first commit

apps/backend/internal/httpapi/problem.go

@@ -0,0 +1,33 @@
+package httpapi
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+type Problem struct {
+	Type     string `json:"type"`
+	Title    string `json:"title"`
+	Status   int    `json:"status"`
+	Detail   string `json:"detail,omitempty"`
+	Instance string `json:"instance,omitempty"`
+}
+
+func problem(c *gin.Context, status int, problemType, title, detail string) {
+	if c.Writer.Written() {
+		return
+	}
+	c.Header("Content-Type", "application/problem+json")
+	c.JSON(status, Problem{
+		Type:     problemType,
+		Title:    title,
+		Status:   status,
+		Detail:   detail,
+		Instance: c.Request.URL.Path,
+	})
+}
+
+func notFound(c *gin.Context) {
+	problem(c, http.StatusNotFound, "https://spotify-rec.local/errors/not-found", "Not found", "The requested resource does not exist.")
+}