From 51d610ea4faedbb2a454b5172037de5634bd3c80 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Aasted=20S=C3=B8rensen?= <has@bitcraft.dk>
Date: Tue, 20 Oct 2020 11:09:41 +0200
Subject: [PATCH] Add query REST endpoint for buyback module balance

---
 x/buyback/client/rest/query.go | 37 ++++++++++++++++++++++++++++++++++
 x/buyback/module.go            |  5 ++++-
 2 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 x/buyback/client/rest/query.go

diff --git a/x/buyback/client/rest/query.go b/x/buyback/client/rest/query.go
new file mode 100644
index 00000000..c22e30b2
--- /dev/null
+++ b/x/buyback/client/rest/query.go
@@ -0,0 +1,37 @@
+package rest
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/gorilla/mux"
+
+	"github.com/cosmos/cosmos-sdk/client/context"
+	"github.com/cosmos/cosmos-sdk/types/rest"
+
+	"github.com/e-money/em-ledger/x/buyback/internal/types"
+)
+
+func RegisterQueryRoutes(cliCtx context.CLIContext, r *mux.Router) {
+	r.HandleFunc("/buyback/balance", queryBalanceHandlerFn(cliCtx)).Methods("GET")
+}
+
+func queryBalanceHandlerFn(cliCtx context.CLIContext) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		route := fmt.Sprintf("custom/%s/%s", types.QuerierRoute, types.QueryBalance)
+
+		cliCtx, ok := rest.ParseQueryHeightOrReturnBadRequest(w, cliCtx, r)
+		if !ok {
+			return
+		}
+
+		res, height, err := cliCtx.QueryWithData(route, nil)
+		if err != nil {
+			rest.WriteErrorResponse(w, http.StatusInternalServerError, err.Error())
+			return
+		}
+
+		cliCtx = cliCtx.WithHeight(height)
+		rest.PostProcessResponse(w, cliCtx, res)
+	}
+}
diff --git a/x/buyback/module.go b/x/buyback/module.go
index 9ef71cd6..8cca52cc 100644
--- a/x/buyback/module.go
+++ b/x/buyback/module.go
@@ -7,6 +7,7 @@ import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/types/module"
 	"github.com/e-money/em-ledger/x/buyback/client/cli"
+	"github.com/e-money/em-ledger/x/buyback/client/rest"
 	"github.com/e-money/em-ledger/x/buyback/internal/keeper"
 	"github.com/gorilla/mux"
 	"github.com/spf13/cobra"
@@ -49,7 +50,9 @@ func (amb AppModuleBasic) ValidateGenesis(json.RawMessage) error {
 	return nil
 }
 
-func (amb AppModuleBasic) RegisterRESTRoutes(context.CLIContext, *mux.Router) {}
+func (amb AppModuleBasic) RegisterRESTRoutes(ctx context.CLIContext, r *mux.Router) {
+	rest.RegisterQueryRoutes(ctx, r)
+}
 
 func (amb AppModuleBasic) GetTxCmd(*codec.Codec) *cobra.Command {
 	return nil