From 391380bef2076f3a378c135a8964a3194f3b0fcc Mon Sep 17 00:00:00 2001
From: Alexis Sellier <alexis@cloudhead.io>
Date: Fri, 4 Aug 2017 18:36:35 +0200
Subject: [PATCH] Refactor app state query code

---
 client/commands/proofs/state.go | 52 +++++++++++++++++++++++++++++----
 1 file changed, 46 insertions(+), 6 deletions(-)

diff --git a/client/commands/proofs/state.go b/client/commands/proofs/state.go
index e55b5b5810..06c4ffe3dd 100644
--- a/client/commands/proofs/state.go
+++ b/client/commands/proofs/state.go
@@ -1,10 +1,14 @@
 package proofs
 
 import (
+	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
 
+	wire "github.com/tendermint/go-wire"
 	"github.com/tendermint/go-wire/data"
-	"github.com/tendermint/light-client/proofs"
+	lc "github.com/tendermint/light-client"
+	"github.com/tendermint/merkleeyes/iavl"
 
 	"github.com/tendermint/basecoin/client/commands"
 )
@@ -24,24 +28,60 @@ If you want json output, use an app-specific command that knows key and value st
 // parse the object, but rather return the raw bytes
 func keyQueryCmd(cmd *cobra.Command, args []string) error {
 	// parse cli
-	height := GetHeight()
 	key, err := ParseHexKey(args, "key")
 	if err != nil {
 		return err
 	}
+	prove := viper.GetBool(commands.FlagTrustNode)
 
 	// get the proof -> this will be used by all prover commands
 	node := commands.GetNode()
-	prover := proofs.NewAppProver(node)
-	proof, err := GetProof(node, prover, key, height)
+
+	////////////////
+	resp, err := node.ABCIQuery("/key", key, prove)
+	if err != nil {
+		return err
+	}
+	ph := int(resp.Height)
+
+	// short-circuit with no proofs
+	if !prove {
+		return OutputProof(data.Bytes(resp.Value), resp.Height)
+	}
+
+	// make sure the proof is the proper height
+	if !resp.Code.IsOK() {
+		return errors.Errorf("Query error %d: %s", resp.Code, resp.Code.String())
+	}
+	// TODO: Handle null proofs
+	if len(resp.Key) == 0 || len(resp.Value) == 0 || len(resp.Proof) == 0 {
+		return lc.ErrNoData()
+	}
+	if ph != 0 && ph != int(resp.Height) {
+		return lc.ErrHeightMismatch(ph, int(resp.Height))
+	}
+
+	check, err := GetCertifiedCheckpoint(ph)
+	if err != nil {
+		return err
+	}
+
+	proof := new(iavl.KeyExistsProof)
+	err = wire.ReadBinaryBytes(resp.Proof, &proof)
+	if err != nil {
+		return err
+	}
+
+	// validate the proof against the certified header to ensure data integrity
+	err = proof.Verify(resp.Key, resp.Value, check.Header.AppHash)
 	if err != nil {
 		return err
 	}
 
 	// state just returns raw hex....
-	info := data.Bytes(proof.Data())
+	info := data.Bytes(resp.Value)
 
 	// we can reuse this output for other commands for text/json
 	// unless they do something special like store a file to disk
-	return OutputProof(info, proof.BlockHeight())
+	return OutputProof(info, resp.Height)
 }