Merge pull request #48 from EspressoSystems/jh/hotshot-liveness

Fetch hotshot liveness with a given L1 height

CODEOWNERS

@@ -2,4 +2,4 @@
 # later match takes precedence, they will be requested for review when someone
 # opens a pull request.
 
-*       @nomaxg @ImJeremyHe @sveitser
+*       @nomaxg @ImJeremyHe @sveitser @zacshowa @Sneh1999

light-client/light_client_reader.go

@@ -16,6 +16,7 @@ type LightClientReaderInterface interface {
 	FetchMerkleRoot(hotShotHeight uint64, opts *bind.CallOpts) (types.BlockMerkleSnapshot, error)
 
 	IsHotShotLive(delayThreshold uint64) (bool, error)
+	IsHotShotLiveAtHeight(height, delayThreshold uint64) (bool, error)
 }
 
 type LightClientReader struct {
@@ -79,3 +80,13 @@ func (l *LightClientReader) IsHotShotLive(delayThreshold uint64) (bool, error) {
 	}
 	return !isDown, nil
 }
+
+func (l *LightClientReader) IsHotShotLiveAtHeight(h, delayThreshold uint64) (bool, error) {
+	threshold := new(big.Int).SetUint64(delayThreshold)
+	height := new(big.Int).SetUint64(h)
+	isDown, err := l.LightClient.LagOverEscapeHatchThreshold(&bind.CallOpts{}, height, threshold)
+	if err != nil {
+		return false, err
+	}
+	return !isDown, nil
+}