1 files changed, 61 insertions, 0 deletions
diff --git a/pkg/backend/lock.go b/pkg/backend/lock.go
new file mode 100644
index 0000000..ef62198
--- /dev/null
+++ b/pkg/backend/lock.go
@@ -0,0 +1,61 @@
+package backend
+
+import (
+	"fmt"
+	"net/http"
+	"regexp"
+	"time"
+
+	"git.adyxax.org/adyxax/tfstated/pkg/database"
+	"git.adyxax.org/adyxax/tfstated/pkg/helpers"
+)
+
+type lockRequest struct {
+	Created   time.Time `json:"Created"`
+	ID        string    `json:"ID"`
+	Info      string    `json:"Info"`
+	Operation string    `json:"Operation"`
+	Path      string    `json:"Path"`
+	Version   string    `json:"Version"`
+	Who       string    `json:"Who"`
+}
+
+var (
+	validID = regexp.MustCompile("[a-f0-9]{8}-(?:[a-f0-9]{4}-){3}[a-f0-9]{12}")
+)
+
+func (l *lockRequest) valid() []error {
+	err := make([]error, 0)
+	if !validID.MatchString(l.ID) {
+		err = append(err, fmt.Errorf("invalid ID"))
+	}
+	return err
+}
+
+func handleLock(db *database.DB) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/" {
+			_ = helpers.Encode(w, http.StatusBadRequest,
+				fmt.Errorf("no state path provided, cannot LOCK /"))
+			return
+		}
+
+		var lock lockRequest
+		if err := helpers.Decode(r, &lock); err != nil {
+			_ = helpers.Encode(w, http.StatusBadRequest, err)
+			return
+		}
+		if errs := lock.valid(); len(errs) > 0 {
+			_ = helpers.Encode(w, http.StatusBadRequest,
+				fmt.Errorf("invalid lock: %+v", errs))
+			return
+		}
+		if success, err := db.SetLockOrGetExistingLock(r.URL.Path, &lock); err != nil {
+			helpers.ErrorResponse(w, http.StatusInternalServerError, err)
+		} else if success {
+			w.WriteHeader(http.StatusOK)
+		} else {
+			_ = helpers.Encode(w, http.StatusConflict, lock)
+		}
+	})
+}