almost all ready

internal/http/handlers/images.go

@@ -0,0 +1,63 @@
+package handlers
+
+import (
+	"database/sql"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+func prestashopImageURL(baseURL string, imageID sql.NullInt64, imageType string) string {
+	if !imageID.Valid || imageID.Int64 == 0 {
+		return ""
+	}
+	id := strconv.FormatInt(imageID.Int64, 10)
+	var path strings.Builder
+	path.Grow(len(baseURL) + len(id)*2 + len(imageType) + 16)
+	path.WriteString(strings.TrimRight(baseURL, "/"))
+	path.WriteString("/img/p")
+	for _, ch := range id {
+		path.WriteByte('/')
+		path.WriteRune(ch)
+	}
+	path.WriteByte('/')
+	path.WriteString(id)
+	if strings.TrimSpace(imageType) != "" {
+		path.WriteByte('-')
+		path.WriteString(strings.TrimSpace(imageType))
+	}
+	path.WriteString(".webp")
+	return path.String()
+}
+
+func requestBaseURL(req *http.Request) string {
+	if req == nil {
+		return ""
+	}
+
+	scheme := "http"
+	if req.TLS != nil {
+		scheme = "https"
+	} else if forwarded := req.Header.Get("X-Forwarded-Proto"); forwarded != "" {
+		if strings.Contains(forwarded, ",") {
+			forwarded = strings.TrimSpace(strings.Split(forwarded, ",")[0])
+		}
+		if strings.TrimSpace(forwarded) != "" {
+			scheme = strings.TrimSpace(forwarded)
+		}
+	}
+
+	host := req.Header.Get("X-Forwarded-Host")
+	if host == "" {
+		host = req.Host
+	}
+	if strings.Contains(host, ",") {
+		host = strings.TrimSpace(strings.Split(host, ",")[0])
+	}
+	host = strings.TrimSpace(host)
+	if host == "" {
+		return ""
+	}
+
+	return scheme + "://" + host
+}