chore(tfstated): refactor backend code to a dedicated package

pkg/backend/get.go

@@ -0,0 +1,28 @@
+package backend
+
+import (
+	"fmt"
+	"net/http"
+
+	"git.adyxax.org/adyxax/tfstated/pkg/database"
+	"git.adyxax.org/adyxax/tfstated/pkg/helpers"
+)
+
+func handleGet(db *database.DB) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Cache-Control", "no-store, no-cache")
+
+		if r.URL.Path == "/" {
+			helpers.ErrorResponse(w, http.StatusBadRequest,
+				fmt.Errorf("no state path provided, cannot GET /"))
+			return
+		}
+
+		if data, err := db.GetState(r.URL.Path); err != nil {
+			helpers.ErrorResponse(w, http.StatusInternalServerError, err)
+		} else {
+			w.WriteHeader(http.StatusOK)
+			_, _ = w.Write(data)
+		}
+	})
+}