JPEGQuality(70)); err != nil {
+	if err := imaging.Save(rImg, outFile, imaging.JPEGQuality(70)); err != nil {
 		log.Fatal(err)
 	}
+
+	return nil
 }
 
 func fetchHeaderImage(w io.Writer, url string) error {

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
+}

data/pending-header-images.json

@@ -0,0 +1,13 @@
+{
+  "images": [
+    {
+      "date": "2025-11-22T13:00:00Z",
+      "url": "https://lmika.org/uploads/2025/pxl-20251120-083552448.jpg",
+      "crop": "bottom"
+    },
+    {
+      "date": "2025-11-30T13:00:00Z",
+      "url": "https://lmika.org/uploads/2025/pxl-20251120-090249613.jpg"
+    }
+  ]
+}