Add GetHostClientState()

ibc/client/queries.go

@@ -1,12 +1,16 @@
 package client
 
 import (
+	"time"
+
 	light_client_types "github.com/pokt-network/pocket/ibc/client/light_clients/types"
 	"github.com/pokt-network/pocket/ibc/client/types"
 	"github.com/pokt-network/pocket/ibc/path"
 	"github.com/pokt-network/pocket/shared/codec"
 	core_types "github.com/pokt-network/pocket/shared/core/types"
 	"github.com/pokt-network/pocket/shared/modules"
+	util_types "github.com/pokt-network/pocket/utility/types"
+	"google.golang.org/protobuf/types/known/durationpb"
 )
 
 // GetConsensusState returns the ConsensusState at the given height for the
@@ -56,3 +60,39 @@ func (c *clientManager) GetHostConsensusState(height modules.Height) (modules.Co
 	}
 	return types.NewConsensusState(consBz, uint64(pocketConsState.Timestamp.AsTime().UnixNano())), nil
 }
+
+// GetHostClientState returns the ClientState at the given height for the host
+// chain, the Pocket network.
+//
+// This function is used to validate the state of a client running on a
+// counterparty chain.
+func (c *clientManager) GetHostClientState(height modules.Height) (*light_client_types.PocketClientState, error) {
+	blockStore := c.GetBus().GetPersistenceModule().GetBlockStore()
+	block, err := blockStore.GetBlock(height.GetRevisionHeight())
+	if err != nil {
+		return nil, err
+	}
+	rCtx, err := c.GetBus().GetPersistenceModule().NewReadContext(int64(height.GetRevisionHeight()))
+	if err != nil {
+		return nil, err
+	}
+	defer rCtx.Release()
+	unbondingBlocks, err := rCtx.GetIntParam(util_types.ValidatorUnstakingBlocksParamName, int64(height.GetRevisionHeight()))
+	if err != nil {
+		return nil, err
+	}
+	// TODO_AFTER(#705): use the actual MinimumBlockTime once set
+	unbondingPeriod := time.Minute * 15 * time.Duration(unbondingBlocks) // approx minutes per block * blocks
+	maxDrift := time.Minute * 15                                         // maximum 15 minutes future
+	return &light_client_types.PocketClientState{
+		NetworkId:       block.BlockHeader.NetworkId,
+		TrustLevel:      &light_client_types.Fraction{Numerator: 2, Denominator: 3},
+		TrustingPeriod:  durationpb.New(unbondingPeriod),
+		UnbondingPeriod: durationpb.New(unbondingPeriod),
+		MaxClockDrift:   durationpb.New(maxDrift),
+		LatestHeight: &types.Height{
+			RevisionNumber: height.GetRevisionNumber(),
+			RevisionHeight: height.GetRevisionHeight(),
+		},
+	}, nil
+}